United States 

Department of 

Agriculture

Animal and 

Plant Health 

Inspection 

Service

Veterinary 

Services

National 

Animal Health 

Monitoring 

System

August 2017

Swine 2012

Part III: Changes in the U.S. Swine Industry, 

1995−2012

Table of 

Contents
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warrants the standard of any product mentioned. Product 

names are mentioned solely to report factually on available data and to provide specific information. 

USDA–APHIS–VS–CEAH–NAHMS

NRRC Building B, M.S. 2E7

2150 Centre Avenue

Fort Collins, CO 80526–8117

970.494.7000

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

#678.0817

Cover photograph courtesy of Pork Checkoff.
USDA APHIS VS / i 

Items of Note

Study population

The number of U.S. swine sites decreased from 168,450 sites in 1995 to 68,300 in 

2012. During those same years, a large decline occurred in the number of traditional 

swine operations that managed all production stages on one site (i.e., farrow-to-finish 

operations). 

Breeding herd management

Reasons for culling older breeding animals did not substantially change from 1995 to 

2012. A lower percentage of sites in 2012 than in 1995 never isolated new breeding 

males, while a higher percentage in 2012 than in the previous study years did not 

introduce breeding males.

Housing

The percentage of farrowing sites that housed pigs in an open building with outside 

access decreased from 1995 to 2012. From 2006 to 2012, the percentage of sites 

that housed gestating animals in an open building with no outside access increased, 

suggesting a move toward more naturally ventilated systems for gestating pigs. 

Pit-holding was the waste-management method used by the highest percentage of sites 

with gestating, nursery, or grower/finisher pigs in 2012.

Disease and health

The percentage of sites reporting porcine reproductive and respiratory syndrome 

or influenza in breeding females or weaned pigs increased from 2000 to 2012. The 

percentage of sites reporting porcine circovirus associated disease in grower/finisher pigs 

decreased from 2006 to 2012, perhaps because during the previous 8 years weaned pigs 

have been vaccinated against PCV2. 

The 2012 study marked the first time that transmissible gastroenteritis was not reported 

as a problem in preweaned pigs on any sites. This finding has a degree of irony, 

considering the similar coronavirus that arrived in the United States only a year later.

USDA APHIS VS / iii 

Introduction 1

Terms Used in This Report 3

Section I: Demographic Changes in the U.S. and World Pork Industries, 

1850−2012 7

A. Historical Changes in the U.S. Swine Industry, 1850−2012 7

1. Total pig inventory 7

2. Number of swine sites and herd size 9

B. U.S. Pork Industry ChangesInventories by State 14

C. World Pork Production ChangesInventories by Country 19

Section II: Management and Productivity Changes in the U.S. Pork

Industry: NAHMS Population Estimates 1995, 2000, 2006, and 2012 21

A. Production Phases 21

B. Sow and Gilt Management 24

1. Mating techniques 24

2. Culling 25

3. Introduction of breeding animals 26

4. Facility type 30

5. Pig flow 31

6. Waste management 32

C. Farrowing Phase 33

1. Farrowing productivity and death loss 33

2. Weaning age 35

3. Facility type 36

4. Pig flow 37

5. Waste management 38

D. Nursery Phase 39

1. Facility type 39

2. Death loss 41

3. Time spent in the nursery and age when leaving nursery 43

4. Pig flow 43

5. Waste management 44

Table of Contents
iv / Swine 2012

E. Grower/Finisher Phase 44

1. Facility type 44

2. Death loss 45

3. Days to market and age when leaving grower/finisher phase 47

4. Pig flow 48

5. Waste management 49

6. Source of pigs 50

F. Biosecurity 52

1. Restrictions to entry 52

2. Trucking 53

3. Proximity to other swine sites 54

4. Rodent control 55

G. General Management 56

1. Environmental testing 56

2. Carcass disposal 57

3. Use of a veterinarian 59

Section III: Health Status Changes in the U.S. Pork Industry, NAHMS Population 

Estimates2000, 2006, and 2012 60

A. Breeding Females and Preweaned Pig Morbidity 60

1. Breeding females 60

2. Preweaned pigs 61

B. Disease Prevention in Breeding Females 62

1. Porcine reproductive and respiratory syndrome 62

2. Influenza A virus in swine 63

C. Use of Antimicrobials in Breeding Females to Treat Disease 

Conditions 65

D. Weaned Pig Morbidity 66

1. Nursery pigs 66

2. Grower/finisher pigs 68

E. Disease Prevention in Weaned PigsVaccination 70

F. Use of Antimicrobials in Weaned Pigs 71

Appendix: Study Objectives and Related Outputs 74
USDA APHIS VS / v 

Acknowledgments

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

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

Health Inspection Service (APHIS). 

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

collected the data. We would also like to thank the personnel at the USDA–APHIS–

Veterinary Services’ Center for Epidemiology and Animal Health for their efforts in 

designing the study, developing the questionnaires, and generating and distributing this 

report.

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

efforts made the Swine 2012 study possible.

Bruce A. Wagner 

Director

Center for Epidemiology and Animal Health
vi / Swine 2012

Suggested bibliographic citation for this report:

USDA. “Changes in the U.S. Pork Industry, 1995–2012”

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

#678.0817

Contacts for further information:

Questions or comments on data analysis: Dr. Charles Haley (970) 494−7000.

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

Feedback

Feedback, comments, and suggestions regarding Swine 2012 study reports are 

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

nahms (Click on “FEEDBACK on NAHMS reports.”)
USDA APHIS VS / 1 

Introduction

Introduction

In 1983, promoters of the concept that would become the USDA’s National Animal Health 

Monitoring System (NAHMS) envisioned a program that would monitor changes and 

trends in national animal health and management, thereby providing periodic snapshots 

of the U.S. food-animal industries. With these industry overviews, members could identify 

opportunities for improvement, provide foundations for research and special studies, and 

detect emerging problems.

Section I of this report presents demographic changes of the U.S. and world pork 

industries from a historical perspective using data provided by the Foreign Agricultural 

Service and the National Agricultural Statistics Service (NASS). Results of past NAHMS 

national studies in sections II and III of this report provide an overview of changes in U.S. 

swine management, productivity, and health.

The 1990 National Swine Survey was NAHMS’ first national study of the U.S. swine 

industry and provided a snapshot of animal health and management that would serve 

as a baseline from which to measure industry changes. NAHMS conducted the 1990 

National Swine Survey in 18 States, with a target population of operations with at least 

1 sow. These States represented 95 percent of the U.S. swine population. National 

estimates generated from this study are reported in “Preweaning Morbidity & Mortality” 

(January 1992).

Swine ’95 was conducted in 16 States representing 91 percent of the U.S. swine 

population. The target population for the first phase of Swine ‘95 was producers with 

at least one pig. National estimates generated from this study are reported in “Part I: 

Reference of 1995 Swine Management Practices” (October 1995). The second phase 

of Swine ’95 was conducted on sites with at least 300 market pigs. National estimates 

generated from this phase of the study are reported in “Part II: Reference of 1995 

Grower/Finisher Health and Management” (May 1996).

Swine 2000 was designed to provide participants and the industry with information on 

U.S. swine herds with 100 or more pigs. NASS collaborated with USDA’s Veterinary 

Services to select a producer sample statistically designed to provide inferences to the 

Nation’s swine populations on operations with 100 or more pigs. Included in the study 

were 17 of the major pork producing States, which represented 94 percent of the U.S. 

pig inventory and 92 percent of U.S. pork producers with 100 or more pigs. Results from 

this study are reported in “Part I: Reference of Swine Health and Management, 2000” 

(September 2001); “Part II: Reference of Swine Health and Management, 2000” (May 

2002); “Part III: Reference of Swine Health and Environmental Management, 2000” 

(September 2002); and “Part IV: Changes in the U.S. Pork Industry, 1990–2000” (April 

2005).
2 / Swine 2012

Introduction

Swine 2006 used a study design similar to that used for the Swine 2000 study. 

Seventeen States participated in the Swine 2006 study, representing 94 percent of 

U.S. swine operations and inventory on operations with 100 or more pigs. The Swine 

2006 sample referred to the population of operations with 100 or more pigs in 17 

States. Results from this study are reported in “Part I: Reference of Swine Health 

and Management, 2006” (October 2007); “Part II: Reference of Swine Health and 

Management, 2006” (December 2007); “Part III: Reference of Swine Health, Productivity 

and General Management in the United States, 2006” (March 2008); and “Part IV: 

Changes in the U.S. Pork Industry, 1990-2006” (November 2008).

The Small-Enterprise Swine 2007 study described the health and management 

practices on operations with fewer than 100 pigs. The study covered States that had 

participated in previous national swine studies, plus States considered at risk for 

exposure to feral swine and the transmission of classical swine fever and pseudorabies. 

Thirty-one States participated in the study. These States represented 88.3 percent of U.S. 

swine and 84.4 percent of operations with fewer than 100 pigs, according to the 2002 

Census of Agriculture.

Swine 2012 comprised two concurrent studies. The core study targeted operations with

100 or more pigs in 13 States (see map on following page). A random sample of 4,600

operations was selected to participate in phase I of the study. There were two versions

of the phase I questionnaire administered from July 16 through August 15, 2012. The full

version was completed during on-farm interviews and a shorter version was administered

via computer-assisted telephone interviews. Producers that completed phase I, either by

phone or interview, were asked to continue with phase II of the study. The questionnaire

used in phase II was administered by State and Federal veterinary medical officers

(VMOs) from September 5 through November 17, 2012. Phase II respondents also had

the opportunity to participate in the collection of feed, feces, or blood for diagnostic

testing and analysis. This report presents results from phase II of the study.

The Small-Enterprise Swine study was conducted concurrently with the core NAHMS

Swine 2012 study. This study targeted operations with fewer than 100 pigs in 31 selected

States. A random sample of 2,000 operations was selected for participation from 

July 17 through September 15, 2012. NASS mailed the study questionnaire and then 

followed up with nonrespondents via computer-assisted telephone interviews. Results 

from the 2012 small-enterprise swine study are presented in “Reference of Management 

Practices on Small-enterprise Swine Operations in the United States, 2012”

(February 2014).

All NAHMS swine study reports are available online at http://www.aphis.usda.gov/

nahms.
USDA APHIS VS / 3 

Introduction

All in, all out: A management approach in which animals are moved as a group, allowing 

a facility to be completely empty for a period of time. Usually, all-in, all-out management 

consists of completely cleaning and disinfecting the facility before refilling it with animals. 

All-in, all-out management can be done at any group level: pen area, room, building, or 

entire facility.

Average: 

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

reporting divided by the number of operations reporting (see average number of days 

quarantine, p 28).

Pig-level average: A single operation value multiplied by the number of animals 

on the operation; then values are summed across operations and divided by total 

number of animals on all operations (see average age at weaning, p 35). 

Breeding pigs: All gilts, sows, and boars used for breeding.

Cull: The action of removing animals from the herd or slating them for removal for a 

reason usually related to poor performance, e.g., sows no longer suitable for breeding.

Continuous flow: A management approach in which animals are not moved as a group 

and, therefore, pens, rooms, or buildings always contain some animals.

Danish entry: A biosecurity measure in which the primary room used for entering the pig 

production area is divided into two sides (“dirty” and “clean”) by a solid barrier. Both sides 

have areas for storing separate clothing and footwear as well facilities and/or supplies for 

cleaning hands. Upon arrival, people enter the dirty side first. Outer clothing and footwear 

are removed and stored on the dirty side. Hands are cleaned using soap and water or 

by using hand sanitizer. People leave the dirty side and enter the clean side in their 

stocking feet, where they dress in coveralls and barn boots. Only then can they enter the 

production area. The process is reversed when leaving the production area.

Feedback: Pigs are fed a biologic material potentially containing a pathogen to boost 

immunity against the pathogen.

Gestation: Period from conception to birth, about 114 days in pigs. Gilts and sows in this 

stage are often called gestating females.

Grower/finisher: Production phase in which pigs are fed-out from approximately 

60 pounds to final market weight for slaughter, at which point they go to market or may be 

selected as breeding animals.

Terms Used in 

This Report
4 / Swine 2012

Introduction

Hand-mating: Term used when females are selected individually to be bred with a 

specific boar. Both sow and boar are placed in the same pen, and a stockperson might 

have to help with the physical aspects of mating.

Mummy: A dry, shriveled stillborn pig, often black in color. Mummies are sometimes 

caused by an infection in the sow during gestation.

Nursery: Production phase in which newly weaned pigs are managed, fed, and housed 

to weights of approximately 60 pounds, at which point they are put into a grower/finisher 

unit.

Open building with no outside access: Any building for housing swine that is open on 

one or more sides all year (natural ventilation). The open sides of the building might have 

a curtain.

Open building with outside access: Any building that allows access to an outside area 

(e.g., an uncovered pen).

Operation: The overall business and top-level management unit for a swine-rearing 

facility, which might consist of one or more sites. An operation can encompass all 

production phases of swine rearing (i.e., gestation, farrowing, nursery, and grower/

finisher) on one or more sites (geographic locations), each devoted to a different 

production phase or combination of phases. (See also “Site.”)

Pen-mating: One or more boars are introduced to female pigs in a pen or other 

enclosure for natural breeding. 

Percent animals: The number of animals on sites with a certain attribute divided by 

the total number of animals on all sites. In some cases, it is assumed that the attribute 

applies to all animals on the site. The animal type is defined in each table and may 

include total inventory, sow inventory, number of pigs that entered the nursery, or other 

specific pig groups. The “percent animals” estimates primarily reflect larger sites, which 

have the majority of pigs.

Percent sites: The number of sites with a certain attribute divided by the total number of 

sites. Percentages will sum to 100 where the attributes are mutually exclusive, but will not 

sum to 100 when the attributes are not mutually exclusive. The “percent sites” estimates 

primarily reflect smaller sites, since they make up the majority of operations.

Pit-holding: A waste management system in which manure is stored in a pit, usually 

under the floor of a facility containing pigs.
USDA APHIS VS / 5 

Introduction

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

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

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

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

mean 95 out of 100 times. Alternatively, the 90-percent confidence interval would be 

created by multiplying the standard error by 1.65 instead of 2. Most estimates in this 

report are rounded to the nearest tenth. If rounded to 0, the standard error was reported 

as (0.0). If there were no reports of the event, no standard error was reported (—).

Rendering: A process that converts animal-tissue waste into useful byproducts such as 

meat and bone meal. 

Scours: Diarrhea.

Site: One geographic location or address that functions as a unit to produce one or more 

production phases in swine rearing. An example would be a gestation/farrowing site. A 

site can encompass more than one production phase, such as a farrow-to-finish, which 

has gestation, farrowing, nursery, and grower/finisher pigs at one location. A site can be 

a part of an operation or it can be the whole operation, if the operation has only one site. 

(See also “Operation.”)

Total confinement: Raising pigs inside a building with mechanical ventilation and no 

outside access.

Wean-to-finish: Production phase in which newly weaned pigs are managed, fed, and 

housed until they go to market or are selected as breeding animals. 

Weaning: When baby pigs are transitioned from nursing their mother to eating feed.

USDA APHIS VS / 7 

Section I: Demographic Changes, 1850−2012–A. Historical Changes in the U.S. Swine Industry

Section I: Demographic Changes in the U.S. and World Pork Industries, 

1850−2012

Note: Where appropriate, column and row totals are shown as 100.0 to aid in 

interpretation; however, estimates may not sum to 100.0 due to rounding.

1. Total pig inventory

The NASS Census of Agriculture has collected hog and pig inventory numbers at 5-year 

intervals since 1850. A relatively stable inventory was seen from 1890 through 1930, 

at about 60 million head. By 1940, inventory had declined 40 percent, only to rebound 

by 1950. Hog and pig inventory peaked in 1959 at nearly 68 million head. Estimates in 

subsequent years consistently remained near 55 million head, increasing to 60 million 

head in 2002. The number of hog sites declined dramatically starting in 1959. The 2007 

Census of Agriculture showed the number of sites at 2.5 percent of those in 1950, while 

the number of head increased. As a result, the average herd size increased from fewer 

than 20 head in 1950 to nearly 900 head in 2007.

A.1.a. Changes in December 1 U.S. hog and pig inventory, and average herd size, 

1850–2012:

Year*

Total inventory 

(1,000 head)

Sites

reporting

Average

herd size

1850 30,354 NA NA

1860 33,513 NA NA

1870 25,135 NA NA

1880 49,773 NA NA

1890 57,427 NA NA

1900 62,868 4,335,363 15

1910 58,186 4,351,751 13

1920 59,346 4,850,807 12

1930 56,288 3,535,119 16

1940 34,037 3,766,675 9

1950 55,789 3,013,549 19

1959 67,949 1,848,784 37

1969 55,455 686,097 81

1978 57,697 445,117 130

1987 52,271 243,398 215

1992 57,563 191,347 301

1997 61,188 124,889 490

2002 60,405 78,895 766

2007 67,786 75,442 899

2012 66,027 63,246 1,044

*NASS Census of Agriculture data. 1850–1950 includes all States except Alaska and Hawaii. 1959–2012 

includes all 50 States.

A. Historical 

Changes in 

the U.S. Swine 

Industry, 

1850−2012
8 / Swine 2012

Section I: Demographic Changes, 1850−2012–A. Historical Changes in the U.S. Swine Industry

Each year, NASS surveys a random sample of producers to provide national estimates of 

animal populations and food production. The table below reports NASS demographics of 

the U.S. pork industry published on December 1 of each year. 

From 1990 through 2012, hog and pig inventory estimates increased 21.7 percent. 

Breeding inventory made up 12.6 percent of total inventory in 1990 compared with 

10.6 percent in 2000 and 8.8 percent in 2012, indicating a more productive breeding 

herd.

A.1.b. Changes in U.S. hog and pig and breeding inventories, December 1, 1990–2012:*

Hogs and Pigs Breeding Inventory

Year

1,000 

head

Pct. 

previous 

year

Pct.

1990

Pct.

1995

Pct. 

2000

1,000 

head

Pct. 

previous 

year

Pct. 

1990

Pct. 

1995

Pct. 

2000

1990 54,416 101.2 100.0 — — 6,847 99.9 100.0 — —

1991 57,649 105.9 105.9 — — 7,229 105.6 105.6 — —

1992 58,202 101.0 107.0 — — 7,109 98.3 103.8 — —

1993 57,940 99.5 106.5 — — 7,166 100.8 104.7 — —

1994 59,738 103.1 109.8 — — 6,998 97.7 102.2 — —

1995 58,201 97.4 107.0 100.0 — 6,770 96.7 98.9 100.0 —

1996 56,124 96.4 103.1 96.4 — 6,578 97.2 96.1 97.2 —

1997 61,158 109.0 112.4 105.1 — 6,957 105.8 101.6 102.8 —

1998 62,204 101.7 114.3 106.9 — 6,682 96.0 97.6 98.7 —

1999 59,335 95.4 109.0 101.9 — 6,233 93.3 91.0 92.1 —

2000 59,110 99.6 108.6 101.6 100.0 6,267 100.5 91.5 92.6 100.0

2001 59,722 101.0 109.8 102.6 101.0 6,201 98.9 90.6 91.6 98.9

2002 59,554 99.7 109.4 102.3 100.8 6,058 97.7 88.5 89.5 96.7

2003 60,453 101.5 111.1 103.9 102.3 6,019 99.4 87.9 88.9 96.0

2004 60,982 100.9 112.1 104.8 103.2 5,980 99.4 87.3 88.3 95.4

2005 61,463 100.8 113.0 105.6 104.0 6,031 100.8 88.1 89.1 96.2

2006 62,516 101.7 114.9 107.4 105.8 6,116 101.4 88.3 90.3 97.6

2007 68,177 109.1 125.3 117.1 115.3 6,233 101.9 91.0 92.1 99.5

2008 67,048 98.3 123.2 115.2 113.4 6,062 97.3 88.5 89.5 96.7

2009 64,687 96.5 118.9 111.1 109.4 5,850 96.5 85.4 86.4 93.3

2010 64,725 100.1 118.9 111.2 109.5 5,778 98.8 84.4 85.3 92.2

2011 66,259 102.4 121.8 113.8 112.1 5,803 100.4 84.8 85.7 92.6

2012 66,224 99.4 121.7 113.8 112.0 5,819 100.3 85.0 86.0 92.9

*Source: National Agricultural Statistics Service (NASS).
USDA APHIS VS / 9 

Section I: Demographic Changes, 1850−2012–A. Historical Changes in the U.S. Swine Industry

2. Number of swine sites and herd size

The number of swine sites has steadily decreased since 1990. By 2006, the number of 

swine sites had decreased to less than one-fourth the number reported in 1990.

A.2.a. Changes in the number of U.S. swine sites, 1990–2012:1

 

Year

Number 

of sites

Pct.

previous 

year

Pct.

1990

Pct. 

1995

Pct.

2000

1990 268,140 89.1 100.0

1991 247,090 92.1 92.1

1992 240,150 97.2 89.6

1993 218,060 90.8 81.3

1994 196,030 89.9 73.1

1995 168,450 85.9 62.8 100.0

1996 142,380 84.5 53.1 84.5

1997 122,160 85.8 45.6 72.5

1998 113,590 93.0 42.4 67.4

1999 99,620 87.7 37.2 59.1

2000 87,470 87.8 32.6 51.9 100.0

2001 81,220 92.9 30.3 48.2 92.9

2002 76,250 93.9 28.4 45.3 87.2

2003 73,720 96.7 27.5 43.8 84.3

2004 69,500 94.3 25.9 41.3 79.5

2005 67,280 96.8 25.1 39.9 76.9

2006 65,940 98.0 24.6 39.1 75.4

20072 75,450 114.4 28.1 44.8 86.3

2008 73,150 97.0 27.3 43.4 83.6

2009 71,450 97.7 26.6 42.4 81.7

2010 69,100 96.7 25.8 41.0 79.0

2011 69,100 100.0 25.8 41.0 79.0

2012 68,300 98.8 25.5 40.5 78.1 1

Source: NASS.

2

Beginning in 2007, NASS changed the definition of hog and pig operations, which likely accounts for the 

increase in the number of sites.
10 / Swine 2012

Section I: Demographic Changes, 1850−2012–A. Historical Changes in the U.S. Swine Industry

0

50

100

150

200

250

300

Number sites 

(x1,000)

268.1

247.1

240.2

218.1

196.0

168.5

142.4

122.2

113.6

99.6

87.5 81.2

1990 1992 1994 1996 1998 2000

Year

Number of swine sites, 1990–20121

1

Source: NASS.

2

Beginning in 2007, NASS changed the definition of hog and pig operations, which likely accounts for the 

increase in the number of sites.

2002

76.3 73.7 69.5 67.3 65.9

2004 2006 20082 2010 2012

75.5 73.1 71.5 69.1 69.1 68.3
USDA APHIS VS / 11 

Section I: Demographic Changes, 1850−2012–A. Historical Changes in the U.S. Swine Industry

Sites with fewer than 100 pigs represented the majority of pig sites. The percentages 

of sites with 100 to 499 pigs and with 500 to 999 pigs has decreased since 1998. The 

percentage of sites with a total inventory of 2,000 or more pigs increased from 

2.1 percent in 1993 to 13.1 percent in 2012.

A.2.b. Percentage of U.S. pig sites by herd size, 1990–2011:1

Percent Sites

Herd Size (number head)

 

Year 1–99 100–499 500–999 

1,000–

1,999 

2,000–

4,999 

5,000 or 

more 

 

Total

1990 63.9 25.0 7.1 4.0 2 2 100.0

1991 61.4 26.4 7.8 4.4 2 2 100.0

1992 60.2 26.5 8.1 5.2 2 2 100.0

1993 60.1 25.8 8.4 3.6 1.6 0.5 100.0

1994 58.6 25.9 8.8 4.2 1.9 0.6 100.0

1995 57.4 26.2 9.0 4.4 2.2 0.8 100.0

1996 57.5 25.0 9.1 4.8 2.5 1.1 100.0

1997 56.9 23.0 9.5 5.5 3.6 1.5 100.0

1998 54.4 23.8 9.9 6.0 4.2 1.7 100.0

1999 54.2 22.8 9.2 6.6 5.1 2.1 100.0

2000 57.3 19.3 8.7 6.7 5.6 2.4 100.0

2001 58.8 17.6 8.3 6.5 6.1 2.7 100.0

2002 59.8 16.1 8.2 6.6 6.3 3.0 100.0

2003 60.3 15.7 7.7 6.6 6.6 3.1 100.0

2004 60.6 14.9 7.4 6.4 7.4 3.3 100.0

2005 60.3 15.0 7.1 6.3 7.8 3.5 100.0

2006 60.5 14.6 6.8 6.4 8.0 3.7 100.0

2007 69.5 9.4 4.8 5.6 7.2 3.4 100.0

2008 69.3 9.2 4.8 5.4 7.3 4.0 100.0

2009 70.5 8.5 4.5 5.0 7.3 4.1 100.0

2010 70.9 7.5 4.1 5.3 7.7 4.5 100.0

2011 71.5 7.4 3.5 4.9 8.0 4.8 100.0

2012 71.3 7.3 3.4 4.8 8.3 4.8 100.0

1

Source: NASS.

2

Only estimates of 1,000 or more head were available in 1990–92.
12 / Swine 2012

Section I: Demographic Changes, 1850−2012–A. Historical Changes in the U.S. Swine Industry

The percentage of pig inventory on sites with 1 to 999 head has decreased steadily since 

1990. As of 2012, only 5.3 percent of all pigs were on sites of this size. Conversely, the 

percentage of pig inventory on sites with 2,000 or more head has increased since 1993. 

As of 2012, 87.4 percent of all pigs were on sites of this size.

A.2.c. Percentage of U.S. total hog and pig inventory by herd size, 1990–2011:1

Percent Total Hog and Pig Inventory

Herd Size (number of head)

 

Year 1–99 100–499 500–999 

1,000–

1,999 

2,000–

4,999 

5,000 or 

more Total

1990 6.4 28.6 23.8 41.2 2 2 100.0

1991 5.5 27.2 23.4 43.9 2 2 100.0

1992 5.3 25.3 22.0 47.4 2 2 100.0

1993 5.0 22.5 21.5 17.5 15.5 18.0 100.0

1994 4.0 20.5 19.5 18.0 17.0 21.0 100.0

1995 3.5 18.0 17.0 17.0 17.0 27.5 100.0

1996 3.0 15.0 15.0 16.0 17.0 34.0 100.0

1997 2.0 11.0 12.0 14.5 20.5 40.0 100.0

1998 2.0 9.5 11.0 14.0 21.5 42.0 100.0

1999 1.5 8.0 9.0 13.0 22.5 46.0 100.0

2000 1.0 6.5 8.0 12.5 22.0 50.0 100.0

2001 1.0 5.5 7.5 12.0 23.0 51.0 100.0

2002 1.0 5.0 6.5 12.0 22.5 53.0 100.0

2003 1.2 4.6 6.4 10.4 24.2 53.2 100.0

2004 1.1 4.2 5.9 9.8 25.7 53.3 100.0

2005 1.0 3.9 5.3 9.5 25.7 54.6 100.0

2006 1.0 3.5 4.8 9.2 25.6 55.9 100.0

2007 0.9 2.7 3.7 8.2 24.4 60.1 100.0

2008 0.9 2.5 3.5 8.0 24.0 61.1 100.0

2009 0.9 2.3 3.3 7.5 24.0 62.0 100.0

2010 0.8 2.1 3.1 8.0 25.0 61.0 100.0

2011 0.8 2.0 2.7 7.5 24.9 62.1 100.0

2012 0.8 1.9 2.6 7.5 25.5 61.9 100.0

1

Source: NASS.

2

Only estimates of 1,000 or more head were available in 1990–92.
USDA APHIS VS / 13 

Section I: Demographic Changes, 1850−2012–A. Historical Changes in the U.S. Swine Industry

Except in 1990, 1993, and 1998, fewer pigs were weaned per litter in December through 

February than during the other quarters. Since 1990, the average number of pigs weaned 

per litter has increased across quarters by more than one piglet.

A.2.d. Changes in the quarterly average number of pigs weaned per litter, per quarter, 

1990–2012:1

 

Year

Dec–

Feb2

Pct. 

1995

Pct. 

2000

Mar– 

May

Pct. 

1995

Pct. 

2000

Jun– 

Aug

Pct. 

1995

Pct. 

2000

Sep–

Nov

Pct. 

1995

Pct. 

2000

1990 7.83 7.94 7.90 7.82

1991 7.87 7.96 7.89 7.89

1992 8.04 8.08 8.14 8.05

1993 8.14 8.13 8.09 8.05

1994 8.10 8.26 8.21 8.16

1995 8.24 100.0 8.32 100.0 8.34 100.0 8.35 100.0

1996 8.43 102.3 8.48 101.9 8.55 102.5 8.54 102.3

1997 8.63 104.7 8.67 104.2 8.72 104.6 8.67 103.8

1998 8.70 105.6 8.75 105.2 8.72 104.6 8.66 103.7

1999 8.73 105.9 8.80 105.8 8.86 106.2 8.78 105.1

2000 8.76 106.3 100.0 8.86 106.5 100.0 8.84 106.0 100.0 8.85 106.0 100.0

2001 8.72 105.8 99.5 8.89 106.9 100.3 8.89 106.6 100.6 8.85 106.0 100.0

2002 8.77 106.4 100.1 8.84 106.3 99.8 8.92 107.0 100.9 8.86 106.1 100.1

2003 8.81 106.9 100.6 8.88 106.7 100.2 8.90 106.7 100.7 8.93 106.9 100.9

2004 8.85 107.4 101.0 8.93 107.3 100.8 9.01 108.0 101.9 8.96 107.3 101.2

2005 8.94 108.5 102.1 9.02 108.4 101.8 9.06 108.6 102.5 9.03 108.1 102.0

2006 9.03 109.6 103.1 9.08 109.1 102.5 9.11 109.2 103.1 9.11 109.1 102.9

2007 9.09 110.3 103.8 9.20 110.6 103.8 9.29 111.4 105.1 9.28 111.1 104.9

2008 9.24 112.1 105.5 9.38 112.7 105.9 9.51 114.0 107.6 9.50 113.8 107.3

2009 9.18 115.0 108.2 9.61 115.5 108.5 9.70 116.3 109.7 9.70 116.2 109.6

2010 9.61 116.6 109.7 9.81 117.9 110.7 9.81 117.6 111.0 9.89 118.4 111.8

2011 9.80 119.0 111.9 10.03 120.6 113.2 10.03 120.3 113.5 10.02 120.0 113.2

2012 9.97 121.0 113.8 10.09 121.3 113.9 10.13 121.5 114.6 10.15 121.6 114.7

1

Source: NASS. Ratio of expected number of pigs weaned to sows/gilts farrowed.

2

December preceding year.
14 / Swine 2012

Section I: Demographic Changes, 1850−2012–B. U.S. Pork Industry ChangesInventories by State

The two tables in this section describe pork industry changes by State for 1990, 2000, 

2006, and 2012. The pig inventories and number of sites are by State and based on 

NASS data. The tables also identify which States participated in the four NAHMS national 

swine studies. Based on the December 1, 2012, inventory, levels have increased 

121.7 percent since 1990. Inventory has become more concentrated in large swine 

States such as Iowa, North Carolina, and Minnesota and has declined in traditional 

swine States such as Illinois, Indiana, South Dakota, and Wisconsin. Several western 

States have seen increases in pig inventory since 1990, including Utah, Oklahoma, 

Colorado, Arizona, and Texas.

B. U.S. Pork 

Industry 

Changes

Inventories by 

State
USDA APHIS VS / 15 

Section I: Demographic Changes, 1850−2012–B. U.S. Pork Industry ChangesInventories by State

B.1. Changes in number of pigs by State:*

Total Pigs (1,000 head) Percent Change

State

Dec. 1, 

1990

Dec. 1, 

2000

Dec. 1, 

2006

Dec. 1, 

2012

2012 pct. 

of 1990

2012 pct.

of 2000

2012 pct.

of 2006

Alabama1 335 165 165 140 41.8 84.8 84.8

Alaska 1.2 0.8 0.9 1 83.3 125.0 111.1

Arizona 110 9 148 170 154.5 1,888.9 114.9

Arkansas3 4 760 685 260 110 14.5 16.1 42.3

California1 195 150 145 105 53.8 70.0 72.4

Colorado1 3 4 300 840 840 720 240.0 85.7 85.7

Connecticut 7 4 3 2.2 31.4 55.0 73.3

Delaware 31 20 10.5 4 13.0 20.0 38.1

Florida 130 40 20 15 11.5 37.5 75.0

Georgia1 2 1,100 380 245 155 14.1 40.8 63.3

Hawaii 36 26 16 12 33.3 46.2 75.0

Idaho 60 24 25 — — — —

Illinois1 2 3 4 5 5,700 4,150 4,200 4,600 80.1 110.8 109.5

Indiana1 2 3 4 5 4,400 3,350 3,350 3,800 86.4 113.4 113.4

Iowa1 2 3 4 5 13,800 15,100 17,300 20,600 149.3 136.4 119.1

Kansas2 3 4 5 1,500 1,520 1,860 1,910 127.3 125.7 102.7

Kentucky 2 920 430 340 315 34.2 73.3 92.6

Louisiana 50 29 14 7 14.0 24.1 50.0

Maine 8 6 4.5 4.5 56.3 75.0 100.0

Maryland1 162 40 33 20 12.3 50.0 60.6

Massachusetts 33 21 13 11 33.3 52.4 84.6

Michigan1 2 3 4 1,250 950 990 1,080 86.4 113.7 110.1

Minnesota1 2 3 4 5 4,500 5,800 6,900 7,650 170.0 131.9 110.9

Mississippi 149 315 335 415 278.5 131.7 123.9

Missouri2 3 4 5 2,800 2,900 2,800 2,750 98.2 94.8 98.2

Montana 185 155 180 175 94.6 112.9 97.2

Nebraska1 2 3 4 5 4,300 3,050 3,050 3,000 69.8 98.4 98.4

Nevada 14 7.5 3.5 2.7 19.3 36.0 77.1

New Hampshire 6 4 2.8 3.3 55.0 82.5 117.9

New Jersey 25 14 9 8 32.0 57.1 88.9

New Mexico 27 3 2 1.3 4.8 43.3 65.0

*Source: NASS.

1

Participated in 1990 National Swine Survey (total of 18 States).

2

Participated in Swine 1995 study (total of 16 States).

3

Participated in Swine 2000 study (total of 17 States).

4

Participated in Swine 2006 study (total of 17 States).

5

Participated in Swine 2012 study (total of 13 States).

continued →
16 / Swine 2012

Section I: Demographic Changes, 1850−2012–B. U.S. Pork Industry ChangesInventories by State

B.1. Changes in number of pigs by State (cont’d): 

Total Pigs (1,000 head) Percent Change

State

Dec. 1, 

1990

Dec. 1, 

2000

Dec. 1, 

2006

Dec. 1,

2012

2012 pct. 

of 1990

2012 pct.

of 2000

2012 pct.

of 2006

New York 103 80 98 66 64.1 82.5 67.3

North Carolina1 2 3 4 5 2,800 9,300 9,500 9,000 321.4 96.8 94.7

North Dakota 265 185 168 135 50.9 73.0 80.4

Ohio1 2 3 4 5 2,000 1,490 1,680 2,045 102.3 137.2 121.7

Oklahoma3 4 5 215 2,310 2,330 2,320 1,079.1 100.4 99.6

Oregon1 80 32 22 12.5 15.6 39.1 56.8

Pennsylvania1 2 3 4 5 920 1,030 1,080 1,130 122.8 109.7 104.6

Rhode Island 5 2.5 2.1 1.9 38.0 76.0 90.5

South Carolina 400 290 295 240 60.0 82.8 81.4

South Dakota2 3 4 5 1,770 1,320 1,270 1,200 67.8 90.9 94.5

Tennessee1 2 620 230 220 150 24.2 65.2 68.2

Texas3 4 5 550 920 940 820 149.1 89.1 87.2

Utah 33 550 680 740 2,242.4 134.5 108.8

Vermont 5 2.5 2.5 3.9 78.0 156.0 156.0

Virginia1 430 425 365 230 53.5 54.1 63.0

Washington 56 27 36 — — — —

W. Virginia 30 10 11 6 20.0 60.0 54.5

Wisconsin1 2 3 4 1,200 610 450 320 26.7 52.5 71.1

Wyoming 20 108 100 86 430.0 79.6 86.0

U.S. 54,416 59,110 62,516 66,348 121.9 112.2 106.1

Source: NASS.

1

Participated in 1990 National Swine Survey (total of 18 States).

2

Participated in Swine 1995 study (total of 16 States).

3

Participated in Swine 2000 study (total of 17 States).

4

Participated in Swine 2006 study (total of 17 States).

5

Participated in Swine 2012 study (total of 13 States).
USDA APHIS VS / 17 

Section I: Demographic Changes, 1850−2012–B. U.S. Pork Industry ChangesInventories by State

In general, the number of swine sites in the Southern States has declined. In addition, 

over the last decade major swine producing States such as Minnesota and Iowa had 

decreases in the number of swine sites. 

B.2. Number of and changes in the number of swine sites: 

Number of Sites Percent Change

State 1990 2000 2006 2012*

2012 

as pct. 

of 1990

2012 

as pct. 

of 2000

2012 

as pct. 

of 2006

Alabama1 4,500 700 450 689 15.3 98.4 153.1

Alaska 40 50 50 37 92.5 74.0 74.0

Arizona 400 230 150 509 127.3 221.3 339.3

Arkansas3 4 3,100 1,100 750 752 24.3 68.4 100.3

California1 4,000 1,000 800 1,437 35.9 143.7 179.6

Colorado1 3 4 2,000 900 800 1,001 50.1 111.2 125.1

Connecticut 450 180 250 318 70.7 176.7 127.2

Delaware 420 100 70 59 14.0 59.0 84.3

Florida 5,000 1,400 1,100 1,642 32.8 117.3 149.3

Georgia1 2 8,000 1,200 700 866 10.8 72.2 123.7

Hawaii 500 230 230 231 46.2 100.4 100.4

Idaho 2,000 400 650 680 34.0 170.0 104.6

Illinois1 2 3 4 5 15,300 5,100 2,900 2,045 13.4 40.1 70.5

Indiana1 2 3 4 5 13,000 4,400 2,800 2,757 21.2 62.7 98.5

Iowa1 2 3 4 5 35,000 12,300 8,700 6,266 17.9 50.9 72.0

Kansas2 3 4 5 6,000 1,600 1,400 1,010 16.8 63.1 72.1

Kentucky 2 6,500 1,300 900 1,284 19.8 98.8 142.7

Louisiana 2,500 650 600 658 26.3 101.2 109.7

Maine 1,600 300 370 752 47.0 250.7 203.2

Maryland1 1,400 430 400 333 23.8 77.4 83.3

Massachusetts 850 300 300 478 56.2 159.3 159.3

Michigan1 2 3 4 5,500 2,500 2,100 2,198 40.0 87.9 104.7

Minnesota1 2 3 4 5 15,000 7,300 4,800 3,355 22.4 46.0 69.9

Mississippi 6,000 1,500 1,000 540 9.0 36.0 54.0

Missouri2 3 4 5 16,000 3,600 2,000 2,128 13.3 59.1 106.4

Montana 1,500 650 500 406 27.1 62.5 81.2

Nebraska1 2 3 4 5 12,500 4,000 2,500 1,476 11.8 36.9 59.0

Nevada 140 100 110 81 57.9 81.0 73.6

New Hampshire 750 250 300 359 47.9 143.6 119.7

New Jersey 700 400 300 298 42.6 74.5 99.3

New Mexico 900 400 350 211 23.4 52.8 60.3

*Source: NASS 2012 Census of Agriculture.

1

Participated in 1990 National Swine Survey (total of 18 States).

2

Participated in Swine 1995 study (total of 16 States).

3

Participated in Swine 2000 study (total of 17 States).

4

Participated in Swine 2006 study (total of 17 States).

5

Participated in Swine 2012 study (total of 13 States).

continued →
18 / Swine 2012

Section I: Demographic Changes, 1850−2012–B. U.S. Pork Industry ChangesInventories by State

B.2. Number of and changes in the number of swine sites (cont’d): 

Number of Sites Percent Changes

State 1990 2000 2006 2012*

2012 

as pct. 

of 1990

2012 

as pct. 

of 2000

2012 

as pct. 

of 2006

New York 2,900 1,100 1,200 1,912 65.9 173.8 159.3

North Carolina1 2 3 4 5 10,000 3,600 2,300 2,217 22.2 61.6 96.4

North Dakota 2,100 700 430 218 10.4 31.1 50.7

Ohio1 2 3 4 5 13,600 5,200 4,000 3,494 25.7 67.2 87.4

Oklahoma3 4 5 5,200 2,700 2,600 1,947 37.4 72.1 74.9

Oregon1 2,400 1,000 1,100 1,124 46.8 112.4 102.2

Pennsylvania1 2 3 4 5 7,500 3,300 3,200 3,097 41.3 93.8 96.8

Rhode Island 90 50 50 77 85.6 154.0 154.0

South Carolina 5,500 900 1,100 838 15.2 93.1 76.2

South Dakota2 3 4 5 7,700 1,900 1,100 681 8.8 35.8 61.9

Tennessee1 2 8,500 1,500 1,100 1,297 15.3 86.5 117.9

Texas3 4 5 11,000 4,300 3,700 4,905 44.6 114.1 132.6

Utah 900 500 450 669 74.3 133.8 148.7

Vermont 1,100 250 280 450 40.1 180.0 160.7

Virginia1 3,500 1,200 850 1,265 36.1 105.4 148.8

Washington 2,500 800 900 934 37.3 116.8 103.8

W. Virginia 2,300 1,000 900 725 31.5 72.5 80.6

Wisconsin1 2 3 4 9,400 2,700 2,200 2,270 24.1 84.1 103.2

Wyoming 400 200 150 270 67.5 135.0 180.0

U.S. 268,140 87,470 65,940 63,246 23.6 72.3 95.9

*Source: NASS 2012 Census of Agriculture.

1

Participated in 1990 National Swine Survey (total of 18 States).

2

Participated in Swine 1995 study (total of 16 States).

3

Participated in Swine 2000 study (total of 17 States).

4

Participated in Swine 2006 study (total of 17 States).

5

Participated in Swine 2012 study (total of 13 States).
USDA APHIS VS / 19 

Section I: Demographic Changes, 1850−2012–C. World Pork Production ChangesInventories by Country

Since 1991, the pig inventory in the Republic of Korea has nearly doubled, while that of 

the Russian Federation is only 45 percent of what it was in 1991.

C.1. Changes in pig inventories, by continent/country:* 

January 1 Inventory (1,000 head)

Continent/Country 1991 1996 2001 2006 2012

North 

America

Canada 10,172 11,588 13,576 15,110 12,625

Mexico 8,593 11,100 9,372 8,911 9,276

United 

States 54,416 58,201 59,110 61,463 66,259

Subtotal 73,181 80,889 82,058 85,484 88,160

South 

America Brazil 32,550 32,068 32,440 32,938 38,336

European 

Union 116,6681 115,9591 158,7652 159,3642 149,8092

Former 

Soviet 

Union

Russian 

Federation 38,314 22,631 15,824 13,812 17,258

Ukraine 19,427 13,144 7,652 7,052 7,373

Subtotal 57,741 35,775 23,476 20,864 24,631

Asia

Peoples 

Republic 

of China

362,408 441,692 416,836 433,191 468,627

 Japan 11,355 9,900 9,788 9,620 9,735

Republic of 

Korea 4,528 6,461 7,350 8,098 8,171

Philippines 8,007 9,023 11,715 13,041 NA

Taiwan 8,565 10,510 7,495 7,172 NA

Subtotal 394,863 477,586 452,684 471,122 486,533

Oceania Australia 2,530 2,600 2,748 2,358 2,285

World total3 726,092 784,375 783,883 875,198 751,418

*Statistical data provided by Foreign Agriculture Service.

1

European Union–includes Austria, Belgium, Denmark, Finland, France, Germany, Greece, Ireland, Italy, 

Luxembourg, Netherlands, Portugal, Spain, Sweden, and U.K.

2

European Union–includes Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, 

France, Germany, Greece, Hungary, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Poland, 

Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, and U.K.

3

Includes countries not presented in table.

C. World Pork 

Production 

Changes

Inventories by 

Country
20 / Swine 2012

Section I: Demographic Changes, 1850−2012–C. World Pork Production ChangesInventories by Country

C.2. Changes in pig inventory percentages in selected countries:* 

Continent/Country

2001 as 

pct. of 

1996

2006 as 

pct. of 

2001

2012 as

pct. of 

1991

2012 as 

pct. of 

1996

2012 as 

pct. of 

2001

2012 as 

pct. of 

2006

North 

America

Canada 117.2 111.3 124.1 108.9 93.0 83.6

Mexico 84.4 95.1 107.9 83.6 99.0 104.1

United 

States 101.6 104.0 121.8 113.8 112.1 107.8

 Subtotal 101.4 104.2 120.5 109.0 107.4 103.1

South 

America Brazil 101.2 101.5 117.8 119.5 118.2 116.4

European 

Union NC 99.1 128.4 129.2 94.4 95.2

Former 

Soviet 

Union

Russian 

Federation69.9 87.3 45.0 76.3 109.1 124.9

Ukraine 58.2 92.2 38.0 56.1 96.4 104.6

 Subtotal 65.6 88.9 42.7 68.8 104.9 118.1

Asia

China, 

Peoples 

Republic 

of

94.3 104.0 129.3 106.1 112.6 108.2

Japan 98.9 98.3 85.7 98.3 99.5 101.2

Korea, 

Republic 

of

113.8 110.2 180.5 126.5 111.2 100.9

Philippines 129.8 111.3 NC NC NC NC

Taiwan 71.3 95.7 NC NC NC NC

 Subtotal 94.8 104.1 123.2 101.9 107.5 103.3

Oceania Australia 105.7 85.8 90.3 87.9 83.2 96.9

World 

total1 97.7 103.8 103.2 99.8 102.2 98.5

*Statistical data provided by Foreign Agriculture Service.

1

Includes countries not presented in table.

NC = Not comparable.
USDA APHIS VS / 21 

Section II: Management and Productivity Changes–A. Production Phases

Note: Where applicable, column or row totals are shown as 100.0 to aid in interpretation; 

however, estimates may not sum to 100.0 due to rounding.

The NAHMS Swine ’95 study collected data on sites with 1 or more or more pigs, while 

the Swine 2000, 2006, and 2012 studies collected data on sites with 100 or more pigs. 

For this report, to account for the discrepancy in study populations, estimates for 1995 

reflect only sites with 100 or more pigs. Therefore, 1995 estimates might differ from 

estimates previously published in the Swine ’95 Part I report. 

Approximately one-fifth of sites had a farrowing phase in 2012 compared with over 

three-fourths of sites in 1995. The percentage of sites with a gestation phase in 2012 was 

less than half of what it was in 2000.

A.1. Percentage of sites by production phase and by study:

Percent Sites

Study 

Swine 1995 Swine 2000 Swine 2006 Swine 20121

Production 

phase Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Gestation NA2 52.6 (1.7) 39.8 (1.2) 21.1 (2.6)

Farrowing 77.4 (2.2) 52.8 (1.7) 39.0 (1.2) 20.8 (2.6)

Nursery 64.2 (2.4) 50.4 (1.7) 53.3 (1.3) 22.3 (3.0)

Grower/finisher 89.5 (1.5) 85.5 (1.1) 80.0 (1.0) 56.0 (5.3)

Wean to finish3 NA NA NA 24.4 (4.5)

1

In 1995, 2000, and 2006, the question asked which production phases were on-site. In 2012, the question 

asked whether animals of the production-phase type were present from December 1, 2011, through May 31, 

2012.

2

Gestation question not asked in 1995.

3

Wean-to-finish-phase question not asked in 1995, 2000, and 2006.

Section II: Management and Productivity Changes in the U.S. Pork

Industry: NAHMS Population Estimates 1995, 2000, 2006, and 2012

A. Production 

Phases
22 / Swine 2012

Section II: Management and Productivity Changes–A. Production Phases

0

20

40

60

80

100

Swine 20121

Swine 2006

Swine 2000

Swine 1995

77.4

64.2

89.5

52.6 52.8

85.5

39.8 39.0

80.0

21.1 20.8

56.0

Gestation2 Farrowing Nursery Grower/finisher

Production phase

Percent

Percentage of sites by production phase and by study 

Study

50.4

53.3

22.3

NA

1

In 1995, 2000, and 2006, the question asked which production phases were present on-site. In 2012, 

the question asked whether animals of the production-phase type were present from December 1, 2011, 

through May 31, 2012.

2

Question not asked in 1995.
USDA APHIS VS / 23 

Section II: Management and Productivity Changes–A. Production Phases

Increased site specialization has resulted in a decrease in the percentage of sites with 

gestation and farrowing phases. In 1995, more than half of sites had the three production 

phases normally associated with traditional “farrow-to-finish” sites compared with only 

6.0 percent of sites in 2012. Conversely, over 40 percent of sites specialized in the 

grower/finisher phase in 2012, more than twice the percentage reported in 1995.

A.2. Percentage of sites by production phase and by study:

Percent Sites

Study

Swine 19951 Swine 2000 Swine 2006 Swine 20122

Production phase Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Breeding only 2.2 (0.9) 5.1 (0.7) 7.6 (0.7) 7.5 (1.2)

Breeding and 

nursery

7.9 (1.4) 4.5 (0.7) 3.7 (0.5) 1.6 (0.3)

Breeding and 

grower/finisher 12.7 (1.7) 7.8 (1.2) 1.3 (0.3) 0.8 (0.2)

Breeding, nursery, 

and grower/finisher 54.5 (2.5) 34.4 (1.7) 26.3 (1.2) 6.0 (0.9)

Breeding and 

wean-to-finish NA NA NA 3.8 (0.6)

Nursery and 

grower/finisher 1.3 (0.6) 6.8 (0.7) 15.3 (0.9) 5.7 (0.8)

Nursery only 0.4 (0.1) 4.1 (0.5) 7.8 (0.6) 8.2 (2.3)

Grower/finisher only 20.9 (2.2) 35.5 (1.6) 36.9 (1.2) 42.7 (6.4)

Wean-to-finish only NA NA NA 19.9 (4.0)

Other combination 0.1 (0.0) 1.8 (0.6) 1.0 (0.3) 3.7 (0.6)

Total 100.0 100.0 100.0 100.0

1

In 1995, producers were not asked if they had a gestation phase; so for that year “breeding” consisted only of 

sites that said they had a farrowing phase.

2

Refers to the period from December 1, 2011, through May 31, 2012.
24 / Swine 2012

Section II: Management and Productivity Changes–B. Sow and Gilt Management

1. Mating techniques

Of sites that did not exclusively use pen-mating, over 90 percent used artificial 

insemination (AI) for at least one mating of sows or gilts in 2012, which was over four 

times the percentage of sites that did so in 2000.

B.1.a. For sites that did not exclusively use pen-mating, percentage of sites by 

predominant mating technique used in at least one mating of sows or gilts, and by study:

Percent Sites

Study

Swine 2000 Swine 2006* Swine 2012*

Mating technique Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Artificial insemination 23.2 (1.7) 84.8 (2.5) 91.1 (1.5)

Individual hand-mating 

naturally 13.0 (1.3) 23.2 (2.8) 9.5 (1.7)

Pen-mating with 

multiple females and 

one or more boars

73.3 (1.8) 10.9 (2.3) 10.4 (1.7)

*Swine 2006 and 2012 asked for information on first, second, or third or more matings, while Swine 2000 only 

asked about first and second matings.

B.1.b. For sites that did not exclusively use pen-mating, percentage of sows or gilts 

serviced on-site, by predominant mating technique used in at least one mating, and by 

study:

Percent Sows and Gilts

Study

Swine 2000 Swine 2006* Swine 2012*

Mating technique Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Artificial insemination 72.6 (2.1) 93.2 (4.7) 99.1 (0.3)

Individual hand-mating 

naturally 17.0 (2.9) 10.2 (4.6) 1.9 (0.9)

Pen-mating with 

multiple females and 

one or more boars

25.9 (2.1) 8.5 (4.7) 1.8 (0.5)

*Swine 2006 and 2012 studies asked for information on first, second, or third or more matings, whereas Swine 

2000 only asked about first and second matings.

B. Sow and Gilt 

Management
USDA APHIS VS / 25 

Section II: Management and Productivity Changes–B. Sow and Gilt Management

2. Culling

A higher percentage of animals were culled in 2006 and 2012 than in 2000. When 

animals were culled, age and reproductive failure were the most common reasons for 

culling in 2000 and 2012.

B.2.a. Breeding-age females culled from December 1 through May 1 of given year, as a 

percentage of sow and gilt inventory, by study:

Percent Sows and Gilts

Study

Swine 1995 Swine 2000 Swine 2006 Swine 2006* Swine 2012

Pct.

Std. 

error Pct.

Std. 

error Pct.

Std.

error Pct.

Std. 

error Pct.

Std. 

error

20.0 (0.9) 17.5 (0.7) 19.5 (0.9) 21.1 (0.9) 25.1 (1.1)

*This number differs from the 2006 part I report due to matching 2000 and 2012 estimates, which included 

only sows and bred gilts for breeding in the denominator.

B.2.b. Percentage of culled breeding-age females from December 1 through May 31 of 

given year, by reason culled and by study:

Percent Culled Breeding-age Females

Study

Swine 1995 Swine 2000 Swine 2006 Swine 2012

Reason culled Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Age 40.2 (2.2) 41.9 (1.8) 36.6 (2.6) 35.2 (3.6)

Lameness 9.6 (0.8) 16.0 (1.2) 15.2 (2.3) 6.8 (1.2)

Performance1 34.5 (2.3) 12.0 (0.7) 13.0 (1.1) 13.5 (2.3)

Disease 2.6 (0.7) NA NA NA

Reproductive failure NA 21.3 (1.3) 26.3 (1.9) 25.4 (3.5)

Injury NA NA 4.0 (0.6) 2.5 (0.6)

Other2 13.1 (2.5) 8.8 (1.6) 4.9 (0.8) 16.5 (6.9)

Total 100.0 100.0 100.0 100.0

1

Small litter size, high preweaning mortality, or low birth weight.

2

Responses included other health problems or multiple causes.
26 / Swine 2012

Section II: Management and Productivity Changes–B. Sow and Gilt Management

3. Introduction of breeding animals

The frequency of isolation or quarantine for new breeding females remained unchanged 

from 1995 to 2006.

B.3.a. Percentage of sites by frequency that new breeding females were typically isolated 

or quarantined, and by study:

Percent Sites*

Study

Swine 1995 Swine 2000 Swine 2006

Frequency Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Always 23.8 (2.1) 32.0 (2.2) 34.3 (2.0)

Sometimes 9.0 (1.3) 8.1 (1.4) 5.0 (0.9)

Never 22.0 (2.2) 16.9 (1.8) 17.0 (1.6)

No new arrivals 45.2 (2.6) 43.0 (2.4) 43.7 (2.2)

Total 100.0 100.0 100.0

*Data not available for 2012.
USDA APHIS VS / 27 

Section II: Management and Productivity Changes–B. Sow and Gilt Management

The percentage of sites that always isolated new breeding males was much lower 

in 2012 than in 1995, 2000, and 2006. In 2012, a higher percentage of sites did not 

introduce any new breeding males compared with the other study years. The decrease 

in the percentage of sites that always isolated or quarantined new males might indicate a 

higher trust in the source of new animals (e.g., known health status of the herd of origin). 

Frequency of isolation or quarantine for breeding males remained unchanged from 1995 

to 2006.

B.3.b. Percentage of sites by frequency that new breeding males were typically isolated 

or quarantined:

Percent Sites

Study

Swine 1995 Swine 2000 Swine 2006 Swine 2012

Frequency Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Always 43.5 (2.4) 54.8 (2.4) 48.6 (2.2) 18.8 (2.9)

Sometimes 11.1 (1.7) 11.3 (1.6) 10.1 (1.4) 2.2 (0.5)

Never 18.2 (1.8) 20.2 (2.0) 20.2 (1.8) 8.1 (2.1)

No new arrivals 27.2 (2.3) 13.7 (1.5) 21.1 (1.7) 70.9 (3.5)

Total 100.0 100.0 100.0 100.0
28 / Swine 2012

Section II: Management and Productivity Changes–B. Sow and Gilt Management

The average number of days newly arriving breeding males were quarantined remained 

relatively constant over the last three swine studies, as did the percentage of sites that 

tested all males before entry into the breeding herd.

B.3.c. For sites that always or sometimes isolated or quarantined new arrivals, site 

average number of days new arrivals were isolated or quarantined, by gender and by 

study:

Site Average Number of Days

Study

Swine 2000 Swine 2006 Swine 2012

Gender Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error

Breeding females 38.7 (1.5) 37.0 (1.3) *

Breeding males 34.3 (0.9) 32.6 (1.1) 38.1 (2.3)

*Data not available.

B.3.d. For sites with newly arrived breeding females, percentage of sites that typically 

tested new females for disease before introduction to the breeding herd, by proportion of 

females tested and by study:

Percent Sites*

Study

Swine 2000 Swine 2006

Proportion females Percent Std. error Percent Std. error

All 43.5 (3.7) 38.6 (2.7)

Some 16.8 (2.4) 20.1 (2.3)

None 39.7 (3.8) 41.3 (2.8)

Total 100.0 100.0

*Data not available for 2012.
USDA APHIS VS / 29 

Section II: Management and Productivity Changes–B. Sow and Gilt Management

B.3.e. For sites with newly arrived breeding males, percentage of sites that typically 

tested new males for disease before introduction to the breeding herd, by proportion of 

males tested and by study:

Percent Sites

Study

Swine 2000 Swine 2006 Swine 2012

Proportion males Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

All 51.8 (3.1) 41.0 (2.4) 41.3 (5.9)

Some 8.3 (1.4) 13.6 (1.8) 21.0 (8.9)

None 39.9 (3.2) 45.4 (2.5) 37.7 (6.5)

Total 100.0 100.0 100.0

Vaccinating breeding stock as a method of acclimating new arrivals was performed on 

roughly the same percentage of sites in 2000 and 2012.

B.3.f. For sites with newly arriving breeding stock, percentage of sites by method used to 

acclimate new arrivals, and by study:

Percent Sites

Study

Swine 2000* Swine 2006 Swine 2012

Method Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Feedback of feces 

from other swine 25.1 (2.8) 20.8 (1.9) 32.8 (5.6)

Feedback of mummies, 

placentas, or 

stillborn pigs

11.3 (1.9) 8.8 (1.4) 14.9 (3.3)

Exposure to 

cull females 49.0 (3.7) 35.8 (2.2) 44.2 (3.7)

Exposure to sick pigs 7.7 (1.5) 6.0 (1.2) 11.3 (3.2)

Give vaccinations 84.1 (2.7) 67.1 (2.3) 76.9 (2.5)

Other 2.6 (1.2) 5.5 (1.2) 4.1 (0.9)

*In 2000, this question was limited to newly arriving breeding females.
30 / Swine 2012

Section II: Management and Productivity Changes–B. Sow and Gilt Management

4. Facility type

Of sites with a gestation phase, a lower percentage in 2012 than in 2000 primarily housed 

pigs in an open building with outside access. A higher percentage of operations in 2012 

than in 2000 and 2006 housed gestating animals in an open building with no outside 

access, suggesting a move toward more naturally ventilated systems for gestation pigs.

B.4. For sites with a gestation phase, percentage of sites by primary facility type used 

and by study:

Percent Sites

Study

Swine 19951 Swine 2000 Swine 2006 Swine 20122

Facility type Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Total confinement NA 22.4 (1.6) 34.6 (1.9) 38.6 (2.5)

Open building with 

no outside access NA 13.9 (1.9) 13.3 (1.5) 25.1 (2.1)

Open building with 

outside access NA 45.2 (2.5) 37.3 (2.2) 25.2 (1.8)

Lot with hut or 

no building NA 10.3 (1.4) 8.6 (1.2) 6.5 (0.8)

Pasture with hut 

or no building NA 8.2 (1.4) 6.2 (1.0) 4.6 (0.7)

Total 100.0 100.0 100.0

1

In 1995, the questionnaire did not ask if there was a gestation phase.

2

In 2012, the question referred to the period from December 1, 2011, through May 31, 2012.
USDA APHIS VS / 31 

Section II: Management and Productivity Changes–B. Sow and Gilt Management

5. Pig flow

Over 60 percent of sites with a gestation phase in 2000, 2006, and 2012 used continuous 

flow management. 

B.5. For sites with a gestation phase, percentage of sites by pig-flow management style 

and by study:

Percent Sites

Study

Swine 2000 Swine 2006 Swine 20121

Management style Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Continuous flow 71.4 (2.2) 61.5 (2.1) 73.7 (1.8)

All swine removed without 

cleaning and disinfecting 4.2 (1.0) 4.6 (1.0) 3.5 (0.6)

All-in/all-out by room2 5.5 (0.7) 10.0 (1.3) 9.1 (1.0)

All-in/all-out by building2 12.2 (1.8) 7.7 (1.2) 9.0 (1.0)

All-in/all-out by site2 1.6 (0.6) 1.4 (0.5) 1.0 (0.3)

Not applicable (no housing) 5.1 (1.0) 14.8 (1.5) 3.8 (0.6)

Total 100.0 100.0 100.0

1

In 2012, the question referred to the period from December 1, 2011, through May 31, 2012. 2

In 2006 and 2012 this response included the phrase “with (room, building, site) cleaned and disinfected.”
32 / Swine 2012

Section II: Management and Productivity Changes–B. Sow and Gilt Management

6. Waste management

The percentage of sites that used pit-holding as a waste management system increased 

steadily from 2000 to 2012. In 2012, about half of sites with a gestation phase pit-held 

manure. The percentage of sites that used flush under slats remained the same from 

2000 to 2006, but increased from 2000 to 2012. 

B.6. For sites with a gestation phase, percentage of sites by primary type of waste 

management system used in the gestation facility, and by study:

Percent Sites

Study

Swine 2000 Swine 2006 Swine 20121

Primary waste 

management system Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

None 14.1 (1.5) 13.5 (1.5) 3.9 (0.8)

Pit-holding 19.4 (1.6) 30.1 (1.9) 52.0 (3.7)

Mechanical scraper/tractor 32.5 (2.6) 30.2 (2.1) 11.2 (1.6)

Hand cleaned 19.1 (2.1) 14.0 (1.6) 4.2 (0.9)

Flush—under slats 5.9 (0.5) 9.3 (1.0) 22.9 (4.7)

Flush—open gutter 1.8 (0.4) 1.8 (0.4) 2.3 (0.8)

Other 7.2 (1.3) 1.1 (0.4) 3.5 (0.8)

Total 100.0 100.0 100.0

1

In 2012, the question referred to the period from December 1, 2011, through May 31, 2012.
USDA APHIS VS / 33 

Section II: Management and Productivity Changes–C. Farrowing Phase

1. Farrowing productivity and death loss

In the 20-plus years since the 1995 swine study, the swine industry has gained an 

average of about one more pig born alive per litter and subsequently weaned.

C.1.a. Site average per-litter productivity from December through May of each study year:

C. Farrowing 

Phase

Site Average Per Litter Productivity

Study

Swine 1995 Swine 2000 Swine 2006 Swine 2012

Measure 

(per litter) No.

Std. 

err. Pct.

Std. 

err. No.

Std. 

err. Pct.

Std. 

err. No.

Std. 

err. Pct.

Std. 

err. No.

Std. 

err. Pct.

Std. 

err.

Stillbirths 

and 

mummies 

0.6 (0.0) 6.2 (0.4) 0.9 (0.0) 8.0 (0.2) 1.0 (0.0) 8.4 (0.3) 1.0 (0.0) 8.6 (0.2)

Born alive 9.3 (0.1) 93.8 (0.4) 10.0 (0.0) 92.0 (0.2) 10.5 (0.1) 91.6 (0.3)10.3 (0.2) 91.4 (0.2)

Total born 9.9 (0.1) 100.0 10.9 (0.0) 100.0 11.5 (0.1) 100.0 11.2 (0.2) 100.0

Preweaning 

deaths 0.9 (0.0) 9.1 (0.4) 1.1 (0.0) 11.0 (0.3) 1.1 (0.0) 10.9 (0.4) 1.0 (0.1) 9.7 (0.6)

Weaned 8.4 (0.1) 90.9 (0.4) 8.9 (0.0) 89.0 (0.3) 9.4 (0.1) 89.1 (0.4) 9.3 (0.1) 90.3 (0.6)

Total born 

alive 9.3 (0.1) 100.0 10.0 (0.0) 100.0 10.5 (0.1) 100.0 10.3 (0.2) 100.0
34 / Swine 2012

Section II: Management and Productivity Changes–C. Farrowing Phase

The percentages of piglets that died by cause of death were similar across study years. 

Being lain on accounted for about half of all piglet deaths.

C.1.b. Percentage of preweaning deaths from December through May of each study year, 

by producer-identified cause:

Percent Preweaning Deaths

Study

Swine 1995 Swine 2000 Swine 2006 Swine 2012

 

Cause Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Scours 16.4 (2.5) 9.3 (1.2) 9.3 (1.1) 10.2 (2.1)

Lain on 47.0 (2.2) 52.1 (1.8) 54.5 (1.9) 48.8 (2.3)

Starvation 15.7 (2.7) 16.7 (2.0) 13.8 (1.2) 15.1 (1.8)

Respiratory NA 3.0 (0.4) 4.7 (1.3) 4.4 (1.3)

Other known 

problem* 9.9 (1.4) 11.5 (1.5) 9.9 (1.7) 15.8 (5.0)

Unknown problem 11.0 (1.3) 7.4 (0.8) 7.8 (1.1) 5.8 (1.4)

Total 100.0 100.0 100.0 100.0

*Included responses such as low viability or multiple causes.
USDA APHIS VS / 35 

Section II: Management and Productivity Changes–C. Farrowing Phase

2. Weaning age

In 2012, the average weaning age was about 5 days less than it was in 1995. A higher 

percentage of sites in 2012 than in 1995 weaned piglets at 16 to 20 days of age.

C.2.a. Average age of piglets (in days) at weaning from December through May of each 

study year:

Average Age (days)

Study

Swine 1995 Swine 2000 Swine 2006 Swine 2012

Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error

25.0 (0.5) 19.3 (0.2) 19.4 (0.2) 20.8 (0.2)

C.2.b. Percentage of sites by age of piglets at weaning from December through May of 

each study year:

Percent Sites

Study

Swine 1995* Swine 2000 Swine 2006 Swine 2012

Weaning age 

(days) Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Less than 16 1.6 (0.6) 4.9 (1.0) 2.7 (0.7) 0.5 (0.2)

16–20 6.1 (0.9) 20.3 (1.6) 24.1 (1.7) 23.8 (2.0)

21–27 22.6 (2.2) 27.3 (2.2) 30.8 (2.1) 40.3 (3.2)

28–34 33.7 (2.8) 18.9 (2.0) 17.5 (1.8) 18.1 (1.5)

35 or more 36.0 (2.5) 28.6 (2.4) 24.9 (2.0) 17.2 (1.4)

Total 100.0 100.0 100.0 100.0

*No time frame in 1995.
36 / Swine 2012

Section II: Management and Productivity Changes–C. Farrowing Phase

3. Facility type

Of sites with a farrowing phase, a higher percentage used an open building with outside 

access in 1995 than in 2012. 

C.3. For sites with a farrowing phase, percentage of sites by primary facility type used 

and by study:

Percent Sites

Study

Swine 1995 Swine 2000 Swine 2006 Swine 2012*

Primary

facility type Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Total confinement 61.9 (2.7) 64.8 (2.5) 67.7 (2.1) 71.8 (2.1)

Open building with 

no outside access 8.4 (1.6) 12.2 (1.8) 10.6 (1.4) 13.9 (2.0)

Open building with 

outside access 22.9 (2.6) 17.0 (2.2) 15.1 (1.7) 9.0 (1.0)

Lot with hut or 

no building 4.0 (0.9) 3.4 (0.9) 3.3 (0.7) 1.9 (0.4)

Pasture with hut 

or no building 2.8 (0.8) 2.6 (0.9) 3.3 (0.8) 3.4 (0.6)

Total 100.0 100.0 100.0 100.0

*In 2012, the question referred to the period from December 1, 2011, through May 31, 2012.
USDA APHIS VS / 37 

Section II: Management and Productivity Changes–C. Farrowing Phase

4. Pig flow

Of sites with a farrowing phase, the percentage that used continuous-flow management 

decreased from 2000 to 2012, while during the same period the percentage of sites that 

used all-in/all-out by room management increased. 

C.4. For sites with a farrowing phase, percentage of sites by pig-flow management style 

and by study:

Percent Sites

Study

Swine 2000 Swine 2006 Swine 20121

Management style Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Continuous flow 38.7 (2.5) 33.5 (2.1) 27.9 (2.0)

All swine removed without 

cleaning and disinfecting 5.8 (1.4) 4.7 (1.1) 2.8 (0.5)

All-in/all-out by room2 25.2 (1.7) 37.1 (2.0) 47.0 (2.9)

All-in/all-out by building2 24.7 (2.2) 16.1 (1.6) 18.2 (1.5)

All-in/all-out by site2 1.2 (0.5) 1.9 (0.6) 1.7 (0.4)

Not applicable (no housing) 4.4 (1.2) 6.7 (1.0) 2.4 (0.5)

Total 100.0 100.0 100.0

1

In 2012, the question referred to the period from December 1, 2011, through May 31, 2012. 2

In 2006 and 2012 this response included the phrase “with (room, building, site) cleaned and disinfected.”
38 / Swine 2012

Section II: Management and Productivity Changes–C. Farrowing Phase

5. Waste management

C.5. For sites with a farrowing phase, percentage of sites by primary type of waste 

management system used in the farrowing facility, and by study:

Percent Sites

Study

Swine 1995 Swine 2000 Swine 2006 Swine 2012*

Primary waste 

management system Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

None 6.8 (1.2) 5.4 (1.1) 5.9 (1.0) 1.5 (0.5)

Pit-holding 34.0 (2.6) 34.7 (2.2) 37.2 (2.1) 49.1 (3.6)

Mechanical 

scraper/ tractor 14.8 (2.0) 13.0 (2.1) 14.0 (1.7) 6.9 (1.2)

Hand cleaned 29.9 (2.8) 23.6 (2.3) 19.1 (1.8) 4.9 (0.9)

Flush—under slats 7.8 (1.2) 15.3 (1.4) 19.9 (1.6) 33.9 (4.2)

Flush—open gutter 3.5 (0.9) 4.4 (1.1) 2.4 (0.7) 2.0 (0.7)

Other 3.3 (0.8) 3.6 (0.9) 1.7 (0.5) 1.5 (0.5)

Total 100.0 100.0 100.0 100.0

*In 2012, the question referred to the period from December 1, 2011, through May 31, 2012.
USDA APHIS VS / 39 

Section II: Management and Productivity Changes–D. Nursery Phase

1. Facility type

In 2012, over 90 percent of sites with a nursery phase housed pigs in total confinement 

compared with about 70 percent of sites in 1995, 2000, and 2006. 

D.1.a. For sites with a nursery phase, percentage of sites by primary facility type used 

and by study:

Percent Sites

Study

Swine 1995 Swine 2000 Swine 2006 Swine 2012*

Primary 

facility type Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Total confinement 68.3 (2.9) 75.9 (2.1) 74.0 (1.7) 91.5 (1.3)

Open building with 

no outside access 9.6 (1.8) 8.2 (1.3) 10.7 (1.2) 5.4 (1.0)

Open building with 

outside access 18.3 (2.3) 12.3 (1.7) 11.3 (1.3) 2.5 (0.6)

Lot with hut or 

no building 3.2 (1.8) 1.7 (0.5) 1.8 (0.5) 0.3 (0.2)

Pasture with hut 

or no building 0.5 (0.3) 1.9 (0.9) 2.2 (0.6) 0.2 (0.1)

Total 100.0 100.0 100.0 100.0

*In 2012, the question referred to the period from December 1, 2011, through May 31, 2012.

D. Nursery 

Phase
40 / Swine 2012

Section II: Management and Productivity Changes–D. Nursery Phase

2. Death loss 

The percentage of nursery-phase deaths was similar across study years. 

D.2.a. Percentage of nursery pigs that died during the nursery phase from December 

through May, by study:

Percent Nursery Pigs Deaths*

Study

Swine 1995 Swine 2000 Swine 2006 Swine 2012

Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

2.4 (0.1) 2.6 (0.1) 2.9 (0.1) 3.6 (0.5)

*As a percentage of pigs that entered the nursery phase.

A lower percentage of nursery pigs died of an unknown problem in 2006 and 2012 than 

in 1995 and 2000. Respiratory problems accounted for the highest percentage of nursery 

deaths in 1995, 2006, and 2012, as reported by producers.

D.2.b. Percentage of nursery pigs that died during the nursery phase from December 

through May, by producer-identified cause and by study:

Percent Nursery Deaths

Study

Swine 1995 Swine 2000 Swine 2006 Swine 2012

 

Cause of death Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Scours 14.7 (1.6) 12.6 (1.2) 12.5 (1.1) 9.4 (1.9)

Starvation 12.4 (1.8) 13.3 (1.1) 9.8 (0.9) 22.1 (6.7)

Respiratory problems 32.4 (2.5) 28.9 (1.7) 44.2 (2.3) 47.3 (6.3)

CNS/meningitis NA NA 18.7 (1.9) 13.0 (2.9)

Other known problems* 18.3 (2.7) 24.5 (3.4) 4.1 (0.8) 1.7 (0.9)

Unknown problems 22.1 (2.5) 20.7 (3.5) 10.7 (1.1) 6.6 (2.8)

Total 100.0 100.0 100.0 100.0

*Includes responses such as unthrifty or multiple causes.
USDA APHIS VS / 41 

Section II: Management and Productivity Changes–D. Nursery Phase

0 20 40 60

Swine 2012

Swine 2006

Swine 2000

Swine 1995

Cause

Percentage of nursery pigs that died during the nursery phase from

December through May, by producer-identified cause and by study

Scours

Starvation

Respiratory

problems

CNS/

meningitis

Percent

47.3

Other known

problems*

Unknown

problems

12.1

12.6

13.3

NA

44.2

18.7

2.4

1.7

20.7

14.7

12.4

22.1

28.9

32.4

13.0

18.3

22.1

6.6

Study

12.5

9.4

9.8

24.5

4.1

10.7

NA

NA

*Includes responses such as unthrifty or multiple causes.
42 / Swine 2012

Section II: Management and Productivity Changes–D. Nursery Phase

3. Time spent in the nursery and age when leaving nursery

D.3. Site average age of nursery pigs when leaving the nursery from December through 

May, by study:

Site Average Age (days)

Study

Swine 1995* Swine 2000 Swine 2006 Swine 2012

Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error

61.3 (1.0) 61.8 (0.6) 66.7 (0.6) 67.6 (0.7)

*No time frame for 1995.

4. Pig flow

The use of continuous-flow management for nursery pigs decreased by about 50 percent 

from 2000 to 2012. 

D.4. For sites with a nursery phase, percentage of sites by pig-flow management style 

and by study:

Percent Sites

Study

Swine 2000 Swine 2006 Swine 20121

Management style Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Continuous flow 32.3 (2.3) 25.0 (1.7) 15.4 (2.9)

All swine removed without 

cleaning and disinfecting 3.9 (1.2) 3.6 (0.8) 1.8 (0.4)

All-in/all-out by room2 24.4 (1.6) 30.5 (1.6) 31.7 (3.4)

All-in/all-out by building2 32.3 (2.1) 29.8 (1.6) 41.2 (3.7)

All-in/all-out by site2 3.5 (0.7) 7.1 (1.0) 9.6 (3.0)

Not applicable (no housing) 3.6 (1.1) 4.0 (0.7) 0.3 (0.1)

Total 100.0 100.0 100.0

1

In 2012, the question referred to the period from December 1, 2011, through May 31, 2012. 2

In 2006 and 2012 this response included the phrase “with (room, building, site) cleaned and disinfected.”
USDA APHIS VS / 43 

Section II: Management and Productivity Changes–D. Nursery Phase

5. Waste management

Of sites with a nursery phase, the highest percentage—regardless of study year—used 

pit-holding as a waste management system in the nursery.

D.4. For sites with a nursery phase, percentage of sites by primary type of waste 

management system used in the nursery facility, and by study:

Percent Sites

Study

Swine 1995 Swine 2000 Swine 2006 Swine 2012*

Primary waste 

management system Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

None 2.9 (0.9) 5.3 (1.2) 3.7 (0.7) 0.7 (0.3)

Pit-holding 42.2 (2.8) 51.6 (2.3) 51.8 (1.8) 59.3 (4.8)

Mechanical 

scraper/ tractor 18.4 (2.3) 10.4 (1.6) 13.1 (1.4) 6.2 (1.2)

Hand cleaned 19.4 (2.8) 12.9 (1.8) 11.2 (1.3) 1.4 (0.4)

Flush—under slats 11.0 (1.6) 15.5 (1.3) 17.6 (1.2) 30.4 (5.6)

Flush—open gutter 2.8 (1.0) 2.3 (0.6) 1.2 (0.4) 1.7 (0.6)

Other 3.3 (0.9) 2.0 (0.7) 1.4 (0.4) 0.3 (0.2)

Total 100.0 100.0 100.0 100.0

*In 2012, the question referred to the period from December 1, 2011, through May 31, 2012.
44 / Swine 2012

Section II: Management and Productivity Changes–E. Grower/Finisher Phase

1. Facility type

Over twice the percentage of sites with a grower/finisher phase in 2012 than in 1995 

housed grower/finisher pigs in total confinement.

E.1.a. For sites with a grower/finisher phase, percentage of sites by primary facility type 

used and by study:

Percent Sites

Study

Swine 1995 Swine 2000 Swine 2006 Swine 2012*

Primary 

facility type Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Total confinement 32.1 (1.9) 42.9 (1.8) 53.2 (1.4) 71.6 (5.8)

Open building with 

no outside access 11.6 (1.5) 18.2 (1.4) 20.4 (1.2) 22.8 (4.8)

Open building with 

outside access 44.4 (2.6) 33.2 (2.0) 23.3 (1.4) 4.8 (1.1)

Lot with hut or 

no building 7.6 (1.9) 4.4 (0.8) 1.8 (0.4) 0.5 (0.2)

Pasture with hut 

or no building 4.3 (1.2) 1.3 (0.5) 1.3 (0.3) 0.2 (0.1)

Total 100.0 100.0 100.0 100.0

*In 2012, the question referred to the period from December 1, 2011, through May 31, 2012.

E. Grower/

Finisher Phase
USDA APHIS VS / 45 

Section II: Management and Productivity Changes–E. Grower/Finisher Phase

2. Death loss

Nearly twice the percentage of pigs died during the grower/finisher phase in 2012 than in 

1995. The percentage of grower/finisher deaths due respiratory problems was higher in 

2012 than in 2000 or 1995.

E.2.a. Percentage of grower/finisher pigs that died during the grower/finisher phase from 

December through May, by study:

Percent Grower/Finisher Pigs Deaths*

Study

Swine 1995 Swine 2000 Swine 2006 Swine 2012

Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

2.1 (0.1) 2.9 (0.1) 3.9 (0.2) 4.1 (0.5)

*As a percentage of pigs that entered the grower/finisher phase.

E.2.b. Percentage of grower/finisher deaths from December through May, by produceridentified cause and by study:

Percent Grower/Finisher Deaths

Study

Swine 1995 Swine 2000 Swine 2006 Swine 2012

 

Cause Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Scours 7.7 (1.3) 5.3 (2.0) 6.7 (0.6) 3.7 (1.6)

Lameness 8.1 (0.8) 8.4 (0.8) 5.4 (0.3) 4.9 (0.9)

Trauma 6.8 (0.7) 8.0 (0.5) 4.9 (0.4) 3.2 (0.8)

Respiratory 

problems 40.8 (2.2) 39.1 (2.0) 61.1 (2.3) 75.1 (8.5)

Stress NA 6.7 (0.6) 3.2 (0.3) 2.5 (0.5)

Other known 

problem 17.2 (1.9) 14.2 (1.5) 8.0 (3.4) 4.9 (2.8)

Unknown problem 20.4 (1.7) 18.3 (1.4) 10.7 (1.0) 5.8 (2.6)

Total 100.0 100.0 100.0 100.0
46 / Swine 2012

Section II: Management and Productivity Changes–E. Grower/Finisher Phase

0 20 40 60 80

Swine 2012

Swine 2006

Swine 2000

Swine 1995

Cause

Percentage of grower/finisher deaths from December through May, by 

producer-identified cause and by study

Scours

Trauma

Respiratory

problems

Stress

Percent

39.1

Other known

problem

Unknown

problem

7.7

6.7

5.4

40.8

4.9

2.5

8.0

18.3

5.3

8.4

6.8

8.0

4.9

6.7

3.2

20.4

5.8

Study

3.7

8.1

4.9

17.2

14.2

10.7

NA

Lameness

3.2

61.1

75.1
USDA APHIS VS / 47 

Section II: Management and Productivity Changes–E. Grower/Finisher Phase

3. Days to market and age when leaving grower/finisher phase

Pigs spent about a week longer in the grower/finisher phase in 2012 than in 2006.

E.3.a. Site average number of days spent in the grower/finisher phase from December 

through May, by study:

Site Average Number of Days

Study

Swine 1995* Swine 2000 Swine 2006 Swine 2012*

Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error

114.8 (1.3) 116.1 (0.9) 111.1 (0.9) 118.2 (2.2)

*No time frame in 1995.

E.3.b. Site average age of grower/finisher pigs when leaving the grower/finisher phase 

from December through May, by study:

Site Average Age (days)

Study

Swine 1995 Swine 2000 Swine 2006 Swine 2012*

Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error

174.9 (1.1) 176.0 (0.8) 177.5 (0.9) 185.9 (2.5)

*No time frame in 1995.
48 / Swine 2012

Section II: Management and Productivity Changes–E. Grower/Finisher Phase

4. Pig flow

From 2000 to 2012, the percentage of grower/finisher sites that used continuous flow 

management decreased. Interestingly, there was no corresponding increase in the use of 

all-in/all-out management; however, over half of sites with grower/finisher pigs used 

all-in/all-out by building in 2012.

E.4. For sites with a grower/finisher phase, percentage of sites by pig-flow management 

style and by study:

Percent Sites

Study

Swine 2000 Swine 2006 Swine 20121

Management style Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Continuous flow 40.5 (2.0) 26.1 (1.3) 10.8 (2.4)

All swine removed without 

cleaning and disinfecting 3.2 (0.7) 6.2 (0.8) 2.2 (0.6)

All-in/all-out by room2 10.7 (0.9) 17.5 (1.2) 13.2 (3.4)

All-in/all-out by building2 32.3 (1.7) 35.0 (1.3) 53.6 (9.5)

All-in/all-out by site2 10.7 (1.1) 12.1 (1.0) 19.8 (5.9)

Not applicable (no housing) 2.6 (0.7) 3.1 (0.5) 0.5 (0.2)

Total 100.0 100.0 100.0

1

 In 2012, the question referred to the period from December 1, 2011, through May 31, 2012. 2

In 2006 and 2012 this response included the phrase “with (room, building, site) cleaned and disinfected.”
USDA APHIS VS / 49 

Section II: Management and Productivity Changes–E. Grower/Finisher Phase

5. Waste management

On sites with grower/finisher pigs, pit-holding was the waste management system used 

by the majority of sites in 2006 and 2012. The percentage of sites that used flush under 

slats increased from 2000 to 2012. 

E.5. For sites with a grower/finisher phase, percentage of sites by primary type of waste 

management system used in the grower/finisher facility, and by study:

Percent Sites

Study

Swine 19951 Swine 2000 Swine 2006 Swine 20122

Primary waste 

management system Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

None 8.2 (1.5) 4.2 (0.8) 4.0 (0.6) 1.4 (0.9)

Pit-holding 31.1 (2.1) 47.1 (1.9) 56.0 (1.5) 75.8 (6.2)

Mechanical 

scraper/tractor 29.5 (2.2) 28.4 (2.0) 21.9 (9.3) 3.6 (0.9)

Hand cleaned 18.8 (2.2) 9.6 (1.3) 6.6 (0.8) 0.8 (0.3)

Flush—under slats 3.8 (0.8) 5.1 (0.4) 7.6 (0.7) 17.0 (5.4)

Flush—open gutter 3.1 (0.6) 2.5 (0.5) 2.4 (0.5) 0.9 (0.4)

Other 5.5 (1.2) 3.1 (0.6) 1.5 (0.3) 0.4 (0.2)

Total 100.0 100.0 100.0 100.0

1 Numbers differ from those in Part I of the 1995 study due to differences in estimation. 2

 In 2012, the question referred to the period from December 1, 2011, through May 31, 2012.
50 / Swine 2012

Section II: Management and Productivity Changes–E. Grower/Finisher Phase

6. Source of pigs

Of sites with a grower/finisher phase, the percentage that obtained new finisher pigs 

from an on-site source (i.e., on-site nursery) in 2012 was less than half the percentage 

reported in 2000 and 2006. Increased site specialization, corporate ownership of multiple 

sites, and an increase in sourcing from other sites belonging to the operation might be 

part of the reason for this decrease.

E.6.a. For sites with a grower/finisher phase, percentage of sites that placed any pigs 

in the grower/finisher phase from December through May, by source(s) of pigs and by 

study:

Percent Sites1

Study

Swine 2000

(12/99–5/00)

Swine 2006

(12/05–5/06)

Swine 2012

(12/11–5/12)

Source Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

On-site 51.4 (1.9) 49.9 (1.5) 19.7 (4.4)

Other sites belonging 

to this operation 13.1 (1.3) 11.8 (1.0) 65.8 (7.5)

Other sites not belonging 

to this operation2 28.0 (1.6) 38.2 (1.4) 14.2 (3.7)

Auction, sale barn, or 

livestock market 3.6 (0.1) 1.8 (0.4) 0.6 (0.2)

Other 7.2 (1.2) 0.7 (1.3) 1.1 (0.4)

1

From December through May of respective year.

2

In 2000, this referred to producers of feeder pigs (contract/noncontract); in 2006 and 2012, this referred to 

farm-to-farm, contract/noncontract.
USDA APHIS VS / 51 

Section II: Management and Productivity Changes–E. Grower/Finisher Phase

The percentage of sites that obtained grower/finisher pigs from different sources and then 

commingled them in the same building or area decreased from 2006 to 2012.

E.6.b. For sites that obtained grower/finisher pigs from different sources from December 

through May, percentage of sites that commingled these pigs in the same building or 

area, by study: 

Percent Sites

Study

Swine 2000 Swine 2006* Swine 2012

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

43.2 (4.5) 18.3 (1.8) 22.5 (7.3)

*The question in 2006 asked whether pigs were commingled with existing pigs.
52 / Swine 2012

Section II: Management and Productivity Changes–F. Biosecurity

1. Restrictions to entry

From 1995 to 2006, the percentage of sites that allowed business or nonbusiness 

visitors on-site access decreased from 42.5 percent to 19.0 percent, respectively, but 

substantially increased to 60.8 percent in 2012. 

F.1.a. Percentage of sites that allowed business or nonbusiness visitors on-site access, 

by study:

Percent Sites

Study

Swine 1995* Swine 2000* Swine 2006 Swine 2012

Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

42.5 (2.4) 34.5 (1.7) 19.0 (1.1) 60.8 (4.9)

*In 1995 and 2000 the question asked if nonemployees were allowed to enter.

The percentage of sites that required nonemployees (business or nonbusiness visitors) to 

shower before entering the site more than doubled from 2000 to 2012.

F.1.b. For sites that allowed on-site access to business or nonbusiness visitors, 

percentage of sites by preventive measure(s) required of visitors before entering pig 

facilities:

Percent Sites

Study

Swine 1995 Swine 2000 Swine 2006 Swine 2012

Preventive measure Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Shower before 

entering site 1.9 (0.4) 9.3 (1.2) 9.9 (1.6) 26.5 (5.6)

Change to clean 

boots and coveralls NA 52.1 (3.0) 47.8 (3.2) 54.3 (4.6)

Footbath 10.4 (1.7) NA NA NA

Use the Danish Entry 

(“Bench”) system NA NA NA 3.5 (1.0)

Wait 24 hr or longer after 

visiting another or any 

other hog site*

16.6 (2.4) 23.6 (1.9) 32.5 (2.9) 34.7 (4.5)

*In 1995 this was worded as: “Have not been on another pig operation the same day as visiting this operation.”

F. Biosecurity
USDA APHIS VS / 53 

Section II: Management and Productivity Changes–F. Biosecurity

2. Trucking

Over study years, about 50 to 60 percent of sites allowed trucks or trailers for livestock 

transport to enter pig areas. 

F.2.a. Percentage of sites that allowed trucks or trailers for livestock transport to enter pig 

areas, by study:

Percent Sites

Study

Swine 2000 Swine 2006* Swine 2012*

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

56.8 (1.8) 51.3 (1.4) 59.9 (5.0)

*In 2006 and 2012 the question asked for commercial livestock transporters or animal haulers.

The percentage of sites that required that the trucks’ animal area be cleaned and or 

disinfected decreased from 2006 to 2012.

F.2.b. For sites that allowed trucks or trailers from commercial livestock transporters 

or animal haulers to enter the pig area, percentage of sites by required practice(s) for 

cleaning and disinfecting livestock trucks or trailers:

Percent Sites

Study

Swine 2000 Swine 2006 Swine 2012

Required practice Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Animal area inside 

truck be cleaned 65.4 (2.4) 72.3 (1.7) 48.7 (6.4)

Animal area inside 

truck be disinfected 47.0 (2.3) 60.5 (1.8) 43.0 (6.9)

Outside of truck be cleaned 54.4 (2.3) 59.7 (1.8) 42.6 (6.9)

Outside of truck be 

disinfected 33.8 (2.0) 44.8 (1.8) 38.0 (7.5)
54 / Swine 2012

Section II: Management and Productivity Changes–F. Biosecurity

3. Proximity to other swine sites

A higher percentage of sites in 2012 than in 1995, 2000, and 2006 were 1 to 2.99 miles 

away from another swine site or operation. For all study years, over 80 percent of sites 

were less than 3 miles from another swine site.

F.3. Percentage of sites by distance (in miles) to the nearest known swine site or 

operation, and by study:

Percent Sites

Study

Swine 1995 Swine 2000 Swine 2006 Swine 2012

Distance* (mi) Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Less than 0.50 32.7 (2.0) 28.3 (1.6) 29.6 (1.3) 20.6 (4.4)

0.50–0.99 27.4 (2.3) 25.6 (1.6) 23.2 (1.1) 27.1 (3.0)

1.00–2.99 25.5 (2.2) 27.9 (1.5) 27.5 (1.2) 41.0 (3.2)

3.00–4.99 7.9 (1.5) 9.3 (0.9) 10.4 (0.8) 3.3 (0.6)

5.00 or more 6.5 (0.9) 8.9 (0.9) 9.3 (0.7) 7.9 (1.2)

Total 100.0 100.0 100.0 100.0

*In 1995 and 2000, the question asked for the distance to the nearest 0.1 mile. In 2006 and 2012, the question 

asked for the distance to the nearest 0.25 mile.
USDA APHIS VS / 55 

Section II: Management and Productivity Changes–F. Biosecurity

4. Rodent control

Less than half the percentage of sites in 2012 than in 1995 used cats to control rodents. 

Across study years, the majority of sites used bait or poison to control rodents.

F.4. Percentage of sites by rodent control method used and by study:

Percent Sites

Study

Swine 1995 Swine 2000 Swine 2006 Swine 2012

Control method Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Cats 68.7 (2.1) 60.6 (1.7) 51.2 (1.3) 30.4 (4.7)

Dogs NA 33.9 (1.8) 26.3 (1.2) 19.8 (4.0)

Traps 15.9 (1.6) 19.6 (1.5) 20.5 (1.1) 21.4 (3.2)

Bait or poison 85.1 (2.1) 88.5 (1.3) 87.9 (0.9) 95.0 (0.8)

Exterminator NA 4.4 (0.5) 5.4 (0.5) 9.2 (2.2)

Other 9.5 (1.8) 2.6 (0.9) 1.8 (0.4) 4.2 (2.4)

Any 98.1 (0.7) 99.0 (0.3) 97.3 (0.5) 99.4 (0.2)
56 / Swine 2012

Section II: Management and Productivity Changes–G. General Management

1. Environmental testing

In 2012, the average number of times that manure was tested for nutrients was more 

than double that reported in previous study years.

G.1. Average number of times the following environmental tests were conducted during 

the previous 3 years, by test type and by study:

Site Average Number of Tests Conducted

Study

Swine 1995 Swine 2000 Swine 2006 Swine 2012

Test type

Avg.

no.

Std. 

error

Avg.

no.

Std. 

error

Avg.

no.

Std. 

error

Avg.

no.

Std. 

error

Groundwater (such 

as for nitrates or 

pathogens)

0.6 (0.1) 0.7 (0.0) 0.8 (0.1) 0.8 (0.2)

Nutrient content of 

manure (such as 

nitrogen level)

0.6 (0.1) 1.2 (0.1) 1.8 (0.1) 4.2 (0.5)

Air quality (such as 

ammonia or hydrogen 

sulfide levels)

0.6 (0.1) 0.2 (0.0) 0.2 (0.1) 0.2 (0.0)

G. General 

Management
USDA APHIS VS / 57 

Section II: Management and Productivity Changes–G. General Management

2. Carcass disposal

The percentage of sites that buried preweaned-pig carcasses on-site decreased from 

1995 to 2012, while the percentage of sites that composted preweaned-pig carcasses 

on-site increased.

G.2.a. Percentage of sites by method(s) used to dispose of preweaned-pig carcasses, 

and by study:

Percent Sites

Study

Swine 19952 Swine 20003 Swine 20064 Swine 20125

Method Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Burial on-site 48.7 (2.9) 45.3 (2.6) 31.9 (2.1) 22.8 (2.0)

Burning on-site 14.2 (1.8) 15.4 (1.7) 15.2 (1.5) 10.3 (1.9)

Renderer 

pickup on-site 15.4 (1.7) 17.2 (2.0) 12.5 (1.5) 13.4 (3.7)

Renderer pickup 

outside site 2.6 (0.5) 4.8 (0.8) 4.0 (0.9) 6.4 (1.0)

Composting 

on-site1 13.2 (1.6) 23.2 (2.1) 37.2 (2.2) 45.9 (2.8)

Composting 

off-site NA NA NA 4.6 (1.0)

Other 5.6 (1.2) 4.4 (1.1) 3.1 (0.7) 1.8 (0.4)

1

The 1995 question was “Composting on farm” and the 2000 question was “Composting.”

2

Sites with preweaned pigs that died from December 1, 1994, through May 31, 1995.

3

Sites with preweaned pigs that died on this site/operation from December 1, 1999, through May 31, 2000.

4

Sites with preweaned pigs that died on this site from December 1, 2005, through May 31, 2006. 5

Sites with preweaned pigs that died on this site from December 1, 2011, through May 31, 2012.
58 / Swine 2012

Section II: Management and Productivity Changes–G. General Management

As with preweaned-pig carcasses, the percentage of sites that buried weaned-pig 

carcasses on-site decreased from 1995 to 2012, while the percentage of sites that 

composted weaned-pig carcasses on-site increased.

G.2.b. Percentage of sites by method(s) used to dispose of weaned- and older-pig 

carcasses, and by study:

Percent Sites

Study

Swine 19952 Swine 20003 Swine 20064 Swine 20125

Method Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Burial on-site 39.3 (2.7) 37.8 (1.8) 25.1 (1.2) 10.4 (1.5)

Burning on-site 8.9 (1.3) 11.6 (1.2) 12.2 (0.9) 5.1 (1.1)

Renderer 

pickup on-site 34.5 (2.2) 34.4 (1.7) 26.3 (1.3) 27.9 (5.0)

Renderer pickup 

outside site 10.2 (1.3) 11.1 (1.1) 10.9 (0.9) 11.1 (2.0)

Composting 

on-site1 7.2 (1.3) 18.0 (1.3) 33.8 (1.3) 39.8 (7.2)

Composting 

off-site NA NA NA 5.4 (1.0)

Other 3.1 (0.8) 2.5 (0.5) 2.3 (0.4) 1.2 (0.4)

1

The 1995 question was “Composting on farm” and the 2000 question was “Composting.”

2

Sites with preweaned pigs that died from December 1, 1994, through May 31, 1995.

3

Sites with preweaned pigs that died on this site/operation from December 1, 1999, through May 31, 2000.

4

Sites with preweaned pigs that died on this site/operation from December 1, 2005, through May 31, 2006. 5

Sites with preweaned pigs that died on this site from December 1, 2011, through May 31, 2012.
USDA APHIS VS / 59 

Section II: Management and Productivity Changes–G. General Management

3. Use of a veterinarian

The percentage of sites that used a local veterinary practitioner was lower in 2012 than 

in 2000, while the percentage of sites that used an on-staff veterinarian increased from 

2000 to 2012.

G.3. Percentage of sites in which a veterinarian had visited for any purpose during the 

12 months before the study interview, by type of veterinarian and by study:

Percent Sites

Study

Swine 2000 Swine 2006 Swine 2012

Type of veterinarian Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Local private practitioner 66.9 (1.5) 49.5 (1.4) 45.9 (4.2)

Consulting or 

second opinion 10.5 (0.9) 11.9 (1.0) 15.9 (3.5)

On-staff 9.9 (0.8) 18.0 (0.9) 28.2 (4.9)

State or Federal 7.6 (1.0) 1.2 (0.4) 0.7 (0.2)

Other type 1.8 (0.4) 1.2 (0.4) 0.9 (0.3)

Any type 78.1 (1.3) 69.1 (1.3) 75.3 (4.8)
60 / Swine 2012

Section III: Management and Productivity Changes–A. Health Status Changes

Note: Where applicable, column or row totals are shown as 100.0 to aid in interpretation; 

however, estimates may not sum to 100.0 due to rounding.

1. Breeding females

Gastric ulcers have remained a problem in breeding females at nearly equivalent 

levels across study years. The percentage of sites with respiratory disease (PRRS, 

Mycoplasma, and influenza) in breeding females increased from 2000 to 2012.

A.1. Percentage of sites in which the following disease problems were known or 

suspected in one or more breeding females during the 12 months before the study 

interview, by study: 

Percent Sites* 

Study

Swine 2000 Swine 2006 Swine 2012

Disease Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Actinobacillus pleuropneumonia

(APP) 3.4 (0.8) 4.2 (1.9) 0.9 (0.5)

Porcine reproductive and 

respiratory syndrome (PRRS) 21.4 (3.1) 27.3 (4.3) 44.5 (4.6)

Mycoplasma pneumonia 14.2 (2.2) 17.0 (3.2) 31.2 (4.7)

Influenza 12.1 (2.0) 22.3 (3.9) 25.5 (4.3)

Salmonella 2.3 (0.7) 6.1 (2.5) 2.6 (1.3)

Swine dysentery 1.3 (0.5) 1.7 (1.4) 5.9 (2.6)

Transmissible gastroenteritis 

(TGE) 2.4 (0.7) 2.0 (1.5) 0.5 (0.4)

Gastric ulcers 10.7 (2.1) 17.8 (3.1) 10.7 (3.0)

Ileitis (Lawsonia intracellularis) NA 16.2 (3.3) 18.7 (3.8)

Leptospirosis 3.2 (0.8) 5.5 (1.8) 1.6 (1.2)

Parvovirus 4.4 (0.9) 5.0 (1.9) 4.5 (1.7)

Erysipelas 6.8 (1.5) 7.1 (2.9) 4.1 (1.4)

Glasser’s disease 

(Haemophilus parasuis) 3.7 (1.0) 5.0 (1.4) 8.3 (2.5)

Roundworms 40.8 (4.7) 26.8 (4.1) 39.1 (5.1)

Other 9.1 (2.2) 6.4 (2.3) 1.5 (1.0)

*This table reflects producer opinion, which may or may not have been confirmed by a veterinarian or laboratory 

diagnosis. Question variations: 2000-”In the last 12 months, were any of the following disease problems present 

in one or more breeding females while in the breeding herd?” 2006-”In the last 12 months, were any of the 

following disease problems known or suspected to have caused sickness or mortality in one or more females in 

the breeding herd?” 2012-”During the last 12 months, were the following disease problems present in breeding 

females?”

Section III: Health Status Changes in the U.S. Swine Industry, 

NAHMS Population Estimates2000, 2006, and 2012

A. Breeding 

Females and 

Preweaned Pig 

Morbidity
USDA APHIS VS / 61 

Section III: Management and Productivity Changes–A. Health Status Changes

2. Preweaned pigs 

The 2012 study marked the first time that no sites reported TGE problems in any 

preweaned pigs. Problems with PRRS in preweaned pigs, however, increased from 2000 

to 2012.

A.2. Percentage of sites in which the following disease problems were known or 

suspected in one or more preweaned pigs during the 12 months before the study 

interview, by study:

Percent Sites*

Study

Swine 2000 Swine 2006 Swine 2012

Disease Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

PRRS 10.7 (2.3) 13.3 (2.9) 33.0 (4.6)

Undifferentiated pneumonia NA 25.0 (3.8) 21.9 (3.5)

TGE 3.2 (0.9) 2.1 (1.5) 0.0 (—)

Rotavirus 5.7 (1.3) 6.9 (1.7) 19.4 (6.2)

E. coli (colibacillosis) 45.2 (4.8) 47.4 (4.6) 47.8 (5.5)

Coccidiosis 8.6 (1.7) 10.6 (2.6) 12.9 (3.0)

Clostridium 9.0 (1.7) 16.2 (2.8) 29.6 (4.6)

Streptococcus suis 29.8 (4.3) 38.5 (4.4) 46.9 (4.7)

Greasy pig disease 25.9 (3.4) 27.6 (4.0) 39.8 (4.7)

Navel infections NA 43.1 (4.3) 60.6 (5.0)

Other 5.7 (2.0) 9.5 (3.2) 3.9 (1.4)

*This table reflects producer opinion, which may or may not have been confirmed by a veterinarian or laboratory 

diagnosis. Question variation: 2000-“In the last 12 months, were any of the following disease problems present 

in one or more preweaned (suckling) pigs?” 2006-“In the last 12 months, were any of the following disease 

problems known or suspected to have caused sickness or mortality in one or more preweaned (suckling) pigs?” 

2012- “During the last 12 months, were the following disease problems present in preweaned (suckling) pigs?”
62 / Swine 2012

Section III: Management and Productivity Changes–B. Disease Prevention in Breeding Females

1. Porcine reproductive and respiratory syndrome (PRRS) 

A higher percentage of sites in 2012 than in 2006 usually vaccinated breeding females 

against PRRS. 

B.1.a. Percentage of sites that usually vaccinated breeding females against PRRS, by 

study:

Percent Sites

Study

Swine 2000 Swine 2006 Swine 2012

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

37.1 (4.7) 27.3 (3.9) 46.4 (5.6)

B.1.b. For sites that vaccinated breeding females against PRRS, percentage of sites that 

usually vaccinated during the following reproductive periods, by study:

Percent Sites

Swine 2000 Swine 2000* Swine 2006 Swine 2012

Period Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Prior to entering breeding herd 10.0 (1.9) 27.0 (5.5) 38.1 (8.4) 30.4 (4.3)

As gilts when entering 

breeding herd 29.9 (4.6) 80.8 (5.4) 69.2 (7.9) 34.0 (4.7)

During gestation up to 

4 weeks before farrowing 4.9 (1.2) 13.3 (3.4) 10.9 (4.5) 10.0 (2.8)

During the last 4 weeks of 

gestation 6.5 (2.0) 17.5 (5.3) 3.5 (1.9) 10.0 (3.2)

From farrowing to weaning 15.9 (4.5) 43.0 (8.7) 6.8 (3.5) 4.1 (1.8)

After weaning through 

breeding/mating 8.7 (2.3) 23.4 (6.0) 28.2 (8.7) 7.8 (2.5)

At regular intervals, regardless 

of reproductive stage 3.4 (1.1) 9.1 (3.1) 47.0 (8.6) 27.3 (4.7)

In response to a PRRS 

outbreak NA NA NA 17.9 (3.0)

*In 2000, estimates were based on all operations (column to the left), while in 2006 and 2012 estimates were 

based on only operations that vaccinated against PRRS. For comparison purposes, the percentages in this 

column reflect operations in 2000 that vaccinated breeding females against PRRS. 

B. Disease 

Prevention 

in Breeding 

Females
USDA APHIS VS / 63 

Section III: Management and Productivity Changes–B. Disease Prevention in Breeding Females

Of sites that usually vaccinated breeding females against PRRS, the percentage that 

used a commercial/noncommercial modified live or killed PRRS vaccine decreased from 

95.3 percent of sites in 2000 to 52.4 percent in 2012.

B.1.c. For sites that usually vaccinated breeding females against PRRS, percentage of 

sites by type of PRRS vaccine used during the 6 months (2000) or 12 months (2006 and 

2012) before the study interview, by study:

Percent Sites

Study

Swine 2000 Swine 20061 Swine 2012

PRRS vaccine type Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Commercial/noncommercial 

modified-live or 

killed PRRS vaccine2

 

95.3 (4.8) 72.5 (7.0) 52.4 (7.5)

Autogenous PRRS vaccine 3.3 (1.1) 30.6 (7.7) 37.0 (8.5)

1

Different numbers from Part II report for that year due to differences in estimation.

2

In 2000 the vaccine was not necessarily “commercial.”

2. Influenza A virus in swine

Close to half of sites vaccinated breeding females against influenza in 2012 compared 

with about 14 percent in 2000. 

B.2.a. Percentage of sites that usually vaccinated breeding females against influenza, by 

study:

Percent Sites

Study

Swine 2000 Swine 2006 Swine 2012

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

14.2 (2.2) 29.3 (3.9) 46.4 (5.6)
64 / Swine 2012

Section III: Management and Productivity Changes–B. Disease Prevention in Breeding Females

From 2000 to 2012, a similar percentage of sites vaccinated breeding females against 

influenza during the last 4 weeks of gestation.

B.2.b. For sites that vaccinated breeding females against influenza, percentage of sites 

that usually vaccinated during the following reproductive periods, by study:

Percent Sites

Study

Swine 2000 Swine 2006 Swine 2012

Period Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Prior to entering the 

breeding herd 37.7 (6.5) 62.9 (7.1) 33.1 (6.2)

As gilts at time of entering 

the breeding herd 75.6 (5.5) 70.1 (6.5) 36.6 (5.8)

During gestation up to 

4 weeks before farrowing 27.4 (5.9) 32.5 (7.4) 17.2 (4.0)

During the last 

4 weeks of gestation 38.8 (7.2) 24.7 (6.1) 26.6 (6.2)

From farrowing to weaning 27.2 (7.4) 4.0 (2.2) 2.2 (1.4)

After weaning through 

breeding/mating 9.9 (4.3) 8.2 (4.2) 1.6 (0.9)

At regular intervals, regardless 

of reproductive stage* 12.1 (3.7) 20.5 (5.8) 11.4 (5.6)

*In 2000 the wording was “once or twice a year, regardless of reproductive stage.”

The percentages of sites that used a commercial killed vaccine and the percentages that 

used an autogenous killed vaccine have remained relatively steady across study years.

B.2.c. For sites that usually vaccinated breeding females against influenza, percentage 

of sites by type of influenza vaccine used during the 6 months (2000) or 12 months (2006 

and 2012) before the study interview, and by study:

Percent Sites

Study

Swine 2000 Swine 2006 Swine 2012

Influenza vaccine type Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Commercial killed vaccine* 93.8 (2.0) 82.1 (5.6) 73.7 (6.1)

Autogenous killed vaccine 31.7 (8.0) 23.7 (6.5) 47.1 (9.9)

*In 2000 the vaccine was not necessarily “commercial.”
USDA APHIS VS / 65 

Section III: Management and Productivity Changes–C. Use of Antimicrobial in Breeding Females

The percentage of sites that used antibiotics to treat breeding females for disease has 

not changed substantially from 2000 to 2012.

C. Percentage of sites that gave antibiotics to any breeding females to treat a disease 

condition during the 12 months before the study interview, by study:

Percent Sites

Study

Swine 2000 Swine 2006 Swine 2012

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

61.3 (4.9) 74.1 (3.9) 59.5 (5.3)

C. Use of 

Antimicrobials 

in Breeding 

Females to 

Treat Disease 

Conditions
66 / Swine 2012

Section III: Management and Productivity Changes–D. Weaned Pig Morbidity

1. Nursery pigs 

Some diseases that affect nursery pigs, such as E. coli diarrhea, were present in similar 

percentages of sites across study years. The percentage of sites with influenza and 

Streptococcus suis problems, however, increased substantially from 2000 to 2012. Nearly 

half of sites with nursery pigs were affected by PRRS in 2012.

D.1. Percentage of sites in which the following disease problems were known or 

suspected in one or more nursery pigs during the 12 months before the study interview, 

by study:

Percent Sites1

Study

Swine 2000 Swine 2006 Swine 2012

Disease Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

APP 6.4 (1.2) 2.9 (0.8) 2.3 (1.2)

Glasser’s disease 7.3 (1.2) 17.4 (3.0) 24.3 (9.2)

Mycoplasma pneumonia 19.6 (2.4) 29.4 (3.8) 30.7 (6.0)

Influenza 7.5 (1.4) 24.6 (3.9) 46.2 (4.8)

PRRS 17.5 (3.4) 26.6 (3.5) 46.6 (7.6)

Salmonella 6.6 (1.2) 8.9 (2.4) 6.7 (2.0)

Swine dysentery 3.2 (1.0) 4.8 (2.0) 6.5 (2.3)

TGE 1.0 (0.4) 1.8 (1.2) 0.0 (—)

E. coli diarrhea2 24.0 (4.2) 31.8 (4.0) 32.4 (4.3)

Other diarrhea NA 20.7 (3.2) 15.2 (3.0)

Edema disease (E. coli) 6.1 (1.7) 9.0 (2.6) 6.1 (1.8)

PMWS/PCV2/PCVAD3 5.7 (1.3) 22.3 (3.2) 12.6 (2.7)

Porcine dermatitis and 

nephropathy syndrome 

(PDNS) 

NA 2.9 (1.3) 1.4 (0.1)

Greasy pig disease 25.3 (3.2) 27.5 (3.5) 33.5 (4.2)

Streptococcus suis 31.6 (3.5) 49.9 (4.2) 65.2 (5.8)

Roundworms 18.0 (3.2) 15.8 (3.1) 10.2 (2.9)

Lice NA 10.8 (2.7) 5.9 (2.2)

Other 3.9 (0.9) 10.5 (2.7) 5.3 (2.1)

1

This table reflects producer opinion, which may or may not have been confirmed by a veterinarian or laboratory diagnosis.

2

In 2000 was “Other E. coli diarrhea.”

3

All are variations of PCVAD caused by porcine circovirus 2 (PCV2) and previously known only as postweaning 

multisystemic wasting syndrome (PMWS).

D. Weaned Pig 

Morbidity
USDA APHIS VS / 67 

Section III: Management and Productivity Changes–D. Weaned Pig Morbidity

0

10

20

30

40

50

Swine 2012

Swine 2006

Swine 2000

29.4

46.6

30.7

19.6

17.5

22.3

Mycoplasma

pneumonia

PRRS

Disease

Percent

Percentage of sites1 in which the following disease problems were known or

suspected in one or more nursery pigs during the 12 months before the study

interview, by study

Study

26.6

5.7

12.6

PMWS/PCV2/PCVAD2

1

This table reflects producer opinion, which may or may not have been confirmed by a veterinarian 

or laboratory diagnosis.

2

All are variations of PCVAD caused by porcine circovirus 2 (PCV2) and previously known only as 

postweaning multisystemic wasting syndrome (PMWS).
68 / Swine 2012

Section III: Management and Productivity Changes–D. Weaned Pig Morbidity

2. Grower/finisher pigs

As with nursery pigs, the percentage of sites with influenza problems in grower/finisher 

pigs increased from 2000 to 2012. The percentage of sites with problems with PCVAD 

increased from 2000 to 2006 but decreased from 2006 to 2012. 

D.2. Percentage of sites in which the following disease problems were known or 

suspected in one or more grower/finisher pigs during the 12 months before the study 

interview, by study:

Percent Sites1

Study

Swine 2000 Swine 2006 Swine 2012

Disease Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

APP 8.1 (1.3) 8.5 (1.8) 4.3 (2.7)

Glasser’s disease 5.4 (1.4) 18.7 (2.9) 29.4 (7.1)

Mycoplasma pneumonia 29.0 (3.1) 39.5 (3.5) 58.8 (6.6)

Influenza 34.3 (4.1) 36.4 (3.6) 59.4 (5.3)

PRRS 16.6 (3.0) 30.2 (3.2) 53.0 (6.6)

Salmonella 8.4 (1.4) 12.0 (2.5) 5.6 (2.1)

Atrophic rhinitis 14.0 (2.1) 5.7 (1.3) 5.9 (2.5)

Swine dysentery 1.7 (0.5) 2.8 (0.9) 4.3 (1.5)

Hemorrhagic bowel syndrome 18.4 (2.7) 36.5 (3.5) 32.7 (7.8)

Ileitis 36.9 (3.8) 41.7 (3.6) 28.7 (5.0)

Gastric ulcers 19.3 (2.5) 28.3 (3.0) 28.4 (5.5)

Erysipelas 4.1 (1.3) 4.0 (1.2) 2.7 (1.3)

PMWS/PCV2/PCVAD2 3.6 (0.7) 31.3 (3.3) 13.7 (3.5)

PDNS NA 6.0 (1.3) 2.1 (1.4)

Roundworms 19.6 (2.9) 15.5 (2.8) 8.8 (2.1)

Mange NA 8.2 (2.6) 4.4 (1.4)

Other 7.5 (2.0) 14.0 (2.2) 4.0 (1.4)

1

This table reflects producer opinion, which may or may not have been confirmed by a veterinarian or laboratory diagnosis.

2

All are variations of PCVAD caused by PCV2 and previously known only as postweaning multisystemic wasting syndrome (PMWS).
USDA APHIS VS / 69 

Section III: Management and Productivity Changes–D. Weaned Pig Morbidity

0

20

40

60

80

Swine 2012

Swine 2006

Swine 2000

39.5

53.0

58.8

29.0

16.6

31.3

Mycoplasma

pneumonia

PRRS

Disease

Percent

Percentage of sites1 in which the following disease problems were known or

suspected in one or more grower/finisher pigs during the 12 months before

the study interview

Study

30.2

3.6

13.7

PMWS/PCV2/PCVAD2

1

This table reflects producer opinion, which may or may not have been confirmed by a veterinarian or 

laboratory diagnosis.

2

All are variations of PCVAD caused by PCV2 and previously known only as postweaning multisystemic 

wasting syndrome (PMWS).
70 / Swine 2012

Section III: Management and Productivity Changes–E. Disease Prevention in Weaned PIgsVaccination

In 2012, nearly all sites with nursery and grower/finisher pigs vaccinated pigs against 

Mycoplasma and influenza, a large percentage increase from previous study years. 

E.1.a. Percentage of sites that usually vaccinated weaned pigs (nursery and grower/

finisher) against the following diseases during the 12 months before the study interview, 

by study:

Percent Sites

Study

Swine 2000 Swine 2006 Swine 2012*

Disease Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Mycoplasma pneumonia 40.9 (3.6) 58.0 (4.2) 99.9 (3.1)

PRRS 5.2 (1.1) 10.1 (2.9) 40.3 (5.9)

Influenza 6.2 (1.1) 17.8 (3.0) 92.6 (4.7)

*Since the 2000 and 2006 studies did not include data on wean-to-finish sites and the 2012 study did, data on 

wean-to-finish sites were excluded from the 2012 estimates for comparison purposes.

In 2012, all sites that vaccinated pigs against influenza used an autogenous killed 

vaccine, and nearly all sites also used a commercial killed vaccine.

E.1.b. For sites that usually vaccinated weaned pigs against influenza, percentage of 

sites by type of influenza vaccine used during the 6 months (2000) or 12 months (2006 

and 2012) before the study interview, by study:

Percent Sites

Study

Swine 2000 Swine 2006 Swine 2012*

Vaccine type Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Commercial killed vaccine 91.1 (3.4) 98.7 (1.3) 94.2 (5.8)

Autogenous killed vaccine 34.3 (9.7) 58.3 (17.9) 100.0 (0.0)

*Excluded wean-to-finish pigs from this calculation to maintain greater comparability with previous years.

E. Disease 

Prevention in 

Weaned Pigs

Vaccination
USDA APHIS VS / 71 

Section III: Management and Productivity Changes–F. Use of Antimicrobials in Weaned Pigs

In 2012, nearly half of sites treated all nursery pigs with antibiotics, including clinically ill 

pigs, in the same airspace. 

F.1.a. Percentage of sites by action taken during the most recent occurrence of 

respiratory disease in nursery pigs, and by study:

Percent Sites

Study

Swine 2000 Swine 2006 Swine 2012

Action Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Did not treat any pigs 

with antibiotics 11.7 (4.6) 2.9 (1.2) 5.8 (2.3)

Treated only clinically 

ill pigs with antibiotics 16.0 (2.5) 23.4 (3.6) 18.0 (3.9)

Treated all pigs in same pen with 

clinically ill pigs with antibiotics 6.0 (2.2) 1.0 (0.9) 0.9 (0.5)

Treated all pigs in same pen and 

pens adjacent to clinically ill pigs 

with antibiotics

6.2 (3.3) 0.2 (0.1) 4.6 (4.1)

Treated all pigs in entire room 

with clinically ill pigs with 

antibiotics (all pigs with shared 

airspace)

31.3 (3.5) 39.6 (4.0) 49.6 (7.5)

Haven’t had clinical respiratory 

disease in nursery pigs in last 

12 mo (2 yr in 2000)

28.8 (3.7) 32.9 (4.2) 21.1 (4.3)

Total 100.0 100.0 100.0

F. Use of 

Antimicrobials in 

Weaned Pigs
72 / Swine 2012

Section III: Management and Productivity Changes–F. Use of Antimicrobials in Weaned Pigs

In 2012, a higher percentage of sites with respiratory disease in grower/finisher pigs 

treated pigs with antibiotics in the same room compared with sites in previous study 

years. In addition, a lower percentage of sites in 2012 than in 2006 had no respiratory 

disease.

F.1.b. Percentage of sites by action taken during the most recent occurrence of 

respiratory disease in grower/finisher pigs, by study:

Percent Sites

Study

Swine 2000 Swine 2006 Swine 2012

Action Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Did not treat any pigs 

with antibiotics 6.5 (2.7) 4.3 (1.5) 2.4 (1.1)

Treated only clinically 

ill pigs with antibiotics 27.1 (4.4) 27.3 (3.2) 23.1 (5.4)

Treated all pigs in same pen with 

clinically ill pigs with antibiotics 7.1 (1.7) 2.9 (1.2) 1.4 (0.7)

Treated all pigs in same pen and pens 

adjacent to clinically ill pigs 

with antibiotics

3.4 (1.0) 2.1 (1.1) 1.1 (0.7)

Treated all pigs in entire room with 

clinically ill pigs with antibiotics (all 

pigs with shared airspace)

39.5 (3.6) 43.3 (3.6) 63.3 (6.3)

Haven’t had clinical respiratory 

disease in grower/finisher pigs in 

last 12 mo (2 yr in 2000)

16.4 (2.7) 20.1 (2.9) 8.6 (2.0)

Total 100.0 100.0 100.0
USDA APHIS VS / 73 

Section III: Management and Productivity Changes–F. Use of Antimicrobials in Weaned Pigs

A higher percentage of sites in 2012 than in 2006 gave nursery pigs any antimicrobials in 

feed or water for any reason during the 6 months before the study interview.

F.1.c. Percentage of sites that gave nursery and/or grower/finisher pigs any antimicrobials 

in feed or water for any reason during the 6 months before the study interview, by 

production type and by study:

Percent Sites

Water* Feed*

Study

Swine 2006 Swine 2012 Swine 2006 Swine 2012

Production type Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Nursery 34.9 (3.9) 66.6 (5.5) 80.2 (3.3) 89.4 (3.0)

Grower/finisher 47.5 (3.6) 74.3 (4.8) 80.2 (2.6) 91.2 (2.0)

*Does not match previous estimates because of elimination of “Other” category.
74 / Swine 2012

Appendix: Study Objectives and Related Outputs

1. Describe current U.S. swine production practices including general management 

practices, housing practices, productivity, disease prevention, and mortality for five 

phases of production: gestation, farrowing, nursery, grow/finish, and wean-to-finish.

• “Part I: Baseline Reference of Swine Health and Management, 2012” 

“Part II: Reference of Swine Health and Health Management in the United States, 

2012” 

• “Reference of Management Practices on Small-enterprise Swine Operations in the 

United States, 2012” 

2. Describe trends in swine health and management practices.

• “Part III: Changes in the U.S. Pork Industry, 1995–2012” 

3. Determine the prevalence and associated risk factors for select respiratory, neurologic, 

gastrointestinal, systemic, and foodborne pathogens found in weaned market pigs.

•	 Salmonella, info sheet

• Commensal Enterococcus on U.S. Swine Sites: Prevalence and Antimicrobial Drug 

Susceptibility, info sheet

•	 E. coli on U.S. Swine Sites: Prevalence and Antimicrobial Drug Susceptibility, info 

sheet

4. Describe antibiotic usage patterns in pigs postweaning to market to control and treat 

disease and promote growth.

• “Part II: Reference of Swine Health and Health Management in the United States, 

2012”

5. Evaluate presence of or exposure to select pathogens and characterize isolated 

organisms from biological specimens (feces, sera, feed).

•	 Salmonella, info sheet

• Commensal Enterococcus on U.S. Swine Sites: Prevalence and Antimicrobial Drug 

Susceptibility, info sheet

•	 E. coli on U.S. Swine Sites: Prevalence and Antimicrobial Drug Susceptibility, info 

sheet

6. Update estimates of the economic cost of select respiratory, neurologic, 

gastrointestinal, systemic, and foodborne pathogens found in commercial swine herds 

and create estimates of the economic cost of different treatment approaches.

• “Part I: Baseline Reference of Swine Health and Management, 2012” 

• “Part II: Reference of Swine Health and Health Management in the United States, 

2012” 

Appendix: Study Objectives and Related Outputs