United States 

Department of 

Agriculture

Animal and 

Plant Health 

Inspection 

Service

Veterinary 

Services

National 

Animal Health 

Monitoring 

System

April 2014

Sheep 2011

Part IV: Changes in Health and Production 

Practices in the U.S. Sheep Industry, 

1996–2011

Table of 

Contents
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USDA–APHIS–VS–CEAH–NAHMS

NRRC Building B, M.S. 2E7

2150 Centre Avenue

Fort Collins, CO 80526–8117

970.494.7000

http://www.aphis.usda.gov/nahms

#633.0414

Cover photograph courtesy of Camilla Kristensen.
USDA APHIS VS / i 

Breed 

Hair sheep accounted for the greatest change in the type of sheep breeds on U.S. sheep 

operations. For example, in 1996 only 1.0 percent of U.S. sheep operations owned hair 

sheep, compared with 4.6 percent in 2001 and 21.7 percent 2011 (p 24). Hair sheep 

breeds are known for parasite resistance and heat tolerance, and a rise in ownership of 

these breeds in hot, parasite-prone regions of the country would be expected. However, 

the percentage of operations with hair sheep has increased in all regions of the country 

(section II, table A.1.c). Hair sheep also represented a higher percentage of the U.S. 

sheep and lamb inventory in 2011 (11.0 percent) than in 2001 and 1996 (1.2, and 

0.4 percent, respectively).

Primary use

Ownership of sheep primarily for meat production increased from 60.7 percent of 

operations in 2001 to 81.6 percent in 2011, while the percentage of operations in which 

the primary use of sheep was wool production or showing remained steady (p 29). 

Producer experience

A higher percentage of sheep producers had been in business for 21 years or longer in 

2011 than in 2001 (59.5 and 39.4 percent, respectively) [p 31].

Animal identification 

Flock and individual-animal identification (ID) are important parts of industry efforts to 

control disease in sheep. In 2011, 81.5 percent of operations used at least one flock ID 

method compared with just 27.4 percent in 2001 (p 42). In November 2001, after the 

Sheep 2001 study, new ID requirements were implemented that required ID for sheep 

that changed ownership and/or entered interstate commerce. These new requirements 

led to a substantial increase in flock ID. 

A higher percentage of culled ewes had flock ID when they left the operation in 2011 than 

in 2001. The difference is especially true for ewes culled from farm or pasture flocks. For 

example, in 2001 just 34.2 percent of cull ewes had flock ID when they left the operation 

compared with 81.6 percent of cull ewes in 2011 (p 82).

Ewe breeding

Breeding ewes out of season was more common in 2011 than in 2001 (24.5 and 

12.1 percent of breeding operations, respectively) [p 52]. Newly approved drugs are rare 

in the sheep industry, but in fall 2009 the Food and Drug Administration approved the use 

of a progesterone controlled internal drug release (CIDR) used to induce estrus in ewes 

Items of Note
ii / Sheep 2011

during seasonal anestrus. Twice the percentage of operations in 2011 used hormone 

treatments compared with operations in 2001. 

The percentage of operations that rated the ability of ewes to breed out of season as 

very or somewhat important more than tripled from 2001 to 2011 (10.3 and 33.6 percent, 

respectively) [p 57]. 

Consistent with previous data showing increases in out-of-season breeding, the use of 

estrus-inducing hormones, and the popularity of ewes that breed out of season, a higher 

percentage of operations in 2011 than in 2001 had lambs born in June through December 

(p 60).

Lamb management

Consistent with the increased percentage of hair sheep—whose tails are typically not 

docked—a lower percentage of operations docked lambs’ tails in 2011 than in 2001 

(p 64]. 

Lambs were weaned at a younger average age in 2011 than in 2001(15.6 and 

17.5 weeks, respectively) [p 72]. 

Cull rams and ewes

Operations cull animals for many reasons, including disease, to reduce flock size, 

improve genetics for desirable phenotypic traits, or to economize during episodes of high 

feed costs. Operations attempting to enlarge their flocks are less likely to cull animals for 

any of these reasons. A lower percentage of rams and ewes were culled in 2011 than in 

2001. Nearly one-fourth of rams (23.8 percent) were culled and sold in 2001 compared 

with 16.2 percent in 2011. Approximately one-fifth of ewes (18.3 percent) were culled and 

sold in 2001 compared with 14.0 percent 2011 (p 79). The average age of culled ewes 

was slightly higher in 2011 than in 2001 (6.3 and 5.9 years, respectively).

Carcass disposal methods

The decision about which methods to use to dispose of carcasses depends on local, 

county, and State laws; a producer’s skill/knowledge of disposal methods (e.g., 

incineration and composting); method costs; and equipment availability (e.g., for burying, 

rendering, and incinerating). The cost of different carcass disposal methods also 

influences a producer’s decision on what methods to use. Composting accounted for the 

biggest change in carcass disposal methods from 2001 to 2011: 6.9 percent of operations 

composted carcasses in 2001 compared with 26.5 percent in 2011 (p 86).
USDA APHIS VS / iii 

Biosecurity

Overall, a higher percentage of operations in 2011 than in 2001 conducted health 

management practices on new additions (p 96). Specifically, in 2011 nearly twice the 

percentage of operations vaccinated new additions prior to arrival at the operation 

compared with operations in 2001 (70.1 and 35.6 percent, respectively). Similarly, more 

than twice the percentage of operations in 2011 conducted external parasite treatments 

on new additions prior to arrival compared with operations in 2001 (29.5 vs. 

13.6 percent, respectively). In general, a higher percentage of operations in 2011 than in 

2001 conducted health management activities after the arrival of new additions. 

Approximately twice the percentage of operations consulted a veterinarian for disease 

diagnosis, disease prevention, and lambing problems in 2011 than in 2001 (p 101). 

Cleaning the lambing area is crucial in preventing disease transmission from ewes to 

lambs and from ewes to ewes. A higher percentage of operations in 2011 than in 2001 

did not clean lambing areas (25.4 and 7.6 percent, respectively). Conversely, a lower 

percentage of operations in 2011 usually removed placentas from the lambing area 

compared with operations in 2001 (p 105). 

For operations in 2011 that had some pregnant ewes abort due to suspected infectious 

causes, 21.6 percent had the cause of abortions diagnosed by a laboratory or 

veterinarian compared with 51.3 percent of operations in 2001 (p 109). This trend of 

fewer suspected cases being diagnosed by a veterinarian or laboratory was also true for 

several other infectious causes of disease (p 109).

A higher percentage of producers were familiar with diseases such as Johne’s disease, 

scrapie, OPP, toxoplasmosis, and Q fever in 2011 than in 2001 (p 112–119).

Shearing 

Changes in the sheep industry in the last several decades include a reduction in wool 

marketing entities and related infrastructure, resulting in difficult marketing schemes with 

fewer domestic wool buyers, increased distances to markets, and fewer selling systems. 

In addition, low wool prices and difficulties in finding shearers have sometimes made 

producing wool a liability. As a result, more producers are raising hair sheep, which do not 

need to be sheared. In 2011, 80.2 percent of operations had sheared sheep and lambs in 

the previous year compared with 90.4 percent of operations in 2001 (p 129). 

USDA APHIS VS / v 

Introduction 1

Terms Used in This Report 3

Section I: Historic Changes in the U.S. Sheep Industry (1996, 2001, and 2011) 5

A. General Trends 5

1. Sheep and lamb inventory 5

2. Number and size of operations with breeding sheep 11

3. Lamb crop 14

4. Wool production 15

5. Sheep and lamb slaughter 16

6. Value of production 19

B. Sheep Inventory by State 20

Section II: Population Estimates (1996, 2001, 2011) 23

A. Changes in Inventory 23

1. Breed categories 23

 2. Primary use 29

B. Flock Management 31

1. Operator experience 31

2. Inventory expectations in 5 years 34

 3. Sources of information on sheep health 36

4. Production records 38

5. Primary flock type 39

6. Animal identification 42

7. Rodent control 46

8. Housing 47

C. Breeding Management 49

 1. Breeding practices 49

2. Breeding seasons 51

3. Ewe breeding 54

4. Ram and ewe lamb selection 55

 5. Outcome of ewes expected to lamb 59

D. Reproductive Outcomes 60

 1. Lambs born 60

 2. Lambing locations 66

3. Lamb feeding supplements 68

4. Castration management 71

 5. Age and weight of weaned lambs 72

Table of Contents
vi / Sheep 2011

E. Marketing Practices 73

 1. Operations that sold or moved lambs 73

 2. Type of marketing 77

 3. Cull rams and ewes 79

F. Lamb and Sheep Deaths and Losses 83

 1. Lamb and sheep losses 83

2. Carcass disposal methods 86

G. Lambs and Sheep on Feed 91

 1. Lambs and sheep on a high-energy diet 91

 2. Weight of market lambs 92

H. Biosecurity Practices 93

 1. Flock additions 93

 2. Contact with other sheep 97

3. Professional consultants 100

4. Manure management 103

I. Reproduction Management 104

 1. Manure and waste-bedding management during lambing 104

2. Placenta removal 105

3. Abortion and sick ewe management 107

4. Feeding practices 111

J. Disease Control, Illness, and Death 112

 1. Johne’s disease 112

2. Weight loss despite normal appetite 113

3. Scrapie 114

4. Ovine progressive pneumonia 117

5. Toxoplasmosis and Q fever 119

6. Diseases present in the last 3 years 120

7. Vaccination practices 121

K. Parasites and Dewormers 123

1. External parasites 123

2. Internal parasites 123

3. Dewormers 124

L. Shearing Practices 127

1. Shearing management 127

2. Wool management and marketing 131
USDA APHIS VS / vii 

M. Pasture Management, Water Sources, and Feeding Practices 133

1. Grazing 133

2. Pasture management 133

3. Water sources 135

Appendix I: Breed Categories 137

Appendix II: Sample Profile 138

A. Responding Operations―1996 138

 1. Number of responding operations by region 138

2. Number of responding operations by number of ewes present on January 1, 

1996 138

 3. Number of responding operations by total sheep inventory present on 

January 1, 1996 139

B. Responding Operations―2001 140

 1. Number of responding operations by flock size 140

2. Number of responding operations by region 140

C. Responding Operations―2011 141

 1. Number of responding operations by herd size 141

2. Number of responding operations by region 141

Appendix III: Response Rates 142

A. Sheep 2001 142

1. Phase I 142

2. Phase II―20 or more ewes 142

B. Sheep 2011 143

1. Phase Ia: general sheep management questionnaire―fewer than 20 ewes 

143

2. Phase Ib: general sheep management questionnaire―20 or more ewes 144

3. Phase II: VS initial visit questionnaire 145

Appendix IV: U.S. Ewes Population and Farms 146

A. Number of Ewes―State, Region, and United States 146

B. Ewes, Size Distribution―State, Region, and United States 147

C. U.S. Sheep and Lamb Population, January 1, 2011, Inventory 148

D. Breeding Sheep: Survey Percent by Size Group, United States 2008–09 149

Appendix V: Study Objectives and Related Outputs 150
viii / Sheep 2011

This report was a cooperative effort between two U.S. Department of Agriculture (USDA) 

Agencies: the National Agricultural Statistics Service (NASS) and the Animal and Plant 

Health Inspection Service (APHIS). 

We would like to thank the NASS enumerators who contacted sheep producers and 

collected the data. Their hard work and dedication were invaluable. Recognition also 

goes to personnel at the USDA–APHIS–Veterinary Services’ Center for Epidemiology 

and Animal Health and individual State Departments of Agriculture for their efforts in 

collecting data and generating and distributing this report.

All participants are to be commended, particularly the producers whose voluntary efforts 

made the Sheep 2011 study possible.

Bruce A. Wagner

Director

National Animal Health Monitoring System

Acknowledgements
USDA APHIS VS / ix 

Suggested bibliographic citation for this report:

USDA. 2014. Sheep 2011: Part IV: Changes in Health and Production Practices in the 

U.S. Sheep Industry, 1996–2011

USDA–APHIS–VS, CEAH. Fort Collins, CO

#633.0414

Contacts for further information:

Questions or comments on data analysis: Dr. Katherine Marshall (970) 494–7000

Information on reprints or other reports: Ms. Abby Zehr (970) 494–7000

Feedback

Feedback, comments, and suggestions regarding Sheep 2011 study reports are 

welcomed. You may submit feedback via online survey at: http://nahms.aphis.usda.gov 

(Click on “FEEDBACK on NAHMS reports.”)

USDA APHIS VS / 1 

Introduction

The National Animal Health Monitoring System (NAHMS) is a nonregulatory program of 

the United States Department of Agriculture’s (USDA) Animal and Plant Health Inspection 

Service (APHIS). NAHMS is designed to help meet the Nation’s animal-health information 

needs and has collected data on sheep health and management practices through two 

previous studies. 

The NAHMS 1996 National Sheep Survey was developed through collaboration with the 

Research and Education Division of the American Sheep Industry Association (ASI) and 

focused on identifying health and productivity issues affecting America’s sheep industry. 

Study results provided an overview of sheep health, productivity, and management on 

5,174 U.S. sheep operations. 

The NAHMS Sheep 2001 study was designed to provide participants and the industry 

with information about the U.S. sheep flock on operations with one or more sheep. 

The USDA’s National Agricultural Statistics Service (NASS) collaborated with APHIS’ 

Veterinary Services (VS) to select a producer sample statistically designed to provide 

inferences to the Nation’s sheep population in 22 participating States. These 22 States 

accounted for 87.4 percent of the U.S. sheep inventory on January 1, 2001, and 72.3 

percent of U.S. sheep operations in 2000. 

The NAHMS Sheep 2011 study was conducted in 22 of the Nation’s major sheepproducing States (see map). The study provides participants, stakeholders, and the 

industry with valuable information representing 70.1 percent of U.S. farms with ewes and 

85.5 percent of the U.S. ewe inventory (NASS 2007 Census of Agriculture). 

This report, “Part IV: Changes in Health and Production Practices in the U.S. Sheep 

Industry, 1996–2011” is the fourth report from the Sheep 2011 study and focuses primarily 

on changes in health and management practices on U.S. sheep operations over time, 

specifically comparing results from each of the three NAHMS national sheep studies. 

Interpreting changes in estimates among the three studies, however, is sometimes 

problematic. For example, comparing results from Sheep 1996 with results from Sheep 

2001 and Sheep 2011 is difficult due to structure and coverage of the 1996 study. Thus, 

results from the 1996 study are only included in a few tables, and these results should be 

interpreted with caution. In addition, the difference between the 2001 and 2011 studies in 

how “feedlot/dry lot” operations were defined resulted in the removal of this classification 

from almost all comparison tables in this report.

In general, major influences behind differences in estimates may be due, in part, 

to differences in the composition of the target population. These differences are 

documented in each summary table to aid in interpretation. Differences also may occur in 

the factors being measured, e.g., changes in question wording, random variation, 

Introduction
2 / Sheep 2011

Introduction

and true secular time trends in the sheep industry. These differences have also been 

documented to aid in interpretation. 

Reports and information sheets from all three NAHMS national sheep studies are 

available at www.aphis.usda.gov/nahms 

The methods used and number of respondents in each study can be found in appendices 

II and III of this report, respectively.

Participating States1 by study year and by region2

2001

2011

2001

2011

2001

2011

2001

2011

2001

2011

2001

2011

2001

2011

2001

2011

2001

2011

2001

2011

2001

2011

2001

2011

2001

2011 2011

2001

2011

2011

2001

2011

2011

2001

2011

2001

2011

2011

2001

2011

2001

2001 2001

2001

1 All 48 contiguous States participated in the 1996 study. 2 2001 and 2011 studies only.

West

Central

East

egions
USDA APHIS VS / 3 

Introduction

Being on back: Sheep that have rolled onto their backs (often referred to as “cast” 

sheep), sometimes due to heavy infestation by keds. Keds may cause excessive itching 

and ewes roll onto their backs to relieve the itch. Heavily pregnant ewes are most 

susceptible, but other sheep types may also be vulnerable, including those with full 

fleeces, stocky builds, or those that have rolled over into a soft spot of ground.

Biosecurity: Management practices used to prevent the spread of disease between 

groups of animals on an operation and reduce the likelihood of disease entering an 

operation.

Coccidiostat: A drug that controls coccidia, the cause of coccidiosis. 

Coxiellosis: A bacterial infection in sheep and other animals caused by Coxiella burnetii, 

also known as Q fever in humans.

Disease: Any morbid condition that impairs the full productive potential of an animal.

Ewe: A female sheep 1 year of age or older.

Primary flock type: The following flock types represent only flocks with 20 or more 

ewes. Although the majority of operations had more than one flock type, all had a primary 

flock type:

Herded/open range—any unfenced acreage, even if a only a few acres surrounded 

by residential areas.

Fenced range—any fenced area not specifically cultivated to raise forage or browse.

Farm/pasture—any fenced area specifically cultivated to raise forage or browse.

Flushing: Temporary but purposeful elevation in nutritional status around breeding time. 

Ewes are fed extra energy rations prior to the breeding season to improve ovulations, 

conception, and embryo implantation rate, ultimately increasing the lamb crop ratio.

Lamb: Sheep less than 1 year old.

Lambing jug: Small, individual pen used to house ewe-lamb pairs shortly after lambing. 

Pen allows the ewe and lamb to bond and also provides a means for ensuring that the 

lamb is nursing properly.

Operation average: A single value for each operation is summed over all operations 

reporting and divided by number of operations reporting.

Terms Used in 

This Report
4 / Sheep 2011

Introduction

Operation size: 

Sheep 2001 (number of ewes):

Very small: fewer than 25

Small: 25 to 99

Medium: 100 to 999

Large: 1,000 or more

Sheep 2011 (number of ewes): 

Very small: fewer than 20

Small: 20 to 99

Medium: 100 to 499

Large: 500 or more

Population estimates: Estimates in this report are provided with a measure of precision 

called the standard error. A 95-percent confidence interval can be created with bounds 

equal to the estimate, plus or minus two standard errors. If the only error is sampling 

error, the confidence intervals created in this manner will contain the true population 

mean 95 out of 100 times. An estimate of 7.5 with a standard error of 1.0 results in limits 

of 5.5 to 9.5 (two times the standard error above and below the estimate). Alternatively, 

the 90-percent confidence interval would be created by multiplying the standard error 

by 1.65 instead of 2. Most estimates in this report are rounded to the nearest tenth. If 

rounded to 0, the standard error was reported (0.0). If there were no reports of the event, 

no standard error was reported (—).

Regions in 2001 and 2011studies:

West: California, Oregon, Washington

Central: Arkansas, Colorado, Idaho, Kansas, Montana, Nevada, New Mexico, South 

Dakota, Texas, Utah, Wyoming

East: Illinois, Indiana, Iowa, Kentucky, Michigan, Minnesota, Missouri, New York, Ohio, 

Pennsylvania, Virginia, Wisconsin

Sheep: Animal 1 year old and older.

Tail docking: The removal of lambs’ tails, usually to prevent accumulation of manure 

around the hindquarters of sheep.
USDA APHIS VS / 5 

Section I: Historic Changes–A. General Trends

The USDA’s National Agriculture Statistics Service (NASS) conducts the census of 

agriculture every 5 years. The census is a complete count of U.S. farms, ranches, and 

the people who manage them. Since 1974, a farm (operation) has been defined as a 

place from which $1,000 or more of agricultural products are produced and sold during 

the year—or normally would have been sold during the census year. The following table 

provides census numbers since 1890 on sheep inventory, number of sheep operations, 

and average number of ewes on hand. 

1. Sheep and lamb inventory

New sheep operations are continually entering the market. As is the case with other 

livestock commodities, newer operations tend to be relatively small. In 2007, the average 

number of ewes per farm was 51.5 compared with the 1978 average of 94.9. The trend 

of fewer ewes per operation is also reflected in the following table’s column “all sheep 

and lambs average flock size.” This column, however, also shows that average flock size 

peaked in 1974 at 141.6 sheep per operation, decreasing to 70.0 sheep per operation 

by 2007. Total sheep inventories peaked in 1930 at 56,975,000 sheep and have steadily 

decreased since. 

Although sheep inventory declined from 2002 to 2007, the number of sheep operations 

increased by nearly 10,000 during the same period. This finding follows the decline in the 

number of sheep operations from 1982 to 2002, which could indicate an influx of new, 

smaller operations to the sheep sector.

Section I: Historic Changes in the U.S. Sheep Industry (1996, 2001, 

and 2011)

A. General 

Trends
6 / Sheep 2011

Section I: Historic Changes–A. General Trends

A.1.a. Changes in U.S. sheep and lamb January 1 inventory, by census year:

Census 

year 

All sheep 

and lambs 

inventory 

(1,000 head)

All sheep 

and lamb 

operations

All sheep 

and lambs 

average 

flock/herd 

size

Ewes 1 year+ 

inventory 

(1,000 head)

Ewes 1 year+ 

farms

Ewes 

1 year+ 

average 

number 

per 

operation

1890 35,935 NA NA

1900 61,504 763,543 80.6 NA NA

1910 52,448 610,894 85.9 NA NA

1920 35,034 538,593 65.0 NA NA

1930 56,975 583,578 97.6 NA NA

1940 40,129 584,935 68.6 NA NA

1945 41,224 456,986 90.2 NA NA

1950 31,406 320,351 98.0 NA NA

1954 31,619 361,001 87.6 NA NA

1959 33,945 341,952 99.3 NA NA

1964 25,471 234,789 108.5 NA NA

1969 21,611 170,888 126.5 NA NA

1974 15,380 108,646 141.6 NA NA

1978 12,243 90,437 135.4 7,808 82,287 94.9

1982 12,438 101,582 122,4 7,666 90,500 84,7

1987 11,059 92,489 119.6 6,882 83,552 82.4

1992 10,770 80,839 133.2 6,401 70,730 90.5

1997 8,083 77,112 104.8 4,579 65,505 69.9

2002 6,342 73,814 85.9 3,632 66,789 54.4

2007 5,819 83,134 70.0 3,516 68,222 51.5

Source: National Agricultural Statistics Service.
USDA APHIS VS / 7 

Section I: Historic Changes–A. General Trends

NASS publishes information on sheep operations in January of each year. The following 

tables include selected data from NASS surveys that generally correspond to the range 

of years from 2001 to 2011 and illustrate the changes in the total U.S. inventory of 

breeding sheep, sheep and lambs, and ewes. The “percent of previous year” column 

reflects annual changes in ewe inventory, while the “percent of 2001” shows trends from 

2001 to 2011. 

With the exception of 2005 and 2006, sheep and lamb inventories declined steadily from 

2001 to 2011. The increases in inventory in 2005 and 2006 were likely due to the USDA’s 

Farm Service Agency’s Ewe Lamb Replacement and Retention Program implemented 

in late 2004; this program provided direct payments to help sheep and lamb producers 

replace and retain their ewe lamb breeding stock. 

A.1.b. Changes in U.S. ewe January 1 inventory, 2001–11:

Year 

Sheep 

and lambs 

inventory 

(1,000 head)

Breeding 

sheep 

inventory 

(1,000 head)

Ewe inventory 

(1,000 head)

Pct. of 

previous year 

ewe inventory

Pct. of 2001 

ewe inventory

2001 6,908 4,952 4,071 96.7 100.0

2002 6,623 4,871 3,939 96.8 96.8

2003 6,321 4,670 3,773 95.8 92.7

2004 6,065 4,464 3,570 94.6 87.7

2005 6,135 4,520 3,545 99.3 87.1

2006 6,200 4,616 3,630 102.4 89.2

2007 6,120 4,553 3,620 99.7 88.9

2008 5,950 4,432 3,540 97.8 87.0

2009 5,747 4,247 3,405 96.2 83.6

2010 5,620 4,185 3,335 97.9 81.9

2011 5,480 4,080 3,225 96.7 79.2

Source: National Agricultural Statistics Service.
8 / Sheep 2011

Section I: Historic Changes–A. General Trends

3,000

4,000

5,000

6,000

7,000

8,000

Ewes

Sheep and lambs
USDA APHIS VS / 9 

Section I: Historic Changes–A. General Trends

Replacement ewe lambs replace ewes that die or are culled. Replacement lambs 

are most often generated within the flock and should represent the best of the flock’s 

genetics. The average age of cull ewes was 6.3 years (NAHMS Sheep 2011, Part I). 

Assuming lambs are bred at about 1 year of age, replacement lambs should represent 

approximately 19 percent of ewe inventory in order to keep the flock of breeding ewes 

approximately the same size. Replacement lambs represented 16.7 percent of ewe 

breeding lambs in 2001. This percentage increased each year until 2005, then decreased 

slightly each year until increasing again in 2010 and 2011. 

A.1.c. Percentage changes in U.S. ewe replacement lambs, January 1 inventory, 

2001–11:

Year 

Ewe replacement 

inventory 

(1,000 head)

Percent of 

previous year Percent of 2001

Percent of ewes 

1 year or older

2001 679 93.7 100.0 16.7

2002 732 107.8 107.8 18.6

2003 703 96.0 103.5 18.6

2004 705 100.2 103.8 19.7

2005 783 111.1 115.3 22.1

2006 786 100.4 115.8 21.7

2007 735 93.4 108.2 20.3

2008 697 94.8 102.7 19.7

2009 647 92.8 95.2 19.0

2010 655 101.3 96.5 19.6

2011 665 101.5 98.9 20.6

Source: National Agricultural Statistics Service.
10 / Sheep 2011

Section I: Historic Changes–A. General Trends

In 2011, there was a slightly higher percentage of breeding sheep in the 1 to 99 flock size 

and a slightly lower percentage of breeding sheep in the other flock sizes compared with 

2003. 

A.1.d. Percentage of U.S. breeding sheep inventory by flock size, 2001–11:

Flock size (number of breeding sheep)

Year 1–99 100–499 500–4,999 5,000 or more Total

2001 NA NA NA NA NA

2002 NA NA NA NA NA

2003 31.7 22.0 33.0 13.3 100.0

2004 30.3 22.0 33.5 14.2 100.0

2005 30.3 22.0 33.5 14.2 100.0

2006 28.7 24.0 33.8 13.5 100.0

2007 32.9 21.4 31.9 13.8 100.0

2008 32.6 22.7 30.2 14.5 100.0

2009 36.2 20.8 31.3 11.7 100.0

2010 35.8 20.1 30.6 13.5 100.0

2011 35.9 21.1 31.1 11.9 100.0

Source: National Agricultural Statistics Service.
USDA APHIS VS / 11 

Section I: Historic Changes–A. General Trends

2. Number and size of operations with breeding sheep

The number of operations with breeding sheep grew from 68,600 in 2001 to 83,130 in 

2007, and then stabilized at 80,000 in 2011.

A.2.a. Changes in the number of operations with breeding sheep, 2001–11:

Year Number of operations Pct. of previous year Pct. of 2001

2001 68,600 99.1 100.0

2002 68,150 99.3 99.3

2003 67,720 99.4 98.7

2004 67,630 99.9 98.6

2005 68,460 101.2 99.8

2006 69,180 101.1 100.8

2007 83,130 120.2 121.2

2008 82,500 99.2 120.3

2009 82,000 99.4 119.5

2010 81,000 98.8 118.1

2011 80,000 98.8 116.6

Source: National Agricultural Statistics Service.
12 / Sheep 2011

Section I: Historic Changes–A. General Trends

The percentage of operations with breeding sheep in the 100 to 499 and 500 to 4,999 

flock sizes declined slightly from 2003 to 2011.

A.2.b. Percentage of operations with breeding sheep, by flock size, 2001–2011:

Flock size (number of breeding sheep)

Year 1–99 100–499 500–4,999 5,000 or more Total

2001 NA NA NA NA NA

2002 NA NA NA NA NA

2003 92.2 6.3 1.4 0.1 100.0

2004 92.0 6.5 1.4 0.1 100.0

2005 92.0 6.5 1.4 0.1 100.0

2006 90.8 7.6 1.5 0.1 100.0

2007 92.5 6.1 1.3 0.1 100.0

2008 92.5 6.2 1.2 0.1 100.0

2009 93.7 5.2 1.0 0.1 100.0

2010 93.8 5.1 1.0 0.1 100.0

2011 93.5 5.4 1.0 0.1 100.0

Source: National Agricultural Statistics Service.

Photograph courtesy of Judy Rodriguez.
USDA APHIS VS / 13 

Section I: Historic Changes–A. General Trends

0

20

40

60

80

100

Inventory 

Operations

Percent

Flock size (number of breeding sheep)

1–99 100–499 500–4,999 5,000 or more

Percentage of operations with breeding sheep and percentage of breeding 

sheep inventory in Sheep 2011, by herd size

93.5

35.9

5.4

21.1

1.0

31.1

0.1

11.9
14 / Sheep 2011

Section I: Historic Changes–A. General Trends

3. Lamb crop

Lamb inventory gradually declined from 4.5 million head in 2001 to 3.5 million in 2011. 

A.3. Changes in U.S. lamb crop, 2001–11:

Year 

Inventory 

(1,000 head)

Percent of 

previous year

Lambs per 100 

ewes on January 1

2001 4,520 97.3 111

2002 4,355 96.4 111

2003 4,035 92.7 107

2004 4,040 100.1 113

2005 4,015 99.4 113

2006 3,950 98.4 109

2007 3,895 98.6 108

2008 3,710 95.3 105

2009 3,690 99.5 108

2010 3,570 96.7 107

2011 3,510 98.3 109

Source: National Agricultural Statistics Service “Sheep and Goats” reports.
USDA APHIS VS / 15 

Section I: Historic Changes–A. General Trends

4. Wool production

The value of wool production increased substantially from 2001 to 2011, while wool 

production fell by nearly 13,000 lb during the same period. 

A.4. Changes in sheep shorn, weight per fleece, and wool production, 2001–11:

Year 

Sheep shorn

(1,000 head)

Pounds per 

fleece

Production

(1,000 lb)

Value of wool 

production 

($1,000)

Pct. of 2001 

value of wool 

production 

2001 5,596 7.5 42,156 14,841 100.0

2002 5,462 7.5 41,078 21,689 146.1

2003 5,077 7.5 38,197 28,129 189.5

2004 5,066 7.4 37,581 29,954 201.8

2005 5,061 7.3 37,182 26,249 176.9

2006 4,847 7.4 35,899 24,300 163.7

2007 4,657 7.5 34,723 30,242 203.8

2008 4,434 7.4 32,963 30,486 205.4

2009 4,195 7.4 30,860 24,337 164.0

2010 4,180 7.3 30,370 35,018 236.0

2011 4,030 7.3 29,290 48,925 329.6

Source: National Agricultural Statistics Service “Sheep and Goats” reports.
16 / Sheep 2011

Section I: Historic Changes–A. General Trends

5. Sheep and lamb slaughter

While the number of sheep slaughtered under Federal inspection declined from 2001 to 

2011, the number of sheep slaughtered under “other” inspection rose slightly. Slaughter 

of mature sheep, lambs, and yearlings equals federally inspected slaughter. Federally 

inspected slaughter plus “other” equals commercial slaughter. From 2001 to 2011, farm 

slaughter increased by 35.0 percent.

A.5.a. Changes in sheep slaughter by class, 2001–11:

Year 

Mature 

sheep

(1,000 head)

Lambs and 

yearlings

(1,000 head)

Federally 

inspected

(1,000 head)

Other 

(1,000 head)

Commercial 

(1,000 head)

Farm 

(1,000 head)

2001 143.7 2,921.3 3,065.0 157.2 3,222.1 65.4

2002 148.0 2,944.3 3,092.3 194.0 3,286.3 65.9

2003 143.2 2,662.0 2,805.2 173.6 2,978.8 72.2

2004 147.3 2,529.0 2,676.3 163.1 2,839.3 73.5

2005 129.3 2,425.1 2,554.4 143.4 2,697.8 74.9

2006 118.1 2,429.0 2,547.0 151.4 2,698.5 79.7

2007 115.6 2,413.1 2,528.7 165.1 2,693.8 84.5

2008 122.3 2,271.1 2,393.5 162.1 2,555.5 91.9

2009 157.7 2,165.3 2,323.1 192.8 2,515.9 95.2

2010 156.4 2,103.7 2,261.1 196.4 2,457.5 95.3

2011 140.7 1,859.5 2,000.2 164.1 2,164.3 93.2

Source: National Agricultural Statistics Service “Livestock Slaughter” reports.
USDA APHIS VS / 17 

Section I: Historic Changes–A. General Trends

0

500

1000

1500

2000

2500

3000

3500

Farm

Other commercial

Federally inspected
18 / Sheep 2011

Section I: Historic Changes–A. General Trends

The average total commercial slaughter weights started high in 2001 (140 lb), declined 

somewhat, then rose again in 2011 (138 lb).

A.5.b. Sheep and lamb slaughter weights by class, 2001–11:

Year 

Federally 

inspected (lb) Other (lb)

Commercial 

production (lb)

2001 142 106 140

2002 135 100 133

2003 136 105 134

2004 138 111 136

2005 140 107 138

2006 138 105 137

2007 138 104 136

2008 138 103 136

2009 139 97 136

2010 137 98 134

2011 141 99 138

Source: National Agricultural Statistics Service “Livestock Slaughter” reports.
USDA APHIS VS / 19 

Section I: Historic Changes–A. General Trends

6. Value of production

Lamb prices have increased since 2007 and in 2011 reached historic highs. These prices 

helped return the value of sheep and lamb production in 2010 to levels not seen since 

2005, despite generally low inventories. 

A.6. Recent changes in value of sheep and lamb production (excludes value of wool), 

2001–11:

Year Production ($1,000) Pct. of 2001

2001 303,186 100.0

2002 313,946 103.5

2003 389.201 128.4

2004 412,691 136.1

2005 451,467 148.9

2006 367,799 121.3

2007 362,941 119.7

2008 351,287 115.9

2009 365,030 120.4

2010 442,899 146.1

2011 NA1

1

Value not reported by NASS for 2011.

Source: National Agricultural Statistics Service “Meat Animals PDI” reports.
20 / Sheep 2011

Section I: Historic Changes–B. Sheep Inventory by State

In 2001, California, Colorado, Montana, South Dakota, Texas, and Wyoming accounted 

for 53.3 percent of the total U.S. sheep and lamb inventory. In 2011, these same States 

accounted for 49.4 percent of the total sheep and lamb inventory. During those same 

years, States with lower inventories, such as Arizona, Missouri, Virginia, and Wisconsin, 

increased their sheep and lamb inventories by 11 to 47 percent of 2001 levels. Some 

of the biggest sheep producing States, however, decreased their inventories during the 

same period.

B. Changes in total sheep and lamb inventory, and number of ewes 1 year and older, 

January 1:

B. Sheep 

Inventory by 

State

2001 2011 Pct. of 2001

State 

Total sheep 

and lambs 

(1,000 head)

Ewes 1+ 

(1,000 head)

Total sheep 

and lambs 

(1,000 head)

Ewes 1+ 

(1,000 head)

Total sheep 

and lambs 

(1,000 head)

Ewes 1+ 

(1,000 head)

Arizona 120 53 150 75 125.0 141.5

California 805 310 600 273 75.8 91.3

Colorado 420 165 370 142 88.1 86.1

Idaho 275 195 235 151 85.5 78.5

Illinois 75 48 56 36 74.7 75.0

Indiana 66 45 50 34 75.8 75.6

Iowa 270 144 200 104 74.1 73.6

Kansas 110 58 70 33 63.6 56.9

Kentucky — — 34 22 — —

Michigan 71 40 74 44 104.2 110.0

Minnesota 170 90 130 77 76.5 85.6

Missouri 73 47 81 57 111.0 121.3

Montana 360 265 230 170 63.9 64.2

Nebraska 114 77 74 46 64.9 59.7

Nevada 95 68 68 46 71.6 67.6

New Mexico 200 130 110 75 55.0 59.2

New York 65 41 70 43 107.7 104.9
USDA APHIS VS / 21 

Section I: Historic Changes–B. Sheep Inventory by State

B. (cont’d.) Changes in total sheep and lamb inventory, and number of ewes 1 year and 

older, January 1:

2001 2011 Pct. of 2001

State 

Total sheep 

and lambs 

(1,000 head)

Ewes 1+ 

(1,000 head)

Total sheep 

and lambs 

(1,000 head)

Ewes 1+ 

(1,000 head)

Total sheep 

and lambs 

(1,000 head)

Ewes 1+ 

(1,000 head)

North Carolina — — 27 16 — —

North Dakota 138 89 78 50 56.5 56.2

Ohio 142 86 129 81 90.8 94.2

Oklahoma 55 33 75 45 136.4 136.4

Oregon 245 120 215 118 87.8 98.3

Pennsylvania 90 64 98 62 108.9 96.9

South Dakota 420 265 265 173 65.5 66.4

Tennessee — — 35 22 — —

Texas 1,150 710 850 515 76.5 73.9

Utah 390 300 280 210 71.8 70.3

Virginia 61 37 90 55 147.5 148.6

Washington 54 35 56 36 103.7 102.9

West Virginia 35 24 34 24 97.1 100.0

Wisconsin 80 53 90 59 112.5 111.3

Wyoming 530 340 365 220 68.9 64.7

New England 49 32 51 32 104.1 94.1

Other States 180 107 140 79 77.8 73.8

United States 6,908 4,071 5,480 3,225 80.1 80.0

Source: National Agricultural Statistics Service “Sheep and Goats” reports.
22 / Sheep 2011

Section I: Historic Changes–B. Sheep Inventory by State

Changes in total sheep and lamb inventory, 2001–11

Percent increase

New England States reported as a group.

Percent loss

-36.1

-12.2

-28.4

-24.2

+25.0

-14.9

-43.5

-35.1

-11.9

-45.0

+36.4

+11.0

-25.3 -24.2

+12.5

+4.2 +7.7

+4.1

+8.9

+47.5

+3.7

-36.4

-25.9

-23.5

-31.1

-34.5

-28.2

-22.5

-9.2

+2.9
USDA APHIS VS / 23 

Section II: Population Estimates–A. Changes in Inventory

Section II: Population Estimates (1996, 2001, 2011)

Note: This report compares results from the Sheep 1996 and Sheep 2001 studies with 

those from the Sheep 2011 study. In some cases, questions were asked about practices 

or occurrences during the calendar year preceding the study (i.e., 1995 for Sheep 1996, 

2000 for Sheep 2001, and 2010 for Sheep 2011), while other questions were asked about 

usual or ongoing practices or occurrences without a specific time frame (i.e., what the 

producer typically does). 

1. Breed categories 

In 2011, the highest percentage of operations (48.6 percent) owned black-faced sheep, 

but black-faced sheep and lambs owned represented just 14.0 percent of the January 1 

sheep and lamb inventory (table A.1.c). In the Sheep 2011 study, the crossbred category 

used in 1996 and 2001 was changed to mottle-, brockle-, or speckle-faced crossbred. 

This change might explain the substantial decline in the percentage of operations that 

reported they owned sheep in this category. The change was made to more clearly 

identify ownership of sheep breeds that have historically been at a higher risk for scrapie 

compared with white-faced breeds. It is possible that in 1996 and 2001 operations 

included white-faced crossbreds in the crossbred category, even though the majority of 

these should have been included in the fine- or medium-wool white-faced categories. It 

is also likely that black-faced crossbreds were included in the crossbred category in 1996 

and 2001.

A. Changes in 

Inventory
24 / Sheep 2011

Section II: Population Estimates–A. Changes in Inventory

The greatest change in 2011 compared with 1996 and 2001 was the increase in the 

percentage of operations that owned hair sheep, which increased from 1.0 percent of 

operations in 1996 to 21.7 percent 2011.

A.1.a. Percentage of operations by breed category of sheep and lambs, and by study: 

Percent Operations

Sheep 1996 Sheep 2001 Sheep 20111

Breed category Pct.

Std.

error Pct.

Std. 

error Pct.

Std. 

error

Black faced, wool 32.3 (1.1) 38.8 (1.6) 48.6 (1.1)

White faced, fine wool 13.0 (0.7) 17.2 (1.1) 26.2 (0.9)

White faced, 

medium wool 20.6 (0.9) 23.3 (1.3) 32.7 (1.1)

Long wool NA 3.8 (0.6) 4.6 (0.5)

Mottle-, brockle-, or 

speckle-faced crossbred 23.82 (1.0) 48.22 (1.6) 13.7 (0.8)

Colored wool 2.4 (0.3) 8.3 (0.9) 5.2 (0.5)

Hair sheep 1.0 (0.3) 4.6 (0.8) 21.7 (1.0)

Milk sheep 0.0 (0.0) 0.1 (0.1) 0.9 (0.2)

Other 6.93 (0.6) 7.4 (0.9) 6.7 (0.6)

Unknown NA 0.24 (0.1) 0.9 (0.2)

An operation may have multiple breeds of sheep.

Question variations:

1

In 2011 only operations with ewes on January 1 were included.

2

Category was “Crossbred” in 1996 and 2001.

3

Category was “Multiple” in 1996.

4

Unknown—feedlot operations only.
USDA APHIS VS / 25 

Section II: Population Estimates–A. Changes in Inventory

0 10 20 30 40 50

Sheep 20111

Sheep 2001

Sheep 1996

Black

face, wool

White face,

fine wool

White face,

medium wool

Long wool

Mottle-, brockle-, or

speckle-faced crossbred

Colored wool

Other

Unknown

Breed

category

Percent

Percentage of operations by breed category of sheep and lambs, and by study

An operation may have had multiple breeds of sheep.

Question variation:

1

In 2011, only operations with ewes on January 1 were included. 2

Category was “Crossbred” in 1996 and 2001.

3

Category was “Multiple” in 1996.

4

Unknown—feedlot operations only.

32.3

13.0

17.2

26.2

20.6

23.3

32.7

3.8

23.82

48.22

21.7

13.7

6.7

6.93

0.9

0.24

Hair

Milk

38.8

48.6

4.6

2.4

8.3

5.2

1.0

4.6

0.0

0.1

0.9

NA

7.4

NA
26 / Sheep 2011

Section II: Population Estimates–A. Changes in Inventory

A substantial downward trend across all regions in the percentage of operations that 

owned mottle-, brockle-, or speckle-faced crossbreds occurred from 2001 to 2011. 

Conversely, there was a substantial upward trend across regions in the percentage of 

operations that owned hair sheep. From 2001 to 2011, the percentage of operations in 

the East region that owned black-faced wool breeds, white-faced medium wool breeds, 

and long-wool breeds increased.

A.1.b. Percentage of operations by breed category of sheep and lambs, and by region:

Percent Operations

Region

West Central East

Sheep 2001 Sheep 20111 Sheep 2001 Sheep 20111 Sheep 2001 Sheep 20111

Breed 

categories Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Black-faced, 

wool 47.6 (4.5) 49.5 (2.5) 37.8 (2.6) 38.9 (1.5) 35.8 (2.2) 46.9 (1.5)

White-faced, 

fine wool 11.6 (2.5) 12.1 (1.6) 28.4 (2.1) 35.0 (1.5) 11.2 (1.5) 13.9 (1.1)

White-faced, 

medium wool 23.6 (3.7) 23.5 (2.1) 22.4 (2.0) 19.8 (1.1) 23.7 (1.9) 34.3 (1.5)

Long wool 5.6 (1.7) 10.8 (1.6) 2.6 (0.8) 1.7 (0.4) 3.8 (0.9) 7.9 (0.9)

Mottle-, brockle-, 

or speckle-faced 

crossbred 2

56.4 (4.5) 12.5 (1.6) 36.9 (2.4) 7.7 (0.7) 53.1 (2.3) 12.4 (0.9)

Colored wool 9.1 (2.5) 9.0 (1.5) 6.1 (1.3) 4.1 (0.6) 9.6 (1.4) 9.2 (1.0)

Hair 3.8 (1.2) 20.4 (2.0) 5.2 (1.8) 27.1 (1.5) 4.4 (1.0) 18.1 (1.2)

Milk 0.1 (0.1) 0.7 (0.4) 0.0 (0.0) 0.6 (0.3) 0.2 (0.1) 0.9 (0.3)

Other 6.1 (2.1) 6.2 (1.2) 5.4 (1.3) 5.5 (0.9) 9.4 (1.4) 8.4 (0.9)

Unknown3 0.6 (0.5) 1.6 (0.7) 0.3 (0.1) 1.0 (0.4) 0.0 (0.0) 1.3 (0.4)

An operation may have multiple breeds of sheep.

Question variations:

1

In 2011 only operations with ewes on January 1 were included.

2

Category was “crossbred” in 2001.

3

Unknown—feedlot operations only in 2001.
USDA APHIS VS / 27 

Section II: Population Estimates–A. Changes in Inventory

In 2011, the white-faced, fine- wool sheep breeds represented the single highest 

percentage of sheep and lamb inventory (43.5 percent of the January 1 sheep and lamb 

inventory). This percentage remained relatively unchanged from 1996 to 2011. Hair 

sheep represented largest increase in the percentage of sheep and lamb inventory by 

breed category. There was a slight uptick in the percentage of hair sheep from 1996 

to 2001, but a 900-percent increase from 2001 to 2011. The percentage decrease of 

operations with mottle-, brockle-, or speckle-faced crossbreds was likely due to a change 

in the definition of this category. 

A.1.c. Percentage of January 1 sheep and lamb inventory, by breed category: 

Percent Sheep and Lambs

Sheep 1996 Sheep 2001 Sheep 20111

Breed categories Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Black-faced, wool 10.2 (0.7) 8.9 (0.6) 14.0 (0.7)

White-faced, fine wool 41.8 (2.4) 34.3 (1.3) 43.5 (1.5)

White-faced, 

medium wool 26.0 (2.4) 17.9 (0.9) 18.3 (0.9)

Long wool NA 0.7 (0.1) 1.0 (0.1)

Mottle-, brockle-, or 

speckle-faced crossbred2 15.6 (2.4) 29.4 (1.5) 5.4 (0.5)

Colored wool 0.6 (0.1) 1.2 (0.3) 0.8 (0.1)

Hair 0.4 (0.1) 1.2 (0.2) 11.0 (0.7)

Milk 0.0 (0.0) 0.1 (0.0) 0.7 (0.4)

Other3 5.4 (0.7) 3.4 (0.9) 4.8 (0.7)

Unknown4 NA 2.9 (0.6) 0.5 (0.2)

Total 100.0 100.0 100.0

Question variations:

1

In 2011 only operations with ewes on January 1 were included.

2

Category was “crossbred” in 1996 and 2001.

3

Category was “multiple” in 1996.

4

Unknown—feedlot operations only.
28 / Sheep 2011

Section II: Population Estimates–A. Changes in Inventory

In the West region, inventories of black-faced wool breeds increased from 10.0 percent 

of sheep and lambs in 2001 to 24.2 percent in 2011. Inventories of white-faced, medium 

wool breeds declined in the Central region and increased in the East region from 2001 to 

2011. Hair sheep inventories increased in all regions.

A.1.d. Percentage of January 1 sheep and lamb inventory by breed category and by 

region:

Percent Sheep and Lambs

Region

West Central East

Sheep 2001 Sheep 20111 Sheep 2001 Sheep 20111 Sheep 2001 Sheep 20111

Breed 

categories Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Black faced, 

wool 10.0 (1.3) 24.2 (2.8) 5.9 (0.8) 7.3 (0.5) 18.2 (1.5) 26.1 (1.2)

White faced, 

fine wool 25.9 (4.2) 33.3 (3.3) 45.0 (1.6) 57.8 (1.9) 5.7 (0.8) 8.5 (0.8)

White faced, 

medium wool 10.7 (2.5) 13.8 (2.0) 20.9 (1.2) 15.1 (1.2) 15.0 (1.3) 28.7 (1.5)

Long wool 1.7 (0.6) 3.1 (0.5) 0.3 (0.1) 0.2 (0.1) 1.1 (0.3) 2.0 (0.3)

Mottle-, brockle-, 

or speckle-faced 

crossbred 2

42.6 (5.0) 9.4 (1.6) 20.9 (1.6) 2.0 (0.4) 45.3 (2.8) 10.4 (1.3)

Colored wool 1.7 (1.0) 1.0 (0.2) 1.0 (0.3) 0.6 (0.2) 1.8 (0.4) 2.5 (0.4)

Hair 1.4 (0.5) 7.2 (1.1) 0.8 (0.2) 12.5 (1.0) 2.1 (0.5) 13.7 (1.1)

Milk 0.0 (0.0) 2.1 (1.9) 0.0 (0.0) 0.1 (0.0) 0.4 (0.2) 1.0 (0.3)

Other 2.8 (0.9) 5.7 (1.7) 1.5 (0.3) 4.0 (0.9) 10.2 (4.6) 6.1 (0.8)

Unknown3 3.0 (1.5) 0.1 (0.0) 3.6 (0.9) 0.4 (0.2) 0.1 (0.1) 1.2 (0.5)

Total 100.0 100.0 100.0 100.0 100.0 100.0

Question variations:

1

In 2011 only operations with ewes on January 1 were included.

2

Category was “crossbred” in 2001.

3

Unknown—feedlot operations only in 2001.
USDA APHIS VS / 29 

Section II: Population Estimates–A. Changes in Inventory

2. Primary use 

Primary uses of sheep and lambs include meat, wool, show, competition, 4-H or club 

lambs, seed or breeding stock, milk, and other uses. In 2001, 60.7 percent of operations 

raised some sheep and lambs primarily for meat compared with 81.6 percent of 

operations in 2011. The percentage of operations that raised some sheep and lambs 

primarily for seed or breeding stock decreased from 35.6 percent in 2001 to 26.5 percent 

in 2011. 

A.2.a. Percentage of operations by primary use of lambs and sheep, and by study:

Percent Operations

Sheep 2001 Sheep 2011

Primary use* Percent Std. error Percent Std. error

Meat 60.7 (1.7) 81.6 (1.0)

Wool 13.3 (1.1) 15.8 (0.8)

Showing, competition, 

4-H, or club 15.0 (1.2) 12.6 (0.8)

Seed or breeding stock 35.6 (1.6) 26.5 (1.1)

Milk 0.3 (0.1) 0.5 (0.1)

Other 10.9 (1.2) 3.3 (0.5)

*An operation may have had sheep and lambs for different purposes. Therefore, one operation may have had 

sheep of more than one primary-use category.
30 / Sheep 2011

Section II: Population Estimates–A. Changes in Inventory

Meat was the primary use of the majority of all sheep and lambs in 2001 and 2011 

(64.8 and 70.4 percent of inventory, respectively). Seed or breeding stock accounted for 

20.4 percent of inventory in 2001 but only 11.5 of inventory in 2011. 

A.2.b. Percentage of January 1 sheep inventory by primary use of lambs and sheep, and 

by study:

Percent Inventory (January 1)

Sheep 2001 Sheep 2011

Primary use Percent Std. error Percent Std. error

Meat 64.8 (1.0) 70.4 (1.3)

Wool 10.3 (0.6) 14.7 (1.2)

Showing, competition, 

4-H, or club 2.8 (0.2) 2.3 (0.2)

Seed or breeding stock 20.4 (0.8) 11.5 (0.8)

Milk 0.1 (0.1) 0.3 (0.1)

Other 1.6 (0.2) 0.8 (0.2)

Total 100.0 100.0

Photograph courtesy of American Sheep Institute.
USDA APHIS VS / 31 

Section II: Population Estimates–B. Flock Management

B. Flock 

Management

1. Operator experience

Operations in which the primary producer had been in the sheep business for 21 years 

or more made up a higher percentage of operations in 2011 (59.5 percent) than in 2001 

(39.4 percent), suggesting a decline in the number of new producers or a decline in the 

number of new producers that stayed in business. 

B.1.a. Percentage of operations by number of years the primary operator had owned or 

managed any sheep, and by study: 

Percent Operations

Sheep 2001 Sheep 2011

Number years Percent Std. error Percent Std. error

1–5 7.7 (0.9) 5.0 (0.5)

6–10 22.5 (1.5) 11.9 (0.8)

11–20 30.4 (1.5) 23.6 (1.0)

21–59 31.8 (1.5) 54.4 (1.2)

60 or more 7.6 (0.7) 5.1 (0.5)

Total 100.0 100.0
32 / Sheep 2011

Section II: Population Estimates–B. Flock Management

0

10

20

30

40

50

60

Sheep 2011

Sheep 2001

Percent

Number years owned or managed sheep

1–5 6–10 11–20 21 or more

Percentage of operations by number of years the primary operator had owned

or managed any sheep, and by study

7.7

5.0

22.5

11.9

30.4

23.6

39.4

59.5
USDA APHIS VS / 33 

Section II: Population Estimates–B. Flock Management

In 2001, the primary operator on 69.5 percent of herded/open range operations and 

55.8 percent of fenced range operations had been in business 21 or more years. In 2011, 

producers on more than half of operations across flock types had been in business 21 to 

59 years. 

B.1.b. Percentage of operations by number of years the primary operator had owned or 

managed any sheep, and by primary flock type:

Percent Operations

Primary Flock Type

Herded/

open range Fenced range Farm/pasture

Number years Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Sheep 2001

1–5 5.8 (3.7) 5.5 (1.9) 8.0 (1.0)

6–10 3.8 (0.9) 17.7 (3.8) 23.4 (1.7)

11–20 20.9 (4.0) 21.0 (2.7) 32.1 (1.7)

21–59 51.0 (7.7) 41.3 (3.8) 30.1 (1.6)

60 or more 18.5 (3.7) 14.5 (1.8) 6.4 (0.8)

Total 100.0 100.0 100.0

Sheep 2011

1–5 3.6 (1.7) 5.3 (1.1) 4.7 (0.7)

6–10 4.1 (1.1) 10.4 (1.5) 12.5 (1.0)

11–20 16.6 (3.5) 22.7 (2.0) 24.2 (1.4)

21–59 59.3 (5.2) 55.2 (2.3) 54.6 (1.5)

60 or more 16.3 (4.6) 6.5 (1.0) 3.9 (0.6)

Total 100.0 100.0 100.0
34 / Sheep 2011

Section II: Population Estimates–B. Flock Management

2. Inventory expectations in 5 years

A lower percentage of producers in 2011 (6.4 percent) expected to leave the sheep 

industry in the next 5 years compared with producers in 2001 (15.6 percent) and 1996 

(11.8 percent). In 2011, 82.9 percent of producers expected to have the same number or 

more sheep in 5 years, compared with 73.6 percent of producers in 2001 and 

78.7 percent in 1996. 

In Sheep 1996, 11.8 percent of producers did not expect to have sheep in 5 years, which 

was a slightly lower percentage than actually went out of business; according to the 

NASS, there were 79,900 U.S. sheep operations in 1995 and only 66,100 in 2000, a 17.3 

percent decrease. 

B.2.a. Percentage of operations by sheep inventory expected in 5 years, as compared 

with the January 1 inventory in 1996, 2001, and 2011:

Percent Operations

Study

Sheep 1996 Sheep 2001 Sheep 2011

Number sheep 

next 5 years Pct.

Std.

error Pct.

Std.

error Pct.

Std.

error

None 11.8 (0.8) 15.6 (1.3) 6.4 (0.6)

Fewer 9.5 (0.7) 10.8 (1.0) 10.6 (0.7)

About the same 43.7 (1.2) 48.5 (1.7) 59.0 (1.2)

More 35.0 (1.1) 25.1 (1.4) 23.9 (1.0)

Total 100.0 100.0 100.0
USDA APHIS VS / 35 

Section II: Population Estimates–B. Flock Management

In 2001, producers on about half the operations that did not expect to have sheep in 

5 years (55.3 percent) reported that the main reason was a personal/family situation (e.g., 

retirement, lack of successor, etc.). The majority of producers in the “Other” category 

cited a combination of the reasons below as to why they did not expect to have sheep 

in 5 years. In 2011, producers on 79.3 percent of operations that did not expect to have 

sheep in 5 years cited personal/family situation as the reason.

B.2.b. For operations that did not expect to have sheep in in the next 5 years, percentage 

of operations by main reason for not having sheep, and by study:

Percent Operations

Sheep 2001 Sheep 2011

Reason Percent Std. error Percent Std. error

Personal/family situation 55.3 (4.7) 79.3 (3.9)

Price of wool 8.8 (2.9) 2.2 (1.7)

Price of lambs 7.3 (2.1) 2.8 (1.8)

Predator loss 2.6 (0.6) 4.7 (1.9)

Labor shortage 2.5 (1.3) 2.7 (1.4)

Government regulations 0.8 (0.5) 0.6 (0.4)

Sheep disease 0.2 (0.1) 0.2 (0.2)

Loss of wool incentive 2.8 (1.6) NA

Other 19.7 (4.0) 7.5 (2.6)

Total 100.0 100.0
36 / Sheep 2011

Section II: Population Estimates–B. Flock Management

3. Sources of information on sheep health

In 2001 and 2011, the top three sources of sheep health information rated by producers 

as very important were veterinarians, other sheep producers, and shearers. The 

percentage of operations in which producers considered the Internet a very important 

source of information tripled from 2001 to 2011 (7.3 and 25.8 percent, respectively). 

B.3.a. Percentage of operations that rated the following sources of sheep health 

information as very important, by study:

Percent Operations

Sheep 2001 Sheep 2011

Health 

information source Percent

Std. 

error Percent

Std. 

error

Sheep Industry Development (SID) 

Sheep Production Handbook 10.5 (1.0) 19.1 (0.9)

Industry meetings 10.2 (1.0) 11.7 (0.7)

Internet 7.3 (0.9) 25.8 (1.0)

Magazines/newsletters 22.7 (1.3) 26.3 (0.9)

University/extension 22.0 (1.3) 27.6 (1.0)

Veterinarians* 39.1 (1.6) 40.4 (1.1)

Feed or drug salespeople 9.2 (0.9) 13.4 (0.8)

Shearers 29.3 (1.5) 31.7 (1.0)

Other sheep producers 30.7 (1.5) 38.3 (1.1)

*2001 question variation: veterinarians, private practitioners, or consultants. 

From 2001 to 2011, herded/open range operations accounted for the biggest increase 

in the percentage of operations in which producers rated the Internet as an important 

source of sheep health information. A higher percentage of producers on herded/open 

range operations valued feed or drug salespeople as important sources of information in 

2011 than producers on the other flock types. 
USDA APHIS VS / 37 

Section II: Population Estimates–B. Flock Management

B.3.b. Percentage of operations that rated the following sources of sheep health 

information as very important, by study and by primary flock type:

Percent Operations

Primary Flock Type

Herded/

open range

Fenced 

range

Farm/

pasture

Health information 

source Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Sheep 2001

Sheep Industry 

Development (SID) 

Sheep Production 

Handbook

8.6 (2.4) 9.7 (2.6) 10.7 (1.1)

Industry meetings 17.8 (3.5) 15.0 (3.2) 9.4 (1.0)

Internet 3.0 (0.7) 5.7 (2.1) 7.5 (1.0)

Magazines/

newsletters 22.1 (3.9) 32.1 (3.6) 21.2 (1.3)

University/

extension 29.0 (4.9) 28.6 (3.7) 21.0 (1.4)

Veterinarians* 45.3 (7.4) 34.5 (3.5) 39.6 (1.8)

Feed or drug 

salespeople 9.6 (1.7) 10.7 (1.6) 8.9 (1.0)

Shearer 30.1 (5.4) 28.3 (3.4) 29.6 (1.7)

Other sheep 

producers 40.0 (6.6) 30.7 (3.3) 30.7 (1.7)

Sheep 2011

Sheep Industry 

Development (SID) 

Sheep Production 

Handbook

16.1 (4.3) 16.8 (1.7) 19.1 (1.3)

Industry meetings 22.6 (3.5) 11.2 (1.2) 13.0 (1.1)

Internet 18.0 (4.1) 17.2 (1.7) 26.8 (1.4)

Magazines/

newsletters 26.1 (4.5) 26.4 (1.9) 30.3 (1.4)

University/

extension 27.6 (4.3) 26.7 (2.0) 29.1 (1.4)

Veterinarians* 45.0 (5.2) 34.5 (2.1) 39.2 (1.5)

Feed or drug 

salespeople 24.8 (5.3) 12.0 (1.4) 10.8 (1.0)

Shearer 47.8 (5.3) 31.0 (1.9) 28.9 (1.4)

Other sheep 

producers 42.7 (5.0) 41.4 (2.2) 38.8 (1.5)

*2001 question variation: veterinarians, private practitioners, or consultants. 
38 / Sheep 2011

Section II: Population Estimates–B. Flock Management

4. Production records 

Record-keeping systems are commonly used to track productivity, reproduction, and 

the health of ewes. In 2011, 30.8 percent of operations (25.7 plus 5.1 percent) used 

computerized record keeping for some or all of their production records. In 2001, only 

10.2 percent of operations used computerized records, and just two of three operations 

(67.9 percent) used either computerized or handwritten/typed records. In 2011, only 

13.3 percent of operations kept no production records compared with 32.1 percent of 

operations in 2001.

B.4. Percentage of operations by type of production records kept, and by study:

Percent Operations

Sheep 1996 Sheep 2001 Sheep 2011

Record type Pct.

Std.

error Pct.

Std.

error Pct.

Std.

error

Computerized 10.8 (0.7) 10.2 (0.9) 5.1 (0.5)

Handwritten/

typed/manual 77.1 (1.1) 64.8 (1.6) 55.9 (1.2)

Either NA 67.9 (1.6) 86.7 (0.9)

Both NA NA 25.7 (1.0)

None 19.5 (1.0) 32.1 (1.6) 13.3 (0.9)

Other (1996) 1.7 (0.3) NA NA
USDA APHIS VS / 39 

Section II: Population Estimates–B. Flock Management

5. Primary flock type

During the 1996, 2001, and 2011 studies, producers were asked how they primarily 

managed their sheep: herded/open range, fenced range, farm/pasture, dry lot/intensive 

confinement, or other. All three studies reported that the majority of operations managed 

at least some of their sheep on farm/pasture. Although only 14.1 percent of all operations 

were primarily fenced/open range operations, 56.0 percent of all sheep and lambs 

were on these type of operations in 2001, which is indicative of the large size of these 

operations compared with farm/pasture operations; farm/pasture operations accounted 

for 85.1 percent of all operations but only 31.5 percent of all sheep and lambs. 

The percentage of operations that primarily managed the sheep in a feedlot/dry lot 

increased from 0.8 percent in 2001 to 7.3 percent in 2011, likely because in the Sheep 

2001 study questionnaire the feedlot category was restricted to only operations that 

managed their sheep in intensive confinement where the primary purpose was to finish 

sheep on a high-energy diet for slaughter. In 2011, any operation that kept its sheep in a 

dry lot (for any reason) was allowed to designate its primary operation type as a feedlot/

dry lot, which might partially explain the lower percentage of operations that managed 

their sheep primarily as a farm/pasture operation in 2011 compared with 2001. In 2011, 

twice the percentage of operations managed their flock as fenced range or herded/open 

range compared with 2001; however, the percentage of ewes on fenced range operations 

remained constant.

B.5.a. Percentage of operations by primary type of flock management used, and by 

study:

Percent Operations

Sheep 1996 Sheep 2001 Sheep 2011

Primary type of 

flock management Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Herded/open range 

(unfenced acreage) 1.0 (0.1) 1.3 (0.2) 3.1 (0.3)

Fenced range (uncultivated 

fenced acreage) 10.0 (0.6) 12.8 (0.9) 27.4 (1.0)

Farm/pasture 

(irrigated or cultivated) 84.9 (0.8) 85.1 (1.0) 62.2 (1.0)

Feedlot/dry lot/intensive 

confinement 2.3 (0.3) 0.8 (0.2) 7.3 (0.6)

Other/multiple (1996) 1.8 (0.3) NA NA

Total 100.0 100.0 100.0
40 / Sheep 2011

Section II: Population Estimates–B. Flock Management

A slightly higher percentage of ewes were managed on herded/open range operations in 

2011 than in 2001. While the percentage of operations that managed sheep on fenced 

range nearly tripled from 1996 to 2011 (table B.5.a), the percentage of sheep on fenced 

range operations remained about the same, suggesting a decrease in the average size of 

fenced operations. 

B.5.b. Percentage of ewes by primary type of flock management used, and by study:

Percent Ewes 

Sheep 1996 Sheep 2001 Sheep 2011

Primary type of flock 

management Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Herded/open range 

(unfenced acreage) 18.9 (2.4) 18.7 (1.1) 26.0 (1.5)

Fenced range (uncultivated 

fenced acreage) 37.3 (2.3) 37.3 (1.2) 35.3 (1.2)

Farm/pasture 

(irrigated or cultivated) 34.6 (1.6) 31.5 (0.8) 34.9 (1.1)

Feedlot/dry lot/intensive 

confinement 6.4 (2.5) 12.5 (1.5) 3.8 (0.4)

Other/multiple (1996) 2.8 (0.5) NA NA

Total 100.0 100.0 100.0
USDA APHIS VS / 41 

Section II: Population Estimates–B. Flock Management

0

10

20

30

40

50

60

70

80

Ewes

Operations

Percent

Primary type of flock management

Herded/open range

(unfenced acreage)

Fenced range

(uncultivated fenced

acreage)

Farm/pasture

(irrigated or cultivated)

Feedlot/dry lot/

intensive confinement

Percentage of operations and percentage of ewes by primary type of flock 

management used in 2011

3.1

26.0 27.4

35.3

62.2

34.9

7.3

3.8
42 / Sheep 2011

Section II: Population Estimates–B. Flock Management

6. Animal identification 

Note: Excludes operations in Sheep 2001 that identified themselves as primarily dry lot 

or feedlot operations.

Flock and individual-animal ID are important parts of industry efforts to control disease. 

Data collected during the Sheep 2001 study represented sheep ID practices used before 

new ID requirements were implemented in November 2001 for sheep that changed 

ownership and/or entered interstate commerce. In 2001, the highest percentage of 

operations (14.2 percent) used ear tags to identify animals. Overall, 27.4 percent of 

operations used some form of flock ID in 2001 compared with 81.5 percent of operations 

in 2011. This substantial increase in flock ID is testament to the scrapie eradication efforts 

made by the sheep industry, producers, and State and Federal agencies. 

B.6.a. Percentage of operations by flock ID methods used and by study:

Percent Operations

Sheep 2001 Sheep 2011

Flock ID method Percent Std. error Percent Std. error

Ear tag (scrapie or other) 14.2 (1.1) 77.6 (1.0)

Ear mark 4.9 (0.4) 11.3 (0.6)

Tattoo 2.0 (0.4) 1.4 (0.3)

Paint brand 5.9 (0.4) 10.7 (0.6)

Hot/freeze brand 0.2 (0.0) NA

Electronic chip 0.1 (0.0) NA

Physical trait 6.9 (1.0) NA

Other 1.2 (0.7) 0.4 (0.1)

At least one method 27.4 (1.4) 81.5 (1.0)
USDA APHIS VS / 43 

Section II: Population Estimates–B. Flock Management

In 2001, 80.5 percent of operations used at least one method of individual-animal ID; 

59.5 percent of these operations used ear tags. By 2011, the use of individual-animal ID 

increased to 93.6 percent of operations, 85.6 percent of which used ear tags. 

B.6.b. Percentage of operations by individual-animal ID method(s) used and by study:

Percent Operations

Sheep 2001 Sheep 2011

Individual-animal 

ID method Percent Std. error Percent Std. error

Ear tag (scrapie or other) 59.5 (1.7) 85.6 (0.9)

Ear mark 9.0 (0.7) 17.7 (0.8)

Tattoo 5.9 (0.7) 5.6 (0.6)

Paint brand 12.8 (0.9) 19.9 (0.9)

Hot/freeze brand 0.1 (0.0) NA

Electronic ID 0.3 (0.1) 0.6 (0.2)

Physical traits 26.4 (1.6) 24.2 (1.1)

Other 2.6 (0.6) 1.3 (0.3)

At least one individualanimal ID method used 80.5 (1.4) 93.6 (0.6)
44 / Sheep 2011

Section II: Population Estimates–B. Flock Management

0 20 40 60 80 100

Sheep 2011

Sheep 2001

Ear tag

(scrapie or other)

Ear mark

Tattoo

Paint brand

Hot/freeze brand

Electronic ID

Other

At least one 

method

Method

Percent

Percentage of operations by individual-animal ID method(s) used, and by study

59.5

85.6

9.0

5.9

5.6

12.8

19.9

0.1

NA

0.3

0.6

26.4

24.2

2.6

80.5

93.6

Physical traits

17.7

1.3
USDA APHIS VS / 45 

Section II: Population Estimates–B. Flock Management

The percentage of operations that used ear tags as a means of individual-animal ID 

increased from 2001 to 2011 for all primary flock types. 

B.6.c. Percentage of operations by individual-animal ID method(s) used and by primary 

flock type:

Percent Operations

Primary Flock Type

Herded/

open range

Fenced 

range

Farm/

pasture

Individual-animal

ID method Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Sheep 2001

Ear tag (scrapie or other) 36.3 (6.2) 43.5 (3.6) 62.3 (1.9)

Ear mark 29.2 (4.8) 19.4 (2.1) 7.1 (0.8)

Tattoo 4.4 (2.1) 5.4 (1.4) 6.0 (0.8)

Paint brand 32.4 (5.2) 14.9 (1.5) 12.2 (1.0)

Hot/freeze brand 1.1 (0.4) 0.6 (0.1) 0.1 (0.0)

Electronic ID 1.9 (1.1) 0.1 (0.1) 0.3 (0.1)

Physical traits 8.2 (2.8) 10.1 (2.6) 29.2 (1.8)

Other 13.9 (11.2) 1.2 (0.4) 2.7 (0.7)

At least one method 73.2 (6.0) 62.7 (4.1) 83.3 (1.4)

Sheep 2011*

Ear tag (scrapie or other) 63.8 (5.5) 75.9 (2.0) 79.2 (1.3)

Ear mark 47.7 (5.2) 26.3 (1.8) 12.7 (0.9)

Tattoo 2.7 (1.7) 4.9 (1.0) 6.2 (0.7)

Paint brand 50.3 (5.2) 17.3 (1.5) 19.5 (1.1)

Hot/freeze brand NA NA NA

Electronic ID 0.3 (0.2) 0.8 (0.4) 0.5 (0.2)

Physical traits 21.9 (4.9) 18.9 (1.8) 26.6 (1.4)

Other 1.4 (0.6) 1.2 (0.4) 1.4 (0.4)

At least one method 91.7 (3.5) 92.3 (1.3) 94.3 (0.8)

*Operations with 20 or more ewes.
46 / Sheep 2011

Section II: Population Estimates–B. Flock Management

7. Rodent control

Rodents contribute to the spread of disease and are attracted to stored livestock 

feed. Sheep feed contaminated with rodent fecal matter can be a potential source of 

pathogens; therefore, rodent control is an important part of any operation’s biosecurity 

efforts. Rodent control was consistently applied by a variety of methods in both studies.

B.7. Percentage of operations by control method(s) used to control rats and mice, and by 

study:

Percent Operations 

Sheep 2001 Sheep 20111

Control method Percent Std. error Percent Std. error

Cats 82.1 (1.8) 79.2 (1.8)

Dogs 28.9 (2.2) 27.1 (2.0)

Traps2 19.2 (1.9)

63.4 (2.1)

Bait and/or poison 56.6 (2.4)

Professional exterminator 0.9 (0.3) 1.9 (0.5)

Other 2.3 (0.6) 2.5 (0.7)

Any method 96.5 (0.7) 95.1 (0.9)

1

Operations with 20 or more ewes. 2

In 2001, “traps” was a separate category from bait and/or poison.
USDA APHIS VS / 47 

Section II: Population Estimates–B. Flock Management

8. Housing

There was little change in the housing structure used for ewes from 2001 to 2011. The 

percentage of operations that used a fully enclosed structure in winter increased from 

6.2 percent in 2001 to 12.4 percent in 2011.

B.8.a. Percentage of operations by housing structure used for the majority of ewes, and 

by season and study:

Percent Operations 

Sheep 2001 Sheep 20112

Housing structure Percent Std. error Percent Std. error

Winter

Structure with four walls and roof 

with door closed most of the time 

(fully enclosed1

)

6.2 (1.3) 12.4 (1.4)

Structure with four walls and roof 

with door open most of the time 

(enclosed structure1

)

39.8 (2.4) 33.4 (2.0)

Structure with roof and three or 

fewer walls (e.g., loafing shed, open 

structure1

)

30.8 (2.4) 27.8 (1.9)

No structure 23.2 (1.6) 26.5 (1.7)

Total 100.0 100.0

Summer

Structure with four walls and roof 

with door closed most of the time 

(fully enclosed1

)

0.5 (0.3) 0.7 (0.3)

Structure with four walls and roof 

with door open most of the time 

(enclosed structure1

)

17.5 (1.9) 22.5 (1.9)

Structure with roof and three or 

fewer walls (e.g., loafing shed, open 

structure1

)

27.7 (2.3) 28.0 (2.0)

No structure 54.3 (2.4) 48.9 (2.1)

Total 100.0 100.0

1

Categories as they were described for the 2011 study.

2

Operations with 20 or more ewes.
48 / Sheep 2011

Section II: Population Estimates–B. Flock Management

B.8.b. Percentage of operations by housing structure typically used for the majority of the 

flock for lambing, and by study:

Percent Operations 

Sheep 20011 Sheep 20112

Housing structure Percent Std. error Percent Std. error

Structure with four walls and roof with 

door closed most of the time (fully 

enclosed3

)

23.6 (2.0) 30.5 (1.9)

Structure with four walls and roof with 

door open most of the time (enclosed 

structure3

)

39.9 (2.3) 34.6 (2.1)

Structure with roof and three or 

fewer walls (e.g., loafing shed, open 

structure3

)

24.0 (2.2) 21.3 (1.7)

No structure 12.5 (1.2) 13.6 (1.4)

Total 100.0 100.0

1

Data for 2001 are for first (or only) lambing season.

2

Operations with 20 or more ewes only.

3

Categories as they were described for the 2001 study.

Photograph courtesy of Camilla Kristensen.
USDA APHIS VS / 49 

Section II: Population Estimates–C. Breeding Management

1. Breeding practices

In 2001 and 2011, nearly all operations bred 1 or more ewes (94.8 and 98.4 percent, 

respectively).

C.1.a. Percentage of operations that bred any ewes, by study:

Percent Operations

Sheep 2001 Sheep 2011

Percent Std. error Percent Std. error

94.8 (0.9) 98.4 (0.3)

The reproductive performance of a sheep flock can be improved by intensive 

management practices such as flushing ewes, crutching, providing a teaser ram, using 

a breeding mark, ultrasound, conducting breeding soundness exams, udder palpation, 

embryo transfer, and estrous synchronization. Flushing is used to provide ewes with extra 

nutrition prior to, and sometimes during, the breeding season. Flushing increases the 

number of ovulations, resulting in a higher proportion of twins and triplets. 

A breeding-soundness examination should be conducted before each breeding season to 

assess buck fertility. A breeding-soundness exam should include a physical examination 

for general health, but examination of the reproductive organs (scrotal palpation/

evaluation and semen evaluation) is the basis for this exam. 

In 2001, 67.7 percent of operations used at least one reproductive management practice 

listed in table C.1.b; in 2011 that percentage increased to 99.6. Flushing was used most 

commonly among operations as a reproductive management practice in 1996, 2001, and 

2011 (54.7, 46.3, and 52.8 percent of operations, respectively). 

C. Breeding 

Management
50 / Sheep 2011

Section II: Population Estimates–C. Breeding Management

The percentage of operations that used artificial insemination remained at less than 

2 percent across studies. The use of udder palpation/bagging of ewes and breeding 

soundness exams of rams decreased from 1996 to 2001 and increased from 2001 to 

2011.

C.1.b. For operations that bred any ewes during the previous year, percentage of 

operations by reproductive practice and by study:

Percent Operations

Sheep 1996 Sheep 2001 Sheep 2011

Reproductive practice Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Flushing (ewes fed extra 

energy ration prior to 

breeding season)

54.7 (1.2) 46.3 (1.6) 52.8 (1.2)

Crutching 

(prelambing shearing) NA NA 22.9 (1.0)

Teaser ram 7.7 (0.5) 4.5 (0.6) 9.7 (0.7)

Breeding mark NA 18.4 (1.2) 21.1 (1.0)

Ultrasound (pregnancy 

diagnosis, fetal counting) 6.0 (0.4) 4.6 (0.7) 7.1 (0.6)

Breeding soundness 

exam (rams) 20.5 (0.9) 14.7 (1.1) 23.4 (1.0)

Udder palpation 

or bagging NA 25.9 (1.4) 38.3 (1.1)

Embryo transfer 0.2 (0.1) 0.1 (0.1) 1.5 (0.3)

Artificial insemination 1.2 (0.2) 1.3 (0.4) 1.4 (0.3)

Estrus synchronization 3.3 (0.3) NA 6.6 (0.6)

Accelerated lambing (1996) 7.9 (0.5) NA NA

Other NA 7.7 (1.0) NA

Any NA 67.7 (1.7) 99.6 (0.2)
USDA APHIS VS / 51 

Section II: Population Estimates–C. Breeding Management

2. Breeding seasons

Although the percentage of operations with one defined breeding season remained about 

the same from 2001 to 2011, a lower percentage of operations in 2011 (10.0 percent) had 

no defined breeding season compared with operations in 2001 (18.6 percent). 

C.2.a. For operations that bred any ewes during the previous year, percentage of 

operations by number of breeding seasons and by study: 

Percent Operations

Sheep 2001 Sheep 2011

Breeding seasons Percent Std. error Percent Std. error

One defined breeding 

season per year

74.2 (1.5) 75.5 (1.1)

Two or more defined breeding 

seasons per year1 7.2 (0.7) 11.9 (0.8)

Three defined breeding 

seasons per 2 years2 NA 2.5 (0.4)

No defined 

breeding season 18.6 (1.4) 10.0 (0.8)

1

In 2011, this category included only operations with two breeding seasons per year.

2

This category was not an option in 2001.
52 / Sheep 2011

Section II: Population Estimates–C. Breeding Management

Out-of-season breeding (February to July) can be advantageous because of better forage 

and weather conditions, decreased parasites, and improved markets for spring lambs. 

Success often depends on using one or more of the reproductive management practices 

listed in table C.2.c.

The percentage of operations that bred ewes out of season decreased from 21.8 percent 

in 1996 to 12.1 percent in 2001 and increased to 24.5 percent in 2011. There were no 

regional differences in the percentage of operations that bred ewes out of season (data 

not shown). For the 2001 and 2011 studies, out-of-season breeding was defined as 

occurring during February through July. For the 1996 study, no definition was provided for 

out-of-season breeding. Therefore, some producers in 1996 may have reported breeding 

ewes bred out of season, even though they bred ewes from August to January.

C.2.b. For operations that bred any ewes during the previous year, percentage of 

operations that bred ewes out of season (February to July):

Percent Operations

Sheep 1996 Sheep 2001 Sheep 2011

Percent Std. error Percent Std. error Percent Std. error

21.8 (0.9) 12.1 (1.1) 24.5 (1.1)

Photograph courtesy of Camilla Kristensen.
USDA APHIS VS / 53 

Section II: Population Estimates–C. Breeding Management

The two methods reported most commonly for out-of-season breeding in 2001 and 2011 

were placing rams with ewes (86.7 and 85.5 percent of operations, respectively) and 

selecting sheep with a genetic predisposition to breed out of season (31.4 and 

33.8 percent, respectively). Putting a teaser (sterile) ram with anestrous ewes that have 

been kept from a ram for at least 30 days produces the “ram effect,” which can induce 

estrous in ewes outside the normal breeding season. Genetically selecting rams and 

ewes for the ability to breed out of season also plays an important role. Many operations 

that reported using an “other” method for breeding out of season did not use any method 

and indicated that out-of-season breeding was accidental. Regulating light as a means 

of breeding ewes out of season was rarely used in either study. At the same time, twice 

the percentage of operations that used hormone treatments in 2001 did so in 2011. This 

increase is likely due to the November 2009 FDA approval of a progesterone controlled 

internal drug release (CIDR), which induces estrus in ewes during seasonal anestrus.

C.2.c. For operations that bred any ewes out of season during the previous year, 

percentage of operations by method used for out-of-season breeding (February to July): 

Percent Operations

Sheep 2001* Sheep 2011

Method Percent Std. error Percent Std. error

Genetic selection for ability 

to breed out of season 31.4 (4.1) 33.8 (2.3)

Placing ram with ewes 86.7 (3.5) 85.5 (1.8)

Regulating light 2.0 (1.1) 0.7 (0.4)

Hormone treatments (CIDRs, 

hormone protocols, etc.)* 6.0 (1.9) 11.6 (1.6)

Other hormone treatment* NA 0.0 (0.0)

Other 8.0 (3.1) 5.5 (1.1)

*In 2001 there was only one option for all hormone treatments.
54 / Sheep 2011

Section II: Population Estimates–C. Breeding Management

3. Ewe breeding 

Overall, 92.4 and 97.4 percent of operations that bred ewes in 2001 and 2011, 

respectively, used natural breeding methods by utilizing rams present on the operation. 

Just over 1 percent used artificial insemination. Of operations that used artificial 

insemination, the majority used frozen semen and semen collected from rams belonging 

to a different operation. While artificial insemination permits the breeding of more ewes 

with genetically superior rams, it can also be a more expensive method, which may 

explain why it was not used widely in 2001 or 2011. The percentage of operations that 

bred ewes naturally using another operation’s ram decreased by half from 2001 to 2011.

C.3.a. Percentage of operations by method used to breed (service) ewes, and by study:

Percent Operations

Sheep 2001 Sheep 2011

Servicing method Percent Std. error Percent Std. error

Artificial insemination 1.3 (0.4) 1.4 (0.3)

Natural, by this

operation’s rams 92.4 (1.1) 97.4 (0.4)

Natural, by another 

operation’s rams 9.6 (1.1) 4.7 (0.5)

The percentage of ewes serviced by artificial insemination was similar in 2001 and 2011.

C.3.b. Percentage of ewes by method used to breed (service) ewes, and by study:

Percent Ewes 

Sheep 2001 Sheep 2011

Servicing method Percent Std. error Percent Std. error

Artificial insemination (AI) 0.2 0.0 0.2 (0.0)

Natural, by this 

operation’s rams 97.3 0.3 97.7 (0.4)

Natural, by another 

operation’s rams 2.5 0.3 2.2 (0.4)

Total 100.0 100.0
USDA APHIS VS / 55 

Section II: Population Estimates–C. Breeding Management

There were no substantial differences in semen type or source of semen used in 2001 

and 2011.

C.3.c. For operations that artificially inseminated ewes in the previous year, percentage of 

operations by type or source of semen used, and by study:

Percent Operations

Sheep 2001 Sheep 2011

Semen type or source Percent Std. error Percent Std. error

Fresh 32.1 (15.4) 28.6 (9.8)

Frozen 99.0 (0.6) 79.3 (9.1)

This operation 47.2 (15.4) 34.8 (10.3)

Other operation 82.5 (8.0) 81.5 (8.1)

C.3.d. For operations that bred any ewes in the previous year, percentage of operations 

that used any rams for natural breeding and percentage of ewes bred naturally, by study: 

Study

Percent 

operations

Std. 

error

Percent 

ewes

Std. 

error

Sheep 2001 92.4 (1.1) 97.3 (0.3)

Sheep 2011 99.8 (0.1) 99.9 (0.4)

4. Ram and ewe lamb selection

Since rams account for half of a flock’s genetics, ram selection is an important part of 

flock health and productivity. The National Sheep Improvement Program (NSIP) offers a 

genetic evaluation system for U.S. sheep flocks. Historically, NSIP has provided expected 

progeny differences to help producers determine the genetic merit of an animal for a 

particular trait, such as number of lambs born, wool characteristics, milking traits, etc. 

NSIP generates estimated breeding values using breed-specific genetic parameters. 

These values allow for genetic evaluations for carcass traits and parasite resistance 

across breeds, as well as other evaluations not previously available. 
56 / Sheep 2011

Section II: Population Estimates–C. Breeding Management

When selecting a ram for natural breeding in 2011, 77.4 percent of operations indicated 

that visual appearance was a very important characteristic compared with 71.5 percent 

in 2001. Genetic resistance to scrapie and to intestinal parasites were very important for 

39.3 and 30.2 percent of operations, respectively, in 2011; these data were not available 

in 2001. Soundness of a ram’s flock of origin was important to a higher percentage of 

operations in 2011 than in 2001 (60.3 and 52.7 percent, respectively).

C.4.a. For operations that used rams for natural breeding during the previous year, 

percentage of operations by ram lamb characteristics that were very important when 

selecting rams:

Percent Operations

Sheep 2001 Sheep 2011

Ram lamb characteristic Percent Std. error Percent Std. error

Visual appearance 71.5 (1.6) 77.4 (1.1)

Scrotal circumference, 

semen quality 34.1 (1.5) 35.3 (1.2)

Wool quality 20.6 (1.3) 21.0 (0.9)

Meat production 61.4 (1.7) 69.8 (1.2)

Ram’s average daily 

gain as a lamb 34.5 (1.6) 28.4 (1.1)

Pedigree 31.4 (1.5) 33.1 (1.2)

Breeding history 34.7 (1.6) 31.3 (1.2)

NSIP records 3.5 (0.5) 5.7 (0.5)

Genetic resistance to scrapie NA 39.3 (1.2)

Genetic resistance to 

intestinal parasites NA 30.2 (1.1)

Genetic resistance 

to other diseases 28.6 (1.5) 7.7 (0.7)

Soundness of ram’s 

flock of origin 52.7 (1.7) 60.3 (1.2)

Nonram-related reasons 

(cost, proximity, availability) 25.8 (1.5) 27.5 (1.1)

Other ram characteristics 20.5 (1.3) NA
USDA APHIS VS / 57 

Section II: Population Estimates–C. Breeding Management

In 2011, a higher percentage of operations acquired ewes based on their genetic 

resistance to scrapie (41.9 percent) than acquired rams for the same reason 

(39.3 percent), even though using ram genetics is more efficient. 

C.4.b. For operations that acquired replacement ewe lambs during the previous year, 

percentage of operations that rated the following ewe-lamb selection characteristics as 

very important:

Percent Operations

Sheep 2001 Sheep 2011

Ewe-lamb characteristic Percent Std. error Percent Std. error

Visual appearance/

conformation 74.0 (1.8) 79.7 (2.5)

Wool quality NA 20.5 (2.3)

Meat production NA 69.8 (2.8)

Ability to breed 

out of season 10.3 (1.1) 14.2 (2.3)

National Sheep Improvement 

Program records 3.5 (0.6) 5.6 (1.5)

Ability to have 

multiple lambs1 49.9 (1.9) 47.0 (3.2)

Health status of 

flock origin 62.6 (1.9) 61.8 (3.1)

Early sexual maturity 28.8 (1.6) 22.6 (2.7)

Pedigree 31.3 (1.8) 36.1 (3.0)

Average daily gain 34.9 (1.9) 26.6 (2.8)

Genetic resistance 

to scrapie (RR) NA 48.3 (3.2)

Genetic resistance 

to intestinal parasites NA 33.8 (3.1)

Other genetic 

resistance to disease2

 40.0 (1.9) 7.3 (1.7)

Non ewe-related reasons 

(cost, availability, etc.) 21.5 (1.6) 22.8 (2.7)

1

Multiple births in 2001.

2

”Genetic resistance to disease” in 2001.
58 / Sheep 2011

Section II: Population Estimates–C. Breeding Management

The majority of replacement ewe lambs and replacement ram lambs were born and 

raised on the operation in in 2001 and 2011. 

C.4.c. For operations that had replacement ewe or ram lambs during the previous year, 

percentage of replacement ewe and ram lambs, by source and by study:

Percent Replacement Lambs

Sheep 2001 Sheep 2011

Source of 

replacement 

lambs 

Pct. 

ewes

Std. 

error

Pct. 

rams

Std. 

error

Pct. 

ewes

Std. 

error

Pct. 

rams

Std. 

error

Born and raised 

on this operation 83.8 (1.4) 73.2 (2.5) 82.7 (1.5) 81.0 (2.6)

Acquired 

elsewhere 16.2 (1.4) 26.8 (2.5) 17.3 (1.5) 19.0 (2.6)

Total 100.0 100.0 100.0 100.0

Overall, in 2011 a lower percentage of operations (3.8 percent) acquired bred and 

pregnant ewes with the intention of lambing them compared with operations in 2001 

(7.3 percent). This finding was more apparent in the West region (1.7 and 5.1 percent, 

respectively) and Central region (2.3 and 7.0 percent, respectively). 

C.4.d. Percentage of operations that acquired bred and pregnant ewes with the intention 

of lambing them in 2001 and for the last breeding season in 2011, by region:

Percent Operations

Region

West Central East All operations

Study Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Sheep 20011 5.1 (1.7) 7.0 (1.0) 8.3 (1.2) 7.3 (0.8)

Sheep 20112 1.7 (0.8) 2.3 (0.4) 5.9 (0.9) 3.8 (0.5)

1

Purchased bred ewes.

2

Purchased pregnant ewes for the most recent lamb crop.
USDA APHIS VS / 59 

Section II: Population Estimates–C. Breeding Management

5. Outcome of ewes expected to lamb

In 2001, just 9.9 percent of bred ewes had multiple births compared with 47.8 percent of 

bred ewes in 2011. 

C.5. Of ewes expected to lamb during the most recent lamb crop, average percentage of 

ewes by breeding outcome:

Percent Ewes

Sheep 2001* Sheep 2011* 

Percent Std. error Percent Std. error

Single live births 79.9 (0.4) 45.3 (0.6)

Multiple births 9.9 (0.4) 47.8 (0.6)

Only dead births 1.5 (0.1) 1.5 (0.1)

Aborted 0.9 (0.0) 0.9 (0.1)

Died prior to lambing 1.6 (0.0) 1.0 (0.1)

Removed from operation 

prior to lambing 0.9 (0.1) 0.4 (0.1)

Never became pregnant 5.3 (0.2) 3.0 (0.2)

Total 100.0 100.0

*The 2001 study questionnaire asked about all ewes exposed.
60 / Sheep 2011

Section II: Population Estimates–D. Reproductive Outcomes

1. Lambs born 

In 2001, over half of all operations (52.4 percent) had one or more lambs born in 

February; the same was true for March (57.4 percent). Also, 77.2 percent of lambs born 

were born in February, March, April, and May (table D.1.b). About twice the percentage of 

operations in 2011 had lambs born in June through December compared with operations 

in 2001. This finding is consistent with other data collected regarding selection of ewes 

for breeding out of season, breeding ewes out of season, and use of hormones to breed 

out of season.

D.1.a. Percentage of operations with one or more lambs born in each of the following 

months, by study:

Percent Operations

Sheep 2001 Sheep 2011

Month Percent Std. error Percent Std. error

January 32.5 (1.5) 41.1 (1.2)

February 52.4 (1.7) 53.6 (1.2)

March 57.4 (1.7) 53.4 (1.3)

April 34.9 (1.5) 41.8 (1.2)

May 16.7 (1.1) 26.7 (1.1)

June 5.8 (0.7) 10.4 (0.7)

July 2.4 (0.5) 5.5 (0.6)

August 1.9 (0.4) 4.4 (0.6)

September 3.7 (0.5) 6.8 (0.7)

October 5.6 (0.7) 10.5 (0.8)

November 6.5 (0.7) 12.5 (0.8)

December 8.3 (0.9) 15.6 (0.9)

D. Reproductive 

Outcomes
USDA APHIS VS / 61 

Section II: Population Estimates–D. Reproductive Outcomes

0 10 20 30 40 50 60

Sheep 2011

Sheep 2001

Percent

Month

January

February

March

April

May

June

July

August

September

October

November

December

Percentage of operations with one or more lambs born in each of the

following months, by study

32.5

41.1

52.4

53.6

57.4

53.4

34.9

41.8

16.7

26.7

5.8

10.4

2.4

5.5

1.9

4.4

3.7

6.8

5.6

10.5

6.5

12.5

8.3

15.6
62 / Sheep 2011

Section II: Population Estimates–D. Reproductive Outcomes

While a higher percentage of operations in 2011 than in 2001 had lambs born out of 

season (end of June to December) [table D.1.a], the percentage of lambs born out of 

season was not substantially different from 2001 to 2011. This finding suggests that small 

operations bred out of season or bred only a few of their ewes out of season. Only 8.7 

and 10.1 percent of all lambs were born from October through December in 2001 and 

2011, respectively.

D.1.b. Percentage of lambs born alive or dead during the previous year, by month and by 

study:

Percent Lambs Born

Sheep 2001 Sheep 2011

Month Percent Std. error Percent Std. error

January 10.5 (0.4) 11.7 (0.6)

February 20.1 (0.6) 17.4 (0.6)

March 22.8 (0.6) 17.5 (0.7)

April 19.6 (0.6) 19.8 (0.9)

May 14.7 (0.5) 18.9 (1.4)

June 2.7 (0.2) 3.0 (0.4)

July 0.2 (0.0) 0.5 (0.1)

August 0.1 (0.0) 0.3 (0.1)

September 0.6 (0.1) 0.9 (0.1)

October 2.7 (0.3) 3.1 (0.3)

November 3.1 (0.3) 3.4 (0.3)

December 2.9 (0.2) 3.6 (0.3)

Total 100.0 100.0
USDA APHIS VS / 63 

Section II: Population Estimates–D. Reproductive Outcomes

There was no difference in the percentage of lambs born alive from 2001 to 2011. 

D.1.c. Percentage of lambs born alive, by primary flock type:

Percent Lambs Born Alive

Primary Flock Type

Herded/

open range

Fenced 

range

Farm/

pasture

All 

operations

Study Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Sheep 2001 96.6 (0.3) 95.9 (0.4) 95.1 (0.2) 95.7 (0.2)

Sheep 2011 96.4 (0.5) 96.7 (0.1) 95.5 (0.2) 96.1 (0.1)

D.1.d. Operation average number of lambs born per ewe exposed, by primary flock type 

and by study:

Operation Average Lambing Rate

Primary Flock Type

Herded/

open range

Fenced 

range

Farm/

pasture

All 

operations

Study Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error

Sheep 2001 1.31 (0.0) 1.25 (0.0) 1.55 (0.0) 1.38 (0.0)

Sheep 2011* 1.29 (0.0) 1.29 (0.0) 1.48 (0.0) 1.38 (0.0)

*20 or more ewes.
64 / Sheep 2011

Section II: Population Estimates–D. Reproductive Outcomes

Tail-docking keeps fecal matter from accumulating on the tail and hindquarters of sheep. 

Fecal matter accumulation attracts flies, can lead to wool maggots, and potentially 

reduces pelt value. Tail-docking is also required for shows, although the required tail 

length can vary by show. Some sheep breeds (e.g., hair sheep, fat-tailed sheep, and rattailed sheep) do not require tail docking. 

A lower percentage of lambs born alive were docked in 2011 than in 2001 (81.5 and 

91.7 percent, respectively). This difference was noted for all flock types. The percentage 

of operations that docked tails also declined from 86.1 percent of operations in 2001 to 

78.6 percent in 2011. This decline occurred mostly in farm/pasture flocks.

D.1.e. Percentage of operations that docked lambs’ tails and percentage of lambs born 

alive that were docked, by primary flock type and by study: 

Percent 

Primary Flock Type

Herded/

open range

Fenced 

range

Farm/

pasture

All 

operations

Study Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Percent operations

Sheep 2001 90.1 (6.2) 76.7 (4.7) 87.4 (1.3) 86.1 (1.3)

Sheep 2011 82.1 (5.3) 75.4 (2.2) 80.0 (1.3) 78.6 (1.1)

Percent lambs

Sheep 2001 94.7 (0.7) 91.1 (0.8) 90.8 (0.7) 91.7 (0.4)

Sheep 2011 89.4 (1.2) 82.2 (1.6) 79.1 (1.3) 81.5 (0.8)
USDA APHIS VS / 65 

Section II: Population Estimates–D. Reproductive Outcomes

The caudal fold is the flap of skin located under and attached to each side of the tail. 

The two sides meet in a “V” at the end of the fold. From 2001 to 2011, The percentage of 

operations that docked lambs’ tails longer than the caudal fold (distal) decreased. 

D.1.f. For operations that docked lambs’ tails, percentage of operations by location of 

docking for the majority of lambs’ tails, and by study:

Percent Operations 

Sheep 2001 Sheep 2011*

Location Percent Std. error Percent Std. error

Shorter than the caudal fold 19.9 (2.1) 25.4 (2.0)

At the “V” of the caudal fold 57.8 (2.4) 61.5 (2.2)

Distal to the caudal fold 22.4 (2.0) 13.1 (1.4)

Total 100.0 100.0

*20 or more ewes.
66 / Sheep 2011

Section II: Population Estimates–D. Reproductive Outcomes

2. Lambing locations

Increased monitoring afforded by more confined lambing areas may influence the 

average number of live lambs born to exposed ewes, since administering assistance 

to ewes and lambs is more easily achieved when the animals are confined. There are, 

however, a number of other factors in addition to lambing observation that also influence 

the average number of live lambs born per ewe exposed. 

In 2001 and 2011, about half the operations (50.3 and 48.4 percent, respectively) had 

lambs born in a barn or shed. A lower percentage of operations in 2011 than in 2001 

(24.0 and 30.8 percent, respectively) had lambs born in individual lambing pens. As a 

general practice, many operations allowed ewes to lamb in a group setting, such as in a 

large pen or shed, but moved ewe lamb pairs to individual jugs after lambing. Conversely, 

a higher percentage of operations in 2011 lambed on the open range (5.9 percent) and in 

dry lots (6.0 percent) compared with 2001 (2.8 and 3.8 percent, respectively). 

D.2.a. For operations with lambs born during the previous year, percentage of operations 

by lambing locations used for at least one lamb, and by study: 

Percent Operations

Sheep 2001 Sheep 2011

Lambing location Percent Std. error Percent Std. error

Individual lambing pen 30.8 (1.5) 24.0 (1.0)

Barn or shed (covered, but 

without individual pens) 50.3 (1.7) 48.4 (1.2)

Special lambing pasture that 

allows increased observation 

and/or shelter

12.6 (1.0) 16.6 (0.9)

Other fenced pasture 16.5 (1.3) 27.8 (1.1)

Open range 2.8 (0.3) 5.9 (0.5)

Dry lot (pen which does 

not allow grazing) 3.8 (0.5) 6.0 (0.5)

Other 1.2 (0.5) 0.5 (0.2)
USDA APHIS VS / 67 

Section II: Population Estimates–D. Reproductive Outcomes

In 2001, almost half the lambs born (48.4 percent) were born in individual lambing pens, 

barns, or sheds. A slightly lower percentage of lambs were born in these facilities in 2011 

(42.9 percent).

D.2.b. For operations with lambs born during the previous year, percentage of lambs 

born, by lambing location and by study:

Percent Lambs

Sheep 2001 Sheep 2011

Lambing location Percent Std. error Percent Std. error

Individual lambing pen 19.8 (0.8) 16.7 (1.2)

Barn or shed (covered, but 

without individual pens) 28.6 (0.8) 26.2 (1.1)

Special lambing pasture that 

allows increased observation 

and/or shelter

14.4 (0.8) 11.7 (0.8)

Other fenced pasture 15.7 (0.8) 21.8 (1.1)

Open range 16.4 (0.9) 18.1 (1.6)

Dry lot (pen which 

does not allow grazing) 4.7 (0.6) 5.2 (0.5)

Other 0.4 (0.1) 0.2 (0.1)

Total 100.0 100.0
68 / Sheep 2011

Section II: Population Estimates–D. Reproductive Outcomes

3. Lamb feeding supplements

Feeding lambs high-quality colostrum following birth helps ensure the transfer of 

antibodies needed to protect lambs against disease. Usually lambs receive adequate 

colostrum from their mothers. Sometimes, however, it is necessary to supplement 

newborns using other colostrum sources. The percentage of operations that 

supplemented lambs with colostrum from a source other than the lambs’ mothers 

decreased from 63.6 percent of operations in 2001 to 54.5 percent in 2011. 

D.3.a. Percentage of operations that supplemented lambs during the last completed lamb 

crop, by supplement source and by study:

Percent Operations

Sheep 2001 Sheep 2011

Supplement source Percent Std. error Percent Std. error

Provided lambs with 

colostrum from a source 

other than its mother

63.6 (2.3) 54.5 (2.2)

Milk or milk replacer 57.5 (2.4) 73.2 (2.0)
USDA APHIS VS / 69 

Section II: Population Estimates–D. Reproductive Outcomes

A higher percentage of operations gave lambs dried sheep colostrum in 2011 than in 

2001. The percentages of other colostrum sources did not change substantially during 

the same period. A similar percentage of operations in both studies provided milk or milk 

replacer from the listed sources.

D.3.b. For operations that supplemented lambs with colostrum or supplemental milk or 

milk replacer in the last completed lamb crop, percentage of operations by source of 

colostrum and supplemental milk or milk replacer, and by study:

Percent Operations 

Sheep 2001 Sheep 20111

Source Percent Std. error Percent Std. error

Colostrum

Sheep colostrum from own operation 73.0 (2.8) 73.2 (2.4)

Liquid sheep colostrum 

from outside source 2.8 (1.0) 3.2 (1.0)

Dried sheep colostrum 8.2 (1.4) 32.2 (2.6)

Cow colostrum from a herd

 tested for Johne’s disease 2.8 (0.9) 3.2 (1.0)

Cow colostrum from a herd 

not tested for Johne’s disease 25.5 (2.7) 17.6 (2.0)

Goat colostrum 16.1 (2.3) 8.6 (1.6)

Other2 5.9 (1.9) 4.9 (1.2)

Milk or milk replacer

Sheep milk from own operation 33.9 (2.9) 27.9 (2.2)

Sheep milk from an outside source 0.2 (0.1) 0.2 (0.1)

Dried milk or milk replacer 90.8 (1.8) 94.6 (1.2)

Fresh cow milk (cow(s) 

tested for Johne’s)3 1.3 (0.7) 2.2 (0.9)

Fresh cow milk (cow(s) 

not tested for Johne’s disease)4 7.8 (1.5) 6.9 (1.2)

Goat milk 13.2 (2.1) 9.7 (1.5)

Other 4.0 (1.7) 0.7 (0.4)

1

20 or more ewes.

2

In the Sheep 2001 questionnaire, an additional category–Synthetic—was an option (24.1 percent; SE=2.7). 

This option was not included in the Sheep 2011 questionnaire.

3

In the Sheep 2001 questionnaire, this category was “cow from herd tested for Johne’s disease.” 4

In the Sheep 2011 questionnaire, this category was “cow from herd with unknown Johne’s disease status.”
70 / Sheep 2011

Section II: Population Estimates–D. Reproductive Outcomes

Feeding pasteurized milk or milk replacer reduces the possibility of disease transmission. 

Nonpasteurized milk can contain a variety of pathogens, including those that cause 

mastitis (e.g., Staphylococcus and Streptococcus species), diarrhea (e.g., Escherichia 

coli and Salmonella species), respiratory disease (e.g., Pasteurella and Mycoplasma 

species), abscesses (Corynebacterium pseudotuberculosis), and a variety of systemic 

disease (e.g., listeriosis, caprine arthritis encephalitis, Johne’s disease, and brucellosis). 

Pasteurization is especially important if supplemented milk is pooled from a number of 

ewes or acquired from another flock, both of which can increase the risk of exposing 

lambs to disease. Scrapie may also be transmitted to sheep or goats through colostrum 

and milk from infected sheep or goats. Pasteurization is unlikely to eliminate scrapie 

infectivity from colostrum or milk. As a result, colostrum or milk should not be sourced 

from other sheep or goat herds of unknown scrapie status. Nearly all operations that 

supplemented lambs with fresh milk in 2001 and 2011 did not pasteurize the milk. 

D.3.c. For operations that supplemented lambs with fresh milk, percentage of operations 

that used pasteurized milk:

Percent Operations 

Sheep 2001 Sheep 2011

Percent Std. error Percent Std. error

3.5 (1.2) 2.5 (1.5)
USDA APHIS VS / 71 

Section II: Population Estimates–D. Reproductive Outcomes

4. Castration management

In 2001 and 2011, ram lambs were castrated on about three-fourths of all operations 

(77.4 and 75.1percent, respectively). 

D.4.a. For operations with ram lambs born alive during the previous year, percentage of 

operations that castrated ram lambs, by primary flock type and by study:

Percent Operations

Primary Flock Type

Herded/

open range

Fenced 

range

Farm/

pasture

All 

operations

Study Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Sheep 2001 88.7 (5.8) 77.4 (4.0) 77.3 (1.7) 77.4 (1.5)

Sheep 2011 86.3 (4.8) 73.0 (2.2) 75.7 (1.4) 75.1 (1.1)

In 2001 and 2011, ram lambs were castrated at just over 3 weeks of age.

D.4.b. For operations with castrated ram lambs during the previous year, operation 

average age (in days) that rams were castrated, by study:

Operation Average Age (days) 

Sheep 2001 Sheep 2011

Average Std. error Average Std. error

22.3 (1.1) 24.7 (0.8)
72 / Sheep 2011

Section II: Population Estimates–D. Reproductive Outcomes

D.4.c. For operations with castrated ram lambs during the previous year, percentage of 

operations that castrated ram lambs, by age of rams at castration and by study:

Percent Operations

Sheep 2001 Sheep 2011

Age at castration

(days) Percent Std. error Percent Std. error

1–7 34.6 (1.7) 38.3 (1.3)

8–21 31.8 (1.8) 24.8 (1.2)

22 or more 33.6 (1.7) 36.9 (1.2)

Total 100.0 100.0

5. Age and weight of weaned lambs 

The average age of lambs at weaning was lower in 2011 than in 2001 (15.6 weeks and 

17.5 weeks, respectively). As expected, lamb weaning weights were also lower in 2011 

than in 2001 (66.7 and 78.9 lb, respectively). 

D.5. For lambs weaned in the previous year, average age and weight of lambs at 

weaning, by study and by primary flock type:

Average

Primary Flock Type

Herded/

open range

Fenced 

range

Farm/

pasture

All

operations

Study Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error

Average age (weeks)

Sheep 2001 21.8 (0.3) 19.4 (0.2) 13.7 (0.2) 17.5 (0.1)

Sheep 2011 20.4 (0.2) 17.6 (0.1) 14.8 (0.0) 15.6 (0.0)

Average weight (lb)

Sheep 2001 95.2 (0.7) 75.4 (0.8) 64.0 (0.5) 78.9 (0.4)

Sheep 2011 89.0 (3.3) 70.7 (1.0) 64.0 (0.7) 66.7 (0.5)
USDA APHIS VS / 73 

Section II: Population Estimates–E. Marketing Practices

This section presents information on sheep that were removed from the operation alive 

and marketed through various channels. It does not include sheep that were slaughtered 

for home consumption or were otherwise dead when removed, nor does it capture sheep 

that were sold and slaughtered on the operation by the buyer or the producer. 

Marketing animals at an auction or sale barn requires little effort in finding a buyer. 

Direct sales to consumers, however, can be more profitable since there may be no 

transportation costs and no middleman or sales commission. Almost all operations 

marketed some sheep or lambs in 2011.

1. Operations that sold or moved lambs 

E.1.a. Percentage of operations that sold, moved, or permanently removed any sheep or 

lambs, by sheep type and by study:

Percent Operations

Study

Sheep 2001 Sheep 2011

Sheep type Percent Std. error Percent Std. error

Lambs 84.5 (1.4) 82.4 (0.9)

Cull sheep 47.4 (1.6) 48.2 (0.9)

Any sheep 51.9 (1.7) 55.1 (1.0)

Any sheep or lambs 86.0 (1.4) 98.0 (0.5)

E. Marketing 

Practices
74 / Sheep 2011

Section II: Population Estimates–E. Marketing Practices

In 2011, a higher percentage of all operations (20.1 percent) moved or sold lambs directly 

to a separate feedlot compared with operations in 2001 (9.5 percent). This trend was also 

evident in fenced range and farm/pasture operations. 

E.1.b. For operations that sold, moved, or permanently removed lambs during the 

previous year, percentage of operations that moved lambs directly to a feedlot separate 

from the operation, by study and by primary flock type:

Percent Operations

Primary Flock Type

Herded/

open range

Fenced 

range

Farm/

pasture

All 

operations

Study Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Sheep 2001 42.1 (7.0) 13.6 (1.7) 8.4 (0.9) 9.5 (0.8)

Sheep 2011 51.2 (5.1) 22.3 (1.8) 17.9 (1.2) 20.1 (0.9)
USDA APHIS VS / 75 

Section II: Population Estimates–E. Marketing Practices

A higher percentage of operations that sold lambs directly to a separate feedlot in 2011 

retained no ownership of the lambs compared with operations in 2001.

E.1.c. For operations that sold, moved, or permanently removed lambs directly to a 

separate feedlot during the previous year, percentage of operations by ownership of the 

majority of lambs sold or moved, and by primary flock type:

Percent Operations 

Primary Flock Type

Herded/

open range

Fenced 

range

Farm/ 

pasture

All 

operations

Lamb 

ownership Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Sheep 2001

Retain complete 

ownership 12.9 (2.6) 22.6 (7.0) 13.1 (3.4) 15.1 (2.9)

Retain partial 

ownership 3.1 (1.2) 4.0 (1.5) 6.2 (3.6) 5.6 (2.7)

Retain no 

ownership 84.0 (3.1) 73.4 (6.8) 80.7 (4.6) 79.3 (3.7)

Total 100.0 100.0 100.0 100.0

Sheep 2011

Retain complete 

ownership 9.4 (3.3) 4.0 (0.8) 4.7 (0.7) 5.0 (0.5)

Retain partial 

ownership 4.1 (3.1) 0.6 (0.4) 0.0 (0.0) 0.4 (0.2)

Retain no 

ownership 86.5 (4.3) 95.4 (0.9) 95.3 (0.7) 94.6 (0.5)

Total 100.0 100.0 100.0 100.0
76 / Sheep 2011

Section II: Population Estimates–E. Marketing Practices

In 2001 and 2011, relatively few lambs were sold in the first quarter (January through 

March). This finding is consistent with seasonal breeding patterns and lambing dates in 

the United States. Weaned lambs sold from July through December in 2011 were more 

evenly distributed across quarters compared with weaned lambs sold during the same 

period in 2001. 

E.1.d. Of weaned lambs sold, moved, or permanently removed during the previous year 

(including lambs weaned at the time of removal), percentage of lambs sold, by quarter 

and by study:

Percent Lambs Sold 

Sheep 2001 Sheep 2011

Quarter Percent Std. error Percent Std. error

January–March 4.4 (0.3) 5.8 (0.4)

April–June 21.5 (0.9) 21.7 (0.9)

July–September 43.3 (1.1) 38.4 (1.3)

October–December 30.8 (1.0) 34.1 (1.4)

Total 100.0 100.0

Weaned lambs sold were slightly younger and lighter in 2011 than in 2001.

E.1.e. Of weaned lambs sold, moved, or permanently removed during the previous year 

(including lambs weaned at the time of removal), operation average age and weight of 

lambs when sold, by study:

Operation Average 

Sheep 2001 Sheep 2011

Average Std. error Average Std. error

Age (weeks) 23.2 (0.2) 22.0 (0.2)

Weight (pounds) 96.8 (0.6) 92.3 (0.7)
USDA APHIS VS / 77 

Section II: Population Estimates–E. Marketing Practices

2. Type of marketing

Over half the operations in 2001 and 2011 (56.8 and 52.5 percent, respectively) marketed 

lambs directly to an auction market/sale barn. In both studies, roughly one-fourth of 

lambs were marketed at the auction market/sale barn (table E.2.b). More marketing 

channel options were offered in the 2011 study questionnaire than in the 2001 study 

questionnaire, which may have influenced producer responses. In 2011, only 10.7 

percent of operations marketed lambs directly to another operation, while 

8.9 percent of operations removed lambs for personal use or because of euthanasia. 

About half the operations in 2011 (50.1 percent) marketed adult sheep directly to another 

operation. This marketing channel was not accounted for in Sheep 2001. In the 2001 

study, operations likely reported this marketing channel as sales at the auction market/

sale barn or in the “Other” category. In 2001, 68.1 percent of operations marketed adult 

sheep at the auction market/sale barn, while in 2011 just 

22.8 percent of operations marketed adult sheep in this channel.

E.2.a. For operations that sold, moved, or permanently removed lambs and sheep, 

percentage of operations by marketing channel used and by study:

Percent Operations 

Lambs Sheep

Sheep 2001 Sheep 2011 Sheep 2001 Sheep 2011

Marketing 

channel Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Slaughter 15.1 (1.2) 19.0 (0.9) 12.8 (1.4) 4.5 (1.0)

Feedlot 5.5 (0.7) 5.6 (0.5) 1.4 (0.4) 0.7 (0.4)

Backgrounder 1.4 (0.3) 2.2 (0.3) 0.6 (0.1) 0.4 (0.3)

Consumer or 

ethnic market 13.9 (1.3) 17.2 (0.9) 4.7 (1.0) 6.7 (1.3)

Another operation NA 10.7 (0.8) NA 50.1 (2.4)

Auction market/

sale barn 56.8 (1.7) 52.5 (1.1) 68.1 (1.9) 22.8 (1.9)

Buyer/dealer 18.0 (1.3) 16.8 (0.9) 13.5 (1.2) 12.9 (1.6)

Personal use/ 

euthanized NA 8.9 (0.7) NA 3.4 (0.9)

Other 13.4 (1.2) 7.5 (0.6) 8.4 (1.2) 3.8 (0.9)
78 / Sheep 2011

Section II: Population Estimates–E. Marketing Practices

E.2.b. For operations that sold, moved, or permanently removed lambs and sheep, 

percentage of lambs and sheep by marketing channel used and by study:

Percent Lambs and Sheep 

Lambs Sheep

Sheep 2001 Sheep 2011 Sheep 2001 Sheep 2011

Marketing 

channel Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Slaughter 22.0 (1.5) 25.5 (1.8) 12.2 (1.7) 2.6 (0.7)

Feedlot 16.7 (0.9) 15.1 (1.4) 1.8 (0.7) 0.1 (0.1)

Backgrounder 3.4 (0.4) 3.9 (0.6) 0.8 (0.2) 0.1 (0.1)

Consumer or 

ethnic market 3.5 (0.5) 3.9 (0.3) 1.6 (0.3) 4.7 (2.8)

Another operation NA 3.4 (0.3) NA 52.5 (5.3)

Auction market/

sale barn 28.5 (0.9) 26.5 (1.2) 45.0 (1.9) 27.2 (4.0)

Buyer/dealer 22.0 (1.0) 17.7 (1.1) 31.0 (1.9) 10.2 (1.7)

Personal use/ 

euthanized NA 0.4 (0.1) NA 0.5 (0.2)

Other 3.9 (0.5) 3.5 (0.6) 7.6 (1.3) 2.1 (0.6)

Total 100.0 100.0 100.0 100.0
USDA APHIS VS / 79 

Section II: Population Estimates–E. Marketing Practices

3. Cull rams and ewes

Operations cull animals because of disease, to reduce operation size, remove 

undesirable genetic or phenotypic traits, and to economize during episodes of high feed 

costs. Operations attempting to enlarge their flocks are less likely to cull animals for any 

of these reasons. 

A lower percentage of rams and ewes were culled in 2011 than in 2001. Nearly onefourth of rams (23.8 percent) were culled and sold in 2001, while16.2 percent of rams 

were culled in 2011. Approximately one-fifth of ewes (18.3 percent) were culled and sold 

in 2001 compared with 14.0 percent of ewes in 2011.

E.3.a. Percentage of sheep culled, by gender and by study: 

Percent Sheep*

Sheep 2001 Sheep 2011

Gender Percent Std. error Percent Std. error

Rams 23.8 (1.0) 16.2 (0.8)

Ewes 18.3 (0.5) 14.0 (1.4)

*As a percentage of the January 1 inventory.
80 / Sheep 2011

Section II: Population Estimates–E. Marketing Practices

In 2001, the highest percentages of culled rams and ewes were sold in July through 

September, while in 2011 the percentages of culled rams and ewes sold were more 

evenly split between July through September and October through December. The lowest 

percentages of culled rams and ewes were sold January through March in 2001 and 

2011.

E.3.b. Of sheep culled during the previous year, percentage of cull rams and percentage 

of ewes, by quarter sheep were sold or removed, and by study:

Percent Cull Rams and Ewes

Rams Ewes

Sheep 2001 Sheep 2011 Sheep 2001 Sheep 2011

Quarter Pct.

Std.

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

January–March 9.1 (0.9) 13.2 (1.5) 8.1 (0.6) 9.5 (1.3)

April–June 24.3 (1.7) 23.1 (1.8) 25.9 (1.2) 28.5 (1.2)

July–September 36.6 (2.1) 29.7 (2.2) 38.3 (1.6) 30.2 (1.5)

October–December 30.0 (1.9) 34.0 (2.6) 27.7 (1.3) 31.8 (1.4)

Total 100.0 100.0 100.0 100.0
USDA APHIS VS / 81 

Section II: Population Estimates–E. Marketing Practices

In 2001, 18.0 percent of ewes culled were culled due to economic issues compared with 

just 1.7 percent of ewes in 2011. A slightly higher percentage of ewes were culled due to 

old age in 2011 than in 2001 (55.6 and 47.9 percent, respectively). Otherwise, there were 

few differences in reasons for culling in 2001 and 2011. 

E.3.c. Of rams and ewes culled during the previous year, percentage of cull rams and 

percentage of ewes, by primary reason for culling and by study:

Percent Cull Rams and Ewes 

Sheep 2001 Sheep 2011

Rams Ewes Rams Ewes

Primary reason 

for culling Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Old age 47.7 (2.1) 47.9 (1.8) 49.3 (2.5) 55.6 (1.4)

Teeth problems 0.8 (0.3) 5.3 (0.5) 3.0 (0.9) 7.6 (1.3)

Poor mothering 3.3 (0.3) 4.7 (0.3)

Hard-bag syndrome 5.3 (0.3) 7.1 (0.8)

Mastitis 3.3 (0.2) 6.7 (0.5)

Failure to lamb 

(open or aborted) 5.5 (0.4) 7.7 (0.5)

Single-lamb births 0.6 (0.1) 1.1 (0.2)

Ram breeding 

soundness 13.8 (1.4) 17.0 (2.3)

Other reproductive 

problems 3.6 (1.1) 1.2 (0.4) 3.1 (1.4) 0.9 (0.3)

Chronic weight loss/ 

thin ewe 1.9 (0.2) 1.2 (0.3) 2.1 (0.6)

Other illness 1.0 (0.3) 0.6 (0.1) 1.9 (0.6) 1.2 (0.4)

Economic issues 

(e.g., drought, flock 

reduction, market 

conditions) 

13.1 (2.0) 18.0 (2.1) 10.2 (2.2) 1.7 (0.4)

Other 20.0 (1.8) 7.1 (1.1) 14.3 (1.7) 3.7 (0.6)

Total 100.0 100.0 100.0 100.0
82 / Sheep 2011

Section II: Population Estimates–E. Marketing Practices

The average age of culled ewes was slightly higher in 2011 than in 2001 across operation 

sizes. 

E.3.d. Average age of sheep, by gender, study, and size of operation:

Average Age (years)

Size of Operation* 

Very small Small Medium Large

All 

operations

Gender Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error

Sheep 2001

Rams 4.4 (0.4) 4.1 (0.3) 4.8 (0.1) 4.9 (0.1) 4.6 (0.1)

Ewes 5.1 (0.3) 5.9 (0.1) 5.9 (0.1) 6.2 (0.1) 5.9 (0.1)

Sheep 2011

Rams NA 4.6 (0.2) 5.2 (0.1) 5.5 (0.1) 4.9 (0.1)

Ewes NA 6.2 (0.1) 6.3 (0.1) 6.8 (0.2) 6.3 (0.1)

*See “Terms Used in This Report” for operation size breakouts. 

Compared with 2001, a higher percentage of all operations in 2011— especially farm/

pasture flocks—culled ewes that had flock ID when they left the operation. 

E.3.e. For operations that culled at least one ewe during the previous year, percentage of 

operations in which any ewes had flock ID when they left the operation, by study and by 

primary flock type:

Percent Operations

Primary Flock Type

Herded/

open range

Fenced 

range

Farm/

pasture

All 

operations

Study Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Sheep 2001 67.2 (3.5) 65.4 (3.4) 34.2 (2.3) 54.9 (2.0)

Sheep 2011 79.9 (5.4) 76.4 (2.5) 81.6 (1.5) 80.9 (1.2)
USDA APHIS VS / 83 

Section II: Population Estimates–F. Lamb and Sheep Deaths and Losses

1. Lamb and sheep losses

The percentage of operations that lost either lambs or sheep to predators declined 

slightly from 2001 to 2011, while nonpredator losses remained constant.

F.1.a. Percentage of operations that lost sheep during the previous year, by sheep type, 

cause of loss, and study: 

Percent Operations

Cause of Loss

Predator Nonpredator Any

Sheep 

2001

Sheep 

2011

Sheep 

2001

Sheep 

2011

Sheep 

2001

Sheep 

2011

Sheep 

type Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Lambs 32.7 (2.0) 23.6 (0.8) 56.4 (1.7) 53.2 (1.0) 63.9 (1.7) 65.1 (1.0)

Sheep 18.3 (1.5) 13.2 (0.6) 50.0 (1.7) 47.2 (1.0) 54.4 (1.7) 53.8 (1.0)

In 2011, operations lost a slightly higher percentage of lambs born alive compared with 

operations in 2001 (11.4 and 10.0 percent, respectively). There was no difference in the 

percentage of sheep lost to all causes from 2001 to 2011. 

F.1.b. Percentage of lambs and sheep lost to all causes during the previous year, by 

study:

Percent Lambs and Sheep

Sheep 2001 Sheep 2011

Sheep type Percent Std. error Percent Std. error

Lambs1 10.0 (0.3) 11.4 (0.3)

Sheep2 5.0 (0.1) 4.8 (0.2)

1

Percentage of lambs born alive. 

2

Percentage of January 1 sheep inventory.

F. Lamb and 

Sheep Deaths 

and Losses
84 / Sheep 2011

Section II: Population Estimates–F. Lamb and Sheep Deaths and Losses

Lamb losses increased slightly in the Central region from 2001 to 2011.

F.1.c. Percentage of lambs and sheep lost to all causes during the previous year, by 

region:

Herded/open range operations lost a higher percentage of lambs in 2011 than in 2001.

F.1.d. Percentage of lambs and sheep lost to all causes during the previous year, by 

primary flock type:

Percent Lambs and Sheep

Region

West Central East

Sheep 

2001

Sheep 

2011

Sheep 

2001

Sheep 

2011

Sheep 

2001

Sheep 

2011

Sheep type Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Lambs1 8.4 (0.5) 8.7 (0.6) 11.3 (0.3) 13.1 (0.5) 8.3 (4.3) 8.7 (0.4)

Sheep2 4.9 (0.1) 4.9 (0.3) 4.8 (0.1) 4.8 (0.2) 5.3 (0.3) 4.8 (0.2)

1

Percentage of lambs born alive. 2

Percentage of January 1 sheep inventory.

Percent Lambs and Sheep

Primary Flock Type

Herded/open range Fenced range Farm/pasture

Sheep 

2001

Sheep 

2011

Sheep 

2001

Sheep 

2011

Sheep 

2001

Sheep 

2011

Sheep type Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Lambs1 10.9 (0.2) 13.9 (0.6) 11.3 (0.5) 11.9 (0.5) 8.9 (0.5) 9.3 (0.5)

Sheep2 4.5 (0.1) 5.0 (0.3) 4.7 (0.1) 4.0 (0.2) 5.6 (0.2) 5.5 (0.3)

1

Percentage of lambs born alive. 

2

Percentage of January 1 sheep inventory.
USDA APHIS VS / 85 

Section II: Population Estimates–F. Lamb and Sheep Deaths and Losses

Old age was responsible for a higher percentage of sheep loss in 2011 than in 2001. In 

addition, a higher percentage of lamb death loss was attributed to weather-related causes 

in 2011 than in 2001 (28.1 and 11.2 percent, respectively). Identifying specific digestive 

problems via the questionnaire, such as internal parasites and enterotoxemia, might have 

resulted in a higher percentage of loss being attributed to those issues in 2011. 

F.1.e. For operations that lost lambs and sheep to nonpredator causes during the 

previous year, percentage of lambs and percentage of sheep by cause of loss and by 

study:

Percent Lambs and Sheep 

Lambs Sheep

Sheep 2001 Sheep 2011 Sheep 2001 Sheep 2011

Nonpredator 

cause Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Digestive problems* 9.9 (0.6) 6.7 (0.6)

Internal parasites 7.5 (0.7) 10.0 (1.0)

Enterotoxemia 

(overeating) 6.4 (0.7) 2.1 (0.3)

Other digestive 

problems 6.4 (0.5) 4.2 (0.5)

Respiratory 

problems 11.7 (0.7) 12.1 (0.7) 7.0 (0.8) 6.1 (0.5)

Metabolic problems 1.0 (0.1) 1.2 (0.2) 3.7 (0.4) 1.2 (0.4)

Other disease 

problems 2.0 (0.3) 2.1 (0.3) 3.0 (0.2) 6.7 (0.9)

Weather-related 

causes

11.2 (0.5) 28.1 (1.4) 5.0 (0.5) 8.8 (1.2)

Lambing problems 12.1 (0.8) 12.3 (0.5) 13.8 (0.9)

Old age 15.4 (0.8) 21.5 (1.1)

Being on back 0.1 (0.0) 0.2 (0.0) 2.7 (0.2) 2.9 (0.2)

Poison 1.0 (0.1) 2.1 (0.3) 4.9 (0.5) 3.1 (0.4)

Theft 0.7 (0.1) 1.2 (0.4) 1.8 (0.4) 1.6 (0.5)

Other known 

nonpredator causes 7.3 (0.5) 6.2 (0.5) 4.3 (0.5) 4.3 (0.6)

Unknown 

nonpredator causes 11.0 (0.6) 14.4 (1.3) 9.7 (0.5) 13.7 (2.1)

Total 100.0 100.0 100.0 100.0

*Digestive problems were not differentiated in Sheep 2001 but were differentiated in 2011.
86 / Sheep 2011

Section II: Population Estimates–F. Lamb and Sheep Deaths and Losses

2. Carcass disposal methods

The decision about which methods to use to dispose of carcasses depends on local, 

county, and State laws; a producer’s skill/knowledge of disposal methods (e.g., 

incineration and composting); method costs; and equipment availability (e.g., for burying, 

rendering, and incinerating). 

Rendering sheep carcasses is allowed only in a few locations, which is reflected by the 

very low percentage of operations that rendered their carcasses. 

The biggest change in carcass-disposal methods from 2001 to 2011 was in composting: 

26.5 percent of operations composted carcasses in 2011 compared with just 6.9 percent 

in 2001. A higher percentage of operations in 2011 than in 2001 left carcasses for 

scavengers, incinerated carcasses, or used put carcasses in a landfill. 

F.2.a. For operations that had any lamb and/or sheep deaths in the previous year, 

percentage of operations by carcass disposal method and by study:

Percent Operations 

Sheep 2001 Sheep 2011

Carcass disposal method Percent Std. error Percent Std. error

Landfill/municipal dump 7.5 (1.0) 13.1 (0.9)

Incineration 12.9 (1.0) 17.1 (1.1)

Burial (not landfill) 51.7 (1.7) 44.9 (1.3)

Rendering 2.3 (0.6) 1.3 (0.3)

Composting 6.9 (0.8) 26.5 (1.2)

Leaving for scavengers 25.3 (1.4) 40.8 (1.3)

Other 2.6 (0.6) 6.4 (0.7)
USDA APHIS VS / 87 

Section II: Population Estimates–F. Lamb and Sheep Deaths and Losses

Photograph courtesy of Camilla Kristensen.

0

10

20

30

40

50

60

Sheep 2011

Sheep 2001

Percent

Carcass disposal method

Landfill/

municipal

dump

Incineration Burial

(not landfill)

Rendering Composting Leaving

for

scavengers

Other

For operations that had any lamb and/or sheep deaths during the previous year, 

percentage of operations by carcass disposal method used and by study

7.5

13.1 12.9

17.1

51.7

44.9

2.3 1.3

6.9

26.5 25.3

40.8

2.6

6.4
88 / Sheep 2011

Section II: Population Estimates–F. Lamb and Sheep Deaths and Losses

Overall, the percentage of operations that composted carcasses increased from 2001 to 

2011. The largest increase occurred in the West region, where 10 times the percentage 

of operations composted carcasses in 2011 compared with operations in 2001 (20.5 and 

2.0 percent, respectively). Composting also increased in the East region from 9.6 percent 

of operations in 2001 to 45.6 percent in 2011. The largest increase in carcass disposal 

by incineration occurred in the West region, where 5.8 percent of operations incinerated 

carcasses in 2001 compared 13.7 percent in 2011. 

F.2.b. For operations that had any lamb and/or sheep deaths during the previous year, 

percentage of operations by carcass disposal method, study, and region:

Percent Operations 

Sheep 2001 Sheep 2011

West Central East West Central East

Carcass 

disposal 

method Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Landfill/ 

municipal dump 10.8 (3.3) 12.1 (1.7) 2.6 (0.8) 19.7 (3.2) 16.7 (1.4) 7.1 (1.2)

Incineration 5.8 (1.7) 10.8 (1.4) 17.2 (1.7) 13.7 (2.8) 13.1 (1.4) 22.0 (1.8)

Burial 

(not landfill) 52.2 (5.0) 32.5 (2.5) 66.1 (2.3) 48.2 (3.8) 39.6 (1.9) 48.5 (2.1)

Rendering 6.9 (2.7) 1.5 (0.7) 1.0 (0.5) 1.8 (0.9) 0.5 (0.2) 1.9 (0.6)

Composting 2.0 (0.8) 5.9 (1.3) 9.6 (1.3) 20.5 (3.2) 7.4 (1.0) 45.6 (2.1)

Leaving for 

scavengers

27.4 (4.3) 44.7 (2.5) 9.8 (1.4) 48.3 (3.8) 57.2 (1.8) 20.7 (1.8)

Other 5.8 (2.4) 1.2 (0.2) 2.4 (0.9) 7.2 (2.2) 8.2 (1.2) 4.4 (1.0)
USDA APHIS VS / 89 

Section II: Population Estimates–F. Lamb and Sheep Deaths and Losses

Nearly half of lamb and sheep carcasses were left for scavengers in 2001 and 2011. 

A lower percentage of carcasses in were buried in 2011 than in 2001, and nearly three 

times the percentage of carcasses were composted in 2011 than in 2001 (14.1 and 5.0 

percent, respectively). 

F.2.c. For lambs and sheep that died during the previous year, percentage of dead lambs 

and sheep by carcass disposal method and by study:

Percent Dead Lambs and Sheep 

Sheep 2001 Sheep 2011

Carcass disposal method Percent Std. error Percent Std. error

Landfill/ municipal dump 6.9 (0.7) 4.4 (0.4)

Incineration 7.5 (0.6) 7.7 (0.9)

Burial (not landfill) 27.1 (1.0) 21.8 (1.1)

Rendering 4.2 (1.2) 0.6 (0.2)

Composting 5.0 (0.5) 14.1 (1.0)

Leaving for scavengers 47.4 (1.3) 48.5 (1.6)

Other 1.9 (0.4) 3.1 (0.4)

Total 100.0 100.0
90 / Sheep 2011

Section II: Population Estimates–F. Lamb and Sheep Deaths and Losses

The percentage of carcasses buried in the West and East regions was higher in 2001 

than in 2011 (42.5 and 25.4 percent, respectively).

F.2.d. For lambs and sheep that died during the previous year, percentage of dead lambs 

and sheep, by carcass disposal method, region, and study:

Percent Dead Lambs and Sheep

Sheep 2001 Sheep 2011

West Central East West Central East

Carcass 

disposal 

method Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Landfill/ 

municipal dump 7.8 (2.0) 7.9 (0.9) 1.9 (0.5) 9.2 (1.9) 4.1 (0.4) 3.0 (0.7)

Incineration 8.2 (2.3) 4.7 (0.6) 18.2 (1.7) 7.5 (2.1) 6.6 (1.2) 10.8 (1.3)

Burial 

(not landfill) 42.5 (3.8) 17.7 (1.0) 53.0 (2.6) 25.4 (2.6) 19.8 (1.5) 25.9 (2.0)

Rendering 1.9 (0.8) 5.5 (1.7) 0.9 (0.5) 2.4 (1.2) 0.1 (0.0) 0.9 (0.3)

Composting 4.0 (1.1) 3.3 (0.6) 12.9 (1.4) 17.5 (3.4) 4.2 (0.6) 42.0 (2.6)

Leaving for 

scavengers

30.4 (2.8) 59.5 (1.6) 12.2 (2.9) 33.5 (3.1) 62.3 (1.9) 14.8 (2.3)

Other 5.2 (2.1) 1.4 (0.3) 1.5 (0.5) 4.5 (1.3) 2.9 (0.5) 2.6 (0.7)
USDA APHIS VS / 91 

Section II: Population Estimates–G. Lambs and Sheep on Feed

1. Lambs and sheep on a high-energy diet

The percentage of all operations that fed lambs or sheep a high-energy diet to finish them 

for slaughter increased from 2001 to 2011. In 2001 and 2011, farm/pasture operations 

accounted for the highest percentage of operations that fed lambs or sheep a highenergy diet to finish them for slaughter. The biggest change between the two studies was 

in fenced-range operations, where over twice the percentage of operations fed a highenergy diet to lambs in 2011 compared with 2001. The majority of animals that were fed a 

high-energy diet in 2011 were lambs (27.3 percent of lambs weaned in 2010. Similar data 

were not collected in Sheep 2001. 

G.1. Percentage of operations that fed a high-energy diet to lambs or sheep during the 

previous year to finish them for slaughter, by study and by primary flock type:

Percent Operations

Primary Flock Type

Herded/

open range

Fenced 

range

Farm/

pasture

All 

operations

Study Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Sheep 2001 7.0 (2.1) 7.6 (1.4) 28.6 (1.5) 26.2 (1.3)

Sheep 2011* 8.1 (1.5) 20.3 (1.7) 35.0 (1.4) 31.4 (1.0)

*For operations with 20 or more ewes.

G. Lambs and 

Sheep on Feed
92 / Sheep 2011

Section II: Population Estimates–G. Changes in Lambs and Sheep on Feed

2. Weight of market lambs

A higher percentage of operations in 2011 than in 2001 placed on feed lambs that 

weighed more than 105 lb. In both studies, the majority of operations that fed a highenergy diet placed lambs weighing less than 65 lb. In addition, in 2011 the single highest 

percentage of lambs were placed on feed when weighing less than 65 lb. In 2001, lambs 

tended to be heavier when placed on feed. 

G.2. For market lambs fed a high-energy diet during the previous year, percentage of 

operations and percentage of lambs by weight of lambs when placed on feed and by 

study: 

Percent 

Operations Lambs

Sheep 2001 Sheep 2011 Sheep 2001 Sheep 2011

Weight (lb) Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Less than 65 65.0 (2.8) 58.3 (2.1) 20.0 (2.1) 43.7 (3.6)

65–84 28.9 (2.6) 25.9 (1.9) 30.5 (2.9) 21.1 (2.4)

85–105 10.7 (1.7) 16.5 (1.5) 37.1 (3.2) 17.2 (4.8)

More than 105 6.6 (1.5) 20.9 (1.7) 12.4 (2.6) 18.0 (2.3)

Total 100.0 100.0
USDA APHIS VS / 93 

Section II: Population Estimates–H. Biosecurity Practices

1. Flock additions

H.1.a. Percentage of operations that added sheep or lambs during the previous year:

Percent Operations 

Sheep 2001 Sheep 2011

Percent Std. error Percent Std. error

33.2 (1.5) 28.6 (0.9)

Keeping a closed flock is one of the best ways to maintain healthy animals, as introducing 

new sheep to a flock poses one of the greatest threats to biosecurity. In a closed flock, 

replacement females are selected from within the flock, and genetic improvements are 

made through artificial insemination. 

Each age group introduced to the flock poses its own biosecurity risks. Bred ewes 

can harbor reproductive pathogens that are detectible only when ewes abort or lamb. 

Replacement lambs can introduce new strains of respiratory and enteric pathogens to 

other lambs. 

H. Biosecurity 

Practices
94 / Sheep 2011

Section II: Population Estimates–H. Biosecurity Practices

For operations that added sheep, similar percentages of operations in 2001 and 2011 

added ewes and rams of all sheep types. In both studies, these operations also added 

roughly the same percentages of ewes and rams of all sheep types.

H.1.b. For operations that added any sheep or lambs during the previous year, 

percentage of operations and percentage of lambs or sheep, by type of sheep added and 

by study:

Percent

Operations Lambs or Sheep

Sheep 2001 Sheep 2011 Sheep 2001 Sheep 2011

Sheep type Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Replacement ewe 

lambs less than 

1 year old

34.4 (2.6) 26.8 (1.8) 14.4 (2.1) 19.6 (3.0)

Replacement ewes 

1 year or older 28.4 (2.3) 30.3 (1.8) 27.8 (2.9) 24.0 (2.9)

Replacement ram 

lambs less than 

1 year old

35.1 (2.4) 36.8 (1.9) 2.1 (0.3) 1.9 (0.3)

Replacement rams 

1 year and older 38.2 (2.5) 42.5 (1.9) 2.4 (0.3) 2.4 (0.3)

All other sheep 

and lambs 11.4 (2.0) 7.1 (1.0) 53.3 (4.7) 52.0 (5.2)

Total 100.0 100.0

Many outwardly healthy animals carry infectious organisms that can affect flock 

productivity. For this reason, quarantining new additions is always recommended. 

Quarantining animals provides an opportunity to detect diseases in the new additions 

without risking disease introduction and transmission to the rest of the flock. For the 

purpose of this report, quarantine is defined as the physical separation of an animal or 

group of animals from other sheep on the operation. 

General recommendations for the minimum length of quarantine vary from 14 to 

28 days. Quarantining should provide sufficient time for the incubation and detection of 

infectious diseases. Diseases for which quarantining is most effective have incubation 

periods shorter than the quarantine period; thus, animals will show signs of infection 

prior to being introduced to the flock. Quarantining is not effective for diseases with long 

incubation periods or for diseases in which animals can be silent carriers. Diseases for 

which quarantining is not effective include Johne’s disease, scrapie, and sore mouth. For 

these diseases, it is especially important to purchase new additions from disease-free, 

closed flocks that have not introduced new animals for a number of years. 
USDA APHIS VS / 95 

Section II: Population Estimates–H. Biosecurity Practices

Quarantine areas should be separate from other housing and far enough away from 

resident sheep to prevent airborne disease transmission. Quarantined animals should 

have no physical contact with other animals; therefore, producers should ensure that 

quarantined animals do not share fence lines, waterers, or feeders, all of which allow 

disease transmission. 

A higher percentage of operations that added sheep in 2011 (47.9 percent) quarantined 

new additions compared with operations in 2001 (33.9 percent). 

H.1.c. For operations that added any sheep or lambs during the previous year, 

percentage of operations that quarantined any sheep or lambs after arrival and 

percentage of sheep or lambs quarantined after arrival, by sheep type and by study:

Percent 

Operations Sheep or Lambs

Sheep 2001 Sheep 2011 Sheep 2001 Sheep 2011

Sheep type Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Replacement ewe 

lambs less than 

1 year old

29.7 (4.2) 47.8 (3.9) 29.0 (6.0) 21.5 (4.7)

Replacement ewes 

1 year or older 30.4 (4.2) 43.4 (3.6) 15.2 (2.1) 24.0 (3.5)

Replacement ram 

lambs less than 

1 year old

41.4 (4.0) 51.8 (3.2) 39.8 (4.3) 36.8 (5.0)

Replacement rams 

1 year and older 27.7 (3.4) 44.2 (3.0) 27.6 (2.4) 30.1 (2.9)

All other sheep 

and lambs 16.3 (7.1) 43.5 (7.1) 12.1 (3.3) 35.0 (8.4)

Any sheep or lambs 33.9 (2.4) 47.9 (2.0) 16.4 (2.4) 29.5 (4.6)
96 / Sheep 2011

Section II: Population Estimates–H. Biosecurity Practices

Overall, the percentage of operations that used health management practices for new 

additions to prevent disease increased from 2001 to 2011. Specifically, nearly twice the 

percentage of operations in 2011 vaccinated new additions before they arrived compared 

with operations in 2001 (70.1 and 35.6 percent, respectively). In addition, more than twice 

the percentage of operations in 2011 conducted external parasite treatments on new 

animals before they arrived compared with operations in 2001. 

H.1.d. For operations that added lambs or sheep during the previous year, percentage of 

operations that performed the following health management practices on all or some of 

the new arrivals before or after their arrival, by study:

Percent Operations

Sheep 2001 Sheep 2011

Prior to arriving 

at operation

After arrival

at operation

Prior to 

arriving at 

operation

After arrival

at operation

Health 

management 

practice Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Any vaccinations 35.6 (2.5) 37.9 (2.5) 70.1 (2.1) 43.5 (2.0)

Shearing 32.2 (2.5) 29.1 (2.4) 44.0 (2.1) 33.0 (1.9)

Foot trim 21.4 (2.1) 31.7 (2.5) 37.7 (2.2) 36.6 (2.0)

Medicated footbath 6.1 (1.4) 12.0 (1.9) 10.5 (1.5) 15.3 (1.5)

Deworm 33.1 (2.5) 57.5 (2.6) 64.2 (2.2) 67.9 (1.9)

External parasite 

treatment 13.6 (1.8) 21.7 (2.0) 29.5 (2.2) 25.2 (1.7)

OPP testing 6.0 (1.2) 0.5 (0.1) 7.6 (1.3) 2.1 (0.6)

Johne’s testing 3.3 (0.9) 0.2 (0.1) 8.4 (1.4) 1.6 (0.5)

Scrapie 

susceptibility testing NA NA 42.1 (2.3) 10.1 (1.3)

Other 3.8 (0.9) 3.3 (0.7) 5.2 (1.1) 2.3 (0.6)
USDA APHIS VS / 97 

Section II: Population Estimates–H. Biosecurity Practices

2. Contact with other sheep

Disease transmission can occur when sheep from one operation have contact with 

sheep from another operation (or their feed or manure). Sharing air space from another 

flock through shared grazing land, at shows, or during breeding also presents risks for 

transmitting disease. The percentages of operations by types of contact the operations’ 

sheep had with sheep from another operation showed little change from 2001 to 2011.

H.2.a. Percentage of operations in which sheep had contact with sheep from another 

operation, by type of contact and by study:

Percent Operations 

Sheep 2001* Sheep 2011

Contact type Percent Std. error Percent Std. error

At shows, exhibitions, breeding, 

etc., then returned to operation 32.4 (2.3) 33.7 (2.1)

Grazed with sheep from 

another operation 6.0 (1.1) 9.9 (1.2)

Had fence-line contact with sheep 

from another operation 11.2 (1.1) 13.1 (1.3)

Had contact with sheep visiting 

from another operation 19.4 (1.8) 21.8 (1.8)

Other 8.3 (1.3) 2.4 (0.6)

Any contact 50.6 (2.4) 50.2 (2.2)

*In 2001, an additional category—temporarily brought rams onto operation for breeding purposes—was also 

included.
98 / Sheep 2011

Section II: Population Estimates–H. Biosecurity Practices

A similar percentage of operations in 2001 and 2011 made an effort to decrease nose-tonose contact between their sheep and sheep from other operations (28.7 and 

34.6 percent, respectively). 

H.2.b. For operations on which sheep had opportunities for contact with sheep from other 

operations, percentage of operations that made efforts to decrease nose-to-nose contact 

with their sheep and sheep from other operations, by study and by primary flock type:

Percent Operations 

Primary Flock Type

Herded/

open range

Fenced 

range

Farm/

pasture

All 

operations

Study Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Sheep 2001 20.4 (4.4) 19.6 (4.1) 30.8 (3.6) 28.7 (3.0)

Sheep 2011 20.7 (6.0) 30.2 (6.3) 36.3 (3.9) 34.6 (3.0)

Cats pose a risk of transmitting diseases (such as toxoplasmosis) to sheep by defecating 

in or around sheep feed areas and by giving birth in sheep-raising areas. Nearly all 

operations in 2001 and 2011 had some type of cat present (96.5 and 94.1 percent, 

respectively). 

Nearly all operations in 2001 and 2011 had some type of rodent control (96.5 and 

94.1 percent, respectively) [table B.7]. For both studies, cats were the predominant 

method of rat and mouse control. Similar percentages of operations in 2001 and 2011 

used each of the control methods in the table below.

H.2.c. Percentage of operations in which outdoor cats, including domestic, stray, or wild 

(e.g., bobcats), were present on the operation, by study and by primary flock type:

Percent Operations 

Primary Flock Type

Herded/

open range

Fenced

range

Farm/

pasture

All 

operations

Study Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Sheep 2001 92.2 (1.8) 96.9 (2.2) 96.4 (1.0) 96.5 (0.9)

Sheep 2011 74.2 (9.8) 91.1 (3.1) 95.6 (1.3) 94.1 (1.1)
USDA APHIS VS / 99 

Section II: Population Estimates–H. Biosecurity Practices

The percentage of operations in which llamas or alpacas had access to sheep or lamb 

areas increased from 9.8 percent in 2001 to 19.4 percent in 2011. Conversely, the 

percentage of operations with cats that had access to sheep or lamb areas decreased 

from 78.2 percent in 2001 to 70.4 percent in 2011. 

H.2.d. Percentage of operations by type of animals that had access to sheep or lamb 

areas (i.e., grazing areas, sheds, holding pens, food, or water) during the previous year, 

and by study:

Percent Operations

Sheep 2001 Sheep 2011*

Animal Percent Std. error Percent Std. error

Goats (domestic or wild) 21.3 (1.3) 24.5 (1.0)

Cattle 42.7 (1.6) 48.3 (1.2)

Horses, donkeys 38.1 (1.6) 39.1 (1.1)

Llamas, alpacas 9.8 (0.9) 19.4 (0.9)

Pigs (domestic and feral) 6.6 (0.8) 8.4 (0.7)

Poultry (chickens, turkeys, etc.) 25.1 (1.5) 28.4 (1.1)

Dogs 77.4 (1.4) 76.6 (1.0)

Cats 78.2 (1.4) 70.4 (1.1)

*In 2011 the question asked about animals having open access to sheep-raising areas.
100 / Sheep 2011

Section II: Population Estimates–H. Biosecurity Practices

3. Professional consultants

A higher percentage of operations in 2011 than in 2001 were visited by Federal/State 

veterinarians, extension agents, or nutritionists.

H.3.a. Percentage of operations by type of professional consultant that visited for any 

sheep-related reason during the previous year, and by study:

Percent Operations 

Sheep 2001 Sheep 2011

Professional consultant Percent Std. error Percent Std. error

Private veterinarian NA 28.2 (1.0)

Federal/State veterinarian 2.9 (0.5) 5.6 (0.5)

Extension agent 3.7 (0.5) 5.6 (0.5)

Nutritionist 2.1 (0.3) 5.2 (0.5)
USDA APHIS VS / 101 

Section II: Population Estimates–H. Biosecurity Practices

While just 28.2 percent of operations were visited by a private veterinarian in 2011 

(table H.3.a), 51.8 percent of operations had consulted with a private veterinarian 

during the previous year. This percentage is higher than the percentage of operations 

that consulted with a private veterinarian in 2001 (46.1 percent). From 2001 to 2011, 

there were substantial increases in the percentage of operations that consulted with a 

veterinarian for disease diagnosis, disease prevention, and lambing problems. 

H.3.b. Percentage of operations that consulted a private veterinarian during the previous 

year, by reason and by study:

Percent Operations

Sheep 2001 Sheep 20111

Reason Percent Std. error Percent Std. error

Sheep disease diagnosis 22.4 (1.3) 46.9 (1.6)

Sheep disease prevention 20.9 (1.2) 45.3 (1.6)

Sheep nutritional information 7.4 (0.7) 12.3 (1.0)

Sheep production 

management practices 6.2 (0.6) 12.4 (1.0)

Lambing problems 19.1 (1.2) 34.7 (1.5)

Lameness 5.7 (0.7) 9.1 (0.9)

Other 8.5 (0.9) 5.6 (0.8)

Any reason2 46.1 (1.6) 51.8 (1.2)

1

In 2011, additional reasons listed and not included here were “interstate health certificate,” “breeding 

soundness exam,” and “pregnancy check.” 

2

Includes all reasons listed as options in 2011.
102 / Sheep 2011

Section II: Population Estimates–H. Biosecurity Practices

0 10 20 30 40 50 60

Sheep 20111

Sheep 2001

Sheep disease

diagnosis

Sheep disease

prevention

Sheep nutritional

information

Sheep production

management practices

Lambing problems

Lameness

Other

Any reason2

Reason

Percent

Percentage of operations that had consulted a private veterinarian during the

previous year, by reason and by study

1

In 2011, additional reasons listed and not included here were “interstate health certificate,” “breeding 

soundness exam,” and “pregnancy check.”

2

Includes all reasons listed as options in 2011.

22.4

46.9

20.9

45.3

7.4

12.3

6.2

12.4

19.1

34.7

5.7

9.1

8.5

5.6

46.1

51.8
USDA APHIS VS / 103 

Section II: Population Estimates–H. Biosecurity Practices

4. Manure management

A higher percentage of operations in 2011 than in 2001 gave away or composted manure.

H.4. Percentage of operations by methods used to dispose of manure:

Percent Operations 

Sheep 2001* Sheep 2011

Method Percent Std. error Percent Std. error

Applied to land either owned or rented 

by the operation 78.2 (2.0) 79.4 (1.7)

Sold or received other compensation 3.0 (0.6) 6.8 (1.1)

Gave away 17.7 (1.8) 32.8 (2.0)

Composted 29.0 (2.2) 40.9 (2.1)

*In 2001, there was an additional category not included here::applied to land not owned, rented, or leased by 

operation.
104 / Sheep 2011

Section II: Population Estimates–I. Reproduction Management

1. Manure and waste-bedding management during lambing

Cleaning the lambing area is crucial for preventing disease transmission between ewes 

and from ewes to lambs. Periparturient ewes, which may be immunosuppressed, and 

newborn lambs, which have immature immune systems, are especially susceptible to 

infectious disease. Also, tissue and fluid left by infected ewes after they have given birth 

often shed pathogenic organisms into the environment. Organisms that pose such risks 

include prions (cause of scrapie); Mycobacterium avium subspecies paratuberculosis 

(cause of Johne’s disease); Coxiella burnetii (cause of Q fever); Toxoplasma gondii; and 

various Salmonella species, to name just a few.

A higher percentage of operations in 2011 did not clean lambing areas compared with 

operations in 2001 (25.4 and 7.6 percent, respectively).

I.1.a. Percentage of operations by frequency that manure and waste bedding were 

cleaned from the lambing area during lambing season, and by study:

Percent Operations 

Sheep 2001 Sheep 2011

Cleaning frequency Percent Std. error Percent Std. error

Between each ewe 24.8 (2.4) 10.9 (1.3)

Between two or more ewes 16.2 (1.8) 14.8 (1.5)

At end of lambing season 51.4 (2.6) 48.8 (2.1)

Not cleaned 7.6 (1.3) 25.4 (1.9)

Total 100.0 100.0

I. Reproduction 

Management
USDA APHIS VS / 105 

Section II: Population Estimates–I. Reproduction Management

I.1.b. Percentage of operations by frequency that the operation cleaned manure and 

waste bedding from jugs for ewe-lamb pairs during lambing season, and by study:

Percent Operations 

Sheep 2001 Sheep 2011

Cleaning frequency Percent Std. error Percent Std. error

Between each ewe 38.4 (2.7) 39.2 (2.2)

Between two or more ewes 18.4 (1.9) 24.1 (2.0)

At end of lambing season 39.5 (2.7) 31.5 (2.2)

Not cleaned 3.7 (1.1) 5.2 (1.1)

Total 100.0 100.0

2. Placenta removal

Placentas can harbor infectious organisms and should be removed from the lambing area 

as soon after lambing as possible. Removing placentas is especially important on highdensity operations in which ewes are clustered, making exposure to harmful organisms in 

placentas more likely. 

I.2.a. Percentage of operations that usually removed placentas from the lambing area, by 

study and by primary flock type:

Percent Operations 

Primary Flock Type

Herded/

open range

Fenced 

range

Farm/

pasture

All 

operations

Study Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Sheep 2001 49.3 (5.4) 55.5 (5.1) 81.0 (2.0) 75.2 (1.9)

Sheep 2011 42.2 (8.3) 62.6 (4.6) 71.0 (2.4) 67.9 (2.0)
106 / Sheep 2011

Section II: Population Estimates–I. Reproduction Management

I.2.b. For operations that usually removed placentas from the lambing area, percentage 

of operations by average length of time placentas were left on the ground before removal, 

and by study:

Percent Operations 

Sheep 2001 Sheep 2011

Time left on ground (hr) Percent Std. error Percent Std. error

Less than 6 68.4 (2.7) 76.0 (2.4)

6–12 23.7 (2.5) 19.2 (2.2)

More than 12 7.9 (1.6) 4.8 (1.2)

Total 100.0 100.0

For operations that removed placentas, the most common methods of removal for 

both studies were composting, throwing out for carnivores, and putting in the landfill/

dump. A higher percentage of operations in 2011 than in 2001 (28.0 and 15.4 percent, 

respectively) removed placentas from the lambing area by throwing them out for 

carnivores .

I.2.c. For operations that usually removed placentas from the lambing area, percentage 

of operations by usual method of placenta disposal and by study:

Percent Operations 

Sheep 2001 Sheep 2011

Method Percent Std. error Percent Std. error

Burn/incinerate 12.7 (1.8) 9.3 (1.5)

Bury 11.2 (1.5) 6.9 (1.3)

Render 0.3 (0.3) 0.1 (0.1)

Landfill/dump 17.9 (2.4) 16.5 (2.0)

Compost 29.4 (2.7) 30.8 (2.5)

Throw out for carnivores 15.4 (2.1) 28.0 (2.4)

Other 13.1 (2.0) 8.5 (1.5)
USDA APHIS VS / 107 

Section II: Population Estimates–I. Reproduction Management

3. Abortion and sick ewe management

There was no difference from 2001 to 2011 in either the percentage of operations that 

had ewes abort or in the percentage of bred ewes that aborted.

I.3.a. Percentage of operations with one or more ewes that aborted, by study and by 

primary flock type:

Percent Operations 

Primary Flock Type

Herded/

open range

Fenced 

range

Farm/

pasture

All 

operations

Study Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Sheep 2001 61.9 (6.3) 41.1 (5.2) 52.4 (2.8) 50.6 (2.4)

Sheep 2011 80.5 (10.2) 45.5 (5.5) 42.6 (3.0) 43.8 (2.4)

I.3.b. Percentage of ewes that aborted, by study: 

Percent Operations 

Sheep 1996 Sheep 2011

Percent Std. error Percent Std. error

1.8 (0.1) 1.7 (0.1)
108 / Sheep 2011

Section II: Population Estimates–I. Reproduction Management

In 2011, a lower percentage of operations with ewes that aborted removed placentas or 

fetuses as soon as possible and disinfected the area compared with operations in 2001.

I.3.c. For operations with ewes that aborted, percentage of operations by practice used 

for aborting ewes and by study:

Percent Operations 

Sheep 2001 Sheep 2011

Practice Percent Std. error Percent Std. error

Remove placentas or fetuses 

as soon as possible 88.8 (1.7) 79.6 (2.5)

Clean the area by removing 

bedding and/or dirt 41.2 (3.2) 30.3 (2.9)

Disinfect the area 20.8 (2.9) 9.6 (1.9)

Physically separate ewes that 

aborted from other ewes 44.1 (3.1) 32.6 (2.9)
USDA APHIS VS / 109 

Section II: Population Estimates–I. Reproduction Management

The percentage of abortions suspected to be caused by Campylobacter did not change 

from 2001 to 2011; however, the percentage of those suspected cases diagnosed by a 

veterinarian or a laboratory decreased from 53.7 percent in 2001 to 22.6 percent in 2011. 

For all listed pathogens, the percentage of suspected causes diagnosed by a veterinarian 

or a laboratory decreased from 2001 to 2011. 

I.3.d. For operations that had ewes that aborted during the previous year, percentage 

of operations by suspected cause of abortions, percentage of operations in which the 

diagnosis was made by either a veterinarian or laboratory, and by study:

Percent Operations 

Suspected

Suspected cases diagnosed by 

a veterinarian or laboratory

Sheep 2001 Sheep 2011 Sheep 2001 Sheep 2011

Abortion cause Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Campylobacteriosis 

(vibrio abortion) 8.8 (1.6) 6.6 (1.3) 53.7 (9.7) 22.6 (6.7)

Chlamydiosis 

(enzootic abortion) 8.5 (1.8) 9.0 (1.6) 43.6 (11.0) 37.3 (8.9)

Toxoplasmosis 6.0 (1.9) 3.4 (1.1) 26.2 (10.0) 6.9 (6.5)

Q fever 1.0 (0.8) 0.1 (0.1) 2 2

Salmonellosis 0.3 (0.1) 0.1 (0.1) 2 2

Listeriosis 1.5 (1.0) 0.7 (0.3) 2 2

Cache Valley virus1 NA 1.1 (0.5) NA 2

Other 5.6 (2.1) 10.3 (1.8) 73.3 (14.3) 3.5 (3.3)

Any infectious 

cause above 24.3 (3.0) 26.2 (2.6) 51.3 (7.4) 21.6 (4.4)

1

Not a choice in the Sheep 2001 questionnaire.

2

Too few observations to report.
110 / Sheep 2011

Section II: Population Estimates–I. Reproduction Management

0 5 10 15 20 25 30

Sheep 2011

Sheep 2001

Campylobacteriosis

(vibrio abortion)

Chlamydiosis

(enzootic abortion)

Toxoplasmosis

Q fever

Salmonellosis

Listeriosis

Cache Valley virus*

Any infectious

cause above

Abortion cause

Percent

For operations that had ewes that aborted during the previous year, percentage of 

operations by suspected cause of abortions and by study

*Not a choice in the Sheep 2001 questionnaire.

8.8

6.6

8.5

9.0

6.0

3.4

1.0

0.1

1.5

0.7

NA

1.1

5.6

10.3

24.3

26.2

Other

0.3

0.1
USDA APHIS VS / 111 

Section II: Population Estimates–I. Reproduction Management

Having a dedicated lambing area separate from the sick-ewe area reduces the risk of 

disease transmission. There was no substantial change in the percentage of operations 

that used the lambing area for sick ewes from 2001 to 2011.

I.3.e. Percentage of operations that used the lambing area for sick ewes, by time period 

and by study:

Percent Operations 

Sheep 2001 Sheep 2011

Time period Percent Std. error Percent Std. error

During lambing 23.0 (2.1) 19.3 (1.6)

At other times of the year 32.2 (2.3) 30.6 (2.0)

4. Feeding practices

I.4.a. Percentage of operations in which weaned lambs less than 12 months old generally 

shared common feed or water sources with adult sheep:

Percent Operations 

Sheep 2001 Sheep 2011

Percent Std. error Percent Std. error

61.5 (2.4) 61.9 (2.0)

Placing thin ewes with younger sheep can expose the younger sheep to chronic diseases 

such as Johne’s disease. A similar percentage of operations in both studies placed ewes 

with younger sheep to encourage or increase the ewes’ feed intake. 

I.4.b. Percentage of operations that ever placed thin ewes with younger sheep to 

encourage or to increase the ewes’ feed intake:

Percent Operations 

Sheep 2001 Sheep 2011

Percent Std. error Percent Std. error

28.0 (2.2) 26.2 (1.9)
112 / Sheep 2011

Section II: Population Estimates–J. Disease Control, Illness, and Death

1. Johne’s disease

Johne’s disease is caused by the bacteria Mycobacterium avium subspecies 

paratuberculosis. All ruminant species are susceptible to Johne’s disease, which is 

considered a common infection of cattle, sheep, goats, deer, and bison. There are 

several strains of this organism, including those that primarily infect cattle and those that 

primarily infect sheep, although some cross-infections do occur. Infected cattle, therefore, 

can pose a risk to sheep and vice versa. Most animals are infected in the first several 

months of life by ingesting bacteria shed in the feces of infected animals. While usually 

infected when young, most sheep do not show clinical signs of Johne’s disease until they 

are 2 to 6 years old. In sheep, the most common sign is losing weight despite a normal 

appetite.

J.1. Percentage of operations by level of familiarity with Johne’s disease and by study:

Percent Operations 

Sheep 2001 Sheep 2011

Level of familiarity Percent Std. error Percent Std. error

Very familiar 6.5 (1.1) 13.6 (1.5)

Somewhat familiar 25.3 (2.2) 30.5 (1.9)

Heard of name only 38.0 (2.3) 28.6 (1.9)

Never heard of 30.2 (2.2) 27.3 (1.9)

Total 100.0 100.0

J. Disease 

Control, Illness, 

and Death
USDA APHIS VS / 113 

Section II: Population Estimates–J. Disease Control, Illness, and Death

2. Weight loss despite normal appetite

A number of infectious diseases can cause ewes to lose weight, despite a normal 

appetite and treatment. Johne’s is one such disease, and since it can infect lambs in 

utero it is recommended that ewes with Johne’s be culled before lambing. If not infected 

in utero, lambs born to ewes infected with Johne’s will likely become infected through 

the dam’s milk or by accidentally ingesting infected feces. There was no substantial 

change from 2001 to 2011 in health management practices used for pregnant ewes that 

demonstrated weight loss, despite a normal appetite and treatment.

J.2. Percentage of operations by the health management practice that best describes 

what would most likely be done if a pregnant ewe demonstrated weight loss but had a 

normal appetite and did not respond to treatment:

Percent Operations 

Sheep 2001 Sheep 2011

Health management practice Percent Std. error Percent Std. error

Cull her before lambing 12.3 (1.3) 11.1 (1.3)

Allow her to lamb and then 

re-evaluate or cull her 79.3 (1.8) 78.9 (1.8)

Keep her regardless of 

the above signs 8.4 (1.4) 10.0 (1.5)

Total 100.0 100.0
114 / Sheep 2011

Section II: Population Estimates–J. Disease Control, Illness, and Death

3. Scrapie

Scrapie is a fatal degenerative disease that affects the central nervous system of sheep 

and goats. Infected flocks with a high percentage of susceptible animals can experience 

significant production losses. In these flocks the number of infected animals increases 

over a period of several years, and the age at onset of clinical signs decreases, making 

these flocks economically unviable. Animals sold from infected flocks can spread scrapie 

to other flocks. The presence of scrapie in the United States also prevents the export 

of breeding stock, semen, and embryos to many other countries. Scrapie is part of an 

eradication program in the United States. For more information, visit 

www.eradicatescrapie.org. 

The impacts of the scrapie eradication program can be seen in the following tables. From 

2001 to 2011, the percentage of operations that were very familiar with scrapie increased, 

while the percentage of operations that had heard of the name only or had never heard of 

scrapie decreased.

J.3.a. Percentage of operations by level of familiarity with scrapie:

Percent Operations 

Sheep 2001 Sheep 2011

Level of familiarity Percent Std. error Percent Std. error

Very familiar 19.5 (1.9) 41.6 (2.1)

Somewhat familiar 44.6 (2.4) 43.2 (2.1)

Heard of name only 28.5 (2.2) 13.3 (1.5)

Never heard of 7.4 (1.2) 1.9 (0.7)

Total 100.0 100.0
USDA APHIS VS / 115 

Section II: Population Estimates–J. Disease Control, Illness, and Death

The percentage of operations that used genetic selection to control scrapie in their flocks 

quadrupled from 2001 to 2011. This increase is likely due to increased knowledge about 

scrapie and the benefits of genetic selection as well as greater testing availability. 

J.3.b. Percentage of operations that used genetic selection to control scrapie in their 

flocks:

Percent Operations 

Sheep 2001 Sheep 2011

Percent Std. error Percent Std. error

10.8 (1.5) 47.3 (2.3)

A higher percentage of operations in 2011 than in 2001 culled genetically more 

susceptible ewes or used genetically less susceptible replacement rams. An RR ram 

has a high genetic resistance to scrapie, and all his offspring will be resistant or less 

susceptible to scrapie.

J.3.c. For operations that genetically selected for scrapie control, percentage of 

operations by genetic selection practice used:

Percent Operations 

Sheep 2001 Sheep 2011

Selection practice Percent Std. error Percent Std. error

Use genetically less susceptible 

replacement rams (i.e., RR alleles) 84.4 (5.1) 98.8 (0.7)

Selecting genetically less susceptible 

ewes (i.e., QR or RR alleles) 31.1 (6.0) 48.6 (3.4)

Culling genetically more susceptible 

ewes (i.e., QQ alleles) 17.0 (4.2) 27.8 (3.1)

Selected less susceptible breeds 22.6 (5.3) NA

Other* 9.2 (5.0) 2.3 (1.0)
116 / Sheep 2011

Section II: Population Estimates–J. Disease Control, Illness, and Death

Photograph courtesy of American Sheep Industry.
USDA APHIS VS / 117 

Section II: Population Estimates–J. Disease Control, Illness, and Death

4. Ovine progressive pneumonia 

Ovine progressive pneumonia (OPP) is a slowly progressive viral disease of adult sheep 

caused by an ovine lentivirus. Most sheep do not show clinical signs of OPP, but the 

sheep that do typically do not show clinical signs until 2 years of age or older because 

of the virus’s long incubation period. Often, the first sign noticed is general loss of body 

condition referred to as “thin ewe syndrome.” Weight loss occurs despite the affected 

sheep having a normal appetite. Increased breathing at rest is another common sign of 

OPP. Often called “lungers,” these sheep tire easily and may be seen trailing the flock. 

Bacterial infections secondary to OPP are very common and result in additional signs 

such a fever, cough, lethargy, and nasal discharge. OPP infection also can cause “hard 

bag,” an enlarged, firm udder with reduced or no milk flow. Infection with OPP can also 

cause other problems such a meningitis and encephalitis. Clinical signs include an 

unsteady gait, twitching, or stumbling, which can progress to hind limb or total paralysis. 

Arthritis may accompany OPP infection as well. Pain and swelling of the joints and a 

shortened gait are common. In addition, flocks infected with OPP can have lowered 

production efficiency because of early culling, decreased milk production, and lower 

weaning weights. 

The percentage of operations that were somewhat familiar with OPP increased from 2001 

to 2011, and the percentage of operations that had heard of the name only decreased 

during the same period.

J.4.a. Percentage of operations by familiarity with OPP and by study:

Percent Operations 

Sheep 2001 Sheep 2011

Level of familiarity Percent Std. error Percent Std. error

Very familiar 10.9 (1.4) 15.4 (1.5)

Somewhat familiar 28.4 (2.1) 38.1 (2.1)

Heard of name only 29.2 (2.3) 20.4 (1.8)

Never heard of 31.5 (2.2) 26.0 (1.9)

Total 100.0 100.0
118 / Sheep 2011

Section II: Population Estimates–J. Disease Control, Illness, and Death

There was no difference from 2001 to 2011 in the percentage of operations that had a 

flock health management program designed specifically to control or prevent OPP.

J.4.b. For operations that were very familiar, somewhat familiar, or had heard of OPP, 

percentage of operations that had a flock-health management program designed 

specifically to control or prevent OPP, by study: 

Study Percent operations Std. error

Sheep 2001 16.7 (2.3)

Sheep 2011 16.2 (2.0)

J.4.c. For operations that had a flock health management program designed specifically 

to control or prevent OPP, percentage of operations by method used to control or prevent 

OPP:

Percent Operations 

Sheep 2001 Sheep 2011

Method Percent Std. error Percent Std. error

Removed all seropositive sheep and 

lambs from flock (sold and/or isolated 

in separate facilities)

36.4 (6.7) 52.6 (6.8)

Kept flock isolated from 

infected sheep or goats 62.8 (6.0) 55.8 (6.7)

Added only seronegative 

sheep to flock 36.3 (6.8) 42.3 (8.3)

Added only sheep from 

OPP-seronegative flocks* NA 42.7 (8.2)

Tested goats (if present) for caprine 

arthritis encephalitis (CAE) 4.9 (3.0) 21.9 (9.7)

Other method 41.9 (6.2) 25.9 (5.6)

*Category not included in the Sheep 2001 questionnaire.
USDA APHIS VS / 119 

Section II: Population Estimates–J. Disease Control, Illness, and Death

The percentage of operations infected with OPP increased from 2001 to 2011. However, 

the percentage of operations that did not know the current OPP status of their flock 

decreased from 2001 to 2011.

 J.4.d. Percentage of operations by current OPP status of flock and by study:

Percent Operations 

Sheep 2001 Sheep 2011

Flock status Percent Std. error Percent Std. error

Currently infected with OPP 1.2 (0.3) 5.4 (1.0)

Previously infected with OPP 

but now negative 1.6 (0.6) 3.3 (0.9)

Never infected with OPP 10.9 (1.8) 18.7 (2.4)

Do not know current OPP status 86.3 (1.9) 72.7 (2.6)

Total 100.0 100.0

5. Toxoplasmosis and Q fever

A higher percentage of operations were very or somewhat familiar with toxoplasmosis 

and Q fever in 2011 than in 2001. 

J.5. Percentage of operations by level of familiarity with toxoplasmosis and Q fever, and 

by study:

Percent Operations 

Disease

Toxoplasmosis Q fever

Sheep 2001 Sheep 2011 Sheep 2001 Sheep 2011

Level of familiarity Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Very familiar 9.7 (1.4) 15.1 (1.6) 2.6 (0.7) 4.0 (0.9)

Somewhat familiar 25.4 (2.2) 30.9 (1.9) 6.0 (1.2) 13.2 (1.4)

Heard of name only 22.6 (2.1) 25.5 (1.9) 15.0 (1.7) 30.8 (2.0)

Never heard of 42.3 (2.3) 28.5 (2.0) 76.4 (2.1) 52.0 (2.2)

Total 100.0 100.0 100.0 100.0
120 / Sheep 2011

Section II: Population Estimates–J. Disease Control, Illness, and Death

6. Diseases present in the last 3 years

The percentage of suspected scrapie cases did not change from 1996 to 2011. However, 

the percentage of those suspected cases that were diagnosed by a veterinarian or 

laboratory more than doubled during the same time period, which might reflect increased 

scrapie eradication efforts. For all other diseases listed, the percentage of suspect cases 

diagnosed by a veterinarian or laboratory either remained the same or declined. 

J.6. Percentage of operations in which the following diseases were suspected during 

the last 3 years, and percentage of operations in which the following diseases were 

diagnosed by a veterinarian or lab, by study:

Percent Operations 

Suspected

Suspected cases 

diagnosed by a 

veterinarian or laboratory 

Sheep 

19961

Sheep 

2001

Sheep 

2011

Sheep 

2001

Sheep 

2011

Disease Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Johne’s 

(paratuberculosis) 0.8 (0.1) 1.6 (0.5) 2.5 (0.6) 33.3 (14.9) 40.8 (12.7)

Scrapie 1.2 (0.2) 1.2 (0.4) 1.7 (0.6) 26.7 (12.0) 70.4 (19.6)

Ovine progressive 

pneumonia (OPP) 5.1 (0.4) 7.1 (1.2) 8.2 (0.9) 21.7 (7.9) 24.6 (4.6)

Footrot 28.1 (1.0) 34.9 (2.2) 37.3 (2.1) 15.2 (2.8) 8.4 (1.9)

Caseous 

lymphadenitis 

(lumpy jaw)

13.8 (0.7) 20.4 (1.9) 24.5 (1.9) 24.9 (5.2) 24.1 (3.8)

Enterotoxemia/

overeating disease 

(clostridium C&D) 

(not grain overload)2

NA 38.8 (2.3) 35.0 (1.9) 30.9 (3.4) 19.7 (2.7)

Other clostridial 

diseases (e.g., 

blackleg, malignant 

edema, braxy, 

tetanus, botulism, 

big head)

9.8 (0.6) 11.9 (1.4) 10.4 (1.2) 17.3 (3.5) 17.7 (4.2)

Coccidiosis 18.2 (0.8) 30.4 (2.3) 34.0 (2.0) 50.0 (4.7) 37.0 (3.5)

Sore mouth 

(contagious 

ecthyma, orf)

20.6 (0.8) 40.0 (2.3) 43.7 (2.1) 17.9 (2.8) 12.2 (2.1)

Ring worm or club 

lamb fungus2 NA 7.3 (1.2) 8.9 (1.3) 22.5 (6.0) 18.8 (6.5)

Bluetongue 2.6 (0.3) 4.2 (1.0) 3.6 (0.7) 37.2 (12.3) 19.6 (9.5)

1

The Sheep 1996 study asked about disease presence in the previous 5 years.

2

These categories were not specifically identified in the Sheep 1996 study.
USDA APHIS VS / 121 

Section II: Population Estimates–J. Disease Control, Illness, and Death

7. Vaccination practices

Because they can reduce the prevalence or severity of disease, vaccines are an integral 

part of any flock management program. Whether an operation should use particular 

vaccines, however, depends on whether the flock is open or closed, the geographic 

region of the country, sheep diet, soil type, age of the sheep, and previous disease 

problems. The percentage of operations that vaccinated nursing lambs for sore mouth 

decreased from 2001 to 2011; there were no substantial differences from 2001 to 2011 in 

the percentages of operations that vaccinated nursing lambs for the other listed diseases. 

J.7.a. Percentage of operations that vaccinated nursing lambs, weaned feeder lambs, 

and/or breeding rams against the following diseases, by vaccine type and by study:

Percent Operations 

Animal Type

Nursing lambs

Weaned feeder 

(market) lambs Breeding rams

Sheep 

2001

Sheep 

2011

Sheep 

2001

Sheep 

2011

Sheep 

2001

Sheep 

2011

Vaccine type Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Clostridial

7- or 8-way (e.g., 

blackleg, malignant 

edema)

15.3 (1.5) 19.2 (1.7) 9.6 (1.3) 12.7 (1.5) 16.8 (1.8) 14.8 (1.5)

Enterotoxemia, 

overeating 66.9 (2.3) 60.5 (2.1) 44.8 (2.6) 39.8 (2.2) 36.0 (2.4) 28.8 (1.9)

Tetanus 55.1 (2.4) 55.0 (2.1) 28.9 (2.5) 32.9 (2.1) 30.7 (2.4) 25.3 (1.9)

Respiratory

Pneumonia 

(Pasteurella/

Mannheimia)

1.8 (0.6) 0.8 (0.3) 0.6 (0.3) 1.4 (0.6) 0.5 (0.2)

Digestive

Scours (E. coli) 2.9 (0.9) 0.3 (0.2) 1.1 (0.4) 0.8 (0.4) 1.4 (0.7)

Reproductive

Ram epididymitis 

bacterin (Brucella) 1.0 (0.5) 0.0 (0.0)

Other

Footrot 2.3 (0.7) 0.3 (0.2) 0.8 (0.3) 0.1 (0.1) 5.7 (1.0) 2.0 (0.6)

Lumpy jaw 

(caseous 

lymphadenitis)

1.2 (0.5) 1.5 (0.6) 0.8 (0.4) 2.4 (0.7) 2.5 (0.7)

Rabies 0.1 (0.1) 0.0 (—) 0.1 (0.1) 0.1 (0.1) 1.1 (0.5)

Sore mouth 

(contagious 

ecthyma)

14.0 (1.4) 8.1 (1.0) 4.9 (1.0) 2.7 (0.7) 4.2 (0.9) 0.9 (0.4)
122 / Sheep 2011

Section II: Population Estimates–J. Disease Control, Illness, and Death

The percentage of operations that vaccinated any sheep for enterotoxemia increased 

from 1996 to 2011, while the percentage of opertions by vaccination practices for the 

other listed diseases remained about the same.

J.7.b. Percentage of operations that vaccinated ewes, weaned replacement lambs, 

replacement or breeding ewes, and/or any sheep against the following diseases during 

the previous year, by vaccine type and by study:

Percent Operations 

Animal Type

Ewes

Replacement 

or breeding 

ewes

Any sheep

Sheep 

2011

Sheep 

2001

Sheep 

1996

Sheep 

2001

Sheep 

2011

Vaccine type Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Clostridial

7- or 8-way (e.g., 

blackleg, malignant 

edema)

20.5 (1.7) 20.9 (1.8) 25.2 (1.0) 25.0 (1.9) 29.5 (1.9)

Enterotoxemia, 

overeating 38.8 (2.1) 48.4 (2.4) 58.7 (1.2) 76.7 (2.0) 71.4 (2.0)

Tetanus 34.0 (2.0) 37.5 (2.4) 56.7 (1.1) 62.8 (2.2) 64.5 (2.1)

Respiratory

Pneumonia 

(Pasteurella/

Mannheimia)

1.5 (0.5) 1.7 (0.6) 2.3 (0.6) 2.1 (0.5)

Digestive

Scours (E. coli) 0.3 (0.2) 2.1 (0.6) 8.8 (0.7) 4.1 (0.9) 0.9 (0.4)

Other

Footrot 3.4 (0.8) 7.1 (1.2) 17.0 (0.8) 7.8 (1.2) 3.5 (0.8)

Lumpy jaw (caseous 

lymphadenitis) 2.4 (0.7) 3.1 (0.9) 2.5 (0.3) 3.2 (1.0) 3.4 (0.8)

Rabies 1.1 (0.5) 0.1 (0.1) 0.2 (0.1) 1.2 (0.5)

Sore mouth 

(contagious 

ecthyma)

1.5 (0.6) 5.1 (0.8) 14.8 (0.8) 15.0 (1.4) 11.0 (1.2)

EAE (Chlamydiophila 

abortus) 7.6 (1.1) 7.6 (1.4) 6.7 (0.5) 7.7 (1.4) 8.1 (1.1)

Leptospirosis 4.1 (0.9) 7.7 (1.4) 7.9 (1.4)

Campylobacter fetus/

jejuni (vibrio) 14.6 (1.4) 15.5 (1.7) 12.3 (0.7) 15.6 (1.7) 15.2 (1.4)
USDA APHIS VS / 123 

Section II: Population Estimates–K. Parasites and Dewormers

1. External parasites

External parasites live on or within the skin of their hosts, are usually more problematic 

in the winter due to closer living conditions, and may cause financial loss and animal 

welfare concerns. External parasites on sheep include ticks, keds, fly larvae, and mites. 

Topical treatments are usually more effective and easier to apply on shorn animals and 

often include the use of pesticides or anthelmintics.

There was no difference from 2001 to 2011 in the percentage of operations that treated 

sheep for external parasites. 

K.1. Percentage of operations that treated any sheep for external parasites (keds, ticks, 

lice, etc.) during the previous year, by study and by primary flock type:

Percent Operations 

Primary Flock Type

Herded/ 

open range

Fenced 

range

Farm/ 

pasture

All 

operations

Study Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Sheep 2001 77.6 (6.2) 37.8 (3.3) 36.5 (1.7) 37.4 (1.5)

Sheep 2011 69.0 (5.5) 38.3 (2.1) 40.9 (1.5) 40.7 (1.1)

2. Internal parasites

A similar percentage of operations performed fecal testing for intestinal parasites in 2001 

and 2011. 

K.2. Percentage of operations that performed fecal testing for intestinal parasites during 

the previous year, by study and by region:

Percent Operations 

Region

West Central East All operations

Study Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Sheep 2001 12.1 (2.8) 15.8 (2.7) 17.4 (2.8) 16.1 (1.8)

Sheep 2011 17.3 (4.0) 9.9 (1.8) 19.8 (2.5) 16.0 (1.5)

K. Parasites and 

Dewormers
124 / Sheep 2011

Section II: Population Estimates–K. Parasites and Dewormers

3. Dewormers

There was no difference in the percentage of operations by frequency dewormers were 

used in sheep feed from 2001 to 2011. Low-level continuous feeding of dewormers 

encourages the development of resistant parasites. A small percentage of operations 

always used dewormers in sheep feed.

K.3.a. Percentage of operations by frequency dewormers were used in sheep feed for 

stomach or intestinal worms (not including coccidia) during the previous year, and by 

study:

Percent Operations 

Sheep 2001 Sheep 2011

Frequency Percent Std. error Percent Std. error

Always 3.9 (1.0) 4.3 (0.9)

Sometimes 7.9 (1.5) 8.1 (1.2)

Never 88.2 (1.7) 87.6 (1.4)

Total 100.0 100.0

In 2001 and 2011, a lower percentage of operations in the Central region used a 

dewormer either orally (not in feed) or by injection compared with operations in the other 

regions. Overall, from 2001 to 2011 a similar percentage of operations used a dewormer 

that was not in feed.

K.3.b. Percentage of operations that used a dewormer given orally (not in feed) or by 

injection during the previous year, by study and by region:

Percent Operations 

Region

West Central East All operations

Study Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Sheep 2001 94.1 (3.2) 86.4 (2.5) 94.8 (1.8) 91.5 (1.4)

Sheep 2011 90.8 (3.0) 78.4 (2.7) 96.2 (1.3) 89.2 (1.3)
USDA APHIS VS / 125 

Section II: Population Estimates–K. Parasites and Dewormers

The percentage of operations that used a dewormer in ewes and lambs because the 

animals were thin or doing poorly increased from 2001 to 2011. 

K.3.c. Percentage of operations that used a dewormer given either orally (not in feed) 

or by injection to ewes and lambs during the previous year, by reason for administering 

dewormer and by study:

Percent Operations 

Dewormer Used in. . . .

Ewes Lambs

Sheep 2001 Sheep 2011 Sheep 2001 Sheep 2011

Reason Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

General preventive 

measure 96.8 (0.5) 87.3 (1.6) 84.6 (1.7) 78.8 (2.0)

Because worms 

were seen

16.9 (1.7) 21.3 (2.0) 19.3 (2.0) 23.9 (2.1)

Fecal test results 

indicated a need 10.3 (1.5) 11.0 (1.3) 10.5 (1.6) 11.5 (1.5)

Because sheep or 

lambs were thin or 

doing poorly

31.8 (2.3) 48.0 (2.3) 27.8 (2.1) 44.0 (2.4)

Bottlejaw, scours, 

and other clinical 

signs*

38.9 (2.2) 33.6 (2.3)

Other 3.4 (0.8) 2.0 (0.6) 3.4 (0.8) 2.2 (0.7)

*Not an option on the Sheep 2001 questionnaire.
126 / Sheep 2011

Section II: Population Estimates–K. Parasites and Dewormers

The percentage of operations that used moxidectin products increased from 2.5 percent 

in 2001 to 32.9 percent in 2011. 

K.3.d. For operations that used dewormers, percentage of operations by type of 

dewormers used and by study:

Percent Operations 

Sheep 2001 Sheep 2011

Dewormer Percent Std. error Percent Std. error

Ivomec®-ivermectin or 

Dectomax® (doramactin) 70.8 (2.2) 69.0 (2.1)

Cydectin®/Quest® (moxidectin) 2.5 (0.9) 32.9 (2.1)

Valbazen® (albendazole), Synanthic® 

(oxfendazole), or Benzimidazole 61.5 (2.5) 69.1 (2.1)

Rumatel® (morantel) or 

Strongid® (pyrantel) 0.5 (0.4) 1.6 (0.6)

Levasole®/Tramisol® (levamisole) 30.8 (2.2) 20.3 (1.8)
USDA APHIS VS / 127 

Section II: Population Estimates–L. Shearing Practices

Changes in the sheep industry in the late 1900s included reduced wool marketing 

entities and related infrastructure, which resulted in difficult marketing schemes with 

fewer domestic wool buyers, distance-to-market challenges, and fewer selling systems. A 

worldwide shortage of shearers magnified problems for sheep producers and limited their 

ability to increase sheep numbers. A combination of low wool prices and the difficulty of 

finding shearers have sometimes made producing wool a liability. Possibly in response 

to this situation, producers have focused on raising hair sheep (table A.1.a), which do not 

need to be sheared. 

1. Shearing management

The wool issues discussed above are reflected in the lower percentage of operations 

that sheared sheep and lambs in 2011 than in 2001 (80.2 and 90.4 percent of operations, 

respectively).

L.1.a. Percentage of operations that sheared sheep and lambs during the previous year, 

by study and by primary flock type:

Percent Operations 

Primary Flock Type

Herded/

open range

Fenced 

range

Farm/

pasture

All 

operations

Study Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Sheep 2001 93.4 (5.5) 85.4 (3.9) 91.2 (1.2) 90.4 (1.1)

Sheep 2011 89.8 (4.4) 73.8 (2.1) 82.0 (1.2) 80.2 (0.9)

L. Shearing 

Practices
128 / Sheep 2011

Section II: Population Estimates–L. Shearing Practices

While a lower percentage of operations in 2011 used a hired individual to shear sheep 

compared with operations in 2001 (50.9 and 65.3 percent, respectively), hiring individual 

shearers is still the most common method for shearing sheep. A higher percentage 

of operations in 2011 used contracted shearing crews to shear sheep compared with 

operations in 2001.

L.1.b. For operations that sheared sheep or lambs during the previous year, percentage 

of operations by type of shearer and by study:

Percent Operations 

Sheep 2001 Sheep 2011

Shearer Percent Std. error Percent Std. error

Employees (including owner) 21.2 (1.4) 26.2 (1.2)

Contracted shearing crew 15.1 (0.9) 29.2 (1.0)

Hired individual 65.3 (1.6) 50.9 (1.3)

Other 3.2 (0.7) 1.7 (0.4)
USDA APHIS VS / 129 

Section II: Population Estimates–L. Shearing Practices

Disinfecting shears between individual sheep can reduce the likelihood of transmitting 

disease from one sheep to another. One disease in particular (caseous lymphadentitis) is 

likely to be transmitted from sheep to sheep when skin is broken or cut by contaminated 

shearing equipment. Shears should always be disinfected between flocks and, ideally, 

should be disinfected between each individual sheep sheared. From 2001 to 2011, 

no change occurred in the percentage of operations that disinfected shears between 

individual sheep. 

L.1.c. For operations that sheared sheep or lambs during the previous year, percentage 

of operations by frequency shears were disinfected between individual sheep, and by 

study:

Percent Operations 

Sheep 2001 Sheep 2011

Frequency Percent Std. error Percent Std. error

Always 5.2 (0.8) 8.4 (0.8)

Sometimes 11.5 (1.1) 15.3 (1.0)

Never 59.7 (1.7) 54.0 (1.3)

Don’t Know 23.6 (1.5) 22.2 (1.1)

Total 100.0 100.0
130 / Sheep 2011

Section II: Population Estimates–L. Shearing Practices

Shearing sheep in order from the youngest to the oldest is one method of reducing the 

risk of transmitting disease between sheep. There was no difference in shearing order 

from 2001 to 2011.

L.1.d. For operations that sheared sheep or lambs during the previous year, percentage 

of operations by shearing practice and by study:

Percent Operations 

Sheep 2001 Sheep 2011

Shearing practice Percent Std. error Percent Std. error

From youngest to oldest 2.3 (1.4) 3.8 (0.5)

From oldest to youngest 4.1 (0.9) 4.5 (0.5)

In no particular order 93.1 (1.6) 91.6 (0.7)

Based on time on feed 0.5 (0.7) NA

Total 100.0 100.0
USDA APHIS VS / 131 

Section II: Population Estimates–L. Shearing Practices

2. Wool management and marketing

Wool is easily stored, so some operations bag and store their wool until market conditions 

improve. Some operations—especially smaller ones—have developed niche markets and 

sell their wool to hand spinners and weavers. 

The percentage of operations that stored wool in bags increased from 38.4 percent 

of operations in 2001 to 48.8 percent in 2011. Nearly three times the percentage of 

operations had their wool analyzed by a laboratory in 2011 than in 2001 (11.3 and 

3.8 percent, respectively). A lower percentage of operations gave wool away in 2011 than 

in 2001.

L.2.a. For operations that sheared lambs or sheep during the previous year, percentage 

of operations by wool management method used and by study:

Percent Operations 

Sheep 2001 Sheep 2011

Wool management method Percent Std. error Percent Std. error

Analyzed by a laboratory 3.8 (0.4) 11.3 (0.6)

Sold on a clean basis 10.8 (1.0) 14.6 (0.8)

Sold on a greasy basis 44.2 (1.6) 61.5 (1.3)

Given away 19.9 (1.5) 14.4 (1.0)

Spun (on this operation 

or elsewhere) 7.9 (1.0) 9.0 (0.8)

Used for animal bedding 2.3 (0.5) 3.3 (0.5)

Used for mulch 3.8 (0.7) 5.8 (0.6)

Used for insulation 1.1 (0.4) 3.2 (0.5)

Stored in bags 38.4 (1.6) 48.8 (1.3)

Thrown away 21.6 (1.5) 18.9 (1.0)

Other 4.4 (0.7) 3.3 (0.5)
132 / Sheep 2011

Section II: Population Estimates–L. Shearing Practices

The primary methods for marketing wool were similar in 2001 and 2011.

L.2.b. For operations that sold any wool during the previous year, percentage of 

operations by primary method used to market wool and by study:

Percent Operations 

Sheep 2001 Sheep 2011

Primary wool 

marketing method Percent Std. error Percent Std. error

Cooperative pools 28.3 (1.9) 33.8 (1.4)

Direct sales 43.6 (2.1) 40.0 (1.4)

Warehouses 21.1 (1.6) 22.7 (1.1)

Other 7.0 (1.2) 3.5 (0.6)
USDA APHIS VS / 133 

Section II: Population Estimates–M. Pasture Management, Water Sources, and Feeding Practices

1. Grazing

The Bureau of Land Management and the U.S. Forest Service manage grazing on public 

lands with the objective of maximizing public land health and productivity. Public land 

grazing permits and leases are given to livestock owners for a fee once they meet certain 

requirements. A higher percentage of operations in 2011 grazed sheep on public land and 

on crop residue compared with operations in 2001. 

M.1. Percentage of operations by type of land used for grazing and by study:

Percent Operations

Sheep 2001 Sheep 2011

Land type Percent Std. error Percent Std. error

Public land 2.0 (0.2) 3.9 (0.3)

Grazing association land 0.4 (0.1) 0.8 (0.1)

Leased, private land 32.0 (1.5) 26.3 (1.0)

Harvested fields for grazing/

crop residue or byproducts 8.1 (0.7) 21.1 (0.9)

2. Pasture management

The percentage of operations that alternated sheep grazing and crop or hay production 

increased from 2001 to 2011; other methods of pasturing did not change.

M.2.a. Percentage of operations that grazed sheep on pasture, by pasturing method used 

during the previous year, and by study:

Percent Operations 

Sheep 2001 Sheep 2011

Pasturing method Percent Std. error Percent Std. error

Alternated grazing sheep and other 

domestic species, such as cattle or 

horses

28.0 (2.1) 28.4 (1.9)

Commingled cattle or horses 

with ewe/lamb pairs 28.6 (2.1) 28.0 (1.8)

Alternated grazing sheep and 

crop or hay production 31.7 (2.1) 43.6 (2.1)

M. Pasture 

Management, 

Water Sources, 

and Feeding 

Practices
134 / Sheep 2011

Section II: Population Estimates–M. Pasture Management, Water Sources, and Feeding Practices

M.2.b. Percentage of operations that used pasture rotation during the previous year, by 

study:

Percent Operations 

Sheep 2001 Sheep 2011

Percent Std. error Percent Std. error

67.8 (2.4) 69.8 (2.0)

M.2.c. For operations that used pasture rotation, percentage of operations by length of 

time (in days) pasture was allowed to rest between sheep grazing, and by study:

Percent Operations 

Sheep 2001 Sheep 2011

Days pasture rested Percent Std. error Percent Std. error

0–21 31.4 (2.7) 34.8 (2.5)

22–63 53.6 (2.9) 55.2 (2.6)

64 or more 15.0 (1.8) 10.0 (1.4)

M.2.d. Percentage of operations that placed harvested or commercial feed directly on the 

ground for sheep to eat during the previous year:

Percent Operations 

Sheep 2001 Sheep 2011

Percent Std. error Percent Std. error

55.5 (2.4) 51.4 (2.2)
USDA APHIS VS / 135 

Section II: Population Estimates–M. Pasture Management, Water Sources, and Feeding Practices

3. Water sources

The percentage of operations that used a bucket with a rim less than 2 feet off the ground 

to water their sheep decreased from 2001 to 2011, but the use of a bucket with a rim 

2 feet or more off the ground increased during the same period in winter and summer.

M.3.a. Percentage of operations in which the flock typically had access to the following 

water sources during winter and summer, by study:

Percent Operations 

Sheep 2001 Sheep 2011

Water source Percent Std. error Percent Std. error

Winter

Pond/lake/reservoir 

(or other standing water) 17.5 (1.5) 23.4 (1.8)

Stream (or other running water) 26.9 (2.0) 28.7 (1.9)

Bucket, trough, or waterer where rim 

was less than 2 ft off the ground 86.5 (1.4) 76.1 (1.8)

Bucket, trough, or waterer where rim 

was 2 ft or more off the ground 18.6 (1.8) 38.0 (2.1)

Other 6.2 (0.9) 4.2 (0.7)

Summer

Pond/lake/reservoir 

(or other standing water) 33.6 (2.2) 38.1 (2.0)

Stream (or other running water) 41.5 (2.3) 40.8 (2.1)

Bucket, trough, or waterer where rim 

was less than 2 ft off the ground 80.1 (1.7) 72.6 (1.9)

Bucket, trough, or waterer where rim 

was 2 ft or more off the ground 17.5 (1.8) 35.1 (2.1)

Other 5.1 (1.1) 1.2 (0.5)
136 / Sheep 2011

Section II: Population Estimates–M. Pasture Management, Water Sources, and Feeding Practices

The percentage of operations in which the primary water source for sheep was a 

bucket with a rim less than 2 feet off the ground decreased from 2001 to 2011, but the 

percentage of operations in which the primary water source was a bucket with a rim 

2 feet or more off the ground increased during the same period in winter and summer.

M.3.b. Percentage of operations by primary water source during winter and summer:

Percent Operations 

Sheep 2001 Sheep 2011

Primary water source Percent Std. error Percent Std. error

Winter

Pond/lake/reservoir 

(or other standing water) 3.9 (0.8) 3.1 (0.8)

Stream (or other running water) 8.5 (1.1) 8.8 (1.2)

Bucket, trough, or waterer where rim 

was less than 2 ft off the ground 70.2 (2.0) 55.8 (2.1)

Bucket, trough, or waterer where rim 

was 2 ft or more off the ground 10.3 (1.3) 22.6 (1.8)

Multiple water sources used equally 3.6 (0.7) 5.8 (1.0)

Other 3.5 (0.7) 4.0 (0.7)

Total 100.0 100.0

Summer

Pond/lake/reservoir 

(or other standing water) 10.2 (1.2) 8.9 (1.1)

Stream (or other running water) 17.5 (1.7) 13.9 (1.4)

Bucket, trough, or waterer where rim 

was less than 2 ft off the ground 56.1 (2.3) 48.5 (2.1)

Bucket, trough, or waterer where rim 

was 2 ft or more off the ground 7.6 (1.2) 19.4 (1.7)

Multiple water sources used equally 7.2 (1.3) 7.9 (1.1)

Other 1.4 (0.6) 1.4 (0.5)

Total 100.0 100.0
USDA APHIS VS / 137 

Appendix I: Breed Categories

Breed categories Breed examples

Black-faced wool breeds Suffolk, Hampshire, Oxford, Clun Forest, Scottish 

Blackfaced, Shropshire

White-faced fine wool American Cormo, Booroola Merino, Debouillet, 

Rambouillet, Delaine Merino, 

White-faced medium wool

Cheviot, Columbia, Corriedale, Finnsheep, 

Montadale, North Country Cheviot, Panama, 

Southdown, Targhee

Long wool Border Leicester, Coopworth, Cotswold, 

Lincoln,Romney, Wensleydale

Colored wool Black Welsh Mountain, California Red, Icelandic, 

Jacob, Navajo-Churro, Shetland

Hair Barbados Blackbelly, Dorper, Katahdin, St. Croix, 

Milk East Friesian, Rideau Arcott, Lacaune

Appendix I: Breed Categories
138 / Sheep 2011

Appendix II: Sample Profile

1. Number of responding operations by region:

Region Number operations

East North Central 844

East South Central 139

Mountain 862

Northeast 510

Southeast 328

West Coast 597

West North Central 1,440

West South Central 454

Total 5,174

2. Number of responding operations by number of ewes present on January 1, 

1996:

Number Operations

Region*

Number 

ewes

West 

Coast

Mountain

West 

North 

Central

West 

South 

Central

East 

North 

Central

East 

South 

Central

NortheastSoutheast

0 120 139 335 111 176 26 99 66

1–49 241 244 512 77 440 75 302 159

50–99 84 92 271 51 145 18 58 69

100–499 99 193 269 94 77 19 46 30

500 or more 47 191 38 119 5 0 4 1

Total 597 862 1,440 454 844 139 510 328

Regions:

West Coast: California, Oregon, Washington

Mountain: Arizona, Colorado, Idaho, Montana, Nevada, New Mexico, Utah, Wyoming

West North Central: Iowa, Kansas, Minnesota, Missouri, Nebraska, North Dakota, South Dakota

West South Central: Oklahoma, Texas

East North Central: Illinois, Indiana, Michigan, Ohio, Wisconsin

East South Central: Alabama, Arkansas, Kentucky, Louisiana, Mississippi, Tennessee

Northeast: Connecticut, Delaware, Maine, Massachusetts, New Hampshire, New Jersey, New York, 

Pennsylvania, Rhode Island, Vermont

Southeast: Florida, Georgia, Maryland, North Carolina, South Carolina, Virginia, West Virginia

Appendix II: Sample Profile

A. Responding 

Operations―

Sheep 1996
USDA APHIS VS / 139 

Appendix II: Sample Profile

3. Number of responding operations by total sheep inventory present on January 

1, 1996:

Number Operations

Region

Number 

sheep

West 

Coast

Mountain

West 

North 

Central

West 

South 

Central

East 

North 

Central

East 

South 

Central

NortheastSoutheast

Fewer 

than 50 337 340 725 173 545 88 369 199

50–99 78 95 267 25 157 27 69 70

100–499 122 212 354 108 128 24 64 50

500–999 22 63 53 63 10 0 6 5

1,000 or 

more

38 152 41 85 4 0 2 2

Not reported 0 0 0 0 0 0 0 2

Total 597 862 1,440 454 844 139 510 328
140 / Sheep 2011

Appendix II: Sample Profile

1. Number of responding operations by flock size

Phase I: general 

sheep management 

report

Phase II: VMO 

initial visit

Flock size 

(number of sheep)

Number of 

responding 

operations

Flock size 

(number of ewes)

Number of 

responding 

operations

1–24 448 Fewer than 100 536

25–99 956 100–499 368

100–999 1,370 500 or more 197

1,000 or more 436 Total 1,101

Total 3,210

2. Number of responding operations by region

Number Operations

Region

Phase I: general sheep 

management report Phase II: VMO initial visit

Pacific 416 168

West Central 1,335 436

Central 1,048 340

Eastern 411 157

Total 3,210 1,101

B. Responding 

Operations―

Sheep 2001
USDA APHIS VS / 141 

Appendix II: Sample Profile

1. Number of responding operations by herd size

Phase Ia: general 

sheep management questionnaire—fewer than 

19 ewes

Phase Ib: general 

sheep management questionnaire —20 or 

more ewes

Phase II: VS 

initial visit questionnaire

Herd size 

(number of ewes) Number of responding operations

1 to 19 887

20 to 99 1,049 343

100 to 499 859 287

500 or more 461 131

Total 887 2,369 761

2. Number of responding operations by region

Phase Ia: general 

sheep management 

questionnaire—

1 to 19 ewes

Phase Ib: general 

sheep management 

questionnaire—

20 or more ewes

Phase II: VS initial 

visit questionnaire

Region Number of responding operations

West 175 325 116

Central 348 1,208 349

East 364 836 296

Total 887 2,369 761

C. Responding 

Operations―

Sheep 2011
142 / Sheep 2011

Appendix III: Response Rates

1. Phase I

Response category Number operations Percent operations

No sheep on January 1, 2001 468 9.2

Out of business* 159 3.1

Refusal 870 17.1

Survey complete and 

VMO consent 1,775 34.9

Survey complete, 

refused VMO consent 993 19.6

Survey complete, 

ineligible for VMO 442 8.7

Out of scope 

(prison, research farm, etc.) 51 1.0

Inaccessible 322 6.4

Total 5,080 100.0

*Operations that sold land and/or sheep and had no intention of returning to sheep business.

2. Phase II—20 or more ewes

Response category Number operations Percent operations

Survey completed 1,101 62.0

Producer not contacted 149 8.3

Poor time of year or no time 189 11.0

Did not want

anyone on operation 6 0.3

Bad experience with

government veterinarians 7 0.3

Did not want to do another

survey or divulge information 131 7.4

Told NASS they did not

want to be contacted 7 0.3

Ineligible (no sheep) 32 1.8

Other reason 40 2.2

Unable to contact 113 6.4

Total 1,775 100.0

A. Sheep 2001

Appendix III: Response Rates
USDA APHIS VS / 143 

Appendix III: Response Rates

1. Phase Ia: general sheep management questionnaire—fewer than 20 ewes 

A total of 1,381 operations were selected for the survey. Of these operations, 64.2 completed the questionnaire.

Measurement Parameter

Response category

Number 

operations

Percent 

operations Contacts Usable1 Complete2

Refused GSM 

questionnaire/

inaccessible 

298 21.6 x3

Ineligible (no sheep or 

lambs on January 1, 

2011)

196 14.2 x x

Complete 887 64.2 x x x

Total 1,381 100.0 887 887

Percent of total 

operations 64.2 64.2

Percent of total 

operations weighted4 60.6 60.6

1

Useable operation—respondent provided answers to inventory questions for the operation (either zero or 

positive number on hand).

2

Survey complete operation—respondent provided answers to all or nearly all questions.

3

The number of operations that refused versus those that were not contacted was not tracked.

4

Weighted response—the rate was calculated using the initial selection weights.

B. Sheep 2011
144 / Sheep 2011

Appendix III: Response Rates

2. Phase Ib: general sheep management questionnaire—20 or more ewes 

A total of 3,539 operations were selected for the survey. Of these operations, 3,191 

(90.2 percent) were contacted. There were 2,661 operations that provided usable 

inventory information (75.2 percent of the total selected and 83.4 percent of those 

contacted). In addition, there were 2,369 operations (66.9 percent) that provided 

“complete” information for the questionnaire. 

Measurement Parameter

Response category

Number 

operations

Percent 

operations Contacts Usable1 Complete2

Zero sheep on 

January 1, 2011 211 5.9 x x

Out of business 81 2.3 x x

Refused GSMQ 530 15.0 x

Complete VMO 

consent signed 1,241 35.1 x x x

Complete VMO 

consent refused 1,025 29.0 x x x

Complete, ineligible 

for VMO 103 2.9 x x x

Out of scope 17 0.5

Office hold (NASS 

elected not to contact) 69 1.9

Inaccessible 262 7.4

Total 3,539 100.0 3,191 2,661 2,369

Percent of total 

operations 90.2 75.2 66.9

Percent of total 

operations weighted3 90.9 77.9 68.5

1

Useable operation—respondent provided answers to inventory questions for the operation (either zero or 

positive number on hand).

2

Survey complete operation—respondent provided answers to all or nearly all questions.

3

Weighted response—the rate was calculated using the initial selection weights.
USDA APHIS VS / 145 

Appendix III: Response Rates

3. Phase II: VS initial visit questionnaire

There were 1,241 operations that consented during Phase I to be contacted by a 

veterinary medical officer (VMO) for Phase II. Of these 1,241, 761 (61.4 percent) agreed 

to continue in Phase II of the study and completed the VMO initial visit questionnaire; 330 

(26.6 percent) refused to participate. Approximately 11.0 percent of the 1,241 operations 

were not contacted, and 1.0 percent were ineligible because they had no sheep at the 

time they were contacted by the VMO during Phase II of the study.

Measurement parameter

Response category

Number 

operations

Percent 

operations Contacts Usable1 Complete2

Survey complete 761 61.3 x x x

Survey refused 330 26.6 x

Not contacted 137 11.0

Ineligible3 13 1.0 x x

Total 1,241 100

Percent of total 

operations 89.0 62.4 61.4

Percent of total 

operations weighted4 88.1 59.6 58.4

1

Useable operation—respondent provided answers to inventory questions for the operation (either zero or 

positive number on hand).

2

Survey complete operation—respondent provided answers to all or nearly all questions.

3

Ineligible—no ewes at time of interview, which occurred from January 1 through February 11, 2011.

4

Weighted response—the rate was calculated using the initial selection weights.
146 / Sheep 2011

Appendix IV: U.S. Ewe Population and Farms

Appendix IV: U.S. Ewes Population and Farms

A. Number of 

Ewes―State, 

Region, and 

United States

Number of Ewes* Number of Farms*

Region State

Ewes on 

farms with 

1 or more 

head

Ewes on 

farms with 

20 or more 

head

Farms with 

20 or more 

head pct. 

of total

Farms with 

1 or more 

head

Farms with 

20 or more 

head

Farms with 

20 or more 

head pct. of 

total

West CA 286,544 269,021 93.9 3,413 946 27.7

OR 119,356 104,842 87.8 2,802 804 28.7

WA 35,138 (D) 1,977 367 18.6

 Total 441,038 (D) 8,192 2,117 25.8

Central CO 200,269 194,698 97.2 1,265 493 39.0

ID 161,935 (D) 1,047 367 35.1

KS 52,614 48,143 91.5 1,011 450 44.5

MT 184,087 (D) 1,375 859 62.5

NM 87,131 78,150 89.7 2,152 756 35.1

SD 210,005 (D) 1,580 1,231 77.9

TX 580,861 550,346 94.7 6,814 2,694 39.5

UT 210,388 203,621 96.8 1,430 514 35.9

WY 258,096 255,618 99.0 817 495 60.6

 Total 1,945,386 (D) 17,491 7,859 44.9

East IA 128,518 113,364 88.2 3,168 1,606 50.7

KY 22,225 15,880 71.5 1,171 309 26.4

MI 48,398 38,932 80.4 1,969 582 29.6

MN 85,049 75,343 88.6 2,225 1,038 46.7

MO 51,328 41,933 81.7 1,911 718 37.6

NY 42,321 35,260 83.3 1,523 497 32.6

OH 74,331 59,700 80.3 2,929 1,103 37.7

PA 62,828 46,728 74.4 3,067 837 27.3

VA 48,219 38,991 80.9 1,796 691 38.5

WI 56,172 44,057 78.4 2,413 780 32.3

 Total 619,389 510,188 82.4 22,172 8,161 36.8

Total (22 States) 3,005,813 (D) 47,855 18,137 37.9

Percent of U.S. 85.5 70.1 74.5

Total U.S. (50 States) 3,516,409 3,193,721 90.8 68,222 24,346 35.7

*Source: NASS 2007 Census of Agriculture.
USDA APHIS VS / 147 

Appendix IV: U.S. Ewe Population and Farms

Flock Size

1–19 20–99 100–499 500 or more

Region State Farms Head Farms Head Farms Head Farms Head

West CA 2,467 17,523 737 28,185 129 24,906 80 215,930

OR 1,998 14,514 633 24,712 133 27,549 38 52,581

WA 1,610 (D) 347 (D) 15 (D) 5 (D)

 Total 6,975 (D) 1,717 (D) 277 (D) 123 (D)

Central CO 772 5,571 347 14,083 88 18,594 58 162,021

ID 680 5,029 276 10,663 50 9,498 41 136,745

KS 561 4,471 353 14,825 76 (D) 21 (D)

MT 516 (D) 486 (D) 277 59,288 96 (D)

NM 1,396 8,981 674 23,660 52 (D) 30 (D)

SD 349 (D) 724 (D) 410 81,396 97 (D)

TX 4,120 30,515 1,762 73,910 666 137,602 266 338,834

UT 916 6,767 344 14,137 85 15,843 85 173,641

WY 322 2,478 298 13,032 96 21,418 101 221,168

 Total 9,632 (D) 5,264 (D) 1,800 368,680 795 1,284,513

East IA 1,562 15,154 1,357 55,777 236 40,053 13 17,534

KY 862 6,345 277 9,786 30 (D) 2 (D)

MI 1,387 9,466 504 20,852 71 12,595 7 5,485

MN 1,187 9,706 848 33,723 177 32,280 13 9,340

MO 1,193 9,395 626 23,980 87 14,503 5 3,450

NY 1,026 7,061 418 16,213 74 15,064 5 3,983

OH 1,826 14,631 995 38,956 103 17,205 5 3,539

PA 2,230 16,100 740 28,103 90 13,962 7 4,663

VA 1,105 9,228 607 23,140 82 (D) 2 (D)

WI 1,633 12,115 682 26,719 97 (D) 1 (D)

 Total 14,011 109,201 7,054 277,249 1,047 (D) 60 (D)

Total (22 States) 29,718 (D) 14,035 (D) 3,124 604,820 978 1,613,763

Percent of U.S. 67.7 71.7 83.2 84.7 95.0 94.2

Total U.S. (50 

States) 43,876 322,688 19,563 767,044 3,753 714,448 1,030 1,712,229

*Source: NASS 2007 Census of Agriculture.

B. Ewes, Size 

Distribution―

State, Region, 

and United 

States*
148 / Sheep 2011

Appendix IV: U.S. Ewe Population and Farms

Flock Size

1–19 20–99 100–499 500 or more

Region State Farms Head Farms Head Farms Head Farms Head

West CA 2,467 17,523 737 28,185 129 24,906 80 215,930

OR 1,998 14,514 633 24,712 133 27,549 38 52,581

WA 1,610 (D) 347 (D) 15 (D) 5 (D)

 Total 6,975 (D) 1,717 (D) 277 (D) 123 (D)

Central CO 772 5,571 347 14,083 88 18,594 58 162,021

ID 680 5,029 276 10,663 50 9,498 41 136,745

KS 561 4,471 353 14,825 76 (D) 21 (D)

MT 516 (D) 486 (D) 277 59,288 96 (D)

NM 1,396 8,981 674 23,660 52 (D) 30 (D)

SD 349 (D) 724 (D) 410 81,396 97 (D)

TX 4,120 30,515 1,762 73,910 666 137,602 266 338,834

UT 916 6,767 344 14,137 85 15,843 85 173,641

WY 322 2,478 298 13,032 96 21,418 101 221,168

 Total 9,632 (D) 5,264 (D) 1,800 368,680 795 1,284,513

East IA 1,562 15,154 1,357 55,777 236 40,053 13 17,534

KY 862 6,345 277 9,786 30 (D) 2 (D)

MI 1,387 9,466 504 20,852 71 12,595 7 5,485

MN 1,187 9,706 848 33,723 177 32,280 13 9,340

MO 1,193 9,395 626 23,980 87 14,503 5 3,450

NY 1,026 7,061 418 16,213 74 15,064 5 3,983

OH 1,826 14,631 995 38,956 103 17,205 5 3,539

PA 2,230 16,100 740 28,103 90 13,962 7 4,663

VA 1,105 9,228 607 23,140 82 (D) 2 (D)

WI 1,633 12,115 682 26,719 97 (D) 1 (D)

 Total 14,011 109,201 7,054 277,249 1,047 (D) 60 (D)

Total (22 States) 29,718 (D) 14,035 (D) 3,124 604,820 978 1,613,763

Percent of U.S. 67.7 71.7 83.2 84.7 95.0 94.2

Total U.S. 

(50 States) 43,876 322,688 19,563 767,044 3,753 714,448 1,030 1,712,229

*Source: NASS 2007 Census of Agriculture.

C. U.S. Sheep 

and Lamb 

Population, 

January 1, 2011, 

Inventory
USDA APHIS VS / 149 

Appendix IV: U.S. Ewe Population and Farms

D. Breeding 

Sheep: Survey 

Percent by Size 

Group, United 

States 2008–09

1–99 Head 200–499 Head 500–4,999 Head 5,000+ Head

2008 2009 2008 2009 2008 2009 2008 2009

Operations 92.5 93.7 6.2 5.2 1.2 1.0 0.1 0.1

Inventory 32.6 36.2 22.7 20.8 30.2 31.3 14.5 11.7

Source: NASS “Farms, Land in Farms, and Livestock Operations, 2009 Summary,” February 2010.
150 / Sheep 2011

Appendix V: Study Objectives and Related Outputs

To develop the objectives for the NAHMS Sheep 2011 study, a needs assessment 

was conducted from December 2009 through February 2010 to determine the current 

issues facing the U.S. sheep industry. A total of 278 stakeholders completed the needs 

assessment questionnaire. In addition, an advisory group of producers, researchers, 

extension veterinarians, and clinicians helped develop the study objectives. 

Objectives for NAHMS Sheep 2011 study 

1. Describe trends in sheep health and management practices from 1996 to 2011.

•	 Part I: Reference of Sheep Management Practices in the United States, 2011, 

May 2012

•	 Part II: Reference of Sheep Marketing and Biosecurity Practices in the United 

States, 2011, December 2012

•	 Part III: Health and Management on U.S. Sheep Operations, 2011, September 

2013 

•	 Part IV: Trends in the U.S. Sheep Industry, 1996–2011, March 2014

•	 Vaccination Practices on U.S. Sheep Operations, 2011, info sheet, January 2014

•	 Sheep and Lamb Losses on U.S. Sheep Operations, 2011, info sheet, December 

2013

•	 Lambing Management on U.S. Sheep Operations, 2011, info sheet, January 

2014

2. Describe management and biosecurity practices used to control common infectious 

diseases, including scrapie, ovine progressive pneumonia, Johne’s disease, and caseous 

lymphadenitis. 

•	 Biosecurity Practices on U.S. Sheep Operations, 2011, info sheet, expected 2014

•	 Parasite Control on U.S. Sheep Operations, 2011, info sheet, expected 2014

•	 Producer Disease Awareness, 2011, info sheet, expected 2014

•	 Antimicrobial Drug Use on U.S. Sheep Operations, 2011, info sheet, expected 

2014

•	 Record-keeping Practices on U.S. Sheep Operations, October 2012

3. Estimate the prevalence of gastrointestinal parasites and anthelmintic resistance.

•	 Gastrointestinal Parasites and Anthelmintic Resistance, 2011, info sheet, 

expected 2014

Appendix V: Study Objectives and Related Outputs
USDA APHIS VS / 151 

Appendix V: Study Objectives and Related Outputs

4. Estimate the prevalence of Mycoplasma ovipneumonia in domestic sheep flocks. 

Relate presence of the organism in blood and nasal secretions to clinical signs and 

demographic and management factors. 

•	 Mycoplasma ovipneumonia in Domestic Sheep Flocks, 2011, info sheet, 

expected 2014

5. Facilitate the collection of information and samples regarding causes of abortion 

storms in sheep.

•	 Toxoplasmosis in Lambs in U.S. Sheep Flocks, 2011, info sheet, expected spring 

2014

•	 Q Fever in Sheep in the United States, 2011, info sheet, expected spring 2014

•	 Campylobacter on U.S. Sheep Operations, 2011, info sheet, expected spring 

2014

•	 Salmonella on U.S. Sheep Operations, 2011, info sheet, July 2013

6. Determine producer awareness of the zoonotic potential of contagious ecthyma (sore 

mouth) and the management practices used to prevent transmission of the disease.

•	 Sore Mouth on U.S. Sheep Operations, 2011, info sheet, expected spring 2014




Table of Contents

Sheep 2011 Part IV

Introduction 1

Terms Used in This Report 3

Section I: Historic Changes 5

A. General Trends 5

1. Sheep and lamb inventory 5

2. Number and size of operations with 

breeding sheep 11

3. Lamb crop 14

4. Wool production 15

5. Sheep and lamb slaughter 16

6. Value of production 19

B. Sheep Inventory by State 20

Section II: Population Estimates 23

A. Changes in Inventory 23

1. Breed categories 23

 2. Primary use 29

B. Flock Management 31

1. Operator experience 31

2. Inventory expectations in 5 years 34

 3. Sources of information on sheep health 36

4. Production records 38

5. Primary flock type 39

6. Animal identification 42

7. Rodent control 46

8. Housing 47

C. Breeding Management 49

1. Breeding practices 49

2. Breeding seasons 51

3. Ewe breeding 54

4. Ram and ewe lamb selection 55

 5. Outcome of ewes expected to lamb 59

D. Reproductive Outcomes 60

1. Lambs born 60

 2. Lambing locations 66

3. Lamb eeding supplements 68

4. Castration management 71

 5. Age and weight of weaned lambs 72

E. Marketing Practices 73

1. Operations that sold or moved lambs 73

 2. Type of marketing 77

 3. Cull rams and ewes 79

F. Lamb and Sheep Deaths and Losses 83

1. Lamb and sheep losses 83

2. Carcass-disposal methods 86

G. Lambs and Sheep on Feed 91

1. Lambs and sheep on a high-energy diet 91

 2. Weight of market lambs 92

H. Biosecurity Practices 93

1. Flock additions 93

 2. Contact with other sheep 97

3. Professional consultants 100

4. Manure management 103

I. Reproduction Management 104

1. Manure and waste bedding management 104

2. Placenta removal 105

3. Abortion and sick ewe management 107

4. Feeding practices 111

J. Disease Control, Illness, and Death 112

1. Johne’s disease 112

2. Weight loss despite normal appetite 113

3. Scrapie 114

4. Ovine progressive pneumonia 117

5. Toxoplasmosis and Q fever 119

6. Diseases present in the last 3 years 120

7. Vaccination practices 121

K. Parasites and Dewormers 123

1. External parasites 123

2. Internal parasites 123

3. Dewormers 124

L. Shearing Practices 127

1. Shearing management 127

2. Wool management and marketing 131

M. Pasture Management, Water Sources, and Feeding 

Practices 133

1. Grazing 133

2. Pasture management 133

3. Water sources 135

Appendix I: Breed Categories 137

Appendix II: Sample Profile 138

Appendix III: Response Rates 142

Appendix IV: U.S. Ewes Population and Farms 146

Appendix V: Study Objectives and Related Outputs 150