United States 

Department of 

Agriculture

Animal and 

Plant Health 

Inspection 

Service

Veterinary 

Services

National 

Animal Health 

Monitoring 

System

May 2012

Sheep 2011

Part I: Reference of Sheep Management 

Practices in the United States, 2011
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USDA:APHIS:VS, CEAH

NRRC Building B, M.S. 2E7

2150 Centre Avenue

Fort Collins, CO 80526–8117

970.494.7000

http://nahms.aphis.usda.gov

#601.0512

Cover photograph courtesy of Keith Weller, USDA Agricultural Research 

Service.
USDA APHIS VS / i 

The U.S. sheep industry is facing new challenges as demand for lamb and wool is at 

an all-time high. In 2011, a major grocery-store chain began promoting American Lamb 

products, and a major retailer committed to selling U.S.-grown lamb exclusively in its 

stores. Nontraditional market channels such as on-farm and farmer’s market sales and 

sales to small processors have also seen recent growth. 

Population estimates and operator experience

Sheep breeds in the United States can be categorized by purpose, fi ber type, and 

face color. Black- or nonwhite-faced breeds include Suffolk, Hampshire, Shropshire, 

Oxford, and Southdown. These breeds are often considered meat producers, while 

white-faced breeds are more often used for wool production. Because each sheep 

breed offers superiority in some trait, producers often blend the breeds to gain the 

superior characteristics of each breed in offspring. These offspring are used to attain the 

phenotypic requirements of their operation’s type and geographical conditions. While the 

highest percentage of operations (44.7 percent) had black-faced wool breeds, the highest 

percentage of sheep and lambs (41.7 percent) were in the white-faced breed category. 

Sheep are a multiuse species. For example, 81.6 percent of operations raised sheep for 

meat, 26.5 percent for seed or breeding stock, 15.8 percent for wool, and nearly 

32.6 percent of operations raised sheep for more than one reason.

When rapid means of communication with producers is important, it can be helpful to 

work with national or State industry organizations to promulgate necessary information. 

Over one-fi fth of producers (22.9 percent) belonged to a national sheep organization, and 

almost one-third (29.0 percent) belonged to a State or local sheep industry association or 

club. These percentages vary by size of operation and by operation type. 

Identifi cation

Flock and individual animal identifi cation (ID) are important tools used to reduce disease 

and increase productivity on U.S. sheep operations. Almost 9 of 10 operations 

(88.6 percent) used some form of individual ID for their sheep. The most commonly used 

form of either individual or fl ock ID was the free Scrapie Program ear tag. 

Lambing management

With the increase of smaller operations, nontraditional marketing methods, and improved 

reproductive techniques, more operations have the ability to lamb during the season 

that best suits their customers’ needs. The highest percentage of lambs were born from 

February through May, which allows producers to make the most use of available forage. 

Spring lambing also coincides with natural breeding and lambing seasons, when ewes 

are likely to produce larger lamb crops. 

Items of Note
ii / Sheep 2011

For operations that managed their sheep primarily on the open range, docking may be 

the fi rst time they view the sheep after lambing. At this time, lambs are tagged, castrated, 

docked, and vaccinated, and ewes are examined to ensure health and fecundity. Overall, 

80.5 percent of lambs born alive were docked. Nearly 7 of 10 operations castrated ram 

lambs at an average age of 23.4 days, and more than 3 of 10 operations castrated ram 

lambs in the fi rst 7 days of age.
USDA APHIS VS / iii 

Introduction 1

Terms Used in This Report 3

Section I: Population Estimates 5

A. Inventory—Primary Use 5

1. Breed categories 5

2. Primary use 13

B. Flock Management 19

1. Flock type 19

2. Inventory expectations in 5 years 27

3. Sources of information on sheep health 31

4. Sheep association and club membership 35

5. Production records 36

6. Operator experience 40

7. Flock identifi cation 43

8. Individual-animal ID 47

C. Breeding Management 51

1. Reproductive practices 51

2. Breeding seasons 56

3. Breeding practices 61

4. Ram and ewe lamb selection 65

5. Outcome of ewes expected to lamb 74

D. Reproductive Outcomes 79

1. Lambs born 79

2. Lambs born alive 80

3. Lambs docked 82

4. Monthly distribution of lambs born 85

5. Lambing locations 91

6. Castration management 97

7. Weaned lamb management 102

Table of Contents
iv / Sheep 2011

Section II: Methodology 111

A. Needs Assessment 111

B. Sampling and Estimation 112

1. State selection 112

2. Operation selection 113

3. Population inferences 113

C. Data Collection 114

1. Data collectors and data collection period 114

D. Data Analysis 114

1. Phase I: Validation—General Sheep Management Questionnaire 114

E. Sample Evaluation 115

1. Phase Ia: General Sheep Management Questionnaire—

fewer than 20 ewes 115

2. Phase Ib: General Sheep Management Questionnaire—

20 or more ewes 116

Appendix I: Sample Profi le 117

Appendix II: U.S. Ewes Population and Farms 118

Appendix III: Study Objectives and Related Outputs 122
USDA APHIS VS / v 

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’d like to thank the NASS enumerators who contacted sheep producers and collected 

the data. Their hard work and dedication were invaluable. We’d also like to thank the 

personnel at the USDA–APHIS–Veterinary Services’ Centers for Epidemiology and 

Animal Health for their efforts in generating and distributing this report.

Additional biological sampling and testing for the Sheep 2011 study were afforded by the 

generous contributions of collaborators, including:

• IDEXX Laboratories, Inc., Westbrook, ME

• Iowa State University, College of Veterinary Medicine

• University of Georgia, College of Veterinary Medicine

• USDA–APHIS–VS National Veterinary Services Laboratories, Ames, IA

• USDA–ARS, Animal Parasitic Disease Laboratory, Beltsville, MD

• USDA–ARS, Bacterial Epidemiology and Antimicrobial Resistance Research 

Unit, Athens, GA

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

made the Sheep 2011 study possible.

Larry M. Granger 

Director

Centers for Epidemiology and Animal Health

Acknowledgments
vi / Sheep 2011

Suggested bibliographic citation for this report:

USDA. 2012. Sheep 2011, Part I: Reference of Sheep Management Practices in the 

United States, 2011

USDA–APHIS–VS–CEAH–NAHMS. Fort Collins, CO

#601.0512

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 division of 

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

Service. 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 both participants and the 

industry with information about the U.S. sheep fl ock on operations with one or more 

sheep. The USDA’s National Agricultural Statistics Service (NASS) collaborated with 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 on next page). 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). 

“Part 1: Reference of Sheep Management Practices in the United States, 2011” is the 

fi rst report containing national information from the NAHMS Sheep 2011 study. Data for 

this report were collected from two samples totaling 4,920 sheep operations. Operations 

with 20 or more ewes were personally interviewed by NASS enumerators on-site from 

January 1 to February 11, 2011, to complete the full version of the study questionnaire. 

Operations with fewer than 20 ewes completed a shorter version of the questionnaire by 

telephone.

The methods used and number of respondents in the study can be found in Section II 

and Appendix I of this report, respectively.

Introduction
2 / Sheep 2011

Introduction

Sheep 2011 Participating States

F L

N M

D E M D

T X O K

K S

N E

S D

N D

M T

W Y

C O

U T

ID

A Z

N V

W A

C A

O R

K Y

M E

N Y

P A

M I

V T N H

M A

R I C T

V A

W V

O H IN

IL

N C

T N

S C

M S A L

A R

L A

M O

IA

M N

W I

N J

G A

Regions

Central

West

East
USDA APHIS VS / 3 

Introduction

Crutching: Prelambing shearing of the perineal area.

Estimated Breeding Values: Breed-specifi c genetic parameters that allow for genetic 

evaluation of carcass traits and parasite resistance across breeds.

Expected progeny difference (EPD): Measurement used to determine the genetic 

value of an animal based on predicted genetically improved offspring. Performance 

records determine the measurement and are based on complex analysis of birth, growth, 

maternal, and carcass traits, and can be compared between animals of the same breed. 

Flock size: Flock sizes are based on the number of ewes for each operation on the 

NASS list sampling frame. Size breakouts are: very small (fewer than 20); small (20–99); 

medium (100–499); and large (500 or more). 

Flock type: The following designations represent fl ocks with 20 or more ewes.

Dry lot/feedlot—pen that does not allow for grazing. 

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

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

by residential areas. 

Pasture—any fenced area specifi cally 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.

Operation average: The average value for all operations. A single value for each 

operation is summed over all operations reporting divided by the number of operations 

reporting. See table D.6.b., operation average age lambs were castrated.

Terms Used in 

This Report
4 / Sheep 2011

Introduction

Population estimates: Estimates in this report are provided 

with a measure of precision called the standard error. A 

95-percent confi dence interval can be created with bounds 

equal to the estimate, plus or minus two standard errors. 

If the only error is sampling error, the confi dence intervals 

created in this manner will contain the true population mean 

95 out of 100 times. In the example to the left, 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). The second estimate of 3.4 shows a standard 

error of 0.3 and results in limits of 2.8 and 4.0. Alternatively, 

the 90-percent confi dence interval would be created by 

multiplying the standard error by 1.65 instead of 2.0. 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:

West: California, Oregon, Washington

Central: Colorado, Idaho, Kansas, Montana, New Mexico, South Dakota, Texas, 

Utah, Wyoming

East: Iowa, Kentucky, Michigan, Minnesota, Missouri, New York, Ohio, Pennsylvania, 

Virginia, Wisconsin

Sheep: Animal 1 year old and older.

Standard Errors

(1.0)

10

9

8

7

6

5

4

3

2

1

0 (0.3)

Examples of a 95% Confidence Interval

95% Confidence 

Intervals
USDA APHIS VS / 5 

Section I: Population Estimates–A. Inventory

Note: Where appropriate, column totals are shown as 100.0 to aid in interpretation. 

However, estimates may not sum to exactly 100.0 due to rounding.

Sheep are important sources of meat, fi ber, and other by-products. Producers 

participating in the Sheep 2011 study were asked to report which breeds of sheep and 

lambs they had on hand on January 1, 2011, and the primary use of these sheep and 

lambs.

1. Breed categories 

Sheep breeds in the United States can be categorized by purpose, fi ber type, and 

face color. Black- or nonwhite-faced breeds include Suffolk, Hampshire, Shropshire, 

Oxford, and Southdown. These breeds are often considered meat producers, while 

the white-faced breeds are more often used for wool production. Because each 

breed offers superiority in some trait, producers often blend the breeds to gain the 

superior characteristics of each breed and to attain the genetic requirements of their 

type of operation and the geographic conditions of the operation’s location. Desired 

characteristics include parasite resistance, ability to thrive on the range, and cold 

hardiness. 

All sheep grow both hair and wool fi bers, but hair breeds have more hair fi bers than wool 

breeds and shed their coats annually. Hair breeds usually do not require shearing. Some 

hair breeds have been developed through crossbreeding with other hair, meat, and wool 

breeds. Wool breeds need to be sheared at least annually and have been specifi cally 

bred to produce either fi ne wool, which has small fi ber diameters and short lengths, or 

long wool, which has large fi ber diameters and long lengths. Medium-wool sheep are 

typically meat breeds. 

Fine-wool breeds include Rambouillet, American Cormo, Booroola Merino, Debouillet, 

and Delaine-Merino. 

Medium-wool sheep breeds include Columbia, Corriedale, East Friesian, Finnsheep, 

Montadale, Panama, Polypay, and Targhee (sometimes produce fi ne wool too). 

Long-wooled breeds include Blueface Leicester, Border Leicester, Coopworth, Cotswold, 

Leicester Longwool, Lincoln, Romney, and Wensleydale. 

Colored-wool breeds include Jacob, Navajo-Churro, Icelandic, California Red, Black 

Welsh Mountain, Romanov, Shetland, and California Variegated Mutant. Milk-sheep 

breeds include East Friesian, Lacaune, and Rideau Arcott. The “other” breeds category 

includes Karakul and Tunis (fat-tail breeds), Saoy, and other minor breeds.

Hair breeds include American Blackbelly, Barbados Blackbelly, Dorper, Katahdin, 

St. Croix, and Wiltshire Horn. 

Section I: Population Estimates

A. Inventory—

Primary Use
6 / Sheep 2011

Section I: Population Estimates–A. Inventory

The highest percentage of operations with one or more ewes and with 20 or more 

ewes had black-faced wool breeds (44.7 and 48.6 percent, respectively). The highest 

percentage of very small, small, and medium operations also had black-faced wool 

breeds, while the highest percentage of large operations had fi ne-wool white-faced 

breeds. The percentage of operations that had fi ne-wool white-faced breeds ranged from 

14.0 percent of very small operations to 72.4 percent of large operations. The percentage 

of operations that had hair breeds increased over fourfold from 2001 to 2011 (4.6 and 

21.5 percent, respectively). 

A.1.a. Percentage of operations by breed category of sheep and lambs, and by fl ock size: 

Percent Operations

Flock Size (number of ewes)

Very small

(fewer 

than 20)

Small

(20–99) 

Medium

(100–499)

Large

(500 or 

more)

All 

operations

(1 or more)

Operations 

with 20

or more 

Breed

category Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Black 

face, wool 40.1 (1.7) 49.8 (1.5) 46.3 (1.6) 42.5 (1.8) 44.7 (1.0) 48.6 (1.1)

Fine wool, 

white face 14.0 (1.3) 19.2 (1.2) 38.4 (1.5) 72.4 (1.7) 20.6 (0.8) 26.2 (0.9)

Medium wool, 

white face 21.5 (1.5) 31.6 (1.4) 38.0 (1.6) 27.0 (1.6) 27.5 (0.9) 32.7 (1.1)

Long wool 8.3 (1.0) 5.1 (0.7) 3.8 (0.6) 1.6 (0.3) 6.3 (0.6) 4.6 (0.5)

Mottle-, 

brockle-, or 

speckle-faced 

crossbred

7.5 (0.9) 13.3 (1.0) 15.8 (1.2) 10.9 (1.1) 10.8 (0.6) 13.7 (0.8)

Colored wool 10.1 (1.1) 5.8 (0.7) 3.9 (0.7) 2.3 (0.6) 7.5 (0.6) 5.2 (0.5)

Hair 21.2 (1.4) 23.5 (1.3) 18.3 (1.3) 11.0 (1.2) 21.5 (0.8) 21.7 (1.0)

Milk 0.6 (0.3) 0.7 (0.3) 1.3 (0.3) 0.7 (0.3) 0.8 (0.2) 0.9 (0.2)

Other 7.5 (1.0) 6.5 (0.8) 7.8 (1.0) 4.6 (0.8) 7.0 (0.6) 6.7 (0.6)

Unknown 1.7 (0.5) 1.0 (0.3) 0.7 (0.2) 0.8 (0.4) 1.3 (0.3) 0.9 (0.2)
USDA APHIS VS / 7 

Section I: Population Estimates–A. Inventory

0 10 20 30 40 50

Black

face, wool

Fine wool,

white face

Medium wool,

white face

Long wool

Mottle-, brockle-,

or speckle-faced

crossbred

Colored wool

Hair

Milk

Other

Unknown

Percent

Breed

category

Percentage of operations by breed category of sheep and lambs 

44.7

20.6

27.5

6.3

10.8

7.5

21.5

0.8

7.0

1.3
8 / Sheep 2011

Section I: Population Estimates–A. Inventory

A higher percentage of operations in the Central region (35.0 percent) had fi ne-wool 

white-faced sheep than operations in the West or East regions (12.1 and 

13.9 percent, respectively). Conversely, a lower percentage of operations in the Central 

region had long-wool, colored-wool, or the mottle-faced crossbreds (1.7, 4.1, and 

7.7 percent, respectively) than operations in the West region (10.8, 9.0, and 12.5 percent, 

respectively) or East region (7.9, 9.2, and 12.4 percent, respectively). 

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

Percent Operations (1 or more ewes)

Region

West Central East

Breed category Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Black face, wool 49.5 (2.5) 38.9 (1.5) 46.9 (1.5)

Fine wool, white face 12.1 (1.6) 35.0 (1.5) 13.9 (1.1)

Medium wool, white face 23.5 (2.1) 19.8 (1.1) 34.3 (1.5)

Long wool 10.8 (1.6) 1.7 (0.4) 7.9 (0.9)

Mottle-, brockle-, or 

speckle-faced crossbred 12.5 (1.6) 7.7 (0.7) 12.4 (0.9)

Colored wool 9.0 (1.5) 4.1 (0.6) 9.2 (1.0)

Hair 20.4 (2.0) 27.1 (1.5) 18.1 (1.2)

Milk 0.7 (0.4) 0.6 (0.3) 0.9 (0.3)

Other 6.2 (1.2) 5.5 (0.9) 8.4 (0.9)

Unknown 1.6 (0.7) 1.0 (0.4) 1.3 (0.4)
USDA APHIS VS / 9 

Section I: Population Estimates–A. Inventory

A higher percentage of herded/open range operations (63.1 percent) had fi ne-wool 

white-faced breeds compared with fenced-range (36.9 percent), pasture (20.7 percent), 

or dry lot/feedlot (19.2 percent) operations. A lower percentage of herded/open range 

operations had long-wool breeds (0.6 percent) compared with fenced-range (2.3 percent), 

pasture (5.5 percent), or dry lot/feedlot (7.1 percent) operations. A lower percentage of 

herded/open range operations (6.1 percent) had hair sheep compared with fenced-range 

(29.1 percent) or pasture (20.0 percent) operations. 

A.1.c. Percentage of operations by breed category of sheep and lambs, and by primary 

fl ock type:

Percent Operations (20 or more ewes)

Primary Flock Type

Herded/

open range Fenced range Pasture 

Dry lot/

feedlot 

Breed category Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Black face, wool 43.0 (5.0) 35.7 (2.0) 53.6 (1.5) 56.2 (4.4)

Fine wool, white 

face 63.1 (5.5) 36.9 (2.0) 20.7 (1.2) 19.2 (3.3)

Medium wool, 

white face 31.7 (4.8) 19.6 (1.6) 37.7 (1.5) 39.2 (4.2)

Long wool 0.6 (0.2) 2.3 (0.7) 5.5 (0.7) 7.1 (2.3)

Mottle-, brockle-, 

or speckle-faced 

crossbred

11.0 (3.7) 6.9 (1.1) 16.2 (1.1) 18.7 (3.3)

Colored wool 3.9 (2.6) 3.4 (0.8) 5.9 (0.7) 6.1 (2.2)

Hair 6.1 (3.1) 29.1 (2.1) 20.0 (1.3) 14.7 (3.3)

Milk 0.3 (0.2) 0.7 (0.4) 0.7 (0.2) 2.1 (1.0)

Other 4.9 (1.3) 5.4 (1.1) 6.8 (0.8) 10.0 (2.8)

Unknown 2.7 (2.5) 1.0 (0.5) 0.8 (0.3) 1.4 (1.0)
10 / Sheep 2011

Section I: Population Estimates–A. Inventory

While the highest percentage of operations (44.7 percent) owned black-faced sheep 

(see table A.1.a.), fi ne-wool white-faced sheep accounted for the highest percentage 

of sheep and lamb inventory on all operations with 1 or more ewes and 20 or more 

ewes (41.7 and 43.5 percent, respectively). Fine-wool white-faced sheep accounted for 

a higher percentage of sheep and lamb inventory on large operations than on any of the 

other operation sizes. 

A.1.d. Percentage of January 1, 2011, sheep and lamb inventory, by breed category and 

by fl ock size: 

Percent Sheep and Lambs

Flock Size (number of ewes)

Very small

(fewer 

than 20)

Small

(20–99) 

Medium

(100–499)

Large

(500 or more)

All 

operations

(1 or more)

Operations 

with 20

or more 

Breed 

category Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Black faced, 

wool 28.2 (2.3) 28.6 (1.4) 15.6 (1.4) 6.9 (1.1) 14.9 (0.7) 14.0 (0.7)

Fine wool, 

white face 13.1 (2.9) 12.9 (1.2) 32.0 (3.9) 62.9 (2.2) 41.7 (1.5) 43.5 (1.5)

Medium wool, 

white face 13.1 (1.6) 18.0 (1.2) 23.3 (1.5) 15.8 (1.5) 18.0 (0.9) 18.3 (0.9)

Long wool 3.6 (0.7) 1.9 (0.4) 1.0 (0.2) 0.6 (0.2) 1.2 (0.1) 1.0 (0.1)

Mottle-, 

brockle-, or 

speckle-faced 

crossbred

4.6 (0.9) 6.0 (0.8) 6.7 (1.2) 4.5 (0.7) 5.4 (0.5) 5.4 (0.5)

Colored wool 7.0 (1.0) 2.1 (0.5) 0.8 (0.2) 0.2 (0.1) 1.1 (0.1) 0.8 (0.1)

Hair 23.7 (2.3) 24.0 (1.8) 13.8 (1.5) 3.9 (0.6) 11.8 (0.6) 11.0 (0.7)

Milk 0.4 (0.3) 2.1 (1.7) 0.8 (0.3) 0.1 (0.0) 0.7 (0.4) 0.7 (0.4)

Other 5.5 (1.0) 3.7 (0.7) 5.2 (0.8) 5.0 (1.2) 4.8 (0.6) 4.8 (0.7)

Unknown 0.7 (0.2) 0.8 (0.6) 0.9 (0.5) 0.1 (0.1) 0.5 (0.2) 0.5 (0.2)

Total 100.0 100.0 100.0 100.0 100.0 100.0
USDA APHIS VS / 11 

Section I: Population Estimates–A. Inventory

Fine-wool white-faced breeds accounted for the highest percentage of sheep and 

lamb inventory on operations in the Central and West regions (57.8 and 33.3 percent, 

respectively). On operations in the East region, black-faced wool breeds and mediumwool white-faced breeds accounted for the highest percentages of the sheep and lamb 

inventory (26.1 and 28.7 percent, respectively).

A.1.e. Percentage of January 1, 2011, sheep and lamb inventory, by breed category and 

by region: 

Percent Sheep and Lambs*

Region

West Central East

Breed categories Pct.

Std.

error Pct.

Std.

error Pct.

Std.

error

Black face, wool 24.2 (2.8) 7.3 (0.5) 26.1 (1.2)

Fine wool, white face 33.3 (3.3) 57.8 (1.9) 8.5 (0.8)

Medium wool, white face 13.8 (2.0) 15.1 (1.2) 28.7 (1.5)

Long wool 3.1 (0.5) 0.2 (0.1) 2.0 (0.3)

Mottle-, brockle-, or 

speckle-faced crossbred 9.4 (1.6) 2.0 (0.4) 10.4 (1.3)

Colored wool 1.0 (0.2) 0.6 (0.2) 2.5 (0.4)

Hair 7.2 (1.1) 12.5 (1.0) 13.7 (1.1)

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

Other 5.7 (1.7) 4.0 (0.9) 6.1 (0.8)

Unknown 0.1 (0.0) 0.4 (0.2) 1.2 (0.5)

Total 100.0 100.0 100.0

*On operations with one or more ewes.
12 / Sheep 2011

Section I: Population Estimates–A. Inventory

Fine-wool white-faced breeds accounted for the highest percentage of sheep and lamb 

inventory on herded/open range and fenced-range operations (65.3 and 59.5 percent, 

respectively). Black-faced wool breeds and medium-wool white-faced breeds each 

accounted for about one-fourth of the sheep and lamb inventory on pasture and dry lot/

feedlot operations. 

A.1.f. Percentage of January 1, 2011, sheep and lamb inventory, by breed category and 

by primary fl ock type: 

Percent Sheep and Lambs* 

 Primary Flock Type

Herded/

open range Fenced range Pasture 

Dry lot/

feedlot

Breed categories Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Black face, wool 4.5 (0.8) 8.1 (0.9) 24.3 (1.5) 27.0 (3.4)

Fine wool, 

white face 65.3 (3.8) 59.5 (1.8) 17.5 (1.5) 10.8 (2.1)

Medium wool, 

white face 18.7 (2.6) 10.1 (1.0) 24.8 (1.4) 26.3 (3.9)

Long wool 0.3 (0.2) 0.2 (0.0) 2.3 (0.3) 0.7 (0.3)

Mottle-, brockle-, 

or speckle-faced 

crossbred

2.9 (0.9) 2.9 (0.8) 8.5 (0.8) 14.5 (5.5)

Colored wool 0.1 (0.0) 0.5 (0.2) 1.4 (0.3) 0.9 (0.4)

Hair 0.6 (0.4) 15.1 (1.4) 14.6 (1.2) 8.5 (2.9)

Milk 0.0 (0.0) 0.2 (0.1) 1.4 (1.1) 2.5 (1.2)

Other 7.5 (2.3) 3.2 (0.9) 4.0 (0.5) 8.2 (3.1)

Unknown 0.0 (0.0) 0.2 (0.1) 1.0 (0.5) 0.6 (0.5)

Total 100.0 100.0 100.0 100.0

*On operations with 20 or more ewes.
USDA APHIS VS / 13 

Section I: Population Estimates–A. Inventory

2. Primary use

Most sheep operations derive sheep-associated income from selling lambs for meat, 

while others sell lambs as seed or breeding stock. Wool production is also a use for 

sheep, although usually less important to operations than meat production. Some 

operations keep sheep only for 4-H activities or for showing at fairs. The dairy-sheep 

industry is small; few operations raise sheep for milk. Most sheep are raised for more 

than one use. 

Overall, 81.6 percent of operations with 20 or more ewes raised sheep primarily for meat. 

A higher percentage of large operations raised sheep primarily for wool compared with 

small and medium operations.

A.2.a. Percentage of operations by primary use of sheep and lambs, and by fl ock size:

Percent Operations

Flock Size (number of ewes)

Very small

(fewer 

than 20)

Small

(20–99) 

Medium

(100–499)

Large

(500 or 

more)

All 

operations

(1 or more)

Operations 

with 20

or more 

Primary use* Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Meat 

production 79.3 (1.3) 86.8 (1.2) 91.4 (1.1) 81.6 (1.0)

Wool 

production 12.8 (1.0) 19.1 (1.3) 42.7 (1.8) 15.8 (0.8)

Showing, 

competition, 

4-H, or club

14.3 (1.1) 9.5 (1.0) 3.0 (0.6) 12.6 (0.8)

Seed or 

breeding 

stock

28.0 (1.4) 23.0 (1.5) 20.1 (1.5) 26.5 (1.1)

Milk 

production 0.4 (0.2) 1.0 (0.3) 0.0 (—) 0.5 (0.1)

Other 4.1 (0.6) 1.5 (0.5) 0.2 (0.1) 3.3 (0.5)

*An operation may have sheep and lambs for more than one purpose. Therefore, some operations may be represented in 

more than one primary use category.
14 / Sheep 2011

Section I: Population Estimates–A. Inventory

A higher percentage of operations in the Central region raised sheep primarily for wool 

(24.3 percent) compared with operations in the East and West regions (8.9 and 

14.6 percent, respectively).

A.2.b. Percentage of operations by primary use of sheep and lambs, and by region:

Percent Operations (20 or more ewes)

Region

West Central East

Primary use* Pct.

Std.

error Pct.

Std.

error Pct.

Std.

error

Meat production 81.4 (2.5) 80.7 (1.4) 82.4 (1.5)

Wool production 14.6 (2.2) 24.3 (1.4) 8.9 (1.0)

Showing, competition, 

4-H, or club 19.3 (2.6) 8.2 (1.0) 14.2 (1.3)

Seed or breeding stock 27.4 (2.9) 23.3 (1.4) 28.9 (1.7)

Milk production 0.2 (0.2) 0.1 (0.1) 0.9 (0.3)

Other 2.5 (1.1) 4.1 (0.9) 2.9 (0.7)

*An operation may have sheep and lambs for more than one purpose. Therefore, some operations may be 

represented in more than one primary use category.

Photograph courtesy of Camilla Kristensen.
USDA APHIS VS / 15 

Section I: Population Estimates–A. Inventory

Sheep kept primarily for meat accounted for the highest percentage of inventory 

on operations with 20 or more ewes (70.4 percent), regardless of fl ock size or region.

 A.2.c. Percentage of January 1, 2011, sheep inventory, by primary use and by fl ock size:

Percent Sheep and Lamb Inventory

Flock Size (number of ewes)

Very small 

(fewer 

than 20)

Small

(20–99) 

Medium

(100–499)

Large

(500 or more)

All

operations 

(1 or more)

Operations 

with 20 

or more

Primary use Pct.

Std.

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Meat 

production 67.4 (1.6) 77.5 (1.9) 67.9 (2.2) 70.4 (1.3)

Wool 

production 7.2 (0.9) 8.4 (1.0) 21.3 (2.2) 14.7 (1.2)

Showing, 

competition, 

4-H, or club

7.0 (0.8) 2.5 (0.4) 0.2 (0.1) 2.3 (0.2)

Seed or 

breeding 

stock

15.2 (1.1) 10.1 (1.1) 10.6 (1.4) 11.5 (0.8)

Milk 

production 0.2 (0.1) 0.9 (0.3) 0.0 (0.0) 0.3 (0.1)

Other 3.0 (0.8) 0.6 (0.2) 0.0 (0.0) 0.8 (0.2)

Total 100.0 100.0 100.0 100.0
16 / Sheep 2011

Section I: Population Estimates–A. Inventory

A.2.d. Percentage of January 1, 2011, sheep inventory, by primary use and by region:

Percent Sheep and Lamb Inventory (20 or more ewes)

Region

West Central East

Primary use Pct.

Std.

error Pct.

Std.

error Pct.

Std.

error

Meat production 71.8 (2.8) 68.3 (2.0) 75.0 (1.4)

Wool production 14.5 (2.7) 18.6 (1.8) 4.0 (0.6)

Showing, competition, 

4-H, or club 2.8 (0.6) 1.4 (0.2) 4.6 (0.6)

Seed or 

breeding stock 10.3 (2.0) 11.0 (1.2) 14.2 (1.1)

Milk production 0.1 (0.1) 0.0 (0.0) 1.2 (0.4)

Other 0.6 (0.3) 0.8 (0.3) 1.0 (0.3)

Total 100.0 100.0 100.0
USDA APHIS VS / 17 

Section I: Population Estimates–A. Inventory

On operations with 20 or more ewes, a higher percentage of sheep used primarily for 

wool were managed on herded/open range (23.3 percent) and fenced range 

(19.0 percent) than were managed on pasture (6.1 percent) or dry lot/feedlot 

(3.3 percent). A higher percentage of sheep used primarily for milk were managed on a 

dry lot/feedlot (2.9 percent) than pasture (0.3 percent), and none was kept on fenced or 

herded/open range.

A.2.e. Percentage of January 1, 2011, sheep inventory, by primary use and by primary 

fl ock type:

Percent Sheep and lamb Inventory (20 or more ewes)

Primary Flock Type

Herded/

open range Fenced range Pasture 

Dry lot/

feedlot 

Primary use Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Meat production 64.6 (4.5) 69.3 (1.6) 75.8 (1.3) 67.6 (3.9)

Wool production 23.3 (4.2) 19.0 (1.6) 6.1 (0.6) 3.3 (0.9)

Showing, 

competition, 

4-H, or club

0.0 (—) 1.9 (0.3) 3.5 (0.4) 9.6 (2.6)

Seed or 

breeding stock 11.7 (2.5) 9.1 (1.0) 13.1 (1.1) 15.0 (2.5)

Milk production 0.0 (—) 0.1 (0.1) 0.3 (0.1) 2.9 (1.4)

Other 0.3 (0.2) 0.7 (0.2) 1.2 (0.4) 1.9 (1.6)

Total 100.0 100.0 100.0 100.0
18 / Sheep 2011

Section I: Population Estimates–A. Inventory

Overall, 32.6 percent of operations with 20 or more ewes kept sheep for more than one 

use. A higher percentage of large operations (49.6 percent) kept sheep for more than one 

use than either small or medium operations (31.2 and 33.2 percent, respectively).

A.2.f. Percentage of operations that kept sheep for more than one use, by fl ock size: 

A.2.g. Percentage of operations that kept sheep for more than one use, by primary fl ock 

type:

Percent Operations (20 or more ewes)

Primary Flock Type

Herded/

open range Fenced range Pasture 

Dry lot/

feedlot 

Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

43.3 (5.0) 34.5 (2.1) 31.2 (1.4) 33.0 (4.1)

Percent Operations

Flock Size (number of ewes)

Very small

(fewer 

than 20)

Small

(20–99) 

Medium

(100–499)

Large

(500 or more)

All

operations

(1 or more)

Operations 

with 20 

or more

Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

31.2 (1.4) 33.2 (1.6) 49.6 (1.8) 32.6 (1.1)
USDA APHIS VS / 19 

Section I: Population Estimates–B. Flock Management

1. Flock type

Large operations, which own the majority of sheep in the United States, frequently raise 

sheep on rangeland. Small and medium operations often graze sheep on irrigated or 

cultivated pasture. Many operations manage sheep on more than one type of feeding 

environment. The highest percentage of operations with 20 or more ewes (75.8 percent) 

managed at least some of their sheep on pasture.

B.1.a. Percentage of operations by type of fl ock management used during the previous 

12 months:

Type of fl ock management 

Percent operations

(20 or more ewes) Std. error

Herded/open range 5.5 (0.4)

Fenced range 40.5 (1.1)

Pasture 75.8 (0.9)

Dry lot/feedlot 37.9 (1.0)

Other 1.9 (0.3)

B. Flock 

Management
20 / Sheep 2011

Section I: Population Estimates–B. Flock Management

Pasture was the primary management type for 62.2 percent of operations. A higher 

percentage of small operations (66.7 percent) kept sheep primarily on pasture than did 

medium and large operations (57.5 and 21.8 percent, respectively). Just over half of large 

operations (50.6 percent) kept sheep primarily on fenced range.

B.1.b. Percentage of operations by primary type of fl ock management used during the 

previous 12 months, and by fl ock size: 

Percent Operations 

Flock Size (number of ewes)

Very small

(fewer 

than 20)

Small

(20–99) 

Medium

(100–499)

Large

(500 or 

more)

All 

operations

(1 or more)

Operations 

with 20

or more 

Primary 

type of fl ock 

management Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Herded/

open range 1.6 (0.4) 2.4 (0.5) 25.5 (1.2) 3.1 (0.3)

Fenced range 24.0 (1.2) 33.0 (1.3) 50.6 (1.5) 27.4 (1.0)

Pasture 66.7 (1.4) 57.5 (1.5) 21.8 (1.5) 62.2 (1.0)

Dry lot/feedlot 7.7 (0.8) 7.1 (0.8) 2.1 (0.6) 7.3 (0.6)

Total 100.0 100.0 100.0 100.0
USDA APHIS VS / 21 

Section I: Population Estimates–B. Flock Management

0

20

40

60

80

Operations with 20 or more

Large (500 or more)

Medium (100–499)

Small (20–99)

Flock size (number of ewes)

Percent

Percentage of operations by primary type of flock management used during the

previous 12 months, and by flock size

Herded/open range Fenced range Pasture Dry lot/feedlot

1.6 2.4

25.5

3.1

24.0

33.0

50.6

27.4

66.7

57.5

21.8

62.2

7.7 7.1

2.1

7.3

Primary type of flock management
22 / Sheep 2011

Section I: Population Estimates–B. Flock Management

A higher percentage of operations in the Central region managed their sheep on herded/

open or fenced range than operations in the West or East regions. Conversely, a higher 

percentage of operations in the West and East regions managed their sheep on pasture 

compared with operations in the Central region. 

B.1.c. Percentage of operations by primary type of fl ock management used during the 

previous 12 months, and by region:

Percent Operations (20 or more ewes)

Region

West Central East

Primary type of fl ock 

management Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Herded/open range 3.4 (0.8) 6.3 (0.7) 0.1 (0.1)

Fenced range 23.0 (2.7) 47.3 (1.7) 11.8 (1.2)

Pasture 67.4 (2.9) 39.2 (1.7) 80.3 (1.4)

Dry lot/feedlot 6.1 (1.7) 7.2 (0.9) 7.8 (0.9)

Total 100.0 100.0 100.0

Photograph courtesy of Camilla Kristensen.
USDA APHIS VS / 23 

Section I: Population Estimates–B. Flock Management

A higher percentage of ewes on small and medium operations (64.6 and 53.0 percent, 

respectively) were managed on pasture compared with ewes on large operations 

(14.1 percent). Nearly half of ewes on large operations (46.7 percent) were managed on 

herded/open range. Although herded/open range fl ocks represented only 3.1 percent of 

operations, they accounted for over one-fourth of ewes on operations with 20 or more 

ewes (26.1 percent).

B.1.d. Percentage of ewes by primary type of fl ock management used during the 

previous 12 months, and by fl ock size:

Percent Ewes 

Flock Size (number of ewes)

Very small

(fewer 

than 20)

Small

(20–99) 

Medium

(100–499)

Large

(500 or 

more)

All 

operations

(1 or more)

Operations 

with 20

or more 

Primary 

type of fl ock 

management Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Herded/

open range 1.3 (0.4) 4.3 (1.1) 46.6 (2.4) 26.0 (1.5)

Fenced range 27.1 (1.7) 35.7 (1.5) 38.4 (2.0) 35.3 (1.2)

Pasture 64.3 (1.7) 53.2 (1.7) 14.1 (1.6) 34.9 (1.1)

Dry lot/feedlot 7.3 (1.0) 6.8 (0.9) 0.9 (0.3) 3.8 (0.4)

Total 100.0 100.0 100.0 100.0
24 / Sheep 2011

Section I: Population Estimates–B. Flock Management

0

20

40

60

80

Ewes

Operations

Percent

For operations with 20 or more ewes, percentage of operations, and percentage of 

ewes on these operations, by primary type of flock management used during the 

previous 12 months

Herded/open

range (unfenced

acerage)

Fenced range

(uncultivated

fenced acreage)

Pasture

(irrigated or

cultivated)

Dry lot

or feedlot*

*Pen that does not allow grazing.

3.1

27.4

62.2

7.3

26.0

35.3 34.9

3.8

Primary type of flock management
USDA APHIS VS / 25 

Section I: Population Estimates–B. Flock Management

In the West and East regions, the highest percentage of ewes (80.2 and 46.1 percent, 

respectively) were managed primarily on pasture. In the Central region, the highest 

percentage of ewes (45.9 percent) were managed on fenced range.

B.1.e. Percentage of ewes on operations with 20 or more ewes by primary type of fl ock 

management used during the previous 12 months, and by region:

Percent Ewes*

Region

West Central East

Primary type of 

fl ock management Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Herded/open range 26.8 (3.9) 34.6 (2.0) 0.1 (0.1)

Fenced range 25.2 (3.7) 45.9 (1.7) 11.0 (1.1)

Pasture 46.1 (3.7) 17.0 (1.1) 80.2 (1.5)

Dry lot/feedlot 1.9 (0.6) 2.5 (0.4) 8.7 (1.1)

Total 100.0 100.0 100.0

*On operations with 20 or more ewes.
26 / Sheep 2011

Section I: Population Estimates–B. Flock Management

Note: Only operations with 20 or more ewes were asked about their primary fl ock type; 

therefore, any table in this report that describes primary fl ock type does not represent 

operations with fewer than 20 ewes. 

Operations with 20 to 99 ewes accounted for 73.1 percent of all operations with 20 or 

more ewes, while large operations (500 or more ewes) accounted for only 5.5 percent 

of all operations with 20 or more ewes. Large operations made up 45.7 percent of all 

herded/open range operations; just over one-third of herded/open range operations 

(37.3 percent) were small operations. 

B.1.f. Percentage of operations by fl ock size and by primary fl ock type:

Percent Operations

Primary Flock Type

Herded/

open range 

Fenced 

range Pasture 

Dry lot/

feedlot

 All 

operations

(20 or more)

Flock size Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Small (20-99) 37.6 (5.6) 64.1 (1.4) 78.3 (0.6) 77.5 (2.6) 73.1 (0.3)

Medium 

(100-499) 16.7 (3.2) 25.8 (1.2) 19.8 (0.6) 20.9 (2.5) 21.4 (0.3)

Large 

(500 or more) 45.7 (4.4) 10.1 (0.6) 1.9 (0.2) 1.6 (0.5) 5.5 (0.1)

Total 100.0 100.0 100.0 100.0 100.0
USDA APHIS VS / 27 

Section I: Population Estimates–B. Flock Management

While small operations made up 73.1 percent of sheep operations with 20 or more 

ewes, they represented only 22.1 percent of all sheep. Conversely, large operations only 

represented 5.5 percent of sheep operations but raised 53.1 percent of all sheep. The 

highest percentage of sheep in herded/open and fenced-range operations were on large 

operations (94.8 and 57.8 percent, respectively).

B.1.g. Percentage of ewes by size of operation and by primary fl ock type:

Percent Ewes

Primary Flock Type

Herded/

open range 

Fenced 

range Pasture 

Dry lot/

feedlot

 All 

operations

(20 or more)

Flock size Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Small 1.1 (0.3) 17.0 (1.1) 40.6 (1.3) 42.8 (4.6) 22.1 (0.6)

Medium 4.1 (1.0) 25.2 (1.1) 38.0 (1.3) 45.1 (4.7) 24.9 (0.6)

Large 94.8 (1.1) 57.8 (1.5) 21.4 (1.9) 12.1 (3.5) 53.0 (1.0)

Total 100.0 100.0 100.0 100.0 100.0

2. Inventory expectations in 5 years

To meet the increasing demand for lamb, wool, and sheep milk in the United States, the 

American Sheep Industry is encouraging sheep producers to increase the size of their 

fl ocks through the “Let’s Grow with Two Plus” program. Producers are encouraged to 

grow their fl ocks by 2 ewes per 100 ewes, increase the average birth rate per ewe to 

2 lambs per year, and increase the harvested lamb crop by 2 percent. Visit http://www.

growourfl ock.org/twoplus for more information on this program.
28 / Sheep 2011

Section I: Population Estimates–B. Flock Management

The highest percentage of operations with 20 or more ewes (59.0 percent) expected 

to have about the same number of sheep in 5 years. A higher percentage of large 

operations (32.4 percent) expected to have more sheep in the next 5 years compared 

with medium and small operations (25.7 and 22.7 percent, respectively). Overall, a higher 

percentage of operations expected to have more sheep (23.9 percent) than operations 

that expected to have fewer sheep (10.6 percent).

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

with the January 1, 2011, inventory, and by fl ock size: 

Percent Operations 

Flock Size (number of ewes)

Very small

(fewer 

than 20)

Small

(20–99) 

Medium

(100–499)

Large

(500 or 

more)

All 

operations

(1 or more)

Operations 

with 20

or more 

Expected 

change in 

Inventory Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

None 7.1 (0.8) 4.5 (0.8) 4.2 (0.8) 6.4 (0.6)

Fewer sheep 11.1 (1.0) 10.1 (1.0) 6.6 (0.9) 10.6 (0.7)

About the

same number 

of sheep

59.0 (1.5) 59.7 (1.6) 56.8 (1.9) 59.0 (1.2)

More sheep 22.7 (1.3) 25.7 (1.5) 32.4 (1.7) 23.9 (1.0)

Total 100.0 100.0 100.0 100.0
USDA APHIS VS / 29 

Section I: Population Estimates–B. Flock Management

The West region accounted for the highest percentage of operations that expected to 

have fewer sheep in the next 5 years. In the Central and East regions, the percentage of 

operations expecting to have more sheep was higher than the percentage expecting to 

have fewer sheep.

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

with the January 1, 2011, inventory, and by region:

Percent Operations (20 or more ewes)

Region

West Central East

Expected change 

in Inventory Pct.

Std. 

error Pct.

Std.

error Pct.

Std. 

error

None 5.4 (1.6) 6.0 (0.8) 7.1 (1.0)

Fewer 17.3 (2.5) 9.4 (1.0) 9.4 (1.1)

About the same 59.1 (3.2) 61.0 (1.7) 57.3 (1.8)

More 18.2 (2.4) 23.6 (1.5) 26.2 (1.6)

Total 100.0 100.0 100.0

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

with the January 1, 2011, inventory, and by primary fl ock type: 

Percent Operations (20 or more ewes)

Primary Flock Type

Herded/

open range Fenced range Pasture

Dry lot/

feedlot

Expected change 

in Inventory Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

None 6.1 (2.9) 5.9 (1.1) 6.9 (0.8) 4.1 (1.7)

Fewer 18.2 (5.4) 7.0 (1.1) 11.5 (1.0) 14.0 (3.0)

About the same 50.3 (5.2) 64.3 (2.2) 56.8 (1.5) 61.2 (4.2)

More 25.4 (4.2) 22.8 (1.9) 24.8 (1.3) 20.7 (3.3)

Total 100.0 100.0 100.0 100.0
30 / Sheep 2011

Section I: Population Estimates–B. Flock Management

Family/personal situation was the most common reason cited for expecting to not have 

sheep in 5 years. 

B.2.d. For operations that did not expect to have sheep in 5 years, percentage of 

operations by main reason and by fl ock size:

Percent Operations 

Flock Size (number of ewes)

Very small

(fewer 

than 20)

Small

(20–99) 

Medium

(100–499)

Large

(500 or more)

All 

operations

(1 or more)

Operations 

with 20

or more 

Reason Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Personal/

family 

situation

81.2 (4.5) 72.6 (8.5) 63.8 (9.0) 79.3 (3.9)

Price of wool 2.1 (2.0) 3.6 (3.3) 0.0 (0.0) 2.2 (1.7)

Price of lambs 3.2 (2.2) 1.1 (0.8) 0.0 (0.0) 2.8 (1.8)

Predator loss 4.8 (2.3) 3.7 (2.3) 5.9 (4.5) 4.7 (1.9)

Labor 

shortage 1.3 (1.3) 9.5 (6.1) 5.9 (4.5) 2.7 (1.4)

Government

regulations 0.0 (0.0) 2.7 (2.4) 5.2 (3.8) 0.6 (0.4)

Sheep 

disease 0.0 (0.0) 0.0 (0.0) 5.9 (4.5) 0.2 (0.2)

Other 7.4 (2.9) 6.8 (6.2) 13.4 (5.5) 7.5 (2.6)

Total 100.0 100.0 100.0 100.0
USDA APHIS VS / 31 

Section I: Population Estimates–B. Flock Management

3. Sources of information on sheep health

Sheep health information can be found through a wide variety of sources. The “Sheep 

Production Handbook,” sponsored by the American Sheep Industry Association, is a 

comprehensive source of information. In addition, many universities offer sheep health 

information through extension resources. Industry meetings, magazine, shearers, and 

other sheep producers are also good resources. Also, a veterinarian familiar with the 

existing conditions on an operation can provide advice specifi c to illnesses, management, 

and production. Veterinarians were considered to be a very important source of 

information on 40.4 percent of operations, while other sheep producers were considered 

a very important source on 38.3 percent of operations. 

B.3.a. Percentage of operations by importance of the following sources of sheep health 

information:

Percent Operations

Importance

Very 

important 

Somewhat 

important

Not

important

Health 

information source Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Total

Sheep Industry 

Development (SID) 

“Sheep Production 

Handbook”

19.1 (0.9) 31.8 (1.0) 49.1 (1.1) 100.0

Industry meetings 11.7 (0.7) 29.2 (1.0) 59.1 (1.1) 100.0

Internet 25.8 (1.0) 33.1 (1.1) 41.1 (1.1) 100.0

Magazines/newsletters 26.3 (0.9) 47.6 (1.1) 26.1 (1.0) 100.0

University/extension 27.6 (1.0) 35.4 (1.0) 37.1 (1.0) 100.0

Veterinarians 40.4 (1.1) 33.1 (1.0) 26.5 (1.0) 100.0

Feed and drug 

salespeople 13.4 (0.8) 30.8 (1.0) 55.8 (1.1) 100.0

Shearer 31.7 (1.0) 24.3 (0.9) 44.0 (1.1) 100.0

Other sheep producers 38.3 (1.1) 40.0 (1.1) 21.8 (0.9) 100.0
32 / Sheep 2011

Section I: Population Estimates–B. Flock Management

Industry meetings were considered very important sources of sheep health information on 

9.6 percent of very small operations, compared with 16.9 percent of medium operations 

and 29.6 percent of large operations. About 5 of 10 large operations (54.5 percent) 

considered other sheep producers a very important source of information, compared with 

about 4 of 10 very small operations (36.1 percent). 

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

information very important, by fl ock size:

Percent Operations 

Flock Size (number of ewes)

Very small

(fewer 

than 20)

Small

(20–99) 

Medium

(100–499)

Large

(500 or more)

All 

operations

(1 or more)

Operations 

with 20

or more 

Health 

information 

source Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Sheep Industry 

Development 

(SID) “Sheep 

Production 

Handbook”

19.6 (1.6) 19.4 (1.3) 16.5 (1.2) 17.5 (1.5) 19.1 (0.9) 18.6 (1.0)

Industry 

meetings 9.6 (1.2) 10.9 (1.0) 16.9 (1.3) 29.6 (1.7) 11.7 (0.7) 13.3 (0.8)

Internet 28.3 (1.8) 24.7 (1.4) 22.5 (1.4) 17.8 (1.4) 25.8 (1.0) 23.8 (1.1)

Magazines/

newsletters 22.5 (1.6) 27.8 (1.4) 32.9 (1.6) 34.1 (1.8) 26.3 (0.9) 29.3 (1.1)

University/

extension 26.5 (1.7) 27.9 (1.4) 28.6 (1.6) 34.0 (1.8) 27.6 (1.0) 28.4 (1.1)

Veterinarians 42.1 (1.9) 38.8 (1.5) 37.8 (1.7) 45.7 (1.9) 40.4 (1.1) 39.0 (1.2)

Feed and drug 

salespeople 15.0 (1.4) 11.5 (1.0) 12.4 (1.2) 18.3 (1.4) 13.4 (0.8) 12.0 (0.8)

Shearer 33.4 (1.8) 29.8 (1.4) 29.4 (1.5) 40.4 (1.8) 31.7 (1.0) 30.4 (1.1)

Other sheep 

producers 36.1 (1.9) 38.5 (1.5) 41.1 (1.7) 54.5 (1.9) 38.3 (1.1) 40.0 (1.2)
USDA APHIS VS / 33 

Section I: Population Estimates–B. Flock Management

0 10 20 30 40 50

 “Sheep

Production

Handbook”

Industry

meetings

Internet

Magazines/

newsletters

University/

extension

Veterinarians

Feed and drug

salespeople

Shearer

Other sheep

producers

Percent

Health

information

source

Percentage of all operations that rated the following sources of sheep 

health information very important

19.1

11.7

25.8

26.3

27.6

40.4

13.4

31.7

38.3
34 / Sheep 2011

Section I: Population Estimates–B. Flock Management

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

information very important, by region: 

Percent Operations (1 or more ewes)

Region

West Central East

Health information 

source Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Sheep Industry 

Development (SID) Sheep 

Production Handbook

20.6 (2.1) 18.6 (1.5) 18.8 (1.3)

Industry meetings 8.4 (1.3) 12.8 (1.3) 12.2 (1.0)

Internet 25.4 (2.3) 25.2 (1.6) 26.3 (1.5)

Magazines/newsletters 21.8 (2.1) 25.7 (1.5) 28.4 (1.4)

University/extension 22.3 (2.1) 25.9 (1.6) 30.6 (1.5)

Veterinarians 37.5 (2.4) 41.4 (1.7) 40.7 (1.6)

Feed and drug 

salespeople 10.1 (1.5) 15.0 (1.3) 13.4 (1.1)

Shearer 23.1 (2.2) 32.0 (1.5) 34.7 (1.6)

Other sheep producers 35.1 (2.4) 39.9 (1.7) 38.3 (1.6)
USDA APHIS VS / 35 

Section I: Population Estimates–B. Flock Management

4. Sheep association and club membership

Overall, 22.9 percent of all operations belonged to a national sheep organization. By 

fl ock size, the percentage of operations that belonged to a national sheep organization 

ranged from 13.6 percent of very small operations to 57.0 percent of large operations. 

The percentage of operations that belonged to a State or local sheep organization ranged 

from 14.8 percent of very small operations to 76.9 percent of large operations. 

B.4.a. Percentage of operations by type of association or club operation belonged to, and 

by fl ock size:

A higher percentage of herded/open range operations (57.0 percent) belonged to State or 

local sheep associations than fenced-range (41.0 percent), pasture (41.3 percent), or dry 

lot/feedlot (34.4 percent) operations.

B.4.b. Percentage of operations by type of association or club operation belonged to, and 

by primary fl ock type:

Percent Operations (20 or more ewes)

 Primary Flock Type

Herded/

open range Fenced range Pasture

Dry lot/

feedlot 

Association/

club type Pct.

Std.

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

National 39.2 (4.2) 25.4 (1.7) 32.6 (1.4) 33.6 (4.1)

State/local 57.0 (5.4) 41.0 (2.1) 41.3 (1.5) 34.4 (4.2)

Percent Operations 

Flock Size (number of ewes)

Very small

(fewer 

than 20)

Small

(20–99) 

Medium

(100–499)

Large

(500 or more)

All 

operations

(1 or more)

Operations 

with 20

or more 

Type of 

association/

club Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

National 13.6 (1.3) 27.5 (1.4) 35.4 (1.6) 57.0 (1.8) 22.9 (0.8) 30.8 (1.1)

State/local 14.8 (1.4) 35.3 (1.4) 51.9 (1.7) 76.9 (1.6) 29.0 (0.9) 41.1 (1.1)
36 / Sheep 2011

Section I: Population Estimates–B. Flock Management

5. Production records 

Production records can be important tools for monitoring animal performance and 

for tracking which lambs should be kept, which ewes should be bred, and which 

animals should be culled. These records can be kept through handwritten notes or in 

computerized databases, spreadsheets, or specialized farm management software. 

Over half of operations (55.9 percent) kept handwritten production records and another 

25.7 percent kept both handwritten and computerized production records. Nearly 

15 percent of small operations kept no records, while only 3.9 percent of large operations 

kept no production records.

B.5.a. Percentage of operations by type of production records used during 2010, and by 

fl ock size: 

Percent Operations 

Flock Size (number of ewes)

Very small

(fewer 

than 20)

Small

(20–99) 

Medium

(100–499)

Large

(500 or more)

All 

operations

(1 or more)

Operations 

with 20

or more 

Record type Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Computerized 5.3 (0.7) 4.2 (0.7) 5.8 (0.8) 5.1 (0.5)

Handwritten 54.9 (1.6) 59.9 (1.7) 55.0 (1.8) 55.9 (1.2)

Both 24.9 (1.3) 25.7 (1.4) 35.3 (1.8) 25.7 (1.0)

None 14.9 (1.1) 10.1 (1.1) 3.9 (0.8) 13.3 (0.9)

Total 100.0 100.0 100.0 100.0
USDA APHIS VS / 37 

Section I: Population Estimates–B. Flock Management

The highest percentage of operations, regardless of primary fl ock type, handwrote 

production records. The majority of herded/open range operations with 20 to 499 ewes 

did not keep any production records, which helps explain the relatively high percentage of 

all herded/open range operations (25.1 percent) that did not use records.

B.5.b. Percentage of operations by type of production records used during 2010, and by 

primary fl ock type:

Percent Operations (20 or more ewes)

Primary Flock Type

Herded/

open range Fenced range Pasture

Dry lot/

feedlot 

Record type Pct.

Std.

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Computerized 4.4 (0.9) 4.8 (1.0) 5.2 (0.7) 5.1 (1.8)

Handwritten 43.8 (5.1) 59.4 (2.2) 56.1 (1.6) 46.7 (4.3)

Both 26.7 (3.3) 21.4 (1.8) 26.1 (1.4) 37.2 (4.2)

None 25.1 (5.8) 14.4 (1.8) 12.5 (1.1) 11.0 (3.0)

Total 100.0 100.0 99.9 100.0
38 / Sheep 2011

Section I: Population Estimates–B. Flock Management

For operations that kept records, the highest percentage kept records on the number of 

lambs born. Records of individual lamb weights—at birth and at weaning— were kept by 

the lowest percentage of operations.

B.5.c. Of operations that kept records, percentage of operations by type of records kept 

during 2010, and by fl ock size:

Percent Operations 

Flock Size (number of ewes)

Very small

(fewer 

than 20)

Small

(20–99) 

Medium

(100–499)

Large

(500 or more)

All 

operations

(1 or more)

Operations 

with 20

or more 

Type of 

record Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Number of 

lambs born 90.4 (1.0) 87.7 (1.1) 80.2 (1.5) 89.2 (0.8)

Individual birth 

weights 18.1 (1.3) 11.1 (1.1) 5.3 (0.9) 15.7 (1.0)

Number of 

lambs weaned 76.6 (1.4) 77.5 (1.5) 89.1 (1.3) 77.5 (1.1)

Individual 

weaning 

weights

15.7 (1.2) 11.0 (1.0) 16.4 (1.4) 14.7 (0.9)

Health and 

treatment/

vaccination 

practices

70.0 (1.6) 64.3 (1.6) 65.1 (1.8) 68.4 (1.2)

Breeding 72.6 (1.5) 71.2 (1.6) 66.0 (1.8) 71.9 (1.1)

Number of 

animals culled 

or died

79.3 (1.4) 80.3 (1.4) 83.1 (1.5) 79.7 (1.0)
USDA APHIS VS / 39 

Section I: Population Estimates–B. Flock Management

A lower percentage of herded/open range operations (3.2 percent) recorded individual 

birth weights compared with fenced range, pasture, or dry lot/feedlot operations (11.8, 

17.7, and 18.0 percent, respectively).

B.5.d. Percentage of operations by type of records kept during 2010, and by primary fl ock 

type:

Percent Operations (20 or more ewes)

Primary Flock Type

Herded/

open range Fenced range Pasture

Dry lot/

feedlot 

Record type Pct.

Std.

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Number of 

lambs born 84.6 (2.9) 85.0 (1.8) 91.2 (0.9) 89.1 (2.9)

Individual 

birth weights 3.2 (1.0) 11.8 (1.6) 17.7 (1.3) 18.0 (3.8)

Number of 

lambs weaned 79.5 (5.5) 76.5 (2.2) 78.1 (1.4) 75.9 (4.0)

Individual 

weaning weights 18.8 (3.1) 13.5 (1.6) 15.4 (1.2) 11.8 (3.1)

Health and 

treatment/

vaccination 

practices

75.4 (4.3) 62.0 (2.3) 70.6 (1.5) 71.2 (4.0)

Breeding 62.8 (5.1) 62.4 (2.3) 75.4 (1.4) 79.9 (3.3)

Number of animals 

culled or died 79.5 (5.5) 76.6 (2.1) 81.1 (1.3) 79.6 (3.8)
40 / Sheep 2011

Section I: Population Estimates–B. Flock Management

6. Operator experience

For all operations, operators averaged 23.9 years of experience. The average number 

of years of experience ranged from 19.1 years for operators on very small operations to 

35.6 years for operators on large operations. 

B.6.a. Average number of years the primary operator had owned or managed any sheep, 

by fl ock size:

Herded/open range operations had the most experienced operators (average of 

37.5 years).

B.6.b. Average number of years the primary operator had owned or managed any sheep, 

by primary fl ock type:

Average Number Years* 

Primary Flock Type 

Herded/

open range Fenced range Pasture

Dry lot/

feedlot

Avg.

Std. 

error Avg.

Std.

error Avg.

Std.

error Avg.

Std. 

error

37.5 (2.7) 28.9 (0.8) 27.2 (0.5) 27.7 (1.5)

*On operations with 20 or more ewes.

Average Number Years

Flock Size (number of ewes)

Very small 

(fewer 

than 20)

Small 

(20–99) 

Medium 

(100–499)

Large 

(500 or more)

All

operations

(1 or more)

Operations 

with 20 

or more

Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error

19.1 (0.6) 26.9 (0.5) 29.5 (0.5) 35.6 (0.6) 23.9 (0.3) 27.9 (0.4)
USDA APHIS VS / 41 

Section I: Population Estimates–B. Flock Management

On operations with 20 or more ewes, operators on over half of operations (54.4 percent) 

had managed sheep for 21 to 59 years. Very small operations accounted for the highest 

percentage of operations (17.2 percent) with the least experienced operators (1 to 

5 years). 

B.6.c. Percentage of operations by number of years the primary operator had owned or 

managed any sheep, and by fl ock size:

Percent Operations

Flock Size (number of ewes)

Very small

(fewer 

than 20)

Small

(20–99) 

Medium

(100–499)

Large

(500 or more)

All 

operations

(1 or more)

Operations 

with 20

or more 

Number

years Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

1–5 17.2 (1.5) 5.5 (0.7) 4.1 (0.6) 1.3 (0.4) 10.6 (0.7) 5.0 (0.5)

6–10 25.7 (1.7) 13.3 (1.1) 8.9 (0.9) 4.8 (0.8) 18.2 (0.9) 11.9 (0.8)

11–20 24.1 (1.6) 24.4 (1.4) 23.2 (1.4) 15.2 (1.3) 23.8 (0.9) 23.6 (1.0)

21–59 30.2 (1.7) 52.6 (1.6) 57.2 (1.6) 67.2 (1.8) 43.3 (1.0) 54.4 (1.2)

60 or more 2.8 (0.6) 4.2 (0.6) 6.6 (0.8) 11.5 (1.3) 4.0 (0.4) 5.1 (0.5)

Total 100.0 100.0 100.0 100.0 100.0 100.0
42 / Sheep 2011

Section I: Population Estimates–B. Flock Management

B.6.d. Percentage of operations by number of years the primary operator had owned or 

managed any sheep, and by region:

Percent Operations (1 or more ewes)

Region

West Central East

Number years Pct.

Std.

error Pct.

Std.

error Pct.

Std.

error

1–5 11.8 (1.7) 11.2 (1.3) 9.6 (1.0)

6–10 19.4 (2.0) 13.5 (1.3) 21.1 (1.4)

11–20 23.1 (2.1) 23.5 (1.4) 24.4 (1.4)

21–59 41.8 (2.4) 46.1 (1.7) 41.9 (1.5)

60 or more 3.9 (0.9) 5.7 (0.8) 3.0 (0.5)

Total 100.0 100.0 100.0

0

20

40

60

80

All operations (1 or more)

Large (500 or more)

Medium (100-499)

Small (20-99)

Very small (fewer than 20)

Flock size (number of ewes)

Percent

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

managed any sheep, and by flock size

1-5 6-10 11-20 21-59 60 or more

Number years

17.2

5.5 4.1

1.3

10.6

25.7

13.3

8.9

4.8

18.2

24.1 24.4 23.2

15.2

23.8

30.2

52.6

67.2

43.3

2.8 4.2

6.6

11.5

4.0

57.2
USDA APHIS VS / 43 

Section I: Population Estimates–B. Flock Management

7. Flock identifi cation 

Note: Estimates in this section do not include operations that were primarily dry lot/

feedlot.

Flock and individual-animal identifi cation (ID) are important tools for reducing disease 

and increasing productivity on U.S. sheep operations. The most basic record keeping 

requires some kind of individual-animal ID, even if it is temporary. The best form of ID is 

permanent, easy to read, and easy to apply.

There are many methods used to identify individual sheep and fl ocks, some of which 

are required by the USDA before sheep leave their place of birth. Required ID includes 

ear tags with the owner’s fl ock ID number on one side and an individual number for the 

sheep or offi cial serial number tags on the other side. Offi cial ear tags and applicators 

can be obtained free of charge from the USDA. All States require that sheep be offi cially 

identifi ed on change of ownership. Some States require that all sheep be offi cially 

identifi ed before intrastate movement. These requirements are part of national efforts to 

eradicate scrapie in the United States. To learn more about national and State-specifi c 

scrapie eradication requirements, go to www.eradicatescrapie.org. Other methods of ID 

include tattoos, ear marks (notches), neck chains, electronic, paint brands, chalks, and 

sprays. 
44 / Sheep 2011

Section I: Population Estimates–B. Flock Management

Overall, 81.5 percent of operations with 20 or more ewes used at least one form of 

fl ock ID, compared with 61.4 percent of operations with one or more ewes. As fl ock size 

increased, so did the percentage of operations that used at least one form of ID. On large 

operations, 96.1 percent used some form of ID, compared with only 39.6 percent of very 

small operations. This same comparison can be made by ID type. The scrapie program 

ear tag was used by 77.9 percent of large operations, compared with only 31.0 percent 

of very small operations. Since smaller operations are probably less likely to move their 

animals, the scrapie ear tag may not be required on these operations.

B.7.a. Percentage of operations by fl ock ID method(s) used and by fl ock size: 

Percent Operations

Flock Size (number of ewes)

Very small

(fewer 

than 20)

Small

(20–99) 

Medium

(100–499)

Large

(500 or 

more)

All 

operations

(1 or more)

Operations 

with 20

or more 

Flock ID 

method* Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Scrapie 

program 

ear tag

31.0 (1.7) 71.8 (1.5) 75.5 (1.5) 77.9 (1.5) 52.8 (1.0) 72.9 (1.1)

Other ear tag 13.6 (1.3) 19.1 (1.3) 23.8 (1.5) 33.1 (1.8) 17.4 (0.8) 20.9 (1.0)

Tattoo 0.7 (0.3) 1.4 (0.4) 1.5 (0.4) 1.8 (0.5) 1.1 (0.2) 1.4 (0.3)

Paint brand 3.0 (0.6) 6.2 (0.7) 17.4 (1.1) 43.3 (1.6) 7.0 (0.4) 10.7 (0.6)

Ear mark 2.8 (0.6) 6.0 (0.8) 19.4 (1.2) 49.4 (1.8) 7.3 (0.5) 11.3 (0.6)

Other 0.5 (0.2) 0.4 (0.2) 0.3 (0.2) 1.8 (0.5) 0.5 (0.1) 0.4 (0.1)

At least one 

form of ID 39.6 (1.8) 78.4 (1.3) 88.1 (1.1) 96.1 (0.7) 61.4 (1.0) 81.5 (1.0)

*All animals in a fl ock have the same ID.
USDA APHIS VS / 45 

Section I: Population Estimates–B. Flock Management

A higher percentage of operations in the Central region used paint brands and ear marks 

(14.4 and 13.9 percent, respectively) than operations in the West region (5.1 and 

4.6 percent, respectively) and East region (2.7 and 3.7 percent, respectively).

B.7.b. Percentage of operations with one or more ewes by fl ock ID method(s) used and 

by region:

Percent Operations (1 or more ewes)

Region

West Central East

Flock ID method* Pct.

Std.

error Pct.

Std.

error Pct.

Std.

error

Scrapie program ear tag 42.0 (2.2) 53.5 (1.5) 56.4 (1.6)

Other ear tag 14.6 (1.7) 18.9 (1.4) 17.4 (1.2)

Tattoo 1.1 (0.5) 0.9 (0.3) 1.2 (0.3)

Paint brand 5.1 (0.9) 14.4 (0.9) 2.7 (0.5)

Ear mark 4.6 (0.8) 13.9 (0.8) 3.7 (0.7)

Other 0.1 (0.0) 0.7 (0.2) 0.4 (0.2)

At least one form of ID 50.9 (2.3) 64.7 (1.6) 63.1 (1.5)

*All animals in a fl ock have the same ID.

Photograph courtesy of Camilla Kristensen.
46 / Sheep 2011

Section I: Population Estimates–B. Flock Management

A higher percentage of herded/open range operations (40.7 percent) used paint brands 

than fenced range operations (15.3 percent) and pasture operations (7.2 percent).

B.7.c. Percentage of operations with 20 or more ewes by fl ock ID method(s) used and by 

primary fl ock type:

Percent Operations (20 or more ewes)

Primary Flock Type

Herded/

open range Fenced range Pasture

Flock ID method* Pct.

Std.

error Pct.

Std.

error Pct.

Std.

error

Scrapie 

program ear tag 58.8 (5.3) 71.3 (2.1) 74.4 (1.4)

Other ear tag 20.6 (2.8) 19.6 (1.7) 21.6 (1.3)

Tattoo 0.6 (0.4) 0.7 (0.2) 1.8 (0.4)

Paint brand 40.7 (4.6) 15.3 (1.2) 7.2 (0.7)

Ear mark 31.1 (3.4) 21.7 (1.6) 6.0 (0.7)

Other 1.2 (0.6) 0.6 (0.2) 0.4 (0.2)

At least one 

form of ID 73.7 (5.7) 81.6 (1.9) 82.1 (1.2)

*All animals in a fl ock have the same ID.
USDA APHIS VS / 47 

Section I: Population Estimates–B. Flock Management

8. Individual-animal ID

Note: Estimates in this section do not include operations that were primarily dry lot/

feedlot.

A higher percentage of operations with 20 or more ewes (93.6 percent) used at least one 

form of individual-animal ID compared with operations with 1 or more ewes 

(88.6 percent). A total of 83.2 percent of very small operations had at least one form of ID, 

while at least 92 percent of small, medium, or large operations had at least one form of 

ID. The scrapie program ear tag was the most commonly used form of individual-animal 

ID; 61.4 percent of operations with one or more ewes and 73.7 percent of operations with 

20 or more ewes used this method of ID.

B.8.a. Percentage of operations by individual-animal ID method(s) used and by fl ock size:

Percent Operations 

Flock Size (number of ewes)

Very small

(fewer 

than 20)

Small

(20–99) 

Medium

(100–499)

Large

(500 or 

more)

All 

operations

(1 or more)

Operations 

with 20

or more 

Individual ID 

method Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Scrapie 

program 

ear tag

48.1 (1.8) 72.7 (1.4) 75.6 (1.4) 78.3 (1.5) 61.4 (1.0) 73.7 (1.1)

Other ear tag 37.7 (1.8) 55.2 (1.6) 58.1 (1.7) 42.2 (1.8) 46.7 (1.1) 55.1 (1.2)

Electronic ID 0.2 (0.2) 0.5 (0.2) 0.7 (0.3) 1.1 (0.4) 0.4 (0.1) 0.6 (0.2)

Tattoo 2.8 (0.7) 5.8 (0.7) 5.5 (0.9) 4.2 (0.8) 4.3 (0.4) 5.6 (0.6)

Paint brand 4.1 (0.7) 16.0 (1.1) 29.0 (1.5) 35.1 (1.6) 12.3 (0.6) 19.9 (0.9)

Ear mark 5.9 (0.9) 12.1 (1.0) 29.1 (1.6) 46.3 (1.9) 12.0 (0.6) 17.7 (0.8)

Physical traits 31.6 (1.7) 26.5 (1.4) 18.8 (1.4) 14.0 (1.3) 27.7 (1.0) 24.2 (1.1)

Other 2.1 (0.6) 1.4 (0.4) 1.1 (0.3) 1.9 (0.5) 1.7 (0.3) 1.3 (0.3)

At least one 

form of ID 83.2 (1.4) 93.1 (0.9) 95.5 (0.6) 92.4 (0.9) 88.6 (0.7) 93.6 (0.6)
48 / Sheep 2011

Section I: Population Estimates–B. Flock Management

0 20 40 60 80 100

Scrapie

program ear tag

Other ear tag

Electronic ID

Tattoo

Paint brand

Ear mark

Physical traits

Other

At least one

form of ID

Percent

ID method

Percentage of all operations by individual-animal ID method(s) used 

61.4

46.7

0.4

4.3

12.3

12.0

27.7

1.7

88.6
USDA APHIS VS / 49 

Section I: Population Estimates–B. Flock Management

A higher percentage of operations in the Central region (19.5 percent) used ear marks to 

individually identify their sheep compared with operations in the West region (7.5 percent) 

and East region (8.6 percent). This relationship was also true for paint-brand ID.

B.8.b. Percentage of operations by individual-animal ID method(s) used and by region:

Percent Operations (1 or more ewes)

Region

West Central East

Individual ID method Pct.

Std.

error Pct.

Std.

error Pct.

Std.

error

Scrapie program ear tag 48.1 (2.4) 59.3 (1.6) 67.9 (1.5)

Other ear tag 42.9 (2.4) 45.4 (1.8) 49.1 (1.6)

Electronic ID 0.0 (0.0) 0.2 (0.1) 0.6 (0.2)

Tattoo 6.9 (1.2) 3.0 (0.5) 4.2 (0.7)

Paint brand 8.1 (1.2) 18.0 (1.0) 10.0 (0.9)

Ear mark 7.5 (1.1) 19.5 (1.2) 8.6 (0.9)

Physical traits 25.8 (2.2) 25.8 (1.5) 29.8 (1.5)

Other 1.5 (0.6) 0.8 (0.2) 2.4 (0.6)

At least one form of ID 81.3 (1.9) 88.4 (1.4) 91.5 (1.0)
50 / Sheep 2011

Section I: Population Estimates–B. Flock Management

A lower percentage of herded/open range operations used scrapie ear tags than fenced 

range and pasture operations.

B.8.c. Percentage of operations with 20 or more ewes by individual-animal ID method(s) 

used and by primary fl ock type:

Percent Operations (20 or more ewes)

Primary Flock Type

Herded/

open range Fenced range Pasture

Individual-animal 

ID method Pct.

Std. 

error Pct.

Std. 

error Pct.

Std.

error

Scrapie 

program ear tag 58.8 (5.3) 73.4 (2.1) 74.4 (1.4)

Other ear tag 36.3 (4.9) 44.9 (2.2) 60.4 (1.5)

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

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)

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

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 

form of ID 91.7 (3.5) 92.3 (1.3) 94.3 (0.8)
USDA APHIS VS / 51 

Section I: Population Estimates–C. Breeding Management

Note: Estimates in this section do not include operations that were primarily dry lot/

feedlot.

Age, weather, time of breeding, and prebreeding practices can all affect reproductive 

outcome and should be considered when breeding ewes. As expected, about 98 percent 

of operations in all size groups bred ewes during 2010. 

1. Reproductive practices

C.1.a. Percentage of operations that bred any ewes during 2010, by fl ock size: 

Reproductive performance can be improved by intensive management practices such 

as fl ushing ewes, crutching, using teaser rams, breeding marks, ultrasound, breeding 

soundness exams, udder palpations, embryo transfer, and estrous synchronization. 

Flushing provides 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 prior to 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 (testicular 

palpation and size evaluation, and semen evaluation) should be the primary basis for this 

exam. 

For operations with 20 or more ewes, 99.6 percent conducted some form of reproductive 

practice. The most commonly performed practice was fl ushing ewes prior to breeding 

(52.8 percent of operations). A higher percentage of small operations (22.6 percent) 

used breeding marks compared with large operations (8.8 percent). A higher percentage 

of large operations (15.0 percent) used ultrasound as part of their breeding strategy 

compared with medium and small operations (8.1 and 6.2 percent, respectively).

C. Breeding 

Management

Percent Operations

Flock Size (number of ewes)

Very small

(fewer 

than 20)

Small

(20–99) 

Medium

(100–499)

Large

(500 or more)

All

operations

(1 or more)

Operations 

with 20 

or more

Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

98.2 (0.4) 98.9 (0.5) 99.4 (0.3) 98.4 (0.3)
52 / Sheep 2011

Section I: Population Estimates–C. Breeding Management

C.1.b. For operations that bred any ewes during 2010, percentage of operations by 

reproductive practice and by fl ock size: 

Percent Operations 

Flock Size (number of ewes)

Very small

(fewer 

than 20)

Small

(20–99) 

Medium

(100–499)

Large

(500 or 

more)

All 

operations

(1 or more)

Operations 

with 20

or more 

Reproductive 

practice Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Flushing 49.9 (1.5) 61.4 (1.6) 58.0 (1.7) 52.8 (1.2)

Crutching 21.7 (1.3) 23.7 (1.4) 35.4 (1.7) 22.9 (1.0)

Teaser ram 8.8 (0.9) 12.0 (1.1) 11.6 (1.2) 9.7 (0.7)

Breeding mark 22.6 (1.3) 19.6 (1.4) 8.8 (1.0) 21.1 (1.0)

Ultrasound 

(pregnancy 

diagnosis, fetal 

counting)

6.2 (0.8) 8.1 (0.9) 15.0 (1.3) 7.1 (0.6)

Breeding 

soundness 

exam (rams)

21.0 (1.3) 26.3 (1.5) 42.7 (1.8) 23.4 (1.0)

Udder palpation 

or bagging 34.3 (1.4) 45.9 (1.6) 59.9 (1.7) 38.3 (1.1)

Embryo 

transfer 1.7 (0.5) 1.0 (0.4) 1.4 (0.5) 1.5 (0.3)

Estrus 

synchronization 6.9 (0.8) 6.7 (0.9) 3.2 (0.6) 6.6 (0.6)

Any 99.5 (0.3) 99.8 (0.2) 100.0 (0.0) 99.6 (0.2)
USDA APHIS VS / 53 

Section I: Population Estimates–C. Breeding Management

0 20 40 60 80 100

Flushing

Crutching

(prelambing shearing)

Teaser ram

Breeding mark

Ultrasound (pregnancy

diagnosis, fetal counting)

Breeding soundness

exam (rams)

Udder palpation

or bagging

Embryo transfer

Estrus

synchronization

Percent

Reproductive

practice

For operations with 20 or more ewes that bred any ewes during 2010, 

percentage of operations by reproductive practice

Any

52.8

22.9

9.7

21.1

7.1

23.4

38.3

1.5

6.6

99.6
54 / Sheep 2011

Section I: Population Estimates–C. Breeding Management

A higher percentage of operations in the East region (63.8 percent) fl ushed their ewes 

prior to breeding than did operations in the West and Central regions (43.0 and 

44.5 percent, respectively). Just 3.8 percent of operations in the Central region, 

7.7 percent in the East region, and 10.5 percent in the West region used estrus 

synchronization. The regional percentage of operations that used breeding marks ranged 

from 12.9 percent in the Central region to 28.4 percent in the East region. 

C.1.c. For operations with 20 or more ewes that bred any ewes during 2010, percentage 

of operations by reproductive practice and by region:

Percent Operations (20 or more ewes)

Region

West Central East

Reproductive practice Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Flushing 43.0 (3.3) 44.5 (1.6) 63.8 (1.9)

Crutching 29.6 (3.0) 19.3 (1.1) 23.7 (1.7)

Teaser ram 11.9 (2.1) 7.1 (0.9) 11.1 (1.2)

Breeding mark 21.4 (2.8) 12.9 (1.1) 28.4 (1.7)

Ultrasound (pregnancy 

diagnosis, fetal counting) 5.4 (1.4) 5.5 (0.7) 9.2 (1.1)

Breeding soundness 

exam (rams) 25.1 (2.8) 25.2 (1.4) 21.3 (1.6)

Udder palpation or bagging 45.3 (3.3) 34.2 (1.3) 39.4 (1.9)

Embryo transfer 2.3 (1.0) 0.7 (0.4) 2.0 (0.6)

Estrus synchronization 10.5 (2.0) 3.8 (0.6) 7.7 (1.1)

Any 99.7 (0.3) 100.0 (0.0) 99.4 (0.4)
USDA APHIS VS / 55 

Section I: Population Estimates–C. Breeding Management

A lower percentage of fenced-range and pasture operations (6.4 and 10.1 percent, 

respectively) used a teaser ram as part of their breeding strategy compared with herded/

open range operations (28.1 percent).

C.1.d. For operations with 20 or more ewes that bred any ewes during 2010, percentage 

of operations by reproductive practice and by primary fl ock type:

Percent Operations (20 or more ewes)

Primary Flock Type

Herded/

open range Fenced range Pasture

Reproductive practice Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Flushing 47.6 (5.0) 43.8 (2.1) 57.0 (1.5)

Crutching 28.0 (3.4) 19.3 (1.6) 24.3 (1.3)

Teaser ram 28.1 (5.6) 6.4 (1.0) 10.1 (0.9)

Breeding mark 6.9 (2.3) 14.9 (1.6) 24.8 (1.3)

Ultrasound (pregnancy 

diagnosis, fetal counting) 9.8 (1.7) 5.3 (0.9) 7.9 (0.8)

Breeding soundness 

exam (rams) 33.5 (3.7) 24.1 (1.8) 22.6 (1.3)

Udder palpation or 

bagging 42.1 (4.3) 31.7 (1.8) 41.1 (1.5)

Embryo transfer 0.3 (0.2) 1.4 (0.6) 1.5 (0.4)

Estrus synchronization 2.0 (0.6) 6.0 (1.1) 7.2 (0.8)

Any 100.0 (0.0) 99.0 (0.6) 99.9 (0.1)
56 / Sheep 2011

Section I: Population Estimates–C. Breeding Management

2. Breeding seasons

Sheep normally breed during fall, although the breeding season varies depending on 

geography, temperature, and breed. Many producers prefer fall lambing for a variety 

of reasons, including warmer weather for newborn lambs and for the often profi table 

Christmas to Easter holiday season. However, breeding in warm weather can adversely 

affect fertility and reduce embryo survival. Overall, 24.5 percent of operations with 20 or 

more ewes bred their ewes out of season (February to July). There was little difference 

by operation size or by region in the percentage of operations that bred ewes out of 

season.

C.2.a. For operations that bred any ewes during 2010, percentage of operations that bred 

ewes out of season (February to July), by fl ock size: 

C.2.b. For operations with 20 or more ewes that bred any ewes during 2010, percentage 

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

Percent Operations (20 or more ewes)

Region

West Central East

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

28.1 (3.0) 22.4 (1.6) 25.0 (1.7)

Percent Operations

Flock Size (number of ewes)

Very small 

(fewer 

than 20)

Small

(20–99) 

Medium

(100–499)

Large

(500 or more)

All

operations

(1 or more)

Operations 

with 20 

or more

Pct.

Std.

error Pct.

Std.

error Pct.

Std.

error Pct.

Std.

error Pct.

Std.

error Pct.

Std.

error

24.6 (1.4) 26.1 (1.5) 16.7 (1.4) 24.5 (1.1)
USDA APHIS VS / 57 

Section I: Population Estimates–C. Breeding Management

About 1 of 20 herded/open range operations (5.6 percent) bred ewes out of season, 

compared with about one-fourth of fenced-range and pasture operations (22.5 and 

26.3 percent, respectively). Many herded/open range operations that bred ewes out of 

season did so in July, as daylight hours began to shorten.

C.2.c. For operations with 20 or more ewes that bred any ewes during 2010, percentage 

of operations that bred ewes out of season (February to July), by primary fl ock type:

Percent Operations (20 or more ewes)

Primary Flock Type

Herded/open range Fenced range Pasture 

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

5.6 (2.2) 22.5 (2.0) 26.3 (1.4)

When ewes are isolated from all rams for at least one month, they typically ovulate 

within several days after rams are re-introduced. Often called the “ram effect,” this fi rst 

ovulation after rams are re-introduced is usually silent, with no signs of estrus and no 

breeding. Most ewes will ovulate and be bred within three to four weeks after rams are 

re-introduced. 
58 / Sheep 2011

Section I: Population Estimates–C. Breeding Management

Placing a ram with ewes was the most commonly used out-of-season breeding method 

(85.5 percent of operations). Certain breeds of sheep have a longer breeding period 

than other breeds and are more successful at out-of-season breeding. Genetic selection 

for ability to breed out of season was the second most common out-of-season breeding 

method used (33.8 percent of operations). 

C.2.d. For operations that bred any ewes out of season during 2010, percentage of 

operations by method used for out-of-season breeding (February to July), and by fl ock 

size: 

Percent Operations 

Flock Size (number of ewes)

Very small 

(fewer 

than 20)

Small

(20–99) 

Medium

(100–499)

Large

(500 or 

more)

All

operations

(1 or more)

Operations 

with 20 

or more

Out-ofseason 

breeding 

method Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Genetic 

selection for 

ability to breed 

out of season

31.9 (3.0) 39.3 (3.3) 37.1 (4.6) 33.8 (2.3)

Placing ram 

with ewes 85.3 (2.4) 85.1 (2.3) 92.5 (2.3) 85.5 (1.8)

Regulating light 0.6 (0.5) 0.7 (0.4) 2.3 (2.0) 0.7 (0.4)

Hormone 

treatments 

(CIDRS, 

hormone 

protocols, etc.)

11.0 (2.0) 15.1 (2.5) 1.8 (0.8) 11.6 (1.6)

Other 4.9 (1.4) 7.3 (1.7) 5.3 (1.8) 5.5 (1.1)
USDA APHIS VS / 59 

Section I: Population Estimates–C. Breeding Management

About three of four operations (75.5 percent) had one defi ned breeding season per year, 

while 11.9 percent of operations had two breeding seasons per year, and 10.0 percent 

had no defi ned breeding season. 

C.2.e. For operations that bred any ewes during 2010, percentage of operations by 

number of breeding seasons per year and by fl ock size:

Percent Operations 

Flock Size (number of ewes)

Very small 

(fewer 

than 20)

Small

(20–99) 

Medium

(100–499)

Large

(500 or 

more)

All

operations

(1 or more)

Operations 

with 20 

or more

Number of

breeding 

seasons Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

One defi ned 

breeding 

season per 

year

74.6 (1.4) 76.1 (1.5) 84.5 (1.4) 75.5 (1.1)

Two defi ned 

breeding 

seasons per 

year

12.0 (1.1) 12.6 (1.2) 9.3 (1.1) 11.9 (0.8)

Three defi ned 

breeding 

seasons 

per 2 years

2.4 (0.5) 3.0 (0.5) 3.1 (0.7) 2.5 (0.4)

No defi ned 

breeding 

season

11.1 (1.0) 8.3 (1.0) 3.1 (0.8) 10.0 (0.8)

Total 100.0 100.0 100.0 100.0
60 / Sheep 2011

Section I: Population Estimates–C. Breeding Management

C.2.f. For operations with 20 or more ewes that bred any ewes during 2010, percentage 

of operations by number of breeding seasons per year, and by region:

Percent Operations (20 or more ewes)

Region

West Central East

Number of breeding seasons Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

One defi ned breeding 

season per year 76.6 (2.9) 74.0 (1.6) 76.4 (1.6)

Two defi ned breeding 

seasons per year 13.8 (2.4) 9.3 (1.1) 13.6 (1.3)

Three defi ned breeding 

seasons per 2 years 2.7 (1.1) 1.4 (0.4) 3.5 (0.7)

No defi ned breeding season 6.9 (1.7) 15.3 (1.5) 6.4 (1.0)

Total 100.0 100.0 100.0
USDA APHIS VS / 61 

Section I: Population Estimates–C. Breeding Management

3. Breeding practices

Only 1.4 percent of operations had used artifi cial insemination to breed at least some 

ewes during the most recent breeding season, while 99.8 percent of operations had bred 

their ewes naturally, either by their own or another operation’s rams.

C.3.a. Percentage of operations by method used to breed (service) ewes during the 

most recent breeding season, and by fl ock size: 

Percent Operations 

Flock Size (number of ewes)

Very small 

(fewer 

than 20)

Small

(20–99) 

Medium

(100–499)

Large

(500 or 

more)

All

operations

(1 or more)

Operations 

with 20 

or more

Servicing 

method Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Artifi cial 

insemination 

(AI)

1.5 (0.4) 1.3 (0.4) 0.2 (0.1) 1.4 (0.3)

Natural, by this 

operation’s 

rams

96.8 (0.6) 99.2 (0.3) 99.0 (0.3) 97.4 (0.4)

Natural, 

by another 

operation’s 

rams

5.3 (0.7) 3.2 (0.6) 3.0 (0.6) 4.7 (0.5)

Natural, 

either by this 

operation’s 

or another 

operation’s ram

99.7 (0.2) 100.0 (0.0) 100.0 (0.0) 99.8 (0.1)
62 / Sheep 2011

Section I: Population Estimates–C. Breeding Management

C.3.b. Percentage of operations with 20 or more ewes by method used to breed 

(service) ewes during the most recent breeding season, and by region:

Percent Operations (20 or more ewes)

Region

West Central East

Servicing method Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Artifi cial insemination (AI) 1.9 (0.8) 0.8 (0.3) 1.8 (0.6)

Natural, by this 

operation’s rams 97.3 (1.1) 97.1 (0.6) 97.8 (0.6)

Natural, by another 

operation’s rams 4.6 (1.4) 4.1 (0.7) 5.3 (0.9)

Natural, either by this 

operation’s or another 

operation’s ram

100.0 (0.0) 100.0 (0.0) 99.6 (0.3)

Across fl ock types, over 9 of 10 operations had used their own rams to breed (service) 

ewes during the last breeding season. 

C.3.c. Percentage of operations with 20 or more ewes by method used to breed 

(service) ewes during the most recent breeding season, and by primary fl ock type:

Percent Operations (20 or more ewes)

Primary Flock Type

Herded/

open range Fenced range Pasture

Servicing method Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Artifi cial insemination 

(AI) 0.0 (—) 1.6 (0.6) 1.4 (0.4)

Natural, by this 

operation’s rams 95.4 (2.7) 96.6 (0.9) 97.9 (0.5)

Natural, by another 

operation’s rams 7.6 (2.8) 3.8 (0.8) 5.0 (0.7)

Natural, either by this 

operation’s or another 

operation’s ram

100.0 (0.0) 99.4 (0.4) 100.0 (0.0)
USDA APHIS VS / 63 

Section I: Population Estimates–C. Breeding Management

Overall, 97.7 percent of ewes were bred naturally by using the operation’s rams. 

C.3.d. Percentage of ewes by method used to breed (service) ewes during the most 

recent breeding season, and by fl ock size: 

Percent Ewes 

Flock Size (number of ewes)

Very small 

(fewer 

than 20)

Small

(20–99) 

Medium

(100–499)

Large

(500 or 

more)

All

operations

(1 or more)

Operations 

with 20 

or more

Servicing 

method Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Artifi cial 

insemination 

(AI)

0.5 (0.2) 0.2 (0.1) 0.0 (0.0) 0.2 (0.0)

Natural, by this 

operation’s 

rams

96.2 (0.6) 98.9 (0.3) 97.7 (0.6) 97.7 (0.4)

Natural, by 

another 

operation’s 

rams

3.3 (0.6) 1.0 (0.3) 2.3 (0.6) 2.2 (0.4)

Total 100.0 100.0 100.0 100.0
64 / Sheep 2011

Section I: Population Estimates–C. Breeding Management

C.3.e. Percentage of ewes by method used to breed (service) ewes during the most 

recent breeding season, and by primary fl ock type:

Percent Ewes*

Primary Flock Type

Herded/

open range Fenced range Pasture

Servicing method Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Artifi cial 

insemination (AI) 0.0 (—) 0.2 (0.1) 0.3 (0.1)

Natural, by this 

operation’s rams 95.7 (1.2) 98.6 (0.3) 98.3 (0.3)

Natural, by another 

operation’s rams 4.3 (1.2) 1.3 (0.3) 1.5 (0.3)

Total 100.0 100.0 100.0

*On operations with 20 or more ewes.

For the 1.4 percent of operations that artifi cially inseminated ewes, 79.3 percent used 

frozen semen and 28.6 percent used fresh semen.

C.3.f. For operations with 20 or more ewes that artifi cially inseminated ewes in 2010,* 

percentage of operations by type of semen used: 

Semen type

Percent operations

(20 or more ewes) Std. error

Fresh 28.6 (9.8)

Frozen 79.3 (9.1)

*During most recent breeding season.
USDA APHIS VS / 65 

Section I: Population Estimates–C. Breeding Management

Most operations (81.5 percent) obtained their semen from another operation.

C.3.g. For operations with 20 or more ewes that artifi cially inseminated ewes during 

2010,* percentage of operations by source of semen and by fl ock size: 

Semen source

Percent operations

(20 or more ewes) Std. error

This operation 34.8 (10.3)

Other operation 81.5 (8.1)

*For the most recent breeding season.

4. Ram and ewe lamb selection

Since rams account for half the fl ock genetics, ram selection is an important determinant 

of fl ock health and productivity. The National Sheep Improvement Program (NSIP) 

offers a genetic evaluation system for U.S. sheep fl ocks. NSIP has historically provided 

expected progeny differences (EPDs) 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 (EBVs) using breed-specifi c 

genetic parameters. These values allow for genetic evaluations for carcass traits and 

parasite resistance across breeds, as well as other evaluations not previously available. 

For operations that used rams for natural breeding during 2010, 77.4 percent reported 

that visual appearance was a very important characteristic while 69.8 percent indicated 

that meat production was very important. A total of 60.3 percent of operations identifi ed 

soundness of rams’ fl ock of origin as very important.
66 / Sheep 2011

Section I: Population Estimates–C. Breeding Management

C.4.a. For operations with 20 or more ewes that used rams for natural breeding during 

2010, percentage of operations by importance of ram selection characteristics:

Percent Operations (20 or more ewes)

Importance

Very 

important 

Somewhat 

important

Not

important

Ram characteristic Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Total

Visual appearance 77.4 (1.1) 18.8 (1.0) 3.9 (0.5) 100.1

Scrotal circumference, 

semen quality 35.3 (1.2) 31.1 (1.2) 33.6 (1.2) 100.0

Wool quality 21.0 (0.9) 22.9 (1.0) 56.1 (1.2) 100.0

Meat production 69.8 (1.2) 18.3 (1.0) 11.9 (0.9) 100.0

Ram’s average daily 

gain as a lamb 28.4 (1.1) 29.5 (1.1) 42.0 (1.2) 99.9

Pedigree 33.1 (1.2) 30.3 (1.2) 36.6 (1.2) 100.0

Breeding history 31.3 (1.2) 29.8 (1.2) 38.9 (1.2) 100.0

National Sheep 

Improvement Program 

(NSIP) records

5.7 (0.5) 13.5 (0.8) 80.8 (1.0) 100.0

Genetic resistance 

to scrapie 

(RR genotype)

39.3 (1.2) 23.3 (1.1) 37.3 (1.2) 99.9

Genetic resistance to 

intestinal parasites 30.2 (1.1) 25.4 (1.1) 44.4 (1.2) 100.0

Genetic resistance 

to other diseases 7.7 (0.7) 3.4 (0.5) 88.9 (0.8) 100.0

Soundness of ram’s 

fl ock of origin 60.3 (1.2) 19.7 (1.0) 20.0 (1.0) 100.0

Nonram-related 

reasons (cost, 

proximity, availability)

27.5 (1.1) 37.6 (1.2) 34.9 (1.2) 100.0

A higher percentage of large operations (80.3 percent) rated meat production as a very 

important characteristic when selecting rams than did small operations (67.7 percent). 

NSIP records were very important for a higher percentage of large operations 

(11.4 percent) than small operations (4.6 percent).
USDA APHIS VS / 67 

Section I: Population Estimates–C. Breeding Management

C.4.b. For operations with 20 or more ewes that used rams for natural breeding during 

2010, percentage of operations by ram characteristics that were very important when 

selecting rams, and by fl ock size: 

Percent Operations (20 or more ewes)

Flock Size (number of ewes)

Very small 

(fewer 

than 20)

Small

(20–99) 

Medium

(100–499)

Large

(500 or 

more)

All

operations

(1 or more)

Operations 

with 20 

or more

Ram 

characteristic Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Visual 

appearance 76.7 (1.4) 78.4 (1.4) 81.6 (1.5) 77.4 (1.1)

Scrotal 

circumference, 

semen quality

32.6 (1.5) 40.5 (1.7) 48.8 (1.9) 35.3 (1.2)

Wool quality 17.0 (1.2) 25.5 (1.4) 54.0 (1.8) 21.0 (0.9)

Meat 

production 67.7 (1.6) 74.1 (1.5) 80.3 (1.5) 69.8 (1.2)

Ram’s average 

daily gain as a 

lamb

27.7 (1.5) 29.7 (1.6) 32.2 (1.8) 28.4 (1.1)

Pedigree 33.3 (1.5) 32.5 (1.7) 32.6 (1.8) 33.1 (1.2)

Breeding 

history 31.8 (1.5) 30.1 (1.7) 28.4 (1.7) 31.3 (1.2)

National Sheep 

Improvement 

Program (NSIP) 

records

4.6 (0.7) 7.8 (0.9) 11.4 (1.2) 5.7 (0.5)

Genetic 

resistance 

to scrapie 

(RR genotype)

40.4 (1.6) 35.7 (1.7) 39.1 (1.8) 39.3 (1.2)

Genetic 

resistance 

to intestinal 

parasites

30.3 (1.5) 29.2 (1.6) 31.9 (1.8) 30.2 (1.1)

Genetic 

resistance 

to other 

diseases

7.8 (0.9) 7.6 (1.0) 6.5 (0.9) 7.7 (0.7)

Soundness of 

ram’s fl ock of 

origin

58.9 (1.6) 64.6 (1.7) 61.8 (1.8) 60.3 (1.2)

Nonram-related 

reasons (cost, 

proximity, 

availability)

27.7 (1.5) 27.0 (1.6) 27.8 (1.6) 27.5 (1.1)
68 / Sheep 2011

Section I: Population Estimates–C. Breeding Management

Overall, 76.2 percent of operations had replacement ram or ewe lambs. As expected, a 

higher percentage of large operations than very small operations had replacement ram or 

ewe lambs (91.3 and 65.3 percent, respectively).

C.4.c. Percentage of operations that had replacement ram or ewe lambs, by fl ock size:

A slightly higher percentage of herded/open range operations had replacement ram or 

ewe lambs than other fl ock types.

C.4.d. Percentage of operations that had replacement rams or ewe lambs, by primary 

fl ock type:

Percent Operations (20 or more ewes)

Primary Flock Type

Herded/

open range Fenced range Pasture 

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

95.0 (1.8) 83.8 (1.7) 86.7 (1.1)

Percent Operations

Flock Size (number of ewes)

Very small

(fewer 

than 20)

Small

(20–99) 

Medium

(100–499)

Large

(500 or more)

All

operations

(1 or more)

Operations 

with 20 

or more

Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

65.3 (1.8) 85.3 (1.1) 87.7 (1.2) 91.3 (1.1) 76.2 (1.0) 86.2 (0.9)
USDA APHIS VS / 69 

Section I: Population Estimates–C. Breeding Management

More than 80 percent of the replacement ram and ewe lambs were born and raised on 

the operation.

C.4.e. For operations that had replacement ram or ewe lambs in 2010, percentage of 

replacement ram and ewe lambs born and raised on the operation and percentage 

acquired elsewhere:

Source of 

replacement lambs

Percent 

rams

Std. 

error

Percent 

ewes

Std. 

error

Born and raised on this operation 81.0 (2.6) 82.7 (1.5)

Acquired elsewhere 19.0 (2.6) 17.3 (1.5)

Total 100.0 100.0
70 / Sheep 2011

Section I: Population Estimates–C. Breeding Management

The majority of operations that acquired replacement ewe lambs rated visual 

appearance/conformation (79.7 percent), meat production (69.8 percent), and health 

status of fl ock of origin (61.8 percent) as very important ewe lamb characteristics.

C.4.f. For operations that acquired replacement ewe lambs during 2010, percentage of 

operations by importance of the following ewe lamb selection characteristics:

Percent Operations (20 or more ewes)

Importance

Very 

important 

Somewhat 

important

Not

important

Ewe lamb 

characteristic* Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Total

Visual appearance/

conformation 79.7 (2.5) 17.4 (2.3) 2.9 (1.2) 100.0

Wool quality 20.5 (2.3) 22.6 (2.5) 56.9 (3.1) 100.0

Meat production 69.8 (2.8) 20.1 (2.4) 10.1 (1.9) 100.0

Ability to breed 

out of season 14.2 (2.3) 19.4 (2.5) 66.4 (3.0) 100.0

National Sheep 

Improvement Program 

records (NSIP) or EPD

5.6 (1.5) 15.3 (2.4) 79.1 (2.7) 100.0

Ability to have 

multiple lambs 47.0 (3.2) 30.0 (2.9) 22.9 (2.7) 100.0

Health status of 

fl ock origin 61.8 (3.1) 24.3 (2.7) 13.9 (2.3) 100.0

Early sexual maturity 22.6 (2.7) 38.5 (3.1) 38.9 (3.1) 100.0

Pedigree 36.1 (3.0) 33.4 (3.0) 30.5 (2.9) 100.0

Average daily gain 26.6 (2.8) 37.8 (3.1) 35.6 (3.1) 100.0

Genetic resistance 

to scrapie 

(RR genotype)

48.3 (3.2) 25.0 (2.8) 26.7 (2.8) 100.0

Genetic resistance to 

intestinal parasites 33.8 (3.1) 25.1 (2.7) 41.2 (3.2) 100.0

Other genetic 

resistance 7.3 (1.7) 3.4 (1.3) 89.4 (2.1) 100.0

Nonewe-related 

reasons (cost, 

availability, etc.)

22.8 (2.7) 40.6 (3.1) 36.6 (3.0) 100.0

*For replacement ewe lambs that were acquired elsewhere.
USDA APHIS VS / 71 

Section I: Population Estimates–C. Breeding Management

Nearly 6 of 10 large operations (59.4 percent) rated wool quality as a very important 

characteristic for choosing replacement ewes, while about 1 of 5 operations with 20 or 

more ewes (20.5 percent) rated wool quality as a very important characteristic. 

C.4.g. For operations with 20 or more ewes that acquired replacement ewe lambs during 

2010, percentage of operations that rated the following ewe lamb characteristics as very

important for selecting replacement ewe lambs, by fl ock size: 

Percent Operations 

Flock Size (number of ewes)

Very small

(fewer 

than 20)

Small

(20–99) 

Medium

(100–499)

Large

(500 or 

more)

All

operations 

(1 or more)

Operations 

with 20 

or more

Ewe lamb 

characteristic* Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Visual 

appearance/

conformation

79.7 (3.3) 79.0 (3.6) 82.2 (3.2) 79.7 (2.5)

Wool quality 14.2 (2.9) 28.9 (3.8) 59.4 (4.2) 20.5 (2.3)

Meat 

production 73.7 (3.6) 59.1 (4.4) 62.1 (4.6) 69.8 (2.8)

Ability to breed 

out of season 12.7 (3.0) 18.2 (3.8) 17.4 (3.5) 14.2 (2.3)

National Sheep 

Improvement 

Program 

records (NSIP) 

or EPD

4.3 (1.8) 10.8 (3.0) 3.4 (1.5) 5.6 (1.5)

Ability to have 

multiple lambs 47.8 (4.2) 45.6 (4.4) 43.4 (4.5) 47.0 (3.2)

Health status 

of fl ock origin 61.6 (4.1) 60.8 (4.3) 66.9 (4.2) 61.8 (3.1)

Early sexual 

maturity 21.4 (3.5) 26.5 (4.0) 23.6 (3.8) 22.6 (2.7)

Pedigree 34.5 (4.0) 42.9 (4.4) 32.4 (4.4) 36.1 (3.0)

Average 

daily gain 26.0 (3.8) 29.2 (4.1) 25.1 (3.7) 26.6 (2.8)

Genetic 

resistance 

to scrapie 

(RR genotype)

50.6 (4.2) 42.7 (4.4) 40.5 (4.6) 48.3 (3.2)

Genetic 

resistance 

to intestinal 

parasites

34.9 (4.1) 29.4 (4.1) 35.2 (4.4) 33.8 (3.1)

Other genetic 

resistance 7.8 (2.2) 6.2 (2.1) 4.8 (2.1) 7.3 (1.7)

Nonewe-related 

reasons (cost, 

availability, etc.)

22.7 (3.6) 21.6 (3.8) 27.6 (4.1) 22.8 (2.7)

*For replacement ewe lambs that were acquired elsewhere.
72 / Sheep 2011

Section I: Population Estimates–C. Breeding Management

Wool quality was a very important characteristic for replacement ewe lambs on 

63.7 percent of herded/open range operations. A lower percentage of fenced-range 

operations (33.0 percent) and pasture operations (13.4 percent) rated wool quality as a 

very important characteristic. As shown in Table A.1.c., a higher percentage of herded/

open range operations had fi ne wool, white-faced sheep than fenced range or pasture 

operations. 

C.4.h. For operations with 20 or more ewes that acquired replacement ewe lambs during 

2010, percentage of operations that rated the following ewe lamb characteristics as very 

important for selecting replacement ewe lambs, by primary fl ock type:

Percent Operations (20 or more ewes)

Primary Flock Type

Herded/

open range Fenced range Pasture

Ewe lamb 

characteristic* Pct.

Std. 

error Pct.

Std. 

error Pct.

Std.

error

Visual appearance/

conformation 79.7 (5.6) 84.5 (4.1) 77.6 (3.3)

Wool quality 63.7 (6.7) 33.0 (5.3) 13.4 (2.5)

Meat production 64.1 (7.3) 68.8 (5.3) 70.8 (3.5)

Ability to breed 

out of season 9.1 (4.0) 16.4 (4.8) 13.8 (2.7)

National Sheep 

Improvement Program 

records (NSIP) or EPD

1.9 (1.1) 9.9 (3.8) 4.2 (1.6)

Ability to have 

multiple lambs 37.5 (7.0) 40.9 (6.1) 50.5 (3.9)

Health status 

of fl ock origin 66.3 (6.1) 67.1 (5.7) 59.8 (3.8)

Early sexual maturity 10.7 (3.9) 30.5 (5.8) 20.6 (3.1)

Pedigree 35.4 (7.2) 42.4 (6.1) 33.5 (3.6)

Average daily gain 10.2 (2.9) 27.5 (5.5) 27.4 (3.5)

Genetic resistance 

to scrapie (RR) 33.2 (7.0) 47.4 (6.2) 49.2 (3.9)

Genetic resistance to 

intestinal parasites 25.3 (6.6) 38.1 (6.0) 33.1 (3.8)

Other genetic resistance 6.7 (4.2) 5.4 (2.7) 8.1 (2.2)

Non-ewe related reasons 

(cost, availability, etc.) 25.4 (6.3) 26.9 (5.6) 21.7 (3.3)

*For replacement ewe lambs that were acquired elsewhere.
USDA APHIS VS / 73 

Section I: Population Estimates–C. Breeding Management

C.4.i. For the most recent lamb crop, percentage of ewes expected to lamb, by breeding 

location and by fl ock size: 

C.4.j. For the most recent lamb crop, percentage of ewes expected to lamb, by breeding 

location and by primary fl ock type:

Percent Ewes* 

Primary Flock Type

Herded/open range Fenced range Pasture

Breeding location Pct.

Std.

error Pct.

Std.

error Pct.

Std.

error

Bred on operation 98.4 (0.6) 99.5 (0.2) 98.8 (0.3)

Purchased pregnant 1.6 (0.6) 0.5 (0.2) 1.2 (0.3)

Total 100.0 100.0 100.0

*On operations with 20 or more ewes.

Percent Ewes 

Flock Size (number of ewes)

Very small

(fewer 

than 20)

Small

(20–99) 

Medium

(100–499)

Large

(500 or 

more)

All

operations 

(1 or more)

Operations 

with 20 

or more

Breeding 

location Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Bred on 

operation 95.1 (2.3) 99.1 (0.3) 98.5 (0.5) 99.0 (0.3) 98.7 (0.2) 98.9 (0.2)

Purchased 

pregnant 4.9 (2.3) 0.9 (0.3) 1.5 (0.5) 1.0 (0.3) 1.3 (0.2) 1.1 (0.2)

Total 100.0 100.0 100.0 100.0 100.0 100.0
74 / Sheep 2011

Section I: Population Estimates–C. Breeding Management

5. Outcome of ewes expected to lamb

The increased demand for lamb and wool products in the United States has resulted in 

high prices for sheep products and a sheep industry goal to increase sheep numbers. 

The new TwoPLUS program of the American Sheep Industry Association encourages 

producers to grow their fl ocks by 2 ewes per 100 ewes, increase the average birth rate 

per ewe to 2 lambs per year, and increase the harvested lamb crop by 2 percent. For this 

to occur, a higher percentage of ewes must deliver multiple lambs. It can be diffi cult for 

producers to distinguish between ewes that did not become pregnant and ewes that did 

become pregnant but aborted prior to lambing; therefore, the following percentages are 

only rough estimates of ewe lambing outcomes. 

A slightly lower percentage of ewes expected to lamb on very small operations 

(40.2 percent) had only single live births compared with ewes on large operations 

(49.5 percent). It follows, then, that a higher percentage of ewes on very small operations 

(54.3 percent) had multiple lambs with at least one live birth compared with ewes on large 

operations (42.8 percent). A lower percentage of ewes on very small operations aborted 

(0.4 percent) or became pregnant but died prior to lambing (0.5 percent) compared with 

ewes on large operations (1.1 and 1.2 percent, respectively).
USDA APHIS VS / 75 

Section I: Population Estimates–C. Breeding Management

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

of ewes by breeding outcome and by fl ock size: 

Percent Ewes 

Flock Size (number of ewes)

Very small

(fewer 

than 20)

Small

(20–99) 

Medium

(100–499)

Large

(500 or 

more)

All

operations 

(1 or more)

Operations 

with 20 

or more

Breeding 

outcome Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Had only single 

live births 40.2 (2.7) 38.2 (1.0) 42.2 (0.8) 49.5 (1.0) 45.0 (0.6) 45.3 (0.6)

Had multiple 

lambs with at 

least one live 

birth

54.3 (2.5) 56.3 (1.0) 51.2 (0.9) 42.8 (1.0) 48.1 (0.6) 47.8 (0.6)

Had only dead 

births 1.8 (0.2) 1.8 (0.1) 1.6 (0.1) 1.4 (0.1) 1.6 (0.1) 1.5 (0.1)

Aborted 0.4 (0.1) 0.6 (0.1) 0.7 (0.1) 1.1 (0.1) 0.9 (0.1) 0.9 (0.1)

Became 

pregnant, but 

died prior to 

lambing

0.5 (0.1) 0.7 (0.1) 0.9 (0.1) 1.2 (0.1) 1.0 (0.1) 1.0 (0.1)

Became 

pregnant, but 

removed from 

the operation 

prior to lambing

0.3 (0.3) 0.3 (0.1) 0.5 (0.1) 0.5 (0.1) 0.4 (0.1) 0.4 (0.1)

Did not become 

pregnant 2.4 (0.3) 2.0 (0.2) 2.8 (0.2) 3.6 (0.3) 3.0 (0.1) 3.0 (0.2)

Total 100.0 100.0 100.0 100.0 100.0 100.0
76 / Sheep 2011

Section I: Population Estimates–C. Breeding Management

A higher percentage of ewes that were expected to lamb in the West and Central regions 

(49.2 and 48.8 percent, respectively) had only single live births compared with ewes in 

East region (31.8 percent). Just under two-thirds of ewes in the East region 

(61.5 percent) had multiple lambs with at least one live birth, while less than half of ewes 

in the West region (43.8 percent) and Central region (44.3 percent) had multiple lambs 

with at least on live birth.

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

of ewes by breeding outcome and by region:

Percent Ewes*

Region

West Central East

Breeding outcome Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Had only single live births 49.2 (1.6) 48.8 (0.8) 31.9 (0.8)

Had multiple lambs with 

at least one live birth 43.8 (1.8) 44.3 (0.8) 61.3 (0.8)

Had only dead births 1.7 (0.1) 1.3 (0.1) 2.1 (0.1)

Aborted 1.1 (0.1) 0.8 (0.1) 0.8 (0.1)

Became pregnant, but died 

prior to lambing 1.0 (0.1) 1.0 (0.1) 0.9 (0.1)

Became pregnant, but removed 

from the operation prior to 

lambing

0.3 (0.1) 0.4 (0.1) 0.4 (0.1)

Did not become pregnant 2.8 (0.3) 3.2 (0.2) 2.6 (0.2)

Total 100.0 100.0 100.0

*On operations with one or more ewes.
USDA APHIS VS / 77 

Section I: Population Estimates–C. Breeding Management

Photograph courtesy of Camilla Kristensen
78 / Sheep 2011

Section I: Population Estimates–C. Breeding Management

About 4 of 10 ewes that were expected to lamb on pasture and herded/open range 

operations (37.1 and 41.0 percent, respectively) had only single live births compared with 

about 6 of 10 ewes on fenced-range operations (57.2 percent). Similarly, the percentage 

of ewes that had multiple lambs with at least one live birth was lower on fenced-range 

operations (36.4 percent) compared with pasture operations (56.0 percent) and herded/

open range operations (51.3 percent). Herded/open range fl ocks were sometimes 

uncertain how many lambs were born alive or born dead and often did not know how 

many ewes had only dead births or did not become pregnant. These estimates may 

refl ect this uncertainty.

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

by breeding outcome and by primary fl ock type:

Percent Ewes*

Primary Flock Type

Herded/

open range Fenced range Pasture

Breeding outcome Pct.

Std.

error Pct.

Std.

error Pct.

Std.

error

Had only single 

live births 41.0 (1.4) 57.2 (0.9) 37.1 (0.9)

Had multiple lambs with 

at least one live birth 51.3 (1.3) 36.4 (0.9) 56.0 (1.0)

Had only dead births 1.5 (0.1) 1.1 (0.1) 2.0 (0.1)

Aborted 0.9 (0.1) 0.8 (0.2) 0.9 (0.1)

Became pregnant, 

but died prior to lambing 1.5 (0.1) 0.9 (0.1) 0.8 (0.1)

Became pregnant, 

but removed from 

the operation prior to 

lambing

0.2 (0.1) 0.4 (0.2) 0.6 (0.1)

Did not become 

pregnant 3.5 (0.3) 3.1 (0.3) 2.7 (0.2)

Total 100.0 100.0 100.0

*On operations with 20 or more ewes.
USDA APHIS VS / 79 

Section I: Population Estimates–D. Reproductive Outcomes

Note: Dry lot and feedlot operations are not represented in this section.

To estimate productivity in a fl ock, producers must track the number of lambs born alive 

and the number born dead; however, for operations in which lambs are born on the 

open range without close monitoring, it is not practical to track lambing rates. For these 

operations, lamb processing (when lambs are docked, vaccinated, castrated, etc.) may 

be the fi rst time they are able to track their lambs. 

Without baseline information on lambing rates, it is diffi cult to provide answers to basic 

questions relative to reasons for low lambing rates. Abortions, poor mothering, lack of 

colostrum, pneumonia, or predators can be causes of low lambing rates. 

1. Lambs born

Close to 100.0 percent of operations had at least one lamb born alive in 2010. Some 

operations were new and had not lambed, while others were changing management 

strategies or had lost their pregnant ewes for one reason or another. 

D.1.a. Percentage of operations that had any lambs born in 2010, by fl ock size:

D.1.b. Percentage of operations that had any lambs born in 2010, by region:

Percent Operations (1 or more ewes)

Region

West Central East

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

100.0 (—) 99.5 (0.2) 99.7 (0.2)

D. Reproductive 

Outcomes

Percent Operations

Flock Size (number of ewes)

Very small 

(fewer 

than 20)

Small

(20–99) 

Medium

(100–499)

Large

(500 or more)

All

operations

(1 or more)

Operations 

with 20 

or more

Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

100.0 (—) 99.3 (0.3) 99.7 (0.2) 99.8 (0.2) 99.7 (0.1) 99.4 (0.2)
80 / Sheep 2011

Section I: Population Estimates–D. Reproductive Outcomes

D.1.c. Percentage of operations with 20 or more ewes that had any lambs born in 2010, 

by primary fl ock type:

Percent Operations (20 or more ewes)

Primary Flock Type

Herded/open range Fenced range Pasture 

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

100.0 (—) 99.1 (0.4) 99.5 (0.2)

2. Lambs born alive

Overall, 96.0 percent of lambs born were born alive. There was little difference in the 

percentage of lambs born alive for very small, small, and medium operations; however, 

the percentage of lambs born alive was higher for large operations than for the other fl ock 

sizes. The relatively high percentage of lambs born alive on large operations is likely due 

to the inability of these operations to detect dead-lamb births.

D.2.a. For the most recent lamb crop, percentage of lambs born alive and percentage 

born dead, by fl ock size:

Percent Lambs Born 

Flock Size (number of ewes)

Very small

(fewer 

than 20)

Small

(20–99) 

Medium

(100–499)

Large

(500 or 

more)

All

operations 

(1 or more)

Operations 

with 20 

or more

Status Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Born alive 94.6 (0.4) 95.3 (0.2) 95.7 (0.1) 96.7 (0.3) 96.0 (0.1) 96.1 (0.1)

Born dead 5.4 (0.4) 4.7 (0.2) 4.3 (0.1) 3.3 (0.3) 4.0 (0.1) 3.9 (0.1)

Total 100.0 99.9 100.0 100.0 100.0 100.0
USDA APHIS VS / 81 

Section I: Population Estimates–D. Reproductive Outcomes

The percentage of lambs born dead ranged from 3.4 percent in the West region to 

5.2 percent in the East region. 

D.2.b. For the most recent lamb crop, percentage of lambs born alive and percentage 

born dead, by region:

Percent Lambs Born*

Region

West Central East

Status Pct.

Std.

error Pct.

Std.

error Pct.

Std.

error

Born alive 96.6 (0.2) 96.5 (0.2) 94.8 (0.2)

Born dead 3.4 (0.2) 3.5 (0.2) 5.2 (0.2)

Total 100.0 100.0 100.0

*On operations with one or more ewes.

D.2.c. For the most recent lamb crop, percentage of lambs born alive and percentage 

born dead, by primary fl ock type:

Percent Lambs Born*

Primary Flock Type

Herded/open range Fenced range Pasture

Status Pct.

Std.

error Pct.

Std.

error Pct.

Std.

error

Born alive 96.4 (0.5) 96.7 (0.1) 95.5 (0.2)

Born dead 3.6 (0.5) 3.3 (0.1) 4.5 (0.2)

Total 100.0 100.0 100.0

*On operations with 20 or more ewes.
82 / Sheep 2011

Section I: Population Estimates–D. Reproductive Outcomes

3. Lambs docked

For operations that managed their sheep primarily on open range, lamb processing 

(when lambs are docked, vaccinated, castrated, etc.) may be the fi rst time these 

operations are able to view their sheep after lambing. During docking, herded/open range 

operations track lambs, vaccinate, ensure that all ewes are healthy, and perform other 

management measures. Not all operations dock any or all of their lambs, depending on 

whether animals are intended for replacements, show, market, or other uses.

Overall, operations with one or more ewes docked 81.5 percent of lambs born alive. 

Large operations docked a higher percentage of lambs born alive (87.7 percent) than 

very small operations (64.5 percent) or small operations (75.2 percent).

D.3.a. For the most recent lamb crop, percentage of lambs born alive that were docked, 

by fl ock size: 

Operations in the Central region docked a higher percentage of lambs born alive

(83.4 percent) than operations in the East region (74.9 percent).

D.3.b. For the most recent lamb crop, percentage of lambs born alive that were docked, 

by region:

Percent Lambs Born*

Region

West Central East

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

83.4 (2.7) 84.4 (0.9) 74.9 (1.4)

*On operations with one or more ewes.

Percent Lambs Born

Flock Size (number of ewes)

Very small

(fewer 

than 20)

Small

(20–99) 

Medium

(100–499)

Large

(500 or more)

All

operations

(1 or more)

Operations 

with 20 

or more

Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

64.5 (2.5) 75.2 (1.5) 81.4 (1.3) 87.7 (1.2) 81.5 (0.8) 82.7 (0.8)
USDA APHIS VS / 83 

Section I: Population Estimates–D. Reproductive Outcomes

Operations that managed their sheep as a herded/open range docked a higher 

percentage of lambs born alive (89.4 percent) than operations that managed their sheep 

on pasture (79.1 percent).

D.3.c. For the most recent lamb crop, percentage of lambs born alive that were docked, 

by primary fl ock type:

Percent Lambs Born*

Primary Flock Type

Herded/open range Fenced range Pasture 

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

89.4 (1.2) 82.2 (1.6) 79.1 (1.3)

*On operations with 20 or more ewes.

The average number of lambs born alive per ewe exposed was 1.3 for all operations. 

D.3.d. For the most recent lamb crop, average number of lambs born alive per ewe 

exposed,* by fl ock size:

Average Number of Lambs

Flock Size (number of ewes)

Very small

(fewer 

than 20)

Small

(20–99) 

Medium

(100–499)

Large

(500 or more)

All

operations 

(1 or more)

Operations 

with 20 

or more

Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error

1.4 (0.0) 1.4 (0.0) 1.3 (0.0) 1.2 (0.0) 1.3 (0.0) 1.3 (0.0)

 * Ewes exposed includes ewes that aborted, had only dead births, did not become pregnant, became pregnant 

but died or were removed prior to lambing. 
84 / Sheep 2011

Section I: Population Estimates–D. Reproductive Outcomes

D.3.e. For the most recent lamb crop, average number of lambs born alive per ewe 

exposed,1 by region:

Average Number of Lambs2

Region

West Central East

Average Std. error Average Std. error Average Std. error

1.3 (0.0) 1.2 (0.0) 1.5 (0.0)

1

Ewes exposed includes ewes that aborted, had only dead births, did not become pregnant, became pregnant 

but died or were removed prior to lambing.

2

On operations with one or more ewes.

D.3.f. For the most recent lamb crop, average number of lambs born alive per ewe 

exposed,1 by primary fl ock type:

Average Number of Lambs2

Primary Flock Type

Herded/open range Fenced range Pasture

Average Std. error Average Std. error Average Std. error

1.2 (0.0) 1.2 (0.0) 1.4 (0.0)

1

Ewes exposed includes ewes that aborted, had only dead births, did not become pregnant, became pregnant 

but died or were removed prior to lambing.

2

On operations with one or more ewes.
USDA APHIS VS / 85 

Section I: Population Estimates–D. Reproductive Outcomes

4. Monthly distribution of lambs born

Lambing in late fall through late winter provides great marketing opportunities, as lamb 

prices are often highest during the Easter period. Lambing in April and May synchronizes 

with the forage production cycle and allows for the most effi cient use of forage. Lambing 

in April and May also coincides with the natural breeding and lambing seasons, when the 

ewes are likely to have larger lamb crops. For all operations, the highest percentage of 

lambs were born in February through May. A higher percentage of lambs born on very 

small operations were born in February than in any other month. April and May saw the 

highest percentages of lambs born on large operations (22.2 and 25.6 of lambs born, 

respectively). July and August were the months with the lowest percentage of lambs born 

for all operations. Lambing during these months requires better parasite and predator 

management.

D.4.a. Percentage of lambs born alive or dead, by month and by fl ock size: 

Percent Lambs 

Flock Size (number of ewes)

Very small

(fewer 

than 20)

Small

(20–99) 

Medium

(100–499)

Large

(500 or 

more)

All

operations 

(1 or more)

Operations 

with 20 

or more

Month born Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

January 17.0 (1.7) 15.1 (0.9) 12.6 (0.7) 9.5 (1.1) 12.0 (0.6) 11.7 (0.6)

February 28.6 (1.8) 23.6 (1.1) 18.8 (0.9) 13.5 (0.9) 18.1 (0.6) 17.4 (0.6)

March 19.3 (1.4) 20.1 (1.1) 18.7 (1.0) 15.6 (1.2) 17.6 (0.7) 17.5 (0.7)

April 16.6 (1.5) 18.2 (1.6) 18.9 (1.0) 21.0 (1.6) 19.6 (0.9) 19.8 (0.9)

May 7.8 (1.1) 8.6 (0.8) 14.9 (1.0) 26.1 (2.7) 18.2 (1.4) 18.9 (1.4)

June 2.8 (0.9) 2.8 (1.2) 2.8 (0.4) 3.3 (0.4) 3.0 (0.4) 3.0 (0.4)

July 1.4 (0.3) 0.7 (0.2) 0.6 (0.1) 0.2 (0.1) 0.5 (0.1) 0.5 (0.1)

August 1.0 (0.3) 0.7 (0.1) 0.3 (0.1) 0.1 (0.0) 0.4 (0.1) 0.3 (0.1)

September 0.8 (0.2) 1.4 (0.4) 1.4 (0.2) 0.4 (0.1) 0.9 (0.1) 0.9 (0.1)

October 0.9 (0.3) 2.2 (0.4) 3.8 (0.5) 3.1 (0.6) 2.9 (0.3) 3.1 (0.3)

November 1.4 (0.4) 2.7 (0.5) 3.4 (0.3) 3.9 (0.5) 3.3 (0.3) 3.4 (0.3)

December 2.3 (0.5) 4.1 (0.5) 3.6 (0.5) 3.3 (0.5) 3.5 (0.3) 3.6 (0.3)

Total 100.0 100.0 100.0 100.0 100.0 100.0
86 / Sheep 2011

Section I: Population Estimates–D. Reproductive Outcomes

0

10

20

30

All operations (1 or more)

Large (500 or more)

Medium (100-499)

Small (20-99)

Very small (fewer than 20)

Flock size (number of ewes)

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Month

Percentage of lambs born alive or dead, by month and by flock size

Percent
USDA APHIS VS / 87 

Section I: Population Estimates–D. Reproductive Outcomes

In the Central region, lambing peaked in April and May, with 22.0 and 24.3 percent of the 

lambs born in those months, respectively. In the West region, lambing peaked in January 

through March, and in the East region in February through April. Of interest is the second, 

smaller peak in October through November in the West region.

D.4.b. Percentage of lambs born alive or dead, by month and by region:

Percent Lambs*

Region

West Central East

Month born Pct.

Std.

error Pct.

Std.

error Pct.

Std.

error

January 19.5 (1.3) 9.1 (0.9) 13.9 (0.8)

February 20.0 (1.2) 14.8 (0.8) 23.7 (0.9)

March 17.2 (1.6) 17.1 (1.0) 18.9 (0.9)

April 8.9 (1.3) 22.0 (1.3) 20.4 (1.4)

May 3.3 (0.9) 24.3 (2.2) 13.9 (1.0)

June 0.6 (0.2) 4.0 (0.6) 2.4 (0.3)

July 0.3 (0.1) 0.5 (0.1) 0.6 (0.1)

August 0.2 (0.1) 0.4 (0.1) 0.3 (0.1)

September 0.9 (0.2) 0.7 (0.1) 1.3 (0.3)

October 9.2 (1.6) 2.0 (0.3) 1.3 (0.2)

November 10.9 (1.3) 2.2 (0.2) 1.4 (0.3)

December 9.2 (0.9) 2.8 (0.4) 1.7 (0.3)

Total 100.0 100.0 100.0

*On operations with one or more ewes.
88 / Sheep 2011

Section I: Population Estimates–D. Reproductive Outcomes

A higher percentage of lambs were born in May on herded/open range operations 

(35.3 percent) compared with fenced-range (15.9 percent) or pasture (11.0 percent) 

operations.

D.4.c. Percentage of lambs born alive or dead, by month and by primary fl ock type:

Percent Lambs*

 Primary Flock Type

Herded/open range Fenced range Pasture

Month born Pct.

Std.

error Pct.

Std.

error Pct.

Std.

error

January 7.5 (1.8) 10.8 (0.9) 14.9 (0.7)

February 11.5 (1.4) 16.5 (1.1) 21.5 (0.8)

March 12.6 (2.0) 18.8 (1.1) 19.4 (0.8)

April 23.7 (2.9) 19.4 (1.1) 17.8 (1.1)

May 35.3 (4.6) 15.9 (1.0) 11.0 (0.8)

June 3.1 (0.6) 3.8 (0.4) 2.4 (0.7)

July 0.1 (0.0) 0.6 (0.2) 0.6 (0.1)

August 0.1 (0.0) 0.5 (0.1) 0.3 (0.1)

September 0.0 (0.0) 1.0 (0.2) 1.4 (0.3)

October 1.9 (0.9) 3.7 (0.5) 3.3 (0.5)

November 2.0 (0.6) 4.4 (0.6) 3.6 (0.5)

December 2.1 (0.6) 4.5 (0.6) 3.8 (0.4)

Total 100.0 100.0 100.0

*On operations with 20 or more ewes.
USDA APHIS VS / 89 

Section I: Population Estimates–D. Reproductive Outcomes

Lambs were born in February and March on the highest percentage of operations; 

however, there were at least some operations lambing throughout the year, which helps 

meet market demands. 

D.4.d. Percentage of operations with one or more lambs born in each of the following 

months, by fl ock size:

Percent Operations 

Flock Size (number of ewes)

Very small

(fewer 

than 20)

Small

(20–99) 

Medium

(100–499)

Large

(500 or 

more)

All

operations 

(1 or more)

Operations 

with 20 

or more

Month born Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

January 28.5 (1.9) 42.8 (1.6) 38.0 (1.7) 31.1 (1.6) 35.5 (1.1) 41.1 (1.2)

February 46.2 (2.0) 55.9 (1.6) 49.7 (1.7) 38.5 (1.8) 50.4 (1.1) 53.6 (1.2)

March 41.1 (2.0) 53.7 (1.6) 54.5 (1.7) 45.9 (1.8) 48.0 (1.1) 53.4 (1.3)

April 29.9 (1.8) 39.3 (1.6) 48.3 (1.7) 50.1 (1.9) 36.6 (1.1) 41.8 (1.2)

May 15.1 (1.5) 23.3 (1.4) 34.1 (1.6) 42.4 (1.7) 21.6 (0.9) 26.7 (1.1)

June 6.1 (1.0) 9.0 (0.9) 13.6 (1.2) 17.3 (1.4) 8.5 (0.6) 10.4 (0.7)

July 5.0 (1.0) 5.6 (0.8) 5.7 (0.9) 3.2 (0.7) 5.3 (0.5) 5.5 (0.6)

August 3.4 (0.8) 4.9 (0.7) 3.5 (0.7) 2.3 (0.6) 4.0 (0.5) 4.4 (0.6)

September 3.2 (0.8) 6.4 (0.8) 8.8 (1.0) 4.2 (0.9) 5.2 (0.5) 6.8 (0.7)

October 2.7 (0.7) 9.1 (1.0) 14.8 (1.2) 11.0 (1.1) 7.0 (0.5) 10.5 (0.8)

November 3.8 (0.8) 11.2 (1.1) 16.4 (1.2) 13.6 (1.3) 8.7 (0.6) 12.5 (0.8)

December 5.9 (1.0) 15.6 (1.2) 15.5 (1.2) 15.3 (1.3) 11.3 (0.7) 15.6 (0.9)
90 / Sheep 2011

Section I: Population Estimates–D. Reproductive Outcomes

In the West region, the highest percentage of operations (61.3 percent) lambed in 

February. In the Central and East regions the highest percentages of operations lambed 

in February (43.0 and 51.7 percent, respectively) and March (46.4 and 50.3 percent, 

respectively).

D.4.e. Percentage of operations with one or more lambs born in each of the following 

months, by region:

Percent Operations (1 or more ewes)

Region

West Central East

Month born Pct.

Std.

error Pct.

Std.

error Pct.

Std.

error

January 48.1 (2.5) 30.2 (1.7) 34.9 (1.6)

February 61.3 (2.6) 43.0 (1.8) 51.7 (1.7)

March 45.0 (2.6) 46.4 (1.8) 50.3 (1.7)

April 22.8 (2.2) 37.3 (1.7) 41.0 (1.6)

May 12.1 (1.7) 24.8 (1.5) 22.8 (1.3)

June 5.9 (1.2) 10.4 (1.1) 8.1 (0.9)

July 4.1 (1.1) 6.7 (1.0) 4.7 (0.7)

August 2.7 (0.9) 6.5 (1.1) 2.6 (0.6)

September 6.4 (1.3) 6.8 (1.0) 3.7 (0.6)

October 8.2 (1.2) 10.2 (1.2) 4.4 (0.6)

November 11.4 (1.5) 12.3 (1.2) 5.2 (0.6)

December 20.3 (1.9) 13.1 (1.3) 6.9 (0.8)
USDA APHIS VS / 91 

Section I: Population Estimates–D. Reproductive Outcomes

5. Lambing locations

On nearly half of operations (48.4 percent), lambs were born in barns or sheds. A smaller 

percentage of large operations (27.9 percent) lambed in barns or sheds compared 

with medium and small operations (45.0 and 50.9 percent, respectively). The highest 

percentage of large operations (37.3 percent) lambed in an “other fenced pasture.” 

D.5.a. For operations with lambs born in 2010, percentage of operations by lambing 

locations used for at least one lamb, and by fl ock size: 

Percent Operations 

Flock Size (number of ewes)

Very small

(fewer 

than 20)

Small

(20–99) 

Medium

(100–499)

Large

(500 or 

more)

All

operations 

(1 or more)

Operations 

with 20 

or more

Lambing

location Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Individual 

lambing pen 25.1 (1.3) 21.4 (1.4) 19.3 (1.4) 24.0 (1.0)

Barn or shed 

(covered, 

but without 

individual pens)

50.9 (1.6) 45.0 (1.6) 27.9 (1.6) 48.4 (1.2)

Special lambing 

pasture 

that allows 

increased 

observation 

and/or shelter

15.0 (1.2) 21.6 (1.4) 17.0 (1.4) 16.6 (0.9)

Other fenced 

pasture 26.8 (1.4) 28.8 (1.5) 37.3 (1.7) 27.8 (1.1)

Open range 4.1 (0.7) 6.9 (0.8) 25.2 (1.6) 5.9 (0.5)

Dry lot (pen 

which does not 

allow grazing)

4.8 (0.7) 9.5 (1.0) 9.0 (1.0) 6.0 (0.5)

Other 0.5 (0.2) 0.4 (0.2) 0.4 (0.3) 0.5 (0.2)
92 / Sheep 2011

Section I: Population Estimates–D. Reproductive Outcomes

In the West region, at least some lambs were born in barns or sheds on 36.1 percent of 

operations, on a special lambing pasture on 32.6 percent, and on “other fenced pasture” 

on 33.4 percent of operations. In the Central and East regions, at least some lambs were 

born in barns or sheds on 39.6 and 60.2 percent of operations, respectively. The Central 

region had the highest percentage of operations (11.8 percent) in which at least some 

lambs were born on the open range. 

D.5.b. For operations with lambs born in 2010, percentage of operations by lambing 

locations used for at least one lamb, and by region:

Percent Operations (20 or more ewes)

Region

West Central East

Lambing location Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Individual lambing pen 18.2 (2.6) 17.2 (1.2) 31.9 (1.8)

Barn or shed (covered, but 

without individual pens) 36.1 (3.2) 39.6 (1.7) 60.2 (1.9)

Special lambing pasture that 

allows increased observation 

and/or shelter

32.6 (3.1) 14.9 (1.3) 12.2 (1.2)

Other fenced pasture 33.4 (3.1) 32.8 (1.7) 21.5 (1.6)

Open range 5.3 (1.4) 11.8 (1.2) 1.0 (0.4)

Dry lot (pen which does 

not allow grazing) 6.8 (1.7) 9.4 (0.9) 2.9 (0.6)

Other 0.2 (0.2) 0.5 (0.3) 0.6 (0.3)
USDA APHIS VS / 93 

Section I: Population Estimates–D. Reproductive Outcomes

A similar percentage of herded/open range operations lambed on the open range or in 

a barn or shed (41.8 and 35.5 percent, respectively). A higher percentage of pasture 

operations than herded/open range and fenced-range operations lambed in a barn or 

shed.

 D.5.c. For operations with 20 or more ewes that had lambs born in 2010, percentage of 

operations by lambing locations used for at least one lamb, and by primary fl ock type:

Percent Operations (20 or more ewes)

Primary Flock Type

Herded/

open range Fenced range Pasture

Lambing location Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Individual lambing pen 19.0 (3.8) 18.3 (1.6) 27.0 (1.4)

Barn or shed (covered, but 

without individual pens) 35.5 (5.3) 35.1 (2.1) 54.3 (1.6)

Special lambing pasture that 

allows increased observation 

and/or shelter

10.5 (2.1) 16.4 (1.6) 16.9 (1.1)

Other fenced pasture 24.9 (5.1) 38.0 (2.2) 23.9 (1.4)

Open range 41.8 (5.1) 9.9 (1.3) 2.5 (0.5)

Dry lot (pen which does 

not allow grazing) 10.8 (3.8) 5.6 (0.9) 6.0 (0.7)

Other 0.0 (—) 0.9 (0.5) 0.2 (0.1)
94 / Sheep 2011

Section I: Population Estimates–D. Reproductive Outcomes

Just over one-fourth of all lambs born (26.2 percent) were born in a barn or shed. The 

single highest percentage of lambs born on small and medium operations (40.3 and 

34.9 percent, respectively) were born in barns or sheds, while the single highest 

percentage of lambs born on large operations (31.8 percent) were born on the open 

range. 

D.5.d. For operations with lambs born in 2010, percentage of lambs born, by lambing 

location and by fl ock size:

Percent Lambs 

Flock Size (number of ewes)

Very small

(fewer 

than 20)

Small

(20–99) 

Medium

(100–499)

Large

(500 or 

more)

All

operations 

(1 or more)

Operations 

with 20 

or more

Lambing 

location Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Individual 

lambing pen 20.4 (1.7) 16.6 (1.3) 14.9 (2.1) 16.7 (1.2)

Barn or shed 

(covered, 

but without 

individual pens)

40.3 (1.8) 34.9 (1.6) 14.5 (1.6) 26.2 (1.1)

Special lambing 

pasture that 

allows increased 

observation 

and/or shelter

12.8 (1.7) 14.6 (1.1) 9.7 (1.3) 11.7 (0.8)

Other fenced 

pasture 20.6 (1.6) 20.3 (1.2) 23.3 (2.0) 21.8 (1.1)

Open range 3.0 (0.7) 6.8 (0.9) 31.8 (2.9) 18.1 (1.6)

Dry lot (pen 

which does not 

allow grazing)

2.7 (0.5) 6.5 (0.8) 5.9 (1.0) 5.2 (0.5)

Other 0.4 (0.2) 0.4 (0.2) 0.0 (—) 0.2 (0.1)

Total 100.0 100.0 100.0 100.0
USDA APHIS VS / 95 

Section I: Population Estimates–D. Reproductive Outcomes

The single highest percentage of lambs born in the East region (46.8 percent) were born 

in barns or sheds.

D.5.e. For operations with lambs born in 2010, percentage of lambs born, by lambing 

location and by region:

Percent Lambs*

Region

West Central East

Lambing location Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Individual lambing pen 7.9 (1.6) 14.6 (1.8) 26.8 (1.9)

Barn or shed (covered, but 

without individual pens) 15.2 (1.6) 19.9 (1.4) 46.8 (2.0)

Special lambing pasture that 

allows increased observation 

and/or shelter

31.8 (3.3) 8.3 (1.0) 7.5 (0.9)

Other fenced pasture 29.2 (3.6) 22.7 (1.5) 15.4 (1.4)

Open range 8.4 (2.4) 28.4 (2.4) 0.7 (0.3)

Dry lot (pen which 

does not allow grazing) 7.5 (1.7) 5.9 (0.8) 2.5 (0.6)

Other 0.0 (0.0) 0.1 (0.1) 0.4 (0.2)

Total 100.0 100.0 100.0

*On operations with 20 or more ewes.
96 / Sheep 2011

Section I: Population Estimates–D. Reproductive Outcomes

D.5.f. For operations with lambs born in 2010, percentage of lambs born, by lambing 

location and by primary fl ock type:

Percent Lambs*

Primary Flock Type

Herded/

open range Fenced range Pasture

Lambing location Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Individual lambing pen 16.7 (3.8) 9.1 (0.9) 22.5 (1.4)

Barn or shed (covered, 

but without individual 

pens)

13.7 (2.8) 20.5 (1.2) 37.0 (1.5)

Special lambing pasture 

that allows increased 

observation and/or 

shelter

6.3 (1.5) 11.7 (1.4) 15.1 (1.3)

Other fenced pasture 11.3 (2.5) 37.0 (1.9) 17.3 (1.4)

Open range 45.8 (4.6) 16.8 (1.7) 2.8 (0.5)

Dry lot (pen which does 

not allow grazing) 6.3 (1.7) 4.5 (0.6) 5.2 (0.6)

Other 0.0 (—) 0.4 (0.2) 0.1 (0.0)

Total 100.0 100.0 100.0

*On operations with 20 or more ewes.
USDA APHIS VS / 97 

Section I: Population Estimates–D. Reproductive Outcomes

6. Castration management

Overall, 68.5 percent of operations castrated lambs. The percentage of operations that 

castrated ram lambs ranged from 60.0 percent of small operations to 94.9 percent of 

large operations. 

D.6.a. For operations with ram lambs born alive in 2010, percentage of operations that 

castrated ram lambs, by fl ock size:

Overall, ram lambs were castrated at an average age of 24.7 days. Ram lambs on large 

operations were castrated at an average age of 28.0 days compared with an average age 

of 21.8 days on small operations. 

D.6.b. For operations with ram lambs castrated in 2010, operation average age (in days) 

that rams were castrated, by fl ock size:

Percent Operations

Flock Size (number of ewes)

Very small 

(fewer 

than 20)

Small 

(20–99)

Medium 

(100–499)

Large 

(500 or more)

All

operations

(1 or more)

Operations 

with 20 

or more

Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

60.0 (2.0) 71.6 (1.4) 81.9 (1.4) 94.9 (1.0) 68.5 (1.1) 75.1 (1.1)

Operation Average Age (days)

Flock Size (number of ewes)

Very small 

(fewer 

than 20)

Small 

(20–99)

Medium 

(100–499)

Large 

(500 or more)

All

operations

(1 or more)

Operations 

with 20 

or more

Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error

21.8 (1.3) 25.3 (1.1) 21.9 (0.9) 28.0 (0.8) 23.6 (0.7) 24.7 (0.8)
98 / Sheep 2011

Section I: Population Estimates–D. Reproductive Outcomes

In the Central region, ram lambs were castrated at an average age of 29.9 days 

compared with an average age of 18.6 days in the East region. 

D.6.c. For operations with ram lambs castrated in 2010, operation average age (in days) 

that rams were castrated, by region:

Operation Average Age (days)*

Region

West Central East

Average Std. error Average Std. error Average Std. error

23.7 (1.6) 29.9 (1.3) 18.6 (0.9)

*On operations with one or more ewes.

The operation average days at castration for ram lambs on herded/open range operations 

was 34.7 days compared with 22.1 days on pasture operations. 

D.6.d. For operations with ram lambs castrated in 2010, operation average age (in days) 

that rams were castrated, by fl ock type:

Operation Average Age (days)*

Flock Type 

Herded/open range Fenced range Pasture

Average Std. error Average Std. error Average Std. error

34.7 (5.8) 28.8 (1.4) 22.1 (0.9)

*On operations with 20 or more ewes.
USDA APHIS VS / 99 

Section I: Population Estimates–D. Reproductive Outcomes

Overall, ram lambs were castrated at 7 days or younger on 38.3 percent of operations. 

D.6.e. For operations with ram lambs castrated in 2010, percentage of operations that 

castrated rams, by age of rams at castration:

Age at castration 

(days)

Percent Operations

(1 or more ewes) Std. error

1–7 38.3 (1.3)

8–21 24.8 (1.2)

22 or more 36.9 (1.2)

Total 100.0

The majority of operations (87.5 percent) used a band to castrate ram lambs. 

Approximately one-third of large operations (34.5 percent) used a knife to castrate ram 

lambs. 

D.6.f. For operations with ram lambs castrated in 2010, percentage of operations by 

primary method of castration and by fl ock size:

Percent Operations 

Flock Size (number of ewes)

Very small

(fewer 

than 20)

Small

(20–99) 

Medium

(100–499)

Large

(500 or 

more)

All

operations 

(1 or more)

Operations 

with 20 

or more

Castration 

method Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Band 93.1 (1.3) 88.1 (1.3) 80.3 (1.5) 56.9 (1.7) 87.5 (0.8) 84.0 (1.0)

Burdizzo or 

emasculator 2.1 (0.7) 3.3 (0.7) 4.5 (0.8) 7.0 (0.9) 3.2 (0.4) 3.8 (0.5)

Knife 4.5 (1.1) 7.8 (1.0) 13.3 (1.2) 34.5 (1.7) 8.5 (0.7) 11.0 (0.8)

Other 0.3 (0.3) 0.9 (0.4) 1.8 (0.5) 1.5 (0.5) 0.8 (0.2) 1.1 (0.3)

Total 100.0 100.0 100.0 100.0 100.0 100.0
100 / Sheep 2011

Section I: Population Estimates–D. Reproductive Outcomes

A lower percentage of operations in the Central region (78.4 percent) castrated ram 

lambs with a band compared with operations in the West or East regions (91.6 and 

93.0 percent, respectively). A higher percentage of operations in the Central region 

(16.3 percent) used a knife for castration compared with operations in the West or East 

regions (4.0 and 4.3 percent, respectively).

D.6.g. For operations with ram lambs castrated during 2010, percentage of operations by 

primary method of castration and by region:

Percent Operations (1 or more ewes)

Region

West Central East

Castration method Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Band 91.6 (1.5) 78.4 (1.5) 93.0 (1.0)

Burdizzo or emasculator 3.9 (1.1) 3.5 (0.7) 2.5 (0.6)

Knife 4.0 (0.9) 16.3 (1.4) 4.3 (0.8)

Other 0.5 (0.5) 1.7 (0.5) 0.2 (0.1)

Total 100.0 100.0 100.0
USDA APHIS VS / 101 

Section I: Population Estimates–D. Reproductive Outcomes

A higher percentage of pasture operations castrated ram lambs with a band. 

D.6.h. For operations with ram lambs castrated during 2010, percentage of operations by 

primary method of castration and by primary fl ock type:

Percent Operations (1 or more ewes)

Primary Flock Type*

Herded/

open range Fenced range Pasture

Castration method Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Band 59.8 (5.1) 70.6 (2.2) 90.9 (1.0)

Burdizzo or emasculator 3.0 (1.0) 6.4 (1.3) 2.8 (0.6)

Knife 36.5 (5.1) 20.4 (1.9) 5.8 (0.8)

Other 0.8 (0.7) 2.6 (0.9) 0.4 (0.2)

Total 100.0 100.0 100.0

*Table does not apply to dry lot or feedlot operations.

For ram lambs castrated at 1 to 7 days of age, the highest percentage of operations used 

a band for castration. 

D.6.i. For operations that castrated ram lambs, percentage of operations by age of rams 

at castration and by method of castration:

Percent Operations (1 or more ewes)

Method of Castration

Band

Burdizzo or 

Emasculator Knife Other

Age (days) Pct.

Std.

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

1–7 41.3 (1.4) 17.0 (5.2) 19.0 (4.0) 5.0 (3.6)

8–21 25.1 (1.3) 28.5 (6.3) 22.7 (3.1) 1.8 (1.5)

22 or more 33.6 (1.3) 54.5 (6.8) 58.3 (4.1) 93.1 (4.0)

Total 100.0 100.0 100.0 100.0
102 / Sheep 2011

Section I: Population Estimates–D. Reproductive Outcomes

7. Weaned lamb management

The operation average number of lambs weaned per ewe exposed was 1.2. This number 

was higher in small fl ocks (1.4 lambs).

D.7.a. For lambs born in 2010, operation average number of lambs weaned per exposed 

ewe,* by fl ock size:

The operation average number of lambs weaned per exposed ewe was higher in the East 

region (1.5) than in the West and Central regions (1.2 and 1.1, respectively).

D.7.b. For lambs born in 2010, operation average number of lambs weaned per exposed 

ewe,1

 by region:

Operation Average2

Region

West Central East

Average Std. error Average Std. error Average Std. error

1.2 (0.0) 1.1 (0.0) 1.5 (0.0)

1

On operations with one or more ewes.

2

Ewes bred on the operation or purchased pregnant.

Operation Average

Flock Size (number of ewes)

Very small 

(fewer 

than 20)

Small 

(20–99)

Medium 

(100–499)

Large 

(500 or more)

All

operations

(1 or more)

Operations 

with 20 

or more

Avg.

Std.

error Avg.

Std.

error Avg.

Std.

error Avg.

Std.

error Avg.

Std.

error Avg.

Std.

error

1.3 (0.1) 1.4 (0.0) 1.3 (0.0) 1.0 (0.0) 1.2 (0.0) 1.2 (0.0)

*Ewes bred on the operation or purchased pregnant.
USDA APHIS VS / 103 

Section I: Population Estimates–D. Reproductive Outcomes

Pasture fl ocks had the highest operation average number of lambs weaned per ewe 

exposed. 

D.7.c. For lambs born in 2010, operation average number of lambs weaned per exposed 

ewe,1 by primary fl ock type:

Operation Average2

Primary Flock Type 

Herded/open range Fenced range Pasture

Average Std. error Average Std. error Average Std. error

1.1 (0.0) 1.1 (0.0) 1.4 (0.0)

1

On operations with one or more ewes.

2

Ewes bred on the operation or purchased pregnant.

The average age and average weight of lambs at weaning on all operations was 

(4.0 months and 65.0 lb). Age and weight at weaning were highest on large operations 

(4.8 months and 82.4 lb, respectively).

D.7.d. For lambs weaned in 2010, operation average age and weight of lambs at 

weaning, by fl ock size:

Operation Average 

Flock Size (number of ewes)

Very small

(fewer 

than 20)

Small

(20–99) 

Medium

(100–499)

Large

(500 or 

more)

All

operations 

(1 or more)

Operations 

with 20 

or more

Avg.

Std.

error Avg.

Std.

error Avg.

Std.

error Avg.

Std.

error Avg.

Std.

error Avg.

Std.

error

Age (months) 4.1 (0.1) 3.8 (0.0) 4.1 (0.1) 4.8 (0.1) 4.0 (0.0) 3.9 (0.0)

Weight (lb) 62.5 (1.1) 64.5 (0.7) 69.4 (0.7) 82.4 (0.7) 65.0 (0.5) 66.7 (0.5)
104 / Sheep 2011

Section I: Population Estimates–D. Reproductive Outcomes

The average weight of lambs at weaning in the East region was 56.3 pounds, but these 

operations weaned a month earlier than operations in the West or Central regions.

D.7.e. For lambs weaned in 2010, operation average age and weight of lambs at 

weaning, by region:

Operation Average (1 or more ewes)

Region

West Central East

Avg.

Std.

error Avg.

Std.

error Avg.

Std.

error

Age (months) 4.4 (0.1) 4.6 (0.1) 3.4 (0.1)

Weight (lb) 77.8 (1.6) 71.1 (0.8) 56.3 (0.7)

Photograph courtesy of Camilla Kristensen
USDA APHIS VS / 105 

Section I: Population Estimates–D. Reproductive Outcomes

Lambs on herded/open range fl ocks averaged 5.1 months of age and 89.0 pounds at 

weaning. 

D.7.f. For lambs weaned in 2010, operation average age and weight of lambs at weaning, 

by primary fl ock type:

Operation Average* (20 or more ewes)

Primary Flock Type

Herded/

open range Fenced range Pasture

Avg.

Std.

error Avg.

Std.

error Avg.

Std.

error

Age (months) 5.1 (0.2) 4.4 (0.1) 3.7 (0.0)

Weight (lb) 89.0 (3.3) 70.7 (1.0) 64.0 (0.7)

*On operations with 20 or more ewes.

Overall, 82.1 percent of operations sold weaned lambs. A lower percentage of very small 

operations (67.6 percent) sold weaned lambs than small (93.4 percent), medium 

(97.1 percent) or large (97.9 percent) operations.

D.7.g. Percentage of operations that sold any weaned lambs in 2010, by fl ock size:

Percent Operations

Flock Size (number of ewes)

Very small 

(fewer 

than 20)

Small 

(20–99) 

Medium 

(100–499)

Large 

(500 or more)

All

operations

(1 or more)

Operations 

with 20 

or more

Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

67.6 (1.8) 93.4 (0.8) 97.1 (0.6) 97.9 (0.5) 82.1 (0.9) 94.5 (0.6)
106 / Sheep 2011

Section I: Population Estimates–D. Reproductive Outcomes

A higher percentage of operations in the East region (84.4 percent) sold weaned lambs 

than operations in the West region (75.6 percent).

D.7.h. Percentage of operations that sold any weaned lambs in 2010, by region:

Percent Operations (1 or more ewes)

Region

West Central East

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

75.6 (2.2) 82.2 (1.5) 84.4 (1.4)

D.7.i. Percentage of operations that sold any weaned lambs, by primary fl ock type:

Percent Operations (20 or more ewes)

Primary Flock Type

Herded/open range Fenced range Pasture 

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

82.9 (5.7) 94.4 (1.1) 95.2 (0.7)

Overall, 82.5 percent of weaned lambs were sold. 

D.7.j. Percentage of weaned lambs sold, by fl ock size:

Percent Weaned Lambs

Flock Size (number of ewes)

Very small 

(fewer 

than 20)

Small 

(20–99) 

Medium 

(100–499)

Large 

(500 or more)

All

operations

(1 or more)

Operations 

with 20 

or more

Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

77.8 (2.0) 80.6 (1.0) 82.4 (0.9) 84.1 (1.5) 82.5 (0.7) 82.8 (0.8)
USDA APHIS VS / 107 

Section I: Population Estimates–D. Reproductive Outcomes

Regionally, the percentage of weaned lambs sold was similar.

D.7.k. Percentage of weaned lambs sold, by region:

Percent Weaned Lambs*

Region

West Central East

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

81.6 (16) 82.8 (1.1) 82.3 (1.1)

*On operations with one or more ewes.

About 8 of 10 weaned lambs sold on large operations (79.3 percent) were sold from 

July through December. Overall, 72.5 percent of lambs were sold from July through 

December.

D.7.l. Of weaned lambs sold in 2010 (including lambs weaned at the time of removal from 

the operation), percentage of lambs sold, by quarter and by fl ock size: 

Percent Weaned Lambs 

Flock Size (number of ewes)

Very small

(fewer 

than 20)

Small

(20–99) 

Medium

(100–499)

Large

(500 or 

more)

All

operations 

(1 or more)

Operations 

with 20 

or more

Quarter Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

January–March 6.3 (0.9) 8.8 (0.8) 3.9 (0.6) 5.8 (0.4)

April–June 30.4 (1.6) 22.5 (1.3) 16.8 (1.5) 21.7 (0.9)

July–

September 35.3 (1.7) 38.1 (1.5) 40.2 (2.3) 38.4 (1.3)

October–

December 28.0 (2.0) 30.5 (1.5) 39.1 (2.5) 34.1 (1.4)

Total 100.0 99.9 100.0 100.0
108 / Sheep 2011

Section I: Population Estimates–D. Reproductive Outcomes

Operations in the West region sold a higher percentage of weaned lambs from April 

through June and a lower percentage from October through December, compared with 

operations in the other regions.

D.7.m. Of weaned lambs sold in 2010 (including lambs weaned at the time of removal 

from the operation) percentage of lambs sold, by quarter and by region: 

Percent Weaned Lambs*

Region

West Central East

Quarter Pct.

Std.

error Pct.

Std.

error Pct.

Std.

error

January–March 4.8 (0.9) 5.0 (0.5) 8.3 (0.9)

April–June 40.7 (3.4) 14.7 (0.9) 26.5 (1.4)

July–September 34.3 (2.7) 41.4 (1.9) 33.9 (1.7)

October–December 20.2 (2.0) 38.9 (2.1) 31.3 (1.6)

Total 100.0 100.0 100.0

*On operations with 20 or more ewes.
USDA APHIS VS / 109 

Section I: Population Estimates–D. Reproductive Outcomes

Over 90 percent of lambs sold from herded/open range fl ocks in 2010 were sold from 

July through December.

D.7.n. Of weaned lambs sold in 2010 (including lambs weaned at the time of removal 

from the operation) percentage of lambs sold, by quarter and by primary fl ock type:

Percent Weaned Lambs*

Primary Flock Type

Herded/

open range Fenced range Pasture

Quarter Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

January–March 2.3 (0.6) 6.3 (0.8) 7.4 (0.7)

April–June 7.6 (1.9) 24.7 (1.5) 27.8 (1.4)

July–September 42.7 (3.9) 38.0 (1.7) 36.3 (1.4)

October–December 47.4 (4.2) 31.0 (1.6) 28.5 (1.4)

Total 100.0 100.0 100.0

*On operations with 20 or more ewes.

Of weaned lambs sold in 2010, the operation average age was 5.5 months. On average, 

lambs from large operations were slightly older than lambs from small operations (5.8 

and 5.4 months, respectively). 

D.7.o. Of weaned lambs sold in 2010 (including lambs weaned at the time of removal 

from the operation) operation average age and weight of lambs when sold, by fl ock size:

Operation Average 

Flock Size (number of ewes)

Very small

(fewer 

than 20)

Small

(20–99) 

Medium

(100–499)

Large

(500 or 

more)

All

operations 

(1 or more)

Operations 

with 20 

or more

Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error

Age (months) 5.4 (0.1) 5.7 (0.1) 5.8 (0.1) 5.5 (0.0)

Weight (lb) 91.2 (1.0) 94.7 (0.8) 97.3 (0.8) 92.3 (0.7)
110 / Sheep 2011

Section I: Population Estimates–D. Reproductive Outcomes

There were no regional differences in the operation average age of lambs sold, but there 

were differences by weight of lambs sold, with operations in the West region selling 

heavier lambs than operations in the other regions.

D.7.p. Of lambs sold in 2010 (including lambs weaned at the time of removal from the 

operation) average age and weight of lambs when sold, by region:

Operation Average (20 or more ewes)

Region

West Central East

Pct.

Std.

error Pct.

Std.

error Pct.

Std.

error

Age (months) 5.8 (0.1) 5.5 (0.1) 5.4 (0.1)

Weight (lb) 99.0 (1.8) 89.5 (1.2) 92.4 (1.1)
USDA APHIS VS / 111 

Section II: Methodology

NAHMS develops study objectives by exploring existing literature and contacting industry 

members about their informational needs and priorities during a needs assessment 

phase. The needs assessment for the NAHMS Sheep 2011 study collected information 

from U.S. sheep producers and other sheep specialists about what they perceived to 

be the most important sheep health and productivity issues. A driving force of the needs 

assessment was the desire of NAHMS to receive as much input as possible from a 

variety of producers, industry experts and representatives; Federal, State, and private 

veterinarians; extension specialists; universities; and industry organizations. Information 

was collected through a Needs Assessment Survey, and top issues were prioritized by 

teleconferences with representatives of the sheep industry, along with extension agents 

and other university affi liates. 

The needs assessment survey 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. Of those, 37.7 percent 

were meat producers, 13.8 percent were wool producers, 0.7 percent were milk 

producers, 7.9 percent raised sheep for 4-H or clubs, 10.1 percent were mixed production 

operations (e.g., both meat and wool), 21.3 percent were from Federal or State 

government, 7.8 percent were veterinary or extension agents, and 0.7 percent were in an 

allied industry. The number of sheep raised by producers was between 1 and 5,000. 

Of the 278 respondents, 48.7 percent were from the Eastern time zone, 35.0 percent 

were from the Central time zone, 7.2 percent were from the Mountain time zone, and 

9.1 percent were from the Pacifi c time zone. 

Ewe health/management was the most important management issue for respondents, 

with 40.0 percent of respondents ranking this as their 1st, 2nd, or 3rd most important 

issue. Infectious disease or diagnostic treatment was the second most important 

management issue (31.0 percent of respondents), followed closely by disease prevention 

(29.8 percent), predator control (22.0 percent), lamb health/management (21.3 percent), 

and death loss (19.6 percent of respondents). If we look only at the fi rst priority issue, 

these rankings change only a little. The top four remain the same but the fi fth most 

important issue is death loss, followed by extra-label drug use and antimicrobial use/

resistance. 

For producers who indicated ewe health was their number one priority, their specifi c 

areas of interest include: mastitis, Q fever, OPP, Johne’s, abortion prevention, parasites, 

nutrition, and proactive information for ewe health. 

Internal parasites were the most important disease issue for respondents. Overall, 

65.0 percent of respondents ranked internal parasites as one of their top three disease 

issues. This top ranking held true for producer respondents and veterinary and university 

Section II: Methodology

A. Needs 

Assessment
112 / Sheep 2011

Section II: Methodology

extension agents. Respondents who indicated internal parasites as their highest 

priority disease cited the following specifi c areas of interest: resistance, detections, 

Haemonchus, new dewormers, immunity to parasites, management, and treatment 

options. The next most important disease issues were scrapie, abortions, and lameness 

(22.2, 19.3, and 20.2 percent of respondents, respectively). 

Since Federal and State veterinarians made up nearly 22 percent of respondents, the 

following describes their responses to the survey. The majority of respondents were in the 

Eastern time zone (61.1 percent) followed by the Central (25.9 percent), Mountain 

(7.4 percent), and Pacifi c (5.6 percent) time zones. The top three management issues 

were: identifi cation, infectious disease, and disease prevalence (48.0, 45.6, and 

39.1 percent of respondents, respectively). The top three disease-specifi c issues were: 

scrapie, internal parasites, and Johne’s (53.3, 40.0, and 31.1 percent of respondents, 

respectively).

Once the most important issues were identifi ed, the study objectives were created 

by prioritizing the needs during discussions with producers, veterinarians, university 

extension agents, and government personnel. These priorities were then evaluated along 

with the effectiveness of the study design to contribute to existing information gaps. The 

study objectives were then developed (see Appendix III).

1. State selection

The preliminary selection of States to be included in the study was done from January 

through April 2010, using the National Agricultural Statistics Service (NASS) 2007 Census 

of Agriculture and the January 29, 2010, “Sheep and Goat Report.” A goal for NAHMS 

national studies is to include States that account for at least 70 percent of both animals 

and producer populations in the United States. The initial review of States identifi ed 

20 major States representing 84.3 percent of the U.S. 2007 Census of Agriculture ewe 

inventory and 68.9 percent of farms with ewes. Sampling discussions were held with 

NASS statisticians; subsequently Arizona was dropped and Kentucky, Kansas, and New 

York were added. The 22 States recommended for inclusion in the study were California, 

Colorado, Iowa, Idaho, Kentucky, Kansas, Michigan, Minnesota, Missouri, Montana, New 

Mexico, New York, Ohio, Oregon, Pennsylvania, South Dakota, Texas, Utah, Virginia, 

Washington, Wisconsin, and Wyoming. These States, according to the 2007 Census of 

Agriculture, represented 85.5 percent of the U.S. ewe inventory and 70.1 percent of U.S. 

farms with ewes. In addition, the States included 84.5 percent of the January 1, 2011, 

ewe inventory.

A memo identifying these 22 States was provided in July 2010 to the USDA–APHIS–VS–

CEAH Director and, in turn, the VS Regional Directors. Each Regional Director sought 

input from the respective States about being included or excluded from the study. The 

22 States were included in the study. 

B. Sampling and 

Estimation
USDA APHIS VS / 113 

Section II: Methodology

2. Operation selection

The list sampling frame was provided by NASS. Within each State a stratifi ed random 

sample was selected. The size stratum was the number of sheep and lambs for each 

operation on the list sampling frame at the time of sample selection. These procedures 

were used to select the sample for the NASS January 2010 Sheep survey. Sampling 

effi ciencies were gained by drawing a subsample of respondents to this survey. This 

procedure eliminated a large number of out-of-business and zero-inventory operations. 

The sample was selected from producers who reported one or more ewes on hand on 

January 1, 2010. The sample of sheep producers was selected in each State. Among 

producers reporting fewer than 20 ewes, 1,381 operations were selected for Phase Ia. 

For operations reporting 20 or more ewes, a total of 3,539 operations were selected for 

contact during Phase Ib. Therefore, a total of 4,920 operations were selected for the 

study.

3. Population inferences

a. Phases Ia and Ib: General Sheep Management Questionnaire

Inferences cover the population of sheep producers with at least 1 ewe on hand January 

1, 2010, in the 22 participating States. As of December 31, 2007 (2007 Census of 

Agriculture), these States accounted for 85.5 percent of all ewes in the United States 

(3,005,813 head out of 3,516,409) and 70.1 percent of farms with ewes (47,855 farms out 

of 68,222). In addition, these States accounted for 84.5 percent of the January 1, 2011, 

ewe inventory in the United States or 2,750,000 head out of 3,255,000. (See Appendix II 

for respective data on individual States.) All respondent data were statistically weighted 

to refl ect the population from which they were selected. The inverse of the probability of 

selection for each operation was the initial selection weight. This selection weight was 

adjusted for nonresponse within each State and size group from the NASS survey as well 

as adjusted for subsampling and again for nonresponse to this study. These adjustments 

and weighting allow for inferences back to the original population from which the sample 

was selected.
114 / Sheep 2011

Section II: Methodology

1. Data collectors and data collection period

a. Phases Ia and 1b: General Sheep Management Questionnaire

All data were collected from January 1 to February 11, 2011. Producers with fewer 

than 20 ewes were contacted via NASS telephone interviewers, who administered the 

questionnaire, which took an average of 30 minutes to complete. NASS enumerators 

administered the General Sheep Management Questionnaire to producers with 20 or 

more ewes via an in-person interview, which took an average of 1 hour to complete. 

1. Phase I: Validation—General Sheep Management Questionnaire

Telephone interviews were conducted via computer-assisted telephone interview software 

at each individual State NASS offi ce. For the questionnaire administered in person, 

initial data entry and validation were also performed in the individual NASS State offi ces. 

Data were entered into a SAS data set and edited. Individual State data fi les were then 

combined and sent to NAHMS national staff, which performed additional data validation 

on the entire data set. 

C. Data 

Collection

D. Data Analysis
USDA APHIS VS / 115 

Section II: Methodology

The purpose of this section is to provide various performance measurement parameters. 

Historically, the term response rate was used as a catchall parameter, but there are many 

ways to defi ne and calculate response rates. Therefore, the following table presents an 

evaluation based on a number of response measurement parameters, which are defi ned 

with an x in categories that contribute to the measurement.

1. Phase Ia: General Sheep Management Questionnaire—fewer than 20 ewes 

A total of 1,381 operations were selected for the survey of operations with fewer than 20 

ewes. Of these operations, 64.2 percent completed the questionnaire. 

Measurement parameter

Response category

Number 

operations

Percent 

operations Contacts Usable1 Complete2

Refused GSM 

questionnaire or 

inaccessible

494 35.8 x x

Complete 887 64.2

Total 1,381 100.0 887 887

Percent of total 

operations 64.2 64.2

Percent of total 

operations weighted3 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

Weighted response—the rate was calculated using the initial selection weights.

E. Sample 

Evaluation
116 / Sheep 2011

Section II: Methodology

2. Phase Ib: General Sheep Management Questionnaire—20 or more ewes 

A total of 3,539 operations were selected for the survey of operations with 20 or more 

ewes. 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 

questionnaire 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

Offi ce 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 / 117 

Appendix I: Sample Profi le

1. Number of responding operations, by herd size

Phase Ia: General 

Sheep Management 

Questionnaire—fewer 

than 20 ewes

Phase Ib: General 

Sheep Management 

Questionnaire—20 or 

more ewes

Herds 

(number of ewes) Number of responding operations

Fewer than 20 887

20 to 99 1,049

100 to 999 859

1,000 or more 461

Total 887 2,369

2. Number of responding operations, by region

Phase Ia: General 

Sheep Management 

Questionnaire—fewer 

than 20 ewes

Phase Ib: General 

Sheep Management 

Questionnaire—20 or 

more ewes

Region Number of responding operations

West 175 325

Central 348 1,208

East 364 836

Total 887 2,369

Appendix I: Sample Profi le

A. Responding 

Operations
118 / Sheep 2011

Appendix II: U.S. Ewes Population and Farms

Appendix II: 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

Pct. of 

total

Farms with 

1 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. D = number not published.
USDA APHIS VS / 119 

Appendix II: U.S. Ewes Population and Farms

B. Ewes, Size Distribution—State, Region, and United States* 

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 6,075 (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 13,7602 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.
120 / Sheep 2011

Appendix II: U.S. Ewes Population and Farms

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

Region State

Ewes

(x1,000 head)

Rams

(x1,000 head)

Replacement 

lambs

(x1,000 head)

Total breeding 

sheep and 

lambs

(x1,000 head)

All sheep and 

lambs

(x1,000 head)

West CA 283 12 45 340 610

OR 118 7 23 148 215

WA 36 3 7 46 56

 Total 437 22 75 534 881

Central CO 142 5 28 175 370

ID 153 6 26 185 235

KS 33 2 8 43 70

MT 170 7 38 215 230

NM 77 5 15 97 110

SD 176 7 32 215 275

TX 525 40 125 690 880

UT 211 9 35 255 280

WY 220 8 47 275 365

 Total 1,707 89 354 2,150 2,815

East IA 106 5 19 130 200

KY 22 1.5 4.5 28 34

MI 44 3 11 58 74

MN 77 4 14 95 130

MO 57 3 13 73 81

NY 43 3 10 56 70

OH 81 6 16 103 129

PA 62 6 16 84 98

VA 55 3 9 67 90

WI 59 3 14 76 90

 Total 606 37.5 126.5 770 996

Total (22 States) 2,750 148.5 555.5 3,454 4,692

Percent of U.S. 84.5 78.2 82.9 83.9 84.8

Total U.S. (50 States) 3,255 190 670 4,115 5,530

Source: NASS Sheep and Goats report, January 28, 2011.
USDA APHIS VS / 121 

Appendix II: U.S. Ewes Population and Farms

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

1–99 head 100–499 head 500–4,999 head 5,000+ head

2008 2009 2008 2009 2008 2009 2008 2009 Total

Operations 92.5 93.7 6.2 5.2 1.2 1.0 0.1 0.1 100.0

Inventory 32.6 36.2 22.7 20.8 30.2 31.3 14.5 11.7 100.0

Source: NASS Farms, Land in Farms, and Livestock Operations, 2009 Summary, February 2010.
122 / Sheep 2011

Appendix III: 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, expected spring 2012

• Part III: Changes in the Sheep Industry, 1996–2011, expected summer 2012

• Part IV: Reference of Sheep Health and Health Management in the United States, 

2011, expected summer 2012

• Vaccination Practices on U.S. Sheep Operations, 2011, info sheet, expected 

summer 2012

• Sheep and Lamb Losses on U.S. Sheep Operations, 2011, info sheet, expected 

summer 2012

• Lambing Management on U.S. Sheep Operations, 2011, info sheet, expected 

summer 2012

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 winter 

2012

• Parasite Control on U.S. Sheep Operations, 2011, info sheet, expected winter 

2012

• Producer Disease Awareness, 2011, info sheet, expected summer 2012

• Antimicrobial Drug Use on U.S. Sheep Operations, 2011, info sheet, expected 

summer 2012

Appendix III: Study Objectives and Related Outputs
USDA APHIS VS / 123 

Appendix III: Study Objectives and Related Outputs

3. Estimate the prevalence of gastrointestinal parasites and anthelmintic resistance.

• Gastrointestinal Parasites and Anthelmintic Resistance, 2011, info sheet, expected 

summer 2012

• Gastrointestinal Parasites and Anthelmintic Resistance on U.S. Sheep Operations, 

2011, info sheet, expected summer 2012

4. Estimate the prevalence of Mycoplasma ovipneumonia in domestic sheep fl ocks. 

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 

summer 2012

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 summer 

2012

• Q Fever in Sheep in the United States, 2011, info sheet, expected summer 2012

• Campylobacter on U.S. Sheep Operations, 2011, info sheet, expected summer 

2012

• Salmonella on U.S. Sheep Operations, 2011, info sheet, expected summer 2012

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 summer 2012