United States 

Department of 

Agriculture

Animal and 

Plant Health 

Inspection 

Service

Veterinary 

Services

National 

Animal Health 

Monitoring 

System

January 2015

Swine 2012

Part I: Baseline Reference of Swine Health 

and Management in the United States, 2012

Table of 

Contents
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USDA–APHIS–VS–CEAH–NAHMS

NRRC Building B, M.S. 2E7

2150 Centre Avenue

Fort Collins, CO 80526–8117

970.494.7000

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

#663.0115

Cover photograph courtesy of Pork Checkoff
USDA APHIS VS / i 

Items of Note

Population

The NAHMS Swine 2012 study updates national estimates on the management and 

productivity of U.S. swine previously collected during the NAHMS Swine 2006 study. 

One component of the Swine 2012 study was conducted on operations that had 100 or 

more swine in total inventory on June 1, 2012, and were located in one of 13 States. This 

report provides national estimates for this population, which includes swine production 

sites of all types. More than three-fourths of sites had no breeding animals (weaned 

pigs only), primarily either a grower/finisher unit (42.7 percent) or wean-to-finish unit 

(19.9 percent). Fewer than 20 percent of sites had a breeding herd with gestation and 

farrowing.

Breeding herd

Sows and gilts were mated almost exclusively via artificial insemination, with less than 

3 percent of either serviced via pen mating. Over 93 percent of sows and gilts serviced in 

large breeding herds received two or more matings.

Over 97 percent of sows and gilts were housed in gestation facilities with no outside 

access, and 75.8 percent of all gestating sows and gilts were housed in individual stalls. 

Overall, 11.3 piglets were born per litter, of which 10.3 were born alive and 9.4 were 

weaned; large breeding herds had substantially more pigs born alive per litter and 

weaned more pigs per litter than medium and small sites. Site average weaning age was 

20.8 days.

Nursery phase

Over 99 percent of nursery pigs were housed in facilities with no outside access. Overall, 

3.6 percent of weaned pigs that entered a nursery phase died. Nursery pigs originated 

from different sources, including on-site farrowing (34.0 percent), other sites belonging to 

the operation (35.0 percent), or other sites not belonging to the operation (29.5 percent).

Grower/finisher phase

Over 99 percent of grower/finisher pigs were housed in facilities with no outside access. 

Over 96 percent of grower/finisher pigs were managed in an all-in/all-out manner. For 

pigs that entered the grower/finisher phase, 4.1 percent died. Unlike the nursery sites, the 

majority of pigs entering the grower/finisher phase came from other sites that belonged to 

the operation.
ii / Swine 2012

Wean-to-finish phase

Almost one-fourth of all sites had a wean-to-finish phase. Over 98 percent of wean-tofinish pigs were housed in facilities with no outside access. Over 98 percent of pigs in 

the wean-to-finish phase were managed all-in/all-out. Nearly 95 percent of sites with a 

wean-to-finish phase sourced their pigs off-site, and over 93 percent of those sites used 

only one off-site source. 

Biosecurity

Almost one-fourth of all sites permitted nonbusiness visitors to enter swine facilities, and 

the majority of those sites required nonbusiness visitors to change into clean boots and 

coveralls before entering swine areas; nonbusiness visitors were also asked to wait 

24 hours after visiting another swine operation before entering the swine area. 

More than half of sites with dead preweaned pigs composted them, with the majority 

of sites doing so on-site. Almost half of sites with weaned-pig deaths composted the 

carcasses. 

More than 80 percent of medium and large sites required employees to change into clean 

boots and coveralls before entering swine facilities. More than half of large sites required 

employees to shower before entering swine facilities.

Overall, 95.0 percent of all swine sites used bait or poison for rodent control. Over 15 

percent of sites were in a county where feral swine were present.
USDA APHIS VS / iii 

Introduction 1

Terms Used in This Report 4

Section I: Population Estimates 7

A. Sow and Gilt Management 7

1. Production phases 7

B. Breeding Herd Management and Productivity 10

1. Sites with breeding herd 10

2. Replacement gilts and new boars 11

3. Breeding methods 21

4. Gestation housing and pig flow 26

5. Farrowing housing and pig flow 36

6. Farrowing productivity and preweaning death loss 45

7. Weaning 50

8. Sow and gilt management 51

C. Nursery Phase 59

1. Facilities and pig flow 59

2. Sourcing of nursery pigs 67

3. Death loss 71

4. Nursery pig management 73

D. Grower/Finisher Phase 75

1. Facilities and pig flow 75

2. Sourcing of grower/finisher pigs 82

3. Death loss 86

4. Grower/finisher pig management 88

E. Wean-to-finish Phase 91

1. Facilities and pig flow 91

2. Sourcing of wean-to-finish pigs 101

3. Death loss 104

4. Wean-to-finish pig management 108

F. Biosecurity and Other Farm Characteristics 111

1. Restrictions to entry 111

2. Trucking 114

3. Proximity to other swine sites 115

4. Rodent control 118

5. Feral swine 119

Table of Contents
iv / Swine 2012

G. General Management 121

1. Environmental testing 121

2. Carcass disposal 122

3. Use of a veterinarian 124

Section II: Methodology 126

A. Needs Assessment and Study Objectives 126

B. Sampling and Estimation 127

1. State selection 127

2. Operation selection 127

3. Site selection 128

4. Population inferences 128

C. Data Collection 128

D. Data Analysis 129

E. Sample Evaluation 130

Appendix I: Sample Profile 131

Appendix II: U.S. Swine Inventory and Number of Farms 132

Appendix III: Study Objectives and Related Outputs 133
USDA APHIS VS / v 

Acknowledgements

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, Ph.D.

Director

National Animal Health Monitoring System
vi / Swine 2012

Suggested bibliographic citation for this report:

USDA. 2015. “Swine 2012 Part I: Baseline Reference of Swine Health and Management 

in the United States, 2012”

USDA–APHIS–VS, CEAH. Fort Collins, CO

#663.0814

Contacts for further information:

Questions or comments on data analysis: Dr. Eric Bush (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

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

the U.S. Department of Agriculture (USDA) Animal and Plant Health Inspection Service. 

NAHMS is designed to help meet the Nation’s animal-health information needs and has 

collected data on animal health, productivity, and management practices on U.S. swine 

operations in five previous studies.

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 in animal health and management. 

NAHMS conducted the 1990 National Swine Survey in 18 States, with a target population 

of operations with at least 1 sow. The States represented 95 percent of the U.S. swine 

population. National estimates generated from this study are reported in “Morbidity/

Mortality and Health Management of Swine in the United States” (November 1991).

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 both participants and the industry with information 

on the U.S. swine herd on operations with 100 or more pigs. The National Agricultural 

Statistics Service (NASS) collaborated with 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 porkproducing States, which accounted for 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” (August 2001); 

“Part II: Reference of Swine Health and Management, 2000” (March 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” (November 2008).

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

Seventeen States participated in the Swine 2006 study, accounting for 94 percent of U.S. 

swine operations and inventory on operations with 100 or more pigs. As with Swine 2000, 

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

17 selected 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 
2 / Swine 2012

Introduction

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 transmission of classical swine fever and pseudorabies. 

The information gathered in this study provided a more complete picture of smallenterprise swine operations and the risk of introduction of these diseases. Thirty-one 

States participated in the study. These States accounted for 88.3 percent of swine and 

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

Agriculture. 

Swine 2012 comprises two concurrent studies. The core study targeted operations 

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

operations was selected to participate in phase 1 of the study. The questionnaire used in 

phase 1 had two versions and was 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 interview. 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 veterinarians 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 1 of the study (NASS data collection).

A 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 questionnaire and then followed-up with 

nonrespondents via telephone interview. 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.”

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

nahms 
USDA APHIS VS / 3 

Introduction

Swine 2012 Participating States

Region

Midwest

East

South
4 / Swine 2012

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 time. Usually, all-in/all-out management also 

includes complete cleaning and disinfecting of the facility before it is refilled with animals. 

A facility may be a room, a building, or an entire site.

Artificial insemination: The deliberate introduction via catheter of boar semen into the 

oviduct or uterus of a sow/gilt.

Hand-mating: Term used when females are individually selected for breeding 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.

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

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

phases of swine rearing (e.g., gestation, farrowing, nursery, and grower/finisher) on one 

or more sites (geographic locations), each devoted to a different production phase or a 

combination of phases (see site definition on next page).

Pen-mating: One or more boars are placed in a pen with one or more breeding females 

for natural breeding.

Percent animals: The number of animals 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 number of animals 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 (i.e., 

percentage of sites located within each region). Percentages will not sum to 100 where 

the attributes are not mutually exclusive (i.e., the percentage of sites using treatment 

methods where sites may have used more than one method). The percent-sites 

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

Pig-level average: A single site value multiplied by the number of animals on that site; 

then values are summed across sites and divided by total number of animals on all sites 

(see table B.7.a). 

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

called the standard error. A 95-percent confidence interval can be approximated 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 

Terms Used in 

This Report
USDA APHIS VS / 5 

Introduction

population mean 95 out of 100 times. For example, an estimate of 7.5 with a standard 

error of 1.0 results in limits of 5.5 to 9.5 (two times the standard error above and below 

the estimate). Alternatively, the 90-percent confidence interval would be created by 

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

rounded to the nearest tenth. If rounded to 0, the standard error was reported (0.0). If 

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

Production phases: 

Farrowing: Production phase with sows or gilts designated for breeding that farrow 

(gave birth to a litter of piglets).

Gestation: Production phase with sows or gilts designated for breeding that service 

(breed) and/or farrow sows and gilts.

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

60 lb to final market weight for slaughter.

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

housed until they go into the grower/finisher phase (at approximately 60 lb).

Wean-to-finish: Specialized production site that receives newly weaned pigs that are 

managed, fed, and housed to final market weight for slaughter.

Regions: 

Midwest: Iowa, Minnesota, Nebraska, South Dakota 

East: Illinois, Indiana, Ohio, Pennsylvania

South: Kansas, Missouri, North Carolina, Oklahoma, Texas

Sample profile: Information that describes characteristics of the operations from which 

Swine 2012 data were collected.

Separate site: This term can mean that a facility is at a completely separate geographic 

location or in the same location but physically separated (no livestock runways or paths 

joining to other production facilities). It also might be managed as its own site, with 

separate procedures, biosecurity measures, and workers.

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 or a nursery site. A site can encompass more than one production phase, such as a 

“farrow-to-finish” site, 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 operation definition on previous page).

Site Average: The average value for each site summed over all sites reporting and 

divided by the number of sites reporting.
6 / Swine 2012

Introduction

Size of site: Size groupings are based on total number of swine present on June 1, 

2012. Size of site was categorized as small (fewer than 2,000), medium (2,000 to 4,999), 

and large (5,000 or more). 

For tables relating to breeding herds, size of site was based on the number of sows and 

gilts on-site: small (fewer than 250), medium (250 to 499), and large (500 or more).

Total inventory: All swine present on-site on June 1, 2012.
USDA APHIS VS / 7 

Section I: Population Estimates–A. Sow and Gilt Management

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

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

1. Production phases

More than half of sites (56.0 percent) had a grower/finisher phase, and almost onefourth (24.4 percent) had a wean-to-finish phase. Many sites had a combination of these 

production phases (table A.1.c).

A.1.a. Percentage of sites by production phase and by size of site:

Percent Sites

Size of Site (total inventory)

Small

(fewer than 

2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Production 

phase Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Gestation 33.2 (2.3) 8.1 (1.7) 23.3 (6.2) 21.1 (2.6)

Farrowing 32.7 (2.3) 8.0 (1.7) 23.3 (6.2) 20.8 (2.6)

Nursery 28.4 (2.4) 14.9 (3.1) 25.5 (7.7) 22.3 (3.0)

Grower/finisher 51.3 (3.4) 60.5 (6.8) 56.3 (10.9) 56.0 (5.3)

Wean-to-finish 25.0 (3.2) 27.7 (6.3) 15.4 (5.4) 24.4 (4.2)

Section I: Population Estimates

A. Sow and Gilt 

Management
8 / Swine 2012

Section I: Population Estimates–A. Sow and Gilt Management

In the South region, only 5.7 percent of sites had a wean-to-finish phase compared with 

31.9 percent of sites in the Midwest region.

A.1.b. Percentage of sites by production phase and by region:

Percent Sites

Region

Midwest East South

Production phase Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Gestation 17.5 (1.9) 22.8 (7.7) 28.0 (6.2)

Farrowing 17.2 (1.9) 22.6 (7.6) 27.8 (6.2)

Nursery 21.7 (2.6) 17.3 (5.9) 32.4 (6.5)

Grower/finisher 52.6 (4.4) 64.0 (12.5) 51.7 (6.5)

Wean-to-finish 31.9 (4.9) 23.4 (8.8) 5.7 (2.0)

Small sites are less likely to use multisite production; therefore, a higher percentage of 

small sites had both sows and market pigs compared with medium and large sites. As 

shown in A.1.a, 56.0 percent of all sites had a grower/finisher phase. Of this 56.0 percent, 

42.7 percent had a grower/finisher phase only. So more than three-fourths of sites with a 

grower/finisher phase (76.2 percent) had no other production phases. 
USDA APHIS VS / 9 

Section I: Population Estimates–A. Sow and Gilt Management

A.1.c. Percentage of sites by combination of production phases and by size of site:

Percent Sites

Size of Site (total inventory)

Small

(fewer 

than 2,000)

Medium

(2,000–

4,999)

Large

(5,000 

or more) All sites

Production phase 

combination Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Single-site production

Gestation, farrowing, 

nursery and grower/ 

finisher

9.8 (0.9) 2.4 (0.5) 5.9 (1.8) 6.0 (0.9)

Gestation and farrowing 

and wean-to-finish 8.4 (0.8) 0.4 (0.1) 1.0 (0.4) 3.8 (0.6)

Multiple-site production

Gestation and 

farrowing only 7.4 (0.8) 4.7 (1.3) 14.6 (4.7) 7.5 (1.2)

Gestation, farrowing, 

and nursery 3.0 (0.4) 0.6 (0.2) 0.9 (0.4) 1.6 (0.3)

Nursery and grower/

finisher only 6.9 (0.8) 5.2 (1.1) 4.0 (1.3) 5.7 (0.8)

Nursery only 7.7 (2.0) 6.4 (2.7) 13.6 (6.6) 8.2 (2.3)

Grower/finisher only 31.9 (3.6) 52.3 (7.6) 45.3 (12.5) 42.7 (6.4)

Wean-to-finish only 15.9 (3.3) 26.7 (6.2) 13.2 (5.2) 19.9 (4.0)

Other combination 9.1 (0.9) 1.4 (0.4) 1.4 (0.5) 4.5 (0.7)

Total 100.0 100.0 100.0 100.0
10 / Swine 2012

Section I: Population Estimates–B. Breeding Herd Management and Productivity

1. Sites with breeding herd 

A higher percentage small sites had a breeding herd compared with medium and large 

sites. 

B.1.a. Percentage of sites with a breeding herd (gestation and/or farrowing phase) from 

December 1, 2011, through May 31, 2012, by size of site:

Percent Sites

Size of Site (total inventory)

Small

(fewer than 2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

33.2 (2.3) 8.1 (1.7) 23.3 (6.2) 21.1 (2.6)

Note: Tables B.1.b. through B.3.i. refer to breeding herds on the 21.1 percent of sites that 

had a breeding herd from December 1, 2011, through May 31, 2012.

B.1.b. Percentage of breeding herds by size of herd:

Percent Breeding Herds

Herd Size (number of sows and gilts)

Small

(fewer than 250)

Medium

(250–499)

Large

(500 or more)

Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Total

57.6 (3.0) 6.8 (0.9) 35.6 (3.3) 100.0

B. Breeding Herd 

Management and 

Productivity
USDA APHIS VS / 11 

Section I: Population Estimates–B. Breeding Herd Management and Productivity

2. Replacement gilts and new boars

Just over 40 percent of small breeding herds (40.9 percent) did not introduce any new 

gilts from December 1, 2011, through May 31, 2012. Almost one-third of small breeding 

herds (32.5 percent) introduced 1 to 20 new gilts, whereas almost two-thirds of large 

breeding herds (64.9 percent) introduced more than 300 new gilts. Over 7 percent of 

large breeding herds were closed to replacement gilts.

B.2.a. Percentage of breeding herds by the number of replacement gilts introduced,* and 

by size of herd:

Percent Breeding Herds

Herd size (number sows and gilts)

Small 

(fewer than 250)

Medium

(250–499)

Large

(500 or more) All sites

Number gilts 

introduced Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

No replacement 

gilts introduced 40.9 (2.1) 3.5 (2.1) 7.2 (2.3) 26.3 (1.9)

1–20 32.5 (2.0) 7.0 (2.8) 0.0 (—) 19.1 (1.5)

21–60 22.6 (1.7) 43.1 (6.1) 1.9 (0.7) 16.6 (1.4)

61–300 3.9 (0.9) 46.4 (6.3) 26.0 (4.3) 14.7 (1.4)

301 or more 0.0 (—) 0.0 (—) 64.9 (5.5) 23.3 (4.0)

Total 100.0 100.0 100.0 100.0

*From December 1, 2011, through May 31, 2012. 
12 / Swine 2012

Section I: Population Estimates–B. Breeding Herd Management and Productivity

More than 30 percent of large breeding herds introduced 12 or more groups of new gilts, 

indicating that a new group was introduced at least every 2 weeks. More than half of 

small and medium breeding herds (53.2 and 68.2 percent, respectively) introduced only 

1 to 5 groups of new gilts, for an average of less than one new group per month.

B.2.b. Percentage of breeding herds by number of groups of replacement gilts 

introduced,* and by size of herd:

Percent Breeding Herds

Herd Size (number sows and gilts)

Small 

(fewer than 250)

Medium

(250–499)

Large

(500 or more) All sites

Number of groups 

introduced Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

1–5 53.2 (2.1) 68.2 (6.4) 43.1 (6.3) 50.6 (2.5)

6–11 4.2 (0.9) 27.1 (6.4) 19.5 (4.1) 11.2 (1.5)

12–25 1.6 (0.5) 1.2 (1.0) 16.7 (5.3) 7.0 (2.1)

26 or more 0.1 (0.1) 0.0 (—) 13.6 (3.5) 4.9 (1.2)

No replacement 

gilts introduced 40.9 (2.1) 3.5 (2.1) 7.2 (2.3) 26.3 (1.9)

Total 100.0 100.0 100.0 100.0

*From December 1, 2011, through May 31, 2012.
USDA APHIS VS / 13 

Section I: Population Estimates–B. Breeding Herd Management and Productivity

0

20

40

60

Percent

Percentage of breeding herds by number of groups of replacement gilts introduced*

No replacement

gilts introduced

1 to 5 6 to 11

7.0

26.3

50.6

4.9

Number of groups introduced

26 or more

11.2

12 to 25

*From December 1, 2011, through May 31, 2012.
14 / Swine 2012

Section I: Population Estimates–B. Breeding Herd Management and Productivity

The average age of replacement gilts entering the breeding herd was similar across all 

herd sizes.

B.2.c. Average age of replacement gilts (in weeks), by stage of entry into breeding herd 

and by size of herd:

Average Age (weeks)

Herd Size (number sows and gilts)

Small 

(fewer than 250)

Medium

(250–499)

Large

(500 or more) All sites

Stage of entry Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error

Designated or 

selected to be part 

of the breeding herd

22.6 (0.5) 23.5 (1.4) 24.2 (1.0) 23.4 (0.5)

Introduced into 

the breeding herd 

(commingled with 

sows)

31.1 (0.6) 32.1 (0.9) 31.5 (0.4) 31.3 (0.3)
USDA APHIS VS / 15 

Section I: Population Estimates–B. Breeding Herd Management and Productivity

On the majority of breeding herds (55.3 percent), replacement gilts came from a parent 

herd. Almost 90 percent of small breeding herds (89.4 percent) used replacement gilts 

from a parent herd or a commercial herd (as terminal cross females). More than onefourth of medium and large breeding herds (28.7 and 26.3 percent, respectively) used 

replacement gilts from grandparent herds compared with less than one-tenth of small 

breeding herds (9.3 percent).

B.2.d. For breeding herds that introduced replacement gilts,1 percentage of herds by 

source of gilts and by size of herd:

Percent Breeding Herds

Herd Size (number sows and gilts)

Small 

(fewer than 250)

Medium

(250–499)

Large

(500 or more) All sites

Source of gilts Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Terminal cross females 

from commercial herd 28.8 (3.7) 29.4 (5.6) 19.0 (3.4) 22.7 (2.6)

Parent herd2 60.6 (4.0) 42.1 (6.3) 55.6 (6.9) 55.3 (4.5)

Grandparent herd 9.3 (2.4) 28.7 (6.7) 26.3 (5.1) 22.2 (3.2)

Great-grandparent 

herd 4.0 (1.6) 3.4 (2.1) 7.0 (2.0) 5.8 (1.3)

Other 6.5 (2.0) 4.5 (2.4) 5.6 (1.6) 5.7 (1.1)

1

 From December 1, 2011, through May 31, 2012.

2

The commercial tier in the breeding pyramid that crosses parent boar and gilt lines to produce terminal stock, 

i.e., market hogs intended for slaughter.
16 / Swine 2012

Section I: Population Estimates–B. Breeding Herd Management and Productivity

Over 70 percent of all replacement gilts introduced to breeding herds were from a parent 

herd, and over 15 percent were from a grandparent herd.

B.2.e. Percentage of replacement gilts introduced to the breeding herd,1 by source of 

gilts:

Percent Gilts

Herd Size (number sows and gilts)

Small 

(fewer than 250)

Medium

(250–499)

Large

(500 or more) All sites

Source of gilts Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Terminal cross 

females from 

commercial herd

33.8 (6.2) 25.5 (6.8) 7.9 (3.1) 8.7 (3.2)

Parent herd2 49.5 (6.4) 39.8 (8.4) 72.6 (10.3) 71.6 (10.2)

Grandparent herd 6.4 (2.7) 28.6 (9.8) 15.5 (6.3) 15.6 (6.1)

Great-grandparent 

herd 1.5 (0.7) 1.5 (1.0) 1.8 (0.8) 1.8 (0.8)

Other 8.8 (5.8) 4.6 (3.0) 2.2 (1.1) 2.4 (1.1)

Total 100.0 100.0 100.0 100.0

1

 From December 1, 2011, through May 31, 2012.

2

The commercial tier in the breeding pyramid that crosses parent boar and gilt lines to produce terminal stock, 

i.e., market hogs intended for slaughter.
USDA APHIS VS / 17 

Section I: Population Estimates–B. Breeding Herd Management and Productivity

0

20

40

60

80

Gilts

Herd

Percent

For breeding herds that introduced replacement gilts,* percentage of herds and 

percentage of gilts introduced, by source of gilts 

Terminal cross

females from

commercial herd

Parent

herd1

Grandparent

herd

Greatgrandparent

herd

55.3

5.8

22.7 22.2

5.7

Source

Other

8.7

71.6

15.6

1.8 2.4

*From December 1, 2011, through May 31, 2012. 1

The commercial tier in the breeding pyramid that crosses parent boar and gilt lines to produce terminal stock,

i.e., market hogs intended for slaughter.
18 / Swine 2012

Section I: Population Estimates–B. Breeding Herd Management and Productivity

B.2.f. Percentage of breeding herds that added new breeding males,* by size of site:

Percent Breeding Herds

Herd Size (number of sows and gilts)

Small

(fewer than 250)

Medium

(250–499)

Large

(500 or more) All sites

Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

27.2 (1.9) 37.1 (5.7) 30.6 (9.2) 29.1 (3.5)

*From December 1, 2011, through May 31, 2012.

B.2.g. For breeding herds that introduced new breeding males,* percentage of herds by 

frequency that new breeding males were typically isolated or quarantined, and by size of 

herd:

Percent Breeding Herds 

Herd Size (number sows and gilts)

Small

(fewer than 250)

Medium

(250–499)

Large

(500 or more) All sites

Frequency Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Always 58.6 (4.0) 84.5 (6.5) 68.0 (13.9) 64.4 (5.7)

Sometimes 13.1 (2.7) 7.3 (4.4) 0.0 (—) 7.7 (1.9)

Never 28.3 (3.7) 8.2 (5.1) 32.0 (13.9) 27.9 (5.7)

Total 100.0 100.0 100.0 100.0

*From December 1, 2011, through May 31, 2012.
USDA APHIS VS / 19 

Section I: Population Estimates–B. Breeding Herd Management and Productivity

B.2.h. For breeding herds that always or sometimes isolated new breeding males, herd 

average number of days new breeding males were isolated or quarantined, by size of 

site:

Breeding Herd Average Number of Days

Herd Size (number sows and gilts)

Small

(fewer than 250)

Medium

(250–499)

Large

(500 or more) All sites

Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error

33.9 (1.6) 37.1 (5.0) 44.5 (3.5) 38.1 (2.3)

B.2.i. For breeding herds that introduced new breeding males,* percentage of herds that 

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

new males tested and by size of herd:

Percent Breeding Herds

Herd Size (number sows and gilts)

Small

(fewer than 250)

Medium

(250–499)

Large

(500 or more) All sites

Proportion 

of new males 

tested Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

All 33.3 (3.7) 51.5 (9.3) 50.3 (15.7) 41.3 (5.9)

Some 6.3 (2.0) 11.7 (5.8) 44.2 (16.7) 21.0 (8.9)

None 60.5 (3.9) 36.8 (8.7) 5.6 (3.7) 37.7 (6.5)

Total 100.0 100.0 100.0 100.0

*From December 1, 2011, through May 31, 2012.
20 / Swine 2012

Section I: Population Estimates–B. Breeding Herd Management and Productivity

In general, a higher percentage of large breeding herds made an effort to acclimate new 

breeding animals compared with small and medium herds. For example, 46.5 and 

55.0 percent of large herds fed back feces to new breeding stock or exposed them to cull 

females, respectively, compared with 18.3 and 28.1 percent of medium herds and 

11.0 and 28.9 percent of small herds, respectively. 

B.2.j. For breeding herds that introduced new breeding stock,* percentage of herds by 

method used to acclimate new arrivals, and by size of herd:

Percent Breeding Herds

Herd Size (number sows and gilts)

Small

(fewer than 250)

Medium

(250–499)

Large

(500 or more) All sites

Method Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Fed back feces from 

other swine 11.0 (2.2) 18.3 (4.6) 46.5 (7.8) 32.8 (5.6)

Fed back 

mummies, 

placentas, or 

stillborn pigs

2.5 (1.0) 8.6 (3.6) 22.3 (5.2) 14.9 (3.3)

Expose to 

cull females 28.9 (3.2) 28.1 (5.5) 55.0 (5.5) 44.2 (3.7)

Expose to 

sick pigs 6.5 (1.6) 6.1 (2.7) 14.7 (5.2) 11.3 (3.2)

Give vaccinations 53.8 (3.6) 79.9 (4.4) 88.2 (2.5) 76.9 (2.5)

Other 8.0 (2.0) 4.0 (1.9) 2.2 (0.8) 4.1 (0.9)

*From December 1, 2011, through May 31, 2012.
USDA APHIS VS / 21 

Section I: Population Estimates–B. Breeding Herd Management and Productivity

3. Breeding methods

Over 93 percent of sows serviced on large breeding herds received two or more matings, 

and less than 1 percent were pen-mated only. On small and medium herds, about 

30 and 20 percent of sows, respectively, were serviced via pen-mating. For all sows 

serviced, less than 2 percent were serviced via pen-mating only. Sows were mated 

almost exclusively via artificial insemination.

B.3.a. Percentage of sows serviced,1 by number of matings per service2 and by size of 

herd:

Percent Sows

Herd Size (number sows and gilts)

Small 

(fewer than 250)

Medium

(250–499)

Large

(500 or more) All sites

Number of 

matings Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Pen-mating 

only 30.0 (4.4) 19.6 (8.2) 0.8 (0.5) 1.7 (0.6)

1 11.0 (2.7) 9.2 (3.5) 6.2 (0.9) 6.4 (0.9)

2 53.6 (4.4) 58.5 (7.8) 81.4 (4.3) 80.4 (4.1)

3 or more 5.4 (1.6) 12.8 (3.7) 11.7 (4.4) 11.6 (4.3)

Total 100.0 100.0 100.0 100.0

1

From December 1, 2011, through May 31, 2012.

2

A service is one or more matings in the same heat cycle or estrus period.
22 / Swine 2012

Section I: Population Estimates–B. Breeding Herd Management and Productivity

Almost half of sows serviced (48.1 percent) received three or more matings via artificial 

insemination.

B.3.b. For breeding herds that did not use pen-mating exclusively, percentage of sows

serviced,* by predominant mating technique used for first, second, and third or more 

matings:

Percent Sows

First 

mating

Second 

mating

Third or 

more matings

Mating technique Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Artificial insemination 98.5 (0.4) 98.1 (0.4) 48.1 (7.8)

Individual hand-mating 

naturally 0.5 (0.2) 0.6 (0.2) 0.3 (0.2)

Pen-mating with multiple 

females and one or more 

boars

1.0 (0.3) 0.8 (0.3) 0.9 (0.4)

NA 0.0 (—) 0.5 (0.2) 50.7 (7.8)

Total 100.0 100.0 100.0

*From December 1, 2011, through May 31, 2012.

B.3.c. For breeding herds that used a second mating for sows, percentage of herds 

and percentage of sows serviced,* by predominant mating technique used for first and 

second matings:

Mating technique Percent breeding herd Percent sows

First mating Second mating Pct.

Std.

error Pct.

Std.

error

Artificial 

insemination

Artificial 

insemination 88.4 (1.9) 98.4 (0.4)

Artificial 

insemination Hand-mating 0.8 (0.4) 0.0 (0.0)

Artificial 

insemination Pen-mating 0.9 (0.4) 0.1 (0.1)

Hand-mating Artificial 

insemination 0.5 (0.3) 0.0 (0.0)

Hand-mating Hand-mating 3.8 (0.9) 0.5 (0.2)

Pen-mating Any other 

technique 5.7 (1.3) 1.0 (0.3)

Total 100.0 100.0

*From December 1, 2011, through May 31, 2012.
USDA APHIS VS / 23 

Section I: Population Estimates–B. Breeding Herd Management and Productivity

B.3.d. For breeding herds that did not use pen-mating exclusively, percentage of herds 

that used artificial insemination as a predominant mating technique during at least one 

mating, by size of herd:

Percent Breeding Herds

Herd Size (number sows and gilts)

Small 

(fewer than 250)

Medium

(250–499)

Large

(500 or more) All sites

Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

66.9 (4.4) 81.2 (4.9) 94.7 (1.4) 87.2 (1.9)

In total, 93.1 percent of gilts serviced on large breeding herds received two or more 

matings. Less than 2 percent of gilts were pen-mated only. On small and medium herds, 

over one-third of gilts were serviced via pen-mating. For all gilts serviced, less than 

3 percent were serviced by pen-mating only. Gilts were mated almost exclusively via 

artificial insemination (table B.3.f).

B.3.e. Percentage of gilts serviced,* by number of matings per service and by size of 

herd:

Percent Gilts

Herd Size (number sows and gilts)

Small 

(fewer than 250)

Medium

(250–499)

Large

(500 or more) All sites

Number of 

matings Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Pen-mating 

only 34.9 (5.4) 35.9 (11.2) 1.8 (1.3) 2.7 (1.5)

1 9.3 (2.7) 7.3 (3.4) 5.1 (2.0) 5.2 (2.0)

2 50.3 (5.5) 43.7 (8.6) 88.3 (4.9) 87.2 (5.1)

3 or more 5.6 (2.2) 13.1 (5.4) 4.8 (3.0) 4.9 (2.9)

Total 100.0 100.0 100.0 100.0

*From December 1, 2011, through May 31, 2012.
24 / Swine 2012

Section I: Population Estimates–B. Breeding Herd Management and Productivity

Only one-fourth of gilts serviced (25.3 percent) received three or more matings via 

artificial insemination.

B.3.f. For sites that did not use pen-mating exclusively, percentage of gilts serviced,* by 

predominant mating technique used for first, second, and third or more matings:

Percent Gilts

First 

mating

Second 

mating

Third or 

more matings

Mating technique Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Artificial insemination 97.6 (1.1) 98.3 (0.8) 25.3 (10.9)

Individual 

hand-mating naturally 1.2 (0.7) 0.4 (0.2) 0.1 (0.1)

Pen-mating with multiple 

females and one or more 

boars

1.2 (0.6) 1.0 (0.5) 0.5 (0.3)

NA (second or third 

mating not used) 0.0 (—) 0.3 (0.2) 74.1 (11.1)

Total 100.0 100.0 100.0

*From December 1, 2011, through May 31, 2012.
USDA APHIS VS / 25 

Section I: Population Estimates–B. Breeding Herd Management and Productivity

B.3.g. For breeding herds that used a second mating for gilts, percentage of herds and 

percentage of gilts serviced,* by predominant mating technique used during first and 

second matings:

Mating technique Percent herds Percent gilts

First mating Second mating Pct.

Std.

error Pct.

Std.

error

Artificial 

insemination

Artificial 

insemination 85.6 (2.5) 97.6 (1.1)

Artificial 

insemination Hand-mating 0.5 (0.3) 0.0 (0.0)

Artificial 

insemination Pen-mating 0.4 (0.3) 0.0 (0.0)

Hand-mating Artificial 

insemination 2.1 (1.1) 0.8 (0.6)

Hand-mating Hand-mating 4.9 (1.1) 0.4 (0.2)

Pen-mating Any other 

technique 6.5 (1.5) 1.2 (0.6)

Total 100.0 100.0

*From December 1, 2011, through May 31, 2012.

B.3.h. For breeding herds that did not use pen-mating exclusively, percentage of herds 

that used AI as a predominant mating technique for gilts during at least one mating, by 

size of site:

Percent Breeding Herds

Herd Size (number sows and gilts)

Small 

(fewer than 250)

Medium

(250–499)

Large

(500 or more) All sites

Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

55.8 (5.4) 78.3 (5.7) 95.1 (1.3) 86.3 (2.1)
26 / Swine 2012

Section I: Population Estimates–B. Breeding Herd Management and Productivity

The majority of small and medium breeding herds (84.5 and 91.6 percent, respectively) 

purchased semen for inseminating sows and gilts. Over 40 percent of large herds 

collected semen off-site from their own boars. One-fourth of small herds collected 

semen on-site from their own boars. Note: columns do not add to 100 percent because 

producers could have used more than one source for semen.

B.3.i. For breeding herds that used artificial insemination, percentage of herds by source 

of semen and by size of herd:

Percent Breeding Herds

Herd Size (number sows and gilts)

Small 

(fewer than 250)

Medium

(250–499)

Large

(500 or more) All sites

Semen source Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Purchased 84.5 (4.3) 91.6 (4.4) 55.5 (8.6) 63.5 (7.3)

Collected and 

processed on-site 25.6 (4.8) 16.4 (5.7) 6.8 (1.6) 10.8 (1.8)

Collected and 

processed off-site, 

but not purchased

3.9 (2.5) 5.6 (3.5) 43.3 (8.7) 33.5 (7.6)

4. Gestation housing and pig flow

B.4.a. Percentage of sites that had a gestation phase,* by size of site:

Percent Sites

Size of Site (total inventory)

Small 

(fewer than 2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Pct.

Std. 

error Pct.

Std. 

error Pct.

Std.

error Pct.

Std. 

error

33.2 (2.3) 8.1 (1.7) 23.3 (6.2) 21.1 (2.6)

*From December 1, 2011, through May 31, 2012.
USDA APHIS VS / 27 

Section I: Population Estimates–B. Breeding Herd Management and Productivity

Note: Tables B.4.b. through B.4.l. refer to breeding herds on the 21.1 percent of sites that 

had a gestation phase from December 1, 2011, through May 31, 2012.

Facility types used for gestating sows and gilts differed by size of breeding herd. A total 

of 98.4 percent of large herds housed gestation sows and gilts in total confinement or in 

buildings with no outside access compared with 82.1 and 39.7 percent of medium and 

small herds, respectively. Over 40 percent of small herds housed gestating sows and gilts 

in open buildings with outdoor access, and almost 20 percent housed gestation sows and 

gilts in a lot or pasture.

B.4.b. Percentage of breeding herds by facility type used for the gestation phase, and by 

size of herd:

Percent Breeding Herds

Herd Size (number sows and gilts)

Small 

(fewer than 250)

Medium

(250–499)

Large

(500 or more) All sites

Facility type Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Total confinement 14.0 (1.4) 43.4 (6.1) 76.8 (5.0) 38.6 (2.5)

Open building 

with natural 

ventilation and no 

outside access

25.7 (1.8) 38.7 (5.8) 21.6 (5.0) 25.1 (2.1)

Open building 

with outside 

access

41.7 (2.0) 15.1 (5.8) 1.0 (0.5) 25.2 (1.8)

Lot with hut 

or no building 11.0 (1.3) 1.7 (1.5) 0.3 (0.3) 6.5 (0.8)

Pasture with hut 

or no building 7.6 (1.1) 1.1 (0.9) 0.3 (0.3) 4.6 (0.7)

Total 100.0 100.0 100.0 100.0
28 / Swine 2012

Section I: Population Estimates–B. Breeding Herd Management and Productivity

Over 97 percent of all sows and gilts were housed in gestation facilities with no outside 

access, although only about half the sows and gilts on small breeding herds were housed 

in such facilities.

B.4.c. Percentage of sows and gilts by facility type used in the gestation phase, and by 

size of breeding herd:

Percent Sows and Gilts

Herd Size (number sows and gilts)

Small 

(fewer than 250)

Medium

(250–499)

Large

(500 or more) All sites

Facility type Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Total confinement 18.3 (2.4) 44.2 (7.6) 79.4 (8.0) 76.7 (7.5)

Open building 

with natural 

ventilation and no 

outside access

30.6 (2.8) 36.7 (6.7) 20.0 (8.0) 20.7 (7.6)

Open building 

with outside 

access

37.6 (2.9) 16.3 (8.5) 0.4 (0.2) 2.0 (0.4)

Lot with hut 

or no building 9.0 (1.5) 2.1 (1.9) 0.0 (0.0) 0.4 (0.1)

Pasture with hut 

or no building 4.6 (1.0) 0.7 (0.6) 0.1 (0.1) 0.3 (0.1)

Total 100.0 100.0 100.0 100.0
USDA APHIS VS / 29 

Section I: Population Estimates–B. Breeding Herd Management and Productivity

For gestation facilities with no outside access, partial slats was the flooring type used 

by the highest percentage of breeding herds (53.4 percent ), followed by complete slats 

(38.1 percent). For open buildings with outside access, solid surface was the flooring type 

used by the majority of herds (70.9 percent), followed by dirt/pasture (22.6 percent). 

B.4.d. Percentage of breeding herds by flooring type used in the gestation phase, and by 

type of facility:

Percent Breeding Herds

Facility Type

No outside 

access

Open building 

with outside 

access Lot or pasture All sites

Flooring type Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Solid surface 8.0 (1.5) 70.9 (5.0) 0.0 (—) 16.1 (2.0)

Partial slats 53.4 (4.2) 5.6 (2.6) 0.0 (—) 44.6 (3.7)

Completely 

slatted 38.1 (4.1) 0.9 (0.8) 0.0 (—) 31.4 (3.5)

Mesh 0.3 (0.1) 0.0 (—) 0.0 (—) 0.2 (0.1)

Dirt/pasture 0.0 (—) 22.6 (4.5) 100.0 (—) 7.5 (1.2)

Other 0.2 (0.2) 0.0 (—) 0.0 (—) 0.2 (0.1)

Total 100.0 100.0 100.0 100.0
30 / Swine 2012

Section I: Population Estimates–B. Breeding Herd Management and Productivity

For the 76.0 percent of breeding herds that used partially or completley slatted floors in 

the gestation phase (see previous table), 98.0 percent used concrete for slatted flooring 

materials. 

B.4.e. Percentage of breeding herds by slatted flooring material used in the gestation 

phase, and by type of facility:

Percent Breeding Herds

Facility Type

No outside 

access

Open building 

with outside 

access Lot or pasture All sites

Slatted flooring 

material Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Concrete 89.9 (1.7) 5.6 (2.6) 0.0 (—) 74.5 (2.7)

Metal 0.8 (0.3) 0.0 (—) 0.0 (—) 0.6 (0.3)

Plastic 0.9 (0.5) 0.9 (0.8) 0.0 (—) 0.9 (0.4)

Mesh or 

solid floor 8.5 (1.5) 93.5 (2.7) 100.0 (—) 24.0 (2.6)

Total 100.0 100.0 100.0 100.0

The percentage of breeding herds that housed gestating sows and gilts in individual 

housing increased as herd size increased. Over three-fourths of the large breeding herds 

(76.6 percent) used individual housing for gestating sows and gilts, while 69.2 percent of 

small breeding herds used group housing for gestating sows and gilts. 

B.4.f. Percentage of sites by primary type of housing used for the majority of sows and 

gilts in the gestation phase, and by size of site:

Percent Breeding Herds

Herd Size (number sows and gilts)

Small 

(fewer than 250)

Medium

(250–499)

Large

(500 or more) All sites

Housing type Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Individual 14.1 (1.4) 49.3 (6.2) 76.6 (4.9) 38.9 (2.5)

Group 69.2 (1.9) 48.0 (6.2) 22.5 (4.9) 51.0 (2.3)

Other 16.7 (1.6) 2.7 (1.7) 0.9 (0.5) 10.1 (1.1)

Total 100.0 100.0 100.0 100.0
USDA APHIS VS / 31 

Section I: Population Estimates–B. Breeding Herd Management and Productivity

Just over three-fourths of all gestating sows and gilts (75.8 percent) were housed in 

individual stalls. 

B.4.g. Percentage of sows and gilts by type of housing used for sows and gilts in the 

gestation phase, and by type of facility:

Percent Sows and Gilts

Facility Type

No outside 

access

Open building 

with outside 

access Lot or pasture All sites

Housing type Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Individual 77.6 (8.9) 14.2 (6.7) 0.4 (0.3) 75.8 (8.6)

Group 22.0 (9.0) 76.3 (6.8) 70.2 (7.6) 23.4 (8.6)

Other 0.4 (0.2) 9.5 (2.7) 29.4 (7.5) 0.8 (0.3)

Total 100.0 100.0 100.0 100.0
32 / Swine 2012

Section I: Population Estimates–B. Breeding Herd Management and Productivity

More than half of all breeding herds (52.0 percent) had gestation facilities with a pitholding waste management system compared with 36.1 percent of small herds. 

B.4.h. Percentage of breeding herds by primary waste management system used in the 

gestation facility, and by size of herd:

Percent Breeding Herds

Herd Size (number sows and gilts)

Small 

(fewer than 250)

Medium

(250–499)

Large

(500 or more) All sites

Waste management 

system Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

None 10.0 (2.1) 3.6 (2.2) 0.7 (0.6) 3.9 (0.8)

Pit-holding 36.1 (3.4) 64.1 (6.6) 58.4 (6.2) 52.0 (3.7)

Mechanical 

scraper/tractor 27.5 (3.3) 13.3 (6.3) 2.3 (0.6) 11.2 (1.6)

Hand-cleaned 12.1 (2.3) 4.7 (2.4) 0.0 (—) 4.2 (0.9)

Flush, under slats 4.6 (1.4) 7.9 (2.5) 35.0 (6.7) 22.9 (4.7)

Flush, open gutter 2.2 (1.0) 1.7 (1.5) 2.4 (1.2) 2.3 (0.8)

Other 7.6 (1.9) 4.7 (2.3) 1.2 (0.5) 3.5 (0.8)

Total 100.0 100.0 100.0 100.0
USDA APHIS VS / 33 

Section I: Population Estimates–B. Breeding Herd Management and Productivity

More than half of breeding herds in the South region used flush under slats to manage 

waste.

B.4.i. Percentage of breeding herds by primary waste management system used in the 

gestation facility, and by region:

Percent Breeding Herds

Region

Midwest East South

Waste management 

system Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

None 2.6 (1.1) 3.4 (1.3) 6.2 (2.4)

Pit-holding 52.7 (3.6) 69.5 (3.5) 34.2 (9.5)

Mechanical scraper/tractor 17.8 (2.6) 7.8 (2.1) 4.7 (2.0)

Hand-cleaned 5.9 (1.5) 5.1 (1.6) 0.8 (0.7)

Flush, under slats 13.0 (3.2) 8.0 (1.8) 52.0 (10.4)

Flush, open gutter 2.9 (1.4) 1.5 (1.5) 2.1 (1.1)

Other 5.1 (1.3) 4.7 (1.6) 0.0 (—)

Total 100.0 100.0 100.0
34 / Swine 2012

Section I: Population Estimates–B. Breeding Herd Management and Productivity

A total of 73.7 percent of all breeding herds had a continuous flow of pigs in gestation; 

9.1 percent practiced all-in/all-out management by room; and 9.0 percent practiced all-in/

all-out management by building.

B.4.j. Percentage of breeding herds by pig-flow management used in the gestation 

phase, and by size of herd:

Percent Breeding Herds

Herd Size (number sows and gilts)

Small

(fewer than 250)

Medium

(250–499)

Large

(500 or more) All sites

Pig-flow 

management Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Continuous flow 65.2 (2.0) 71.6 (5.2) 87.5 (2.3) 73.7 (1.8)

All swine removed 

without cleaning and 

disinfecting room 

5.2 (0.9) 3.2 (1.9) 0.9 (0.5) 3.5 (0.6)

All-in/all-out by room 9.1 (1.2) 15.3 (3.9) 7.9 (1.7) 9.1 (1.0)

All-in/all-out 

by building 13.3 (1.4) 5.5 (2.5) 2.7 (0.9) 9.0 (1.0)

All-in/all-out by site 1.2 (0.4) 1.6 (1.4) 0.6 (0.4) 1.0 (0.3)

NA 6.0 (1.0) 2.8 (1.8) 0.3 (0.3) 3.8 (0.6)

Total 100.0 100.0 100.0 100.0
USDA APHIS VS / 35 

Section I: Population Estimates–B. Breeding Herd Management and Productivity

Over 90 percent of all sows and gilts were in continuous flow gestation facilities.

B.4.k. Percentage of sows and gilts by pig-flow management used for sows and gilts in 

the gestation phase, and by herd size:

Percent Sows and Gilts

Herd Size (number sows and gilts)

Small 

(fewer than 250)

Medium

(250–499)

Large

(500 or more) All sites

Pig-flow 

management Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Continuous flow 68.7 (2.8) 74.1 (5.7) 92.4 (2.0) 91.2 (2.0)

All swine removed 

without cleaning and 

disinfecting

3.6 (0.9) 2.9 (2.0) 0.5 (0.4) 0.7 (0.4)

All-in/all-out by room 11.0 (2.1) 13.4 (4.1) 5.3 (1.6) 5.6 (1.5)

All-in/all-out 

by building 10.6 (1.9) 5.3 (2.6) 0.9 (0.3) 1.3 (0.4)

All-in/all-out by site 2.0 (0.9) 1.6 (1.5) 0.9 (0.7) 0.9 (0.7)

NA 4.2 (1.0) 2.8 (2.0) 0.0 (—) 0.2 (0.1)

Total 100.0 100.0 100.0 100.0
36 / Swine 2012

Section I: Population Estimates–B. Breeding Herd Management and Productivity

5. Farrowing housing and pig flow

B.5.a. Percentage of sites with a farrowing phase* by size of site:

Percent Sites

Size of Site (total inventory)

Small

(fewer than 2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

32.7 (2.3) 8.0 (1.7) 23.3 (6.2) 20.8 (2.6)

*From December 1, 2011, through May 31, 2012.

Note: Tables B.5.b. through B.5.l. refer to breeding herds on the 20.8 percent of sites that 

had a farrowing phase from December 1, 2011, through May 31, 2012.

Overall, 85.7 percent of breeding herds farrowed sows in indoor facilities only. This 

percentage increased to over 95 percent for medium and large herds. Almost one-fourth 

of small herds had farrowing facilities with some outdoor access.

B.5.b. Percentage of breeding herds by facility type used for sows and gilts in the 

farrowing phase, and by size of site:

Percent Breeding Herds

Herd Size (number sows and gilts)

Small 

(fewer than 250)

Medium

(250–499)

Large

(500 or more) All sites

Facility type Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Total confinement 58.8 (2.1) 81.3 (4.6) 90.4 (5.3) 71.8 (2.1)

Open building with 

natural ventilation and 

no outside access

17.0 (1.6) 14.0 (4.0) 9.0 (5.3) 13.9 (2.0)

Open building with 

outside access 15.1 (1.6) 4.8 (2.4) 0.2 (0.2) 9.0 (1.0)

Lot with hut 

or no building 3.3 (0.8) 0.0 (—) 0.0 (—) 1.9 (0.4)

Pasture with hut 

or no building 5.8 (1.0) 0.0 (—) 0.3 (0.3) 3.4 (0.6)

Total 100.0 100.0 100.0 100.0
USDA APHIS VS / 37 

Section I: Population Estimates–B. Breeding Herd Management and Productivity

Almost all sows and gilts (98.9 percent) farrowed in facilities with no outside access.

B.5.c. Percentage of sows and gilts by facility type used for sows and gilts in the 

farrowing phase, and by size of site:

Percent Sows and Gilts

Herd Size (number sows and gilts)

Small 

(fewer than 250)

Medium

(250–499)

Large

(500 or more) All sites

Facility type Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Total confinement 71.0 (2.4) 81.7 (4.9) 89.6 (7.5) 88.6 (6.9)

Open building with 

natural ventilation and 

no outside access

12.5 (1.7) 13.5 (4.3) 10.1 (7.5) 10.3 (7.0)

Open building with 

outside access 9.4 (1.4) 4.8 (2.6) 0.1 (0.1) 0.6 (0.1)

Lot with hut or no 

building 3.5 (1.2) 0.0 (—) 0.0 (—) 0.2 (0.1)

Pasture with hut

or no building 3.7 (0.9) 0.0 (—) 0.3 (0.3) 0.4 (0.2)

Total 100.0 100.0 100.0 100.0
38 / Swine 2012

Section I: Population Estimates–B. Breeding Herd Management and Productivity

Mesh was the flooring type used by the highest percentages of breeding herd sites with 

a farrowing phase, regardless of facility type, although more than one-quarter of herds 

were in farrowing facilities with completely slatted flooring. 

B.5.d. Percentage of breeding herds by primary flooring type used for sows and gilts in 

the farrowing phase, and by type of facility:

Percent Breeding Herds

Facility Type

No outside 

access

Open building 

with outside 

access Lot or pasture All sites

Flooring type Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Solid surface 4.1 (1.0) 30.8 (5.7) 14.4 (6.8) 8.2 (1.3)

Partial slats 5.5 (1.1) 3.7 (1.9) 0.0 (—) 5.0 (0.9)

Completely slatted 27.6 (3.8) 19.3 (4.2) 15.2 (6.4) 25.9 (3.2)

Mesh 60.6 (4.0) 39.1 (6.0) 24.8 (7.8) 56.0 (3.5)

Dirt/pasture 0.0 (—) 5.7 (2.5) 45.6 (9.1) 2.8 (0.7)

Other 2.2 (1.6) 1.4 (1.2) 0.0 (—) 2.0 (1.3)

Total 100.0 100.0 100.0 100.0
USDA APHIS VS / 39 

Section I: Population Estimates–B. Breeding Herd Management and Productivity

For the 30.9 percent of breeding herds that used farrowing facilities with partially or 

completely slatted floors (see table B.5.d), about half (50.2 percent=15.5/30.9) used 

metal for slatted flooring material . 

B.5.e. Percentage of breeding herds by primary slatted flooring material used for sows 

and gilts in the farrowing phase, and by type of facility:

Percent Breeding Herds

Facility Type

No outside 

access

Open building 

with outside 

access Lot or pasture All sites

Slatted flooring 

material Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Concrete 5.8 (1.1) 2.3 (1.5) 4.3 (3.7) 5.3 (1.0)

Metal 16.4 (3.9) 13.1 (3.6) 6.1 (3.6) 15.5 (3.2)

Plastic 9.6 (1.5) 5.4 (2.3) 4.9 (4.3) 8.8 (1.3)

Wood 0.3 (0.3) 0.0 (—) 0.0 (—) 0.2 (0.2)

Other 1.0 (0.4) 2.1 (1.3) 0.0 (—) 1.1 (0.4)

Mesh or 

solid floor 66.9 (3.8) 77.0 (4.5) 84.8 (6.4) 69.1 (3.2)

Total 100.0 100.0 100.0 100.0
40 / Swine 2012

Section I: Population Estimates–B. Breeding Herd Management and Productivity

Almost 90 percent of breeding herds with a farrowing phase (88.1 percent) used 

individual housing for farrowing sows. Almost 15 percent of small sites (14.5 percent) 

used pen farrowing.

B.5.f. Percentage of breeding herds by primary type of housing used for sows and gilts in 

the farrowing phase, and by size of site:

Percent Breeding Herds

Herd Size (number sows and gilts)

Small 

(fewer than 250)

Medium

(250–499)

Large

(500 or more) All sites

Housing type Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Individual 79.8 (1.7) 100.0 (—) 99.0 (0.5) 88.1 (1.2)

Group 14.5 (1.5) 0.0 (—) 1.0 (0.5) 8.6 (1.0)

Other 5.7 (1.0) 0.0 (—) 0.0 (—) 3.3 (0.6)

Total 100.0 100.0 100.0 100.0

Nearly all sows and gilts (98.6 percent) farrowed in individual housing.

B.5.g. Percentage of sows and gilts in the farrowing phase by primary housing type used 

for sows and gilts, and by type of facility:

Percent Sows and Gilts

Facility Type

No outside 

access

Open building 

with outside 

access Lot or pasture All sites

Housing type Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Individual 99.4 (0.4) 80.6 (4.3) 55.6 (14.4) 98.6 (0.5)

Group 0.5 (0.4) 13.9 (3.8) 35.8 (16.2) 1.2 (0.5)

Other 0.0 (0.0) 5.5 (2.3) 8.6 (3.6) 0.2 (0.1)

Total 100.0 100.0 100.0 100.0
USDA APHIS VS / 41 

Section I: Population Estimates–B. Breeding Herd Management and Productivity

Almost half of breeding herds (49.1 percent) used a pit-holding waste management 

system in farrowing facilities. Similar percentages of small breeding herds used 

mechanical scraper/tractor, hand-cleaned, or flushed, under slats. A substantial 

percentage of medium and large breeding herds used flush under slats.

B.5.h. Percentage of breeding herds primary waste management system used in the 

farrowing facility, and by size of herd:

Percent Breeding Herds

Herd Size (number of sows and gilts)

Small

(fewer 

than 250)

Medium

(250-499)

Large

(500 or more) All sites

Waste management 

system Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

None 5.0 (1.5) 0.0 (—) 0.0 (—) 1.5 (0.5)

Pit-holding 45.4 (3.6) 54.3 (6.3) 50.1 (5.8) 49.1 (3.6)

Mechanical 

scraper/tractor 14.9 (2.7) 12.0 (3.9) 1.8 (0.9) 6.9 (1.2)

Hand-cleaned 14.9 (2.6) 1.2 (1.0) 0.3 (0.3) 4.9 (0.9)

Flush, under slats 15.6 (2.6) 27.7 (5.6) 44.8 (6.1) 33.9 (4.2)

Flush, open gutter 1.9 (0.9) 4.8 (3.1) 1.7 (0.9) 2.0 (0.7)

Other 2.4 (1.3) 0.0 (—) 1.3 (0.5) 1.5 (0.5)

Total 100.0 100.0 100.0 100.0
42 / Swine 2012

Section I: Population Estimates–B. Breeding Herd Management and Productivity

Over half of breeding herds in South region (58.4 percent) used a flush, under slats 

waste management system in farrowing facilities. A higher percentage of herds in the 

Midwest and East regions used pit-holding systems (49.5 and 65.3 percent, respectively) 

compared with breeding herds in the South region (32.9 percent).

B.5.i. Percentage of breeding herds by primary waste management system used in the 

farrowing facility, and by region:

Percent Sites

Region

Midwest East South

Waste management system Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

None 0.4 (0.4) 1.3 (0.8) 3.5 (1.6)

Pit-holding 49.5 (3.7) 65.3 (3.8) 32.9 (9.5)

Mechanical scraper/tractor 12.3 (2.2) 3.3 (1.3) 2.6 (1.3)

Hand cleaned 6.9 (1.6) 4.9 (1.6) 2.1 (1.2)

Flush, under slats 25.6 (3.5) 21.4 (3.3) 58.4 (9.8)

Flush, open gutter 2.2 (1.0) 3.3 (1.7) 0.6 (0.6)

Other 3.1 (1.0) 0.7 (0.6) 0.0 (—)

Total 100.0 100.0 100.0
USDA APHIS VS / 43 

Section I: Population Estimates–B. Breeding Herd Management and Productivity

A relatively small percentage of breeding herds (27.9 percent) used continuous-flow 

management in farrowing facilities; small herds accounted for the highest percentage of 

herds that used continuous-flow management. Over 80 percent of large herds used all-in/

all-out by room management, and more than one-fourth of small and medium herds used 

all-in/all-out by building.

B.5.j. Percentage of breeding herds by pig-flow management used in the farrowing 

phase, and by size of herd:

Percent Breeding Herds

Herd Size (number sows and gilts)

Small 

(fewer 

than 250)

Medium

(250–499)

Large

(500 or more) All sites

Pig-flow management Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Continuous flow 38.4 (2.0) 20.7 (5.9) 12.5 (2.5) 27.9 (2.0)

All swine removed 

without cleaning and 

disinfecting room 

4.3 (0.8) 2.6 (1.5) 0.4 (0.3) 2.8 (0.5)

All-in/all-out by room 25.4 (1.8) 46.7 (6.0) 81.5 (3.3) 47.0 (2.9)

All-in/all-out by building 25.7 (1.8) 28.3 (5.4) 4.2 (1.3) 18.2 (1.5)

All-in/all-out by site 2.2 (0.6) 1.8 (1.6) 1.0 (0.5) 1.7 (0.4)

NA 4.0 (0.8) 0.0 (—) 0.4 (0.3) 2.4 (0.5)

Total 100.0 100.0 100.0 100.0
44 / Swine 2012

Section I: Population Estimates–B. Breeding Herd Management and Productivity

Only 12.0 percent of sows and gilts in the farrowing phase were in continuous-flow 

facilities. Over 80 percent of sows and gilts were in facilities managed all-in/all-out by 

room.

B.5.k. Percentage of sows and gilts by pig-flow management used in the farrowing 

phase, and by size of herd:

Percent Sows and Gilts

Herd Size (number sows and gilts)

Small 

(fewer than 250)

Medium

(250–499)

Large

(500 or more) All sites

Pig-flow management Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Continuous flow 33.7 (2.6) 23.2 (7.4) 10.6 (3.1) 12.0 (3.0)

All swine removed 

without cleaning and 

disinfecting room

3.9 (1.0) 2.0 (1.3) 0.2 (0.1) 0.4 (0.2)

All-in/all-out by room 32.1 (2.8) 46.4 (7.0) 83.6 (4.3) 80.4 (4.2)

All-in/all-out by building 25.6 (2.5) 26.9 (5.6) 4.7 (2.9) 6.2 (2.7)

All-in/all-out by site 1.6 (0.6) 1.5 (1.4) 0.8 (0.5) 0.9 (0.5)

NA 3.0 (0.8) 0.0 (—) 0.0 (—) 0.1 (0.0)

Total 100.0 100.0 100.0 100.0
USDA APHIS VS / 45 

Section I: Population Estimates–B. Breeding Herd Management and Productivity

6. Farrowing productivity and preweaning death loss

The average number of litters per sow per year increased as herd size increased.

B.6.a. Breeding herd average litters per sow, per year, by size of herd:

Herd Average Litters per Sow per Year

Herd Size (number sows and gilts)

Small 

(fewer than 250)

Medium

(250–499)

Large

(500 or more) All sites

No.

Std. 

error No.

Std. 

error No.

Std. 

error No.

Std. 

error

2.1 (0.0) 2.3 (0.0) 2.4 (0.0) 2.2 (0.0)

Overall, 11.3 piglets were born per litter, of which 10.3 were born alive and 9.3 were 

weaned.

B.6.b. Average per litter productivity1

:

Average Per Litter Productivity

Measure (per litter) Number Std. error Percent2 Std. error

Stillbirths and mummies 1.0 (0.0) 8.6 (0.2)

Born alive 10.3 (0.2) 91.4 (0.2)

 Total born 11.2 (0.2) 100.0 (0.0)

Preweaning deaths 1.0 (0.1) 9.7 (0.6)

Weaned 9.3 (0.1) 90.3 (0.6)

 Total born alive 10.3 (0.2) 100.0 (0.0)

1

From December 1, 2011, through May 31, 2012.

2

Estimated percentages shown differ from percentages calculated from estimates in number column due to 

rounding.
46 / Swine 2012

Section I: Population Estimates–B. Breeding Herd Management and Productivity

Large breeding herds had substantially more pigs born alive per litter and weaned more 

pigs per litter than small and medium sites. The number and percentage of preweaning 

deaths per litter were higher in large herds than in small and medium herds. Note: Some 

standard errors round to 0. See “Terms Used in This Report” for explanation.

B.6.c. Average per litter productivity* by size of breeding herd:

Average Per Litter Productivity

Herd Size (number sows and gilts)

Small (fewer than 250) Medium (250–499) Large (500 or more)

Measure 

(per litter) No.

Std. 

err. Pct.

Std. 

err. No.

Std. 

err. Pct.

Std. 

err. No.

Std. 

err. Pct.

Std. 

err.

Stillbirths and 

mummies 0.9 (0.0) 8.8 (0.3) 0.9 (0.1) 7.9 (0.6) 1.1 (0.1) 8.5 (0.4)

Born alive 9.4 (0.2) 91.2 (0.3) 10.2 (0.2) 92.1 (0.6) 11.7 (0.2) 91.5 (0.4)

 Total born 10.3 (0.2) 100.0 (0.0) 11.1 (0.2) 100.0 (0.0) 12.7 (0.2) 100.0 (0.0)

Preweaning 

deaths 0.7 (0.0) 7.6 (0.5) 0.9 (0.1) 8.6 (0.6) 1.5 (0.1) 12.6 (0.9)

Weaned 8.7 (0.2) 92.4 (0.5) 9.4 (0.1) 91.4 (0.6) 10.2 (0.1) 87.4 (0.9)

 Total born 

alive 9.4 (0.2) 100.0 (0.0) 10.2 (0.2) 100.0 (0.0) 11.7 (0.2) 100.0 (0.0)

*From December 1, 2011, through May 31, 2012.
USDA APHIS VS / 47 

Section I: Population Estimates–B. Breeding Herd Management and Productivity

0

5

10

15

20

Large (500 or more)

Medium (250-499)

Small (fewer than 250)

Percent

Average per litter productivity* by size of breeding herd

Total number born Number born alive

10.2

8.7

9.5

10.3 10.2

Measure (per litter)

Number weaned

Size of breeding herd

(number sows and gilts)

11.7 11.1

12.7

9.4

*From December 1, 2011, through May 31, 2012.
48 / Swine 2012

Section I: Population Estimates–B. Breeding Herd Management and Productivity

Nearly half of all preweaning deaths were attributed to crushing by sow. Failure to thrive 

and scours accounted for 15.1 and 10.2 percent of preweaning deaths, respectively. 

Other known problems mostly consisted of low viability pigs.

B.6.d. Percentage of preweaning deaths*, by producer-identified cause and by size of 

herd:

Percent Preweaning Deaths

Herd Size (number sows and gilts)

Small

(fewer than 250)

Medium

(250–499)

Large

(500 or more) All sites

Cause Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Scours 13.1 (2.3) 9.3 (2.1) 10.2 (2.2) 10.2 (2.1)

Crushing 

by sow 52.6 (3.1) 54.7 (3.1) 48.7 (2.4) 48.8 (2.3)

Failure to thrive 15.1 (2.0) 19.4 (2.7) 15.0 (1.9) 15.1 (1.8)

Respiratory 

problems 6.1 (2.9) 6.7 (1.8) 4.3 (1.3) 4.4 (1.3)

Other known 

problems 2.6 (0.7) 3.7 (1.3) 16.1 (5.1) 15.8 (5.0)

Unknown 

problems 10.5 (2.5) 6.1 (1.5) 5.7 (1.4) 5.8 (1.4)

Total 100.0 100.0 100.0 100.0

*Percentage of preweaning death summed over all sites from December 1, 2011, through May 31, 2012.
USDA APHIS VS / 49 

Section I: Population Estimates–B. Breeding Herd Management and Productivity

0 10 20 30 40 50 60

Percent

Percentage of preweaning deaths,* by producer-identified cause

Scours

Crushing

by sow

Failure

to thrive

Respiratory

problems

Other known

problems

Unknown

problems

*Percentage of preweaning death estimate over all sites from December 1, 2011, through May 31, 2012.

48.8

15.8

15.1

10.2

5.8

4.4

Cause
50 / Swine 2012

Section I: Population Estimates–B. Breeding Herd Management and Productivity

7. Weaning

On average, medium and large breeding herds weaned pigs at 22 and 21 days, 

respectively, whereas small herds did not wean until pigs were over 30 days of age. For 

all pigs weaned, the average weaning age was 20.8 days.

B.7.a. Site average age (in days) of piglets at weaning, by size of breeding herd:

Site Average Age (days)

Herd Size (number sows and gilts)

Small

(fewer than 250)

Medium

(250–499)

Large

(500 or more) All sites Pig average

Avg.

Std. 

error Avg.

Std.

error Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error

30.2 (0.4) 22.0 (0.5) 20.9 (0.2) 26.3 (0.4) 20.8 (0.2)

Nearly 60 percent of small breeding herds weaned pigs at 28 or more days of age, 

whereas less than 2 percent of large herds weaned at that age. Almost half of large 

breeding herds and more than one-third of medium herds weaned at 20 days or less.

B.7.b. Percentage of breeding herds by age piglets were weaned, and by size of site:

Percent Breeding Herds

Herd Size (number sows and gilts)

Small

(fewer than 250)

Medium

(250–499)

Large

(500 or more) All sites

Weaning age 

(days) Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Less than 16 0.6 (0.3) 1.2 (1.1) 0.2 (0.1) 0.5 (0.2)

16–20 8.5 (1.2) 34.3 (6.2) 46.2 (6.8) 23.8 (2.0)

21–27 31.7 (1.9) 52.1 (6.2) 51.6 (7.0) 40.3 (3.2)

28–34 29.6 (1.9) 9.1 (3.2) 1.6 (0.6) 18.1 (1.5)

35 or more 29.6 (1.9) 3.3 (2.0) 0.3 (0.3) 17.2 (1.4)

Total 100.0 100.0 100.0 100.0
USDA APHIS VS / 51 

Section I: Population Estimates–B. Breeding Herd Management and Productivity

8. Sow and gilt management 

The average parity in large breeding herds was lower than in small breeding herds.

B.8.a. Site average parity of breeding-age females, by size of herd:

Herd Average Parity

Herd Size (number sows and gilts)

Small

(fewer than 250)

Medium

(250–499)

Large

(500 or more) All sites

Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error

3.6 (0.1) 3.5 (0.2) 2.9 (0.2) 3.3 (0.1)

Medium breeding herds had lower sow mortality than small or large herds. Large herds 

culled a higher percentage of breeding females (25.6 percent) compared with small and 

medium breeding herds 

(19.2 and 16.3 percent, respectively) over the 6-month period.

B.8.b. Breeding-age females that died or were culled,* as a percentage of June 1, 2012, 

sow and gilt inventory, by size of herd:

Percent Breeding-Age Females

Herd Size (number sows and gilts)

Small

(fewer than 250)

Medium

(250–499)

Large

(500 or more) All sites

Reason 

removed Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Died 3.8 (0.2) 2.8 (0.2) 4.4 (0.3) 4.3 (0.3)

Culled 19.2 (1.0) 16.3 (1.1) 25.6 (1.2) 25.1 (1.1)

*From December 1, 2011, through May 31, 2012. 
52 / Swine 2012

Section I: Population Estimates–B. Breeding Herd Management and Productivity

Though culling rates differed by size of breeding herd, the reasons for culling did not. 

Across herds sizes, the highest percentages of sows were culled for old age and for 

reproductive failure. Relatively small percentages of sows were culled for lameness or for 

injury. Other reasons for culling were mostly unknown.

B.8.c. Percentage of culled breeding-age females, by reason culled1 and by size of site:

Percent Culled Females

Herd Size (number sows and gilts)

Small

(fewer than 250)

Medium

(250–499)

Large

(500 or more) All sites

Reason culled1 Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Old age 40.2 (3.2) 42.6 (4.1) 35.0 (3.7) 35.2 (3.6)

Lameness 8.6 (1.2) 10.3 (1.3) 6.7 (1.2) 6.8 (1.2)

Performance2 11.7 (1.3) 18.2 (2.5) 13.4 (2.4) 13.5 (2.3)

Reproductive failure 25.8 (3.5) 22.6 (2.4) 25.5 (3.6) 25.4 (3.5)

Injury 3.0 (0.5) 4.5 (0.7) 2.5 (0.6) 2.5 (0.6)

Other reason 10.6 (3.3) 1.9 (0.9) 16.8 (7.1) 16.5 (6.9)

Total 100.0 100.0 100.0 100.0

1

Percentage of preweaning deaths summed over sites from December 1, 2011, through May 31, 2012. 2

Small litter size, high preweaning mortality, or low birth weight.
USDA APHIS VS / 53 

Section I: Population Estimates–B. Breeding Herd Management and Productivity

0 10 20 30 40

Percent

Percentage of culled breeding-age females, by reason culled

Other

reason

Old age

Performance2

Injury

Reproductive

failure

Lameness

1

Percentage of preweaning deaths summed over sites from December 1, 2011, through May 31, 2012. 2

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

35.2

25.4

16.5

13.5

6.8

2.5

Reason

culled1
54 / Swine 2012

Section I: Population Estimates–B. Breeding Herd Management and Productivity

More than half of small and medium breeding herds and about one-third of large herds 

had a sow mortality of less than 3 percent. 

B.8.d. Percentage of breeding herds by the percentage of breeding-age females that 

died,* and by size of herd:

Percent Breeding Herds

Herd Size (number sows and gilts)

Small

(fewer than 250)

Medium

(250–499)

Large

(500 or more) All sites

Percent 

that died Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

0 36.8 (2.0) 3.2 (2.0) 1.4 (0.6) 21.8 (1.6)

0.1–2.9 18.5 (1.6) 57.1 (6.3) 32.3 (5.1) 26.1 (1.9)

3.0–4.9 15.8 (1.5) 27.9 (6.4) 28.1 (5.0) 21.1 (2.1)

5.0–9.9 18.9 (1.7) 11.8 (3.2) 36.0 (6.8) 24.5 (3.0)

10.0 or more 10.1 (1.3) 0.0 (—) 2.1 (0.9) 6.5 (0.9)

Total 100.0 100.0 100.0 100.0

*From December 1, 2011, through May 31, 2012. 
USDA APHIS VS / 55 

Section I: Population Estimates–B. Breeding Herd Management and Productivity

Almost one-fourth of small breeding herds (23.2 percent) did not cull any sows from 

December 1, 2011, through May 31, 2012; 74.9 percent of medium herds and 

92.9 percent of large herds culled 10 percent or more breeding-age females during the 

6-month period.

B.8.e. Percentage of breeding herds by percentage of breeding-age females culled,* and 

by size of herd:

Percent Breeding Herds

Herd Size (number sows and gilts)

Small

(fewer than 250)

Medium

(250–499)

Large

(500 or more) All sites

Percent culled Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

0 23.2 (1.7) 1.6 (1.4) 0.3 (0.3) 13.5 (1.2)

0.1–9.9 15.1 (1.5) 23.6 (5.3) 6.8 (1.5) 12.7 (1.2)

10.0–19.9 27.2 (1.9) 47.4 (6.2) 26.6 (4.7) 28.4 (2.1)

20.0 or more 34.5 (2.0) 27.5 (5.0) 66.3 (5.4) 45.4 (3.0)

Total 100.0 100.0 100.0 100.0

*From December 1, 2011, through May 31, 2012. 
56 / Swine 2012

Section I: Population Estimates–B. Breeding Herd Management and Productivity

The large majority of breeding herds dewormed sows. A lower percentage of large herds 

routinely treated sows for mange/lice compared with small and medium herds.

B.8.f. Percentage of breeding herds by preventive treatments administered to sows,* and 

by size of site:

Percent Breeding Herds

Herd Size (number sows and gilts)

Small

(fewer than 250)

Medium

(250–499)

Large

(500 or more) All sites

Preventive 

treatment Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Deworming 85.6 (2.5) 89.6 (3.4) 78.8 (4.6) 82.1 (2.7)

Mange/lice treatment 67.7 (3.2) 56.8 (6.2) 12.0 (2.3) 34.0 (3.3)

*From December 1, 2011, through May 31, 2012.

Nearly three-fourths of breeding herds (72.1 percent) dewormed boars.

B.8.g. Percentage of breeding herds by preventive treatments administered to boars,*

and by size of herd:

Percent Breeding Herds

Herd Size (number sows and gilts)

Small

(fewer than 250)

Medium

(250–499)

Large

(500 or more) All sites

Preventive 

treatment Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Deworming 75.9 (3.1) 76.1 (5.2) 69.4 (5.5) 72.1 (3.3)

Mange/lice treatment 62.7 (3.4) 55.4 (6.2) 9.9 (2.0) 31.2 (3.1)

*From December 1, 2011, through May 31, 2012.
USDA APHIS VS / 57 

Section I: Population Estimates–B. Breeding Herd Management and Productivity

Less than 7 percent of large breeding herds routinely dewormed piglets or treated them 

for mange/lice, compared with more than 37 percent of small and medium herds. Less 

than 10 percent of all herds provided piglets with oral vitamin D. More than 95 percent of 

medium and large herds provided iron to piglets.

B.8.h. Percentage of breeding herds by preventive treatments administered to piglets,*

and by size of herd:

Percent Breeding Herds

Herd Size (number sows and gilts)

Small

(fewer 

than 250)

Medium

(250–499)

Large

(500 or more) All sites

Preventive 

treatment Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Deworming 58.4 (3.6) 43.4 (6.1) 6.9 (1.6) 26.9 (2.7)

Mange/lice treatment 46.2 (3.6) 37.1 (6.5) 3.4 (1.1) 20.3 (2.3)

Oral vitamin D 8.1 (1.1) 15.9 (4.9) 9.5 (1.9) 9.1 (1.0)

Iron (oral/injection) 82.1 (1.6) 95.1 (2.5) 96.5 (1.1) 88.2 (1.1)

*From December 1, 2011, through May 31, 2012.
58 / Swine 2012

Section I: Population Estimates–B. Breeding Herd Management and Productivity

More than three-fourths of breeding animals were routinely dewormed. Almost all piglets 

(97.0 percent) received iron.

B.8.i. Percentage of pigs by preventive treatment1 and by type of pig:

Percent Pigs

Type of Pig

Sows2 Boars3 Piglets4

Preventive treatment Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Deworming 78.3 (4.9) 77.2 (5.0) 4.9 (1.1)

Mange/lice treatment 8.2 (1.5) 22.3 (4.1) 2.4 (0.6)

Oral vitamin D 

(as young pigs) NA NA 9.5 (2.7)

Iron (oral/injection) NA NA 97.0 (1.3)

1

From December 1, 2011, through May 31, 2012.

2

As a percentage of sow and bred gilt inventory on June 1, 2012.

3

As a percentage of boar inventory on June 1, 2012.

4

As a percentage of pigs born alive (6 months).
USDA APHIS VS / 59 

Section I: Population Estimates–C. Nursery Phase

Percentage of sites that had a nursery phase,* by size of site:

Percent Sites

Size of Site (total inventory)

Small 

(fewer than 2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

28.4 (2.4) 14.9 (3.1) 25.5 (7.7) 22.3 (3.0)

*From December 1, 2011, through May 31, 2012.

Note: All remaining tables in this section refer to the 22.3 percent of sites with a nursery 

phase from December 1, 2011, through May 31, 2012. Site size categories are based on 

total inventory.

1. Facilities and pig flow

Over 95 percent of all sites with a nursery phase housed nursery pigs in facilities with no 

outside access.

C.1.a. Percentage of sites by facility type used most for the nursery phase, and by size of 

site:

Percent Sites

Size of Site (total inventory)

Small 

(fewer 

than 2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Facility type Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Total confinement 86.3 (1.8) 96.5 (1.4) 98.2 (1.8) 91.5 (1.3)

Open building 

with natural 

ventilation and no 

outside access

7.8 (1.3) 3.5 (1.4) 1.8 (1.8) 5.4 (1.0)

Open building 

with outside 

access

4.9 (1.1) 0.0 (—) 0.0 (—) 2.5 (0.6)

Lot with hut 

or no building 0.6 (0.3) 0.0 (—) 0.0 (—) 0.3 (0.2)

Pasture with hut 

or no building 0.4 (0.2) 0.0 (—) 0.0 (—) 0.2 (0.1)

Total 100.0 100.0 100.0 100.0

C. Nursery 

Phase
60 / Swine 2012

Section I: Population Estimates–C. Nursery Phase

Over 99 percent of all nursery pigs were housed in facilities with no outside access.

C.1.b. Percentage of nursery pigs by facility type most used on sites with a nursery 

phase:

Percent Nursery Pigs*

Size of Site (total inventory)

Small 

(fewer 

than 2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Facility type Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Total confinement 95.6 (1.4) 96.7 (2.1) 97.6 (2.5) 97.1 (1.7)

Open building 

with natural 

ventilation and no 

outside access

2.7 (1.0) 3.3 (2.1) 2.4 (2.5) 2.7 (1.7)

Open building 

with outside 

access

1.5 (0.7) 0.0 (—) 0.0 (—) 0.2 (0.1)

Lot with hut 

or no building 0.1 (0.1) 0.0 (—) 0.0 (—) 0.0 (0.0)

Pasture with hut 

or no building 0.1 (0.1) 0.0 (—) 0.0 (—) 0.0 (0.0)

Total 100.0 100.0 100.0 100.0

*As a percentage of pigs entering the nursery phase.
USDA APHIS VS / 61 

Section I: Population Estimates–C. Nursery Phase

For the 96.9 percent of nursery sites with indoor-only facilities, the majority (92.1 percent) 

used mesh or completely slatted flooring. For the 3.0 percent of sites with nursery 

facilities that had outdoor access, more than half used solid surface flooring.

C.1.c. Percentage of sites by primary flooring type used in the nursery phase, and by 

type of facility:

Percent Sites

Facility Type

No outside 

access

Outside 

access All sites

Flooring type Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Solid surface 2.4 (0.6) 51.9 (13.5) 3.2 (0.7)

Partial slats 3.2 (0.7) 0.0 (—) 3.2 (0.7)

Completely slatted 41.3 (5.8) 0.0 (—) 40.6 (5.6)

Mesh 50.8 (6.7) 11.6 (7.5) 50.2 (6.7)

Dirt/pasture 0.0 (—) 36.4 (12.5) 0.6 (0.3)

Other 2.3 (1.0) 0.0 (—) 2.3 (1.0)

Total 100.0 100.0 100.0
62 / Swine 2012

Section I: Population Estimates–C. Nursery Phase

C.1.d. Percentage of sites by primary slatted flooring material used in the nursery phase, 

and by type of facility:

Percent Sites

Facility Type

No outside 

access

Outside 

access All sites

Slatted flooring 

material Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Concrete 8.7 (1.9) 0.0 (0.0) 8.6 (1.9)

Metal 5.1 (1.3) 0.0 (0.0) 5.0 (1.3)

Plastic 29.6 (4.4) 0.0 (0.0) 29.1 (4.3)

Other 1.0 (0.4) 0.0 (0.0) 1.0 (0.4)

Mesh or solid floor* 55.6 (6.2) 100.0 (0.0) 56.4 (6.0)

*May not match table C.1.c due to item nonresponse.
USDA APHIS VS / 63 

Section I: Population Estimates–C. Nursery Phase

The highest percentage of sites used either pit-holding or flush under slats for waste 

management, regardless of site size. 

C.1.e. Percentage of sites by primary waste management system used in the nursery 

facility, and by size of site:

Percent Sites

Size of Site (total inventory)

Small 

(fewer 

than 2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Waste 

management 

system Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

None 1.5 (0.6) 0.0 (—) 0.3 (0.3) 0.7 (0.3)

Pit-holding 58.8 (6.1) 46.1 (9.5) 78.2 (7.5) 59.3 (4.8)

Mechanical 

scraper/tractor 8.4 (1.7) 6.8 (2.2) 1.1 (0.6) 6.2 (1.2)

Hand cleaned 3.0 (0.8) 0.3 (0.2) 0.0 (—) 1.4 (0.4)

Flush, under slats 24.4 (7.3) 46.0 (10.9) 20.4 (7.2) 30.4 (5.6)

Flush, open gutter 3.3 (1.1) 0.7 (0.6) 0.0 (—) 1.7 (0.6)

Other 0.6 (0.4) 0.2 (0.2) 0.0 (—) 0.3 (0.2)

Total 100.0 100.0 100.0 100.0
64 / Swine 2012

Section I: Population Estimates–C. Nursery Phase

A higher percentage of nursery sites in the South region used a flush, under slats system 

compared with sites in the Midwest and East regions. Pit-holding was used by a higher 

percentage of sites in the Midwest and East regions than in the South region.

C.1.f. Percentage of sites by primary waste management system used in the nursery 

facility, and by region:

Percent Sites

Region

Midwest East South

Waste management system Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

None 0.7 (0.4) 1.1 (0.7) 0.4 (0.4)

Pit-holding 64.5 (3.2) 75.3 (3.5) 38.8 (12.8)

Mechanical scraper/tractor 9.7 (1.6) 4.1 (1.5) 1.8 (1.1)

Hand cleaned 1.2 (0.5) 2.7 (1.1) 0.9 (0.7)

Flush, under slats 20.9 (3.0) 14.9 (2.7) 57.6 (12.9)

Flush, open gutter 2.3 (1.0) 1.8 (1.0) 0.5 (0.5)

Other 0.7 (0.3) 0.0 (—) 0.0 (—)

Total 100.0 100.0 100.0
USDA APHIS VS / 65 

Section I: Population Estimates–C. Nursery Phase

Almost 95 percent of large sites with a nursery moved pigs all-in/all-out by room or by 

building. About one of five small and medium sites used continuous flow management.

C.1.g. Percentage of sites by pig flow management in the nursery phase, and by size of 

site:

Percent Sites

Size of Site (total inventory)

Small 

(fewer 

than 2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Pig-flow management Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Continuous flow 19.0 (2.2) 17.5 (10.0) 3.2 (1.2) 15.4 (2.9)

All swine removed 

without cleaning and 

disinfecting room

3.3 (0.8) 0.3 (0.3) 0.0 (—) 1.8 (0.4)

All-in/all-out by room 25.8 (2.9) 25.6 (5.8) 55.9 (11.3) 31.7 (3.4)

All-in/all-out by building 37.9 (3.6) 50.1 (8.0) 37.8 (11.6) 41.2 (3.7)

All-in/all-out by site 13.6 (5.8) 6.5 (2.5) 3.1 (1.7) 9.6 (3.0)

NA 0.5 (0.3) 0.0 (—) 0.0 (—) 0.3 (0.1)

Total 100.0 100.0 100.0 100.0
66 / Swine 2012

Section I: Population Estimates–C. Nursery Phase

More than 80 percent of nursery pigs were moved all-in/all-out by room or by building.

C.1.h. Percentage of nursery pigs by pig-flow management used in the nursery phase, 

and by size of site:

Percent Nursery Pigs*

Size of Site (total inventory)

Small 

(fewer 

than 2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Pig-flow management Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Continuous flow 5.0 (1.6) 23.3 (13.5) 2.7 (1.5) 9.4 (4.6)

All swine removed 

without cleaning and 

disinfecting room

1.3 (0.5) 0.2 (0.2) 0.0 (—) 0.2 (0.1)

All-in/all-out by room 21.4 (6.4) 19.7 (7.7) 44.2 (13.2) 33.8 (7.8)

All-in/all-out by building 39.0 (11.2) 47.8 (11.8) 49.4 (13.6) 47.4 (8.6)

All-in/all-out by site 32.9 (17.7) 8.9 (4.7) 3.7 (3.0) 9.1 (3.3)

No housing 0.3 (0.3) 0.0 (—) 0.0 (—) 0.0 (0.0)

Total 100.0 100.0 100.0 100.0

*As a percentage of pigs entering the nursery phase.
USDA APHIS VS / 67 

Section I: Population Estimates–C. Nursery Phase

2. Sourcing of nursery pigs

Less than 1 percent of sites with a nursery received pigs from an auction or sale barn. A 

lower percentage of large sites than medium and small sites received nursery pigs from 

sites not belonging to the operation. The most frequently reported source in the “other” 

category was sow coops.

C.2.a. Percentage of sites that brought or placed any pigs into the nursery phase,* by 

source of pigs and by size of site:

Percent Sites

Size of Site (total inventory)

Small 

(fewer 

than 2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Source Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

On-site farrowing 34.8 (4.1) 20.4 (4.6) 46.2 (11.1) 32.8 (3.8)

Other sites 

belonging to this 

operation

16.0 (3.8) 22.4 (9.5) 37.5 (11.5) 23.1 (4.7)

Other sites not 

belonging to this 

operation

45.4 (5.8) 53.4 (8.1) 15.6 (6.1) 41.0 (4.2)

Auction, sale barn, 

or livestock market 0.8 (0.4) 0.4 (0.4) 0.0 (—) 0.5 (0.2)

Other 3.9 (1.1) 5.5 (2.0) 1.0 (0.6) 3.7 (0.9)

*From December 1, 2011, through May 31, 2012.
68 / Swine 2012

Section I: Population Estimates–C. Nursery Phase

The percentages of weaned pigs entering a nursery were roughly equal between three 

sources: on-site farrowing (34.0 percent), other sites belonging to the operation 

(34.9 percent), and other sites not belonging to the operation (29.5 percent).

C.2.b. Percentage of pigs that entered the nursery phase,1 by source of pigs and by size 

of site:

Percent Pigs2

Size of Site (total inventory)

Small 

(fewer 

than 2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Source Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

On-site 16.1 (4.9) 11.9 (4.4) 49.9 (14.4) 34.0 (9.7)

Other sites 

belonging to this 

operation

18.9 (7.7) 31.8 (13.3) 40.1 (13.8) 34.9 (9.0)

Other sites not 

belonging to this 

operation

61.1 (11.9) 54.5 (12.7) 8.9 (4.3) 29.5 (7.1)

Auction, sale barn, 

or livestock market 0.4 (0.3) 0.1 (0.1) 0.0 (—) 0.1 (0.1)

Other 3.5 (1.4) 1.6 (0.8) 0.7 (0.5) 1.3 (0.5)

Total 100.0 100.0 100.0 100.0

1

From December 1, 2011, through May 31, 2012.

2

As a percentage of pigs entering the nursery phase.
USDA APHIS VS / 69 

Section I: Population Estimates–C. Nursery Phase

More than two-thirds of sites with a nursery phase used an off-site source for obtaining 

nursery pigs. 

C.2.c. Percentage of sites that used any off-site sources to obtain nursery pigs,1 by size 

of site:

Percent Sites2

Size of Site (total inventory)

Small 

(fewer than 2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

65.7 (4.1) 80.2 (4.6) 54.1 (11.1) 67.6 (3.8)

1

Placed from December 1, 2011, through May 31, 2012. 

2

Estimates differ slightly from those calculated from table C.2.a because the two tables are based on two 

different questions, and there were slight differences in the number of respondents completing the two 

questions.

More than three-fourths of sites that used an off-site source to obtain pigs used just one 

source.

C.2.d. For sites that obtained any nursery pigs from an off-site source,* percentage of 

sites by number of different sources and by size of site:

Percent Sites

Size of Site (total inventory)

Small 

(fewer 

than 2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Number off-site 

sources Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

1 87.8 (3.5) 80.3 (13.1) 56.2 (21.0) 78.8 (7.9)

2 6.8 (2.5) 18.1 (13.4) 41.1 (21.8) 17.8 (8.3)

3 or more 5.4 (2.1) 1.7 (1.0) 2.7 (2.3) 3.4 (1.1)

Total 100.0 100.0 100.0 100.0

*Placed from December 1, 2011, through May 31, 2012. 
70 / Swine 2012

Section I: Population Estimates–C. Nursery Phase

Only 3.3 percent of sites commingled nursery pigs from multiple sources.

C.2.e. For nursery pigs placed,1 percentage of sites that commingled (shared airspace) 

nursery pigs obtained from different sources in the same building or area as existing pigs, 

by type of site and by size of site.

Percent Sites

Size of Site (total inventory)

Small 

(fewer 

than 2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Site type Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Single source2 92.7 (1.8) 84.7 (10.6) 78.1 (13.4) 86.6 (5.4)

Multiple 

sources and not 

commingled

2.8 (0.9) 14.5 (10.7) 17.5 (14.0) 10.1 (5.7)

Multiple sources 

and commingled 4.5 (1.6) 0.9 (0.5) 4.4 (3.1) 3.3 (1.1)

Total 100.0 100.0 100.0 100.0

1

From December 1, 2011, through May 31, 2012. 

2

Either on-site source or one off-site source.
USDA APHIS VS / 71 

Section I: Population Estimates–C. Nursery Phase

3. Death loss

Of weaned pigs that entered a nursery phase, 3.6 percent died.

C.3.a. Percentage of nursery pigs that died in the nursery phase,1 by size of site:

Percent Nursery Pigs2

Size of Site (total inventory)

Small 

(fewer than 2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

2.7 (0.4) 3.4 (0.9) 3.9 (0.7) 3.6 (0.5)

1

From December 1, 2011, through May 31, 2012. 

2

As a percentage of pigs that entered the nursery phase.

Respiratory problems accounted for almost half of nursery pigs deaths (47.3 percent). 

Meningitis accounted for 13.0 percent of nursery pigs deaths. More than one-fifth of 

nursery pig deaths (22.1 percent) were attributed to failure to thrive. Causes of death 

were not substantially different across size of site.

C.3.b. Percentage of nursery pig deaths* by producer-identified cause and by size of site:

Percent Deaths

Size of Site (total inventory)

Small 

(fewer 

than 2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Cause Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Scours 8.6 (1.9) 9.7 (4.6) 9.3 (2.4) 9.4 (1.9)

Failure to thrive 11.8 (2.8) 12.5 (2.1) 28.1 (9.7) 22.1 (6.7)

Respiratory 

problems 46.1 (9.8) 62.8 (12.4) 40.1 (4.3) 47.3 (6.3)

CNS/meningitis 16.1 (4.1) 9.3 (3.5) 14.2 (3.7) 13.0 (2.9)

Other identified 

problems 4.8 (2.4) 0.8 (0.6) 1.7 (1.3) 1.7 (0.9)

Unknown problems 12.5 (3.7) 4.8 (2.8) 6.5 (3.7) 6.6 (2.8)

Total 100.0 100.0 100.0 100.0
72 / Swine 2012

Section I: Population Estimates–C. Nursery Phase

0

20

40

60

Percent

Percentage of nursery pig deaths, by producer-identified cause

Failure to Scours

thrive

Respiratory

problems

Other identified

problems

22.1

1.7

9.4

47.3

6.6

Cause

Unknown

problems

13.0

CNS/

meningitis
USDA APHIS VS / 73 

Section I: Population Estimates–C. Nursery Phase

4. Nursery pig management

On average, pigs spent 45.6 days in the nursery phase, arriving at 21.4 days of age and 

leaving at 67.0 days of age.

C.4.a. Site average age of pigs when entering and leaving the nursery phase, by size of 

site:

Site Average Age (days)

Size of Site (total inventory)

Small 

(fewer than 

2,000)

Medium

(2,000–4,999)

Large

(5,000 or 

more) All sites Pig average

Age Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error

Entering 24.0 (0.3) 21.1 (0.4) 21.1 (0.4) 22.6 (0.2) 21.4 (0.4)

Leaving 68.1 (0.7) 68.8 (1.3) 64.5 (2.0) 67.6 (0.7) 67.0 (1.5)

C.4.b. Site average number of days pigs spent in the nursery, by size of site:

Site Average Number of Days

Size of Site (total inventory)

Small 

(fewer than 2,000)

Medium

(2,000-4,999)

Large

(5,000 or more) All sites

Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error

44.1 (0.6) 47.8 (1.2) 43.4 (2.3) 45.0 (0.7)
74 / Swine 2012

Section I: Population Estimates–C. Nursery Phase

C.4.c. Percentage of sites that regularly gave the following treatments to nursery pigs,* 

by size of site:

Percent Sites

Size of Site (total inventory)

Small 

(fewer 

than 2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Treatment Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Dewormer 30.4 (4.1) 11.0 (2.8) 2.5 (1.1) 17.7 (2.8)

Oral Vitamin D 

(as young pigs) 9.7 (2.0) 10.3 (2.8) 7.4 (3.1) 9.4 (1.6)

Mange/lice treatment 16.1 (2.4) 5.0 (1.6) 1.7 (1.2) 9.1 (1.5)

*From December 1, 2011, through May 31, 2012.

C.4.d. Percentage of all nursery pigs that were on sites that regularly gave the following 

treatments to nursery pigs,1 by size of site:

Percent Nursery Pigs2

Size of Site (total inventory)

Small 

(fewer 

than 2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Practice Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Dewormer 14.4 (4.6) 6.4 (2.9) 1.0 (0.6) 4.4 (1.5)

Oral Vitamin D 

(as young pigs) 9.6 (4.1) 5.6 (2.4) 8.1 (4.9) 7.5 (3.2)

Mange/lice treatment 6.9 (2.3) 1.5 (0.7) 2.9 (2.8) 2.9 (1.7)

1

From December 1, 2011, through May 31, 2012.

2

As a percentage of pigs entering nursery.
USDA APHIS VS / 75 

Section I: Population Estimates–D. Grower/Finisher Phase

Percentage of sites that had a grower/finisher phase,* by size of site:

Percent Sites

Size of Site (total inventory)

Small

(fewer than 2,000)

Medium

(2,000-4,999)

Large

(5,000 or more) All sites

Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

51.3 (3.4) 60.5 (6.8) 56.3 (10.9) 56.0 (5.3)

*From December 1, 2011, through May 31, 2012.

Note: All remaining tables in this section refer to the 56.0 percent of sites that had a 

grower/finisher phase from December 1, 2011, through May 31, 2012.

1. Facilities and pig flow

All large sites, 99.7 percent of medium sites, and 85.5 percent of small sites that had a 

grower/finisher phase kept pigs in facilities with no outside access. 

D.1.a. Percentage of sites by facility type used for the grower/finisher phase, and by size 

of site:

Percent Sites

Size of Site (total inventory)

Small 

(fewer 

than 2,000)

Medium

(2,000-4,999)

Large

(5,000 or more) All sites

Facility type Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Total confinement 46.1 (5.1) 86.3 (3.8) 88.6 (5.0) 71.6 (5.8)

Open building with 

natural ventilation and 

no outside access

39.4 (4.2) 13.4 (3.7) 11.4 (5.0) 22.8 (4.8)

Open building with 

outside access 12.5 (1.7) 0.3 (0.1) 0.0 (—) 4.8 (1.1)

Lot with hut 

or no building 1.4 (0.4) 0.0 (—) 0.0 (—) 0.5 (0.2)

Pasture with hut 

or no building 0.5 (0.2) 0.0 (—) 0.0 (—) 0.2 (0.1)

Total 100.0 100.0 100.0 100.0

D. Grower/

Finisher Phase
76 / Swine 2012

Section I: Population Estimates–D. Grower/Finisher Phase

Over 99 percent of all grower/finisher pigs were housed in facilities with no outside 

access.

D.1.b. Percentage of finishing pigs by facility type used on sites with a grower/finisher 

phase, and by size of site:

Percent Pigs*

Size of Site (total inventory)

Small 

(fewer 

than 2,000)

Medium

(2,000-4,999)

Large

(5,000 or more) All sites

Facility type Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Total confinement 66.8 (12.5) 92.0 (3.1) 84.7 (9.4) 85.8 (6.0)

Open building with 

natural ventilation and 

no outside access

29.9 (11.4) 7.8 (3.1) 15.3 (9.4) 13.7 (5.8)

Open building with 

outside access 3.1 (1.2) 0.2 (0.1) 0.0 (—) 0.4 (0.2)

Lot with hut 

or no building 0.1 (0.1) 0.0 (—) 0.0 (—) 0.0 (0.0)

Pasture with hut 

or no building 0.1 (0.1) 0.0 (—) 0.0 (—) 0.0 (0.0)

Total 100.0 100.0 100.0 100.0

*As a percentage of pigs entering the grower/finisher phase.
USDA APHIS VS / 77 

Section I: Population Estimates–D. Grower/Finisher Phase

Over three-fourths of sites that had grower/finisher facilities with indoor-only facilities 

(77.9 percent) had completely slatted flooring.

D.1.c. Percentage of sites by flooring type used in the grower/finisher facility, and by type 

of facility:

Percent Sites

Facility Type

No outside 

access

Outside 

access All sites

Flooring type Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Solid surface 5.7 (2.6) 73.9 (5.4) 7.8 (2.2)

Partial slats 15.9 (4.2) 4.1 (2.1) 15.5 (4.1)

Completely slatted 77.9 (3.1) 3.5 (1.7) 75.5 (3.2)

Mesh 0.2 (0.1) 0.0 (—) 0.2 (0.1)

Dirt/pasture 0.2 (0.1) 15.4 (4.4) 0.7 (0.2)

Other 0.2 (0.1) 3.2 (2.0) 0.3 (0.1)

Total 100.0 100.0 100.0

D.1.d. Percentage of sites by slatted flooring material in the grower/finisher facility, and by 

type of facility:

Percent Sites

Facility Type

No outside 

access

Outside 

access All sites

Slatted flooring 

material Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Concrete 93.1 (2.4) * 90.4 (2.0)

Metal 0.1 (0.1) * 0.1 (0.1)

Plastic 0.6 (0.2) * 0.6 (0.2)

Other 0.0 (—) * 0.0 (0.0)

No slatted flooring 6.2 (2.5) * 9.0 (2.1)

*Too few respondents with slatted flooring to estimate.
78 / Swine 2012

Section I: Population Estimates–D. Grower/Finisher Phase

Over three-fourths of all grower/finisher sites used pit-holding to manage waste. Over 

20 percent of medium and large sites used flush, under slats. 

D.1.e. Percentage of sites by primary waste management system used in the grower/

finisher facility, and by size of site:

Percent Sites

Size of Site (total inventory)

Small 

(fewer 

than 2,000)

Medium

(2,000-4,999)

Large

(5,000 or more) All sites

Waste 

management 

system Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

None 1.8 (1.3) 1.7 (1.1) 0.1 (0.1) 1.4 (0.9)

Pit-holding 79.2 (2.9) 73.8 (8.8) 74.8 (11.6) 75.8 (6.2)

Mechanical 

scraper/tractor 9.1 (1.6) 0.6 (0.2) 1.5 (0.8) 3.6 (0.9)

Hand cleaned 2.5 (0.6) 0.0 (—) 0.0 (—) 0.8 (0.3)

Flush, under slats 5.4 (1.4) 22.7 (8.7) 23.0 (11.1) 17.0 (5.4)

Flush, open gutter 1.3 (0.5) 0.8 (0.5) 0.5 (0.4) 0.9 (0.4)

Other 0.5 (0.2) 0.4 (0.3) 0.0 (—) 0.4 (0.2)

Total 100.0 100.0 100.0 100.0
USDA APHIS VS / 79 

Section I: Population Estimates–D. Grower/Finisher Phase

A higher percentage of sites in the South region used flush under slats than used pitholding.

D.1.f. Percentage of sites by primary waste management system used in the grower/

finisher facility, and by region:

Percent Sites

Region

Midwest East South

Waste management system Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

None 2.7 (1.7) 0.2 (0.2) 0.3 (0.3)

Pit-holding 81.0 (4.3) 93.4 (4.1) 26.1 (9.0)

Mechanical scraper/tractor 6.1 (1.2) 1.2 (0.8) 1.3 (0.7)

Hand cleaned 1.4 (0.4) 0.5 (0.4) 0.0 (—)

Flush, under slats 7.7 (4.0) 3.9 (2.7) 69.4 (9.0)

Flush, open gutter 0.9 (0.3) 0.4 (0.3) 2.2 (1.6)

Other 0.3 (0.1) 0.3 (0.4) 0.8 (0.5)

Total 100.0 100.0 100.0
80 / Swine 2012

Section I: Population Estimates–D. Grower/Finisher Phase

More than half of all grower/finisher sites moved pigs all-in/all-out by building. About 

20 percent of sites moved pigs all-in/all-out by site. A higher percentage of small sites 

than medium and large sites had a continuous flow of pigs.

D.1.g. Percentage of sites by pig-flow management used in the grower/finisher phase, 

and by size of site:

Percent Sites

Size of Site (total inventory)

Small 

(fewer 

than 2,000)

Medium

(2,000-4,999)

Large

(5,000 or more) All sites

Pig-flow management Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Continuous flow 21.7 (2.5) 5.4 (2.9) 1.3 (0.6) 10.8 (2.4)

All swine removed 

without cleaning and 

disinfecting room

4.9 (0.9) 0.5 (0.2) 0.8 (0.4) 2.2 (0.6)

All-in/all-out by room 17.2 (3.2) 9.6 (3.4) 13.8 (6.2) 13.2 (3.4)

All-in/all-out by building 40.0 (5.8) 62.0 (10.1) 60.8 (16.7) 53.6 (9.5)

All-in/all-out by site 15.0 (2.6) 22.4 (7.9) 23.2 (13.8) 19.8 (5.9)

NA 1.2 (0.4) 0.1 (0.1) 0.0 (—) 0.5 (0.2)

Total 100.0 100.0 100.0 100.0
USDA APHIS VS / 81 

Section I: Population Estimates–D. Grower/Finisher Phase

Over 95 percent of grower/finisher pigs were managed all-in/all-out, either by room, 

building, or site.

D.1.h. Percentage of pigs by pig-flow management used in the grower/finisher phase, 

and by size of site:

Percent Pigs*

Size of Site (total inventory)

Small 

(fewer 

than 2,000)

Medium

(2,000-4,999)

Large

(5,000 or more) All sites

Pig-flow management Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Continuous flow 7.3 (2.8) 4.2 (2.9) 0.6 (0.3) 3.0 (1.6)

All swine removed 

without cleaning and 

disinfecting room

2.2 (0.9) 0.5 (0.3) 0.4 (0.2) 0.6 (0.3)

All-in/all-out by room 15.1 (6.5) 6.1 (2.9) 23.5 (12.3) 14.8 (6.7)

All-in/all-out by building 63.1 (14.3) 67.1 (12.7) 49.5 (19.1) 58.9 (15.1)

All-in/all-out by site 12.0 (5.2) 22.1 (10.7) 26.0 (15.8) 22.6 (11.7)

NA 0.3 (0.2) 0.1 (0.1) 0.0 (—) 0.1 (0.0)

Total 100.0 100.0 100.0 100.0

*As a percentage of pigs entering the grower/finisher phase.
82 / Swine 2012

Section I: Population Estimates–D. Grower/Finisher Phase

2. Sourcing of grower/finisher pigs

For large sites with a grower/finisher phase, 81.2 percent obtained pigs from other sites 

that belonged to the operation compared with 49.0 percent of small sites. Almost onethird of small sites obtained pigs from an on-site nursery.

D.2.a. Percentage of sites that brought or placed any pigs into the grower/finisher phase, 

by source of pigs and by size of site:

Percent Sites

Size of Site (total inventory)

Small

(fewer 

than 2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Source Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

On-site nursery 30.6 (3.9) 13.1 (3.6) 17.4 (7.0) 19.7 (4.4)

Other sites belonging 

to this operation 49.0 (6.3) 71.1 (7.3) 81.2 (7.6) 65.8 (7.5)

Other sites not 

belonging to this 

operation

18.0 (2.9) 16.1 (5.3) 2.7 (1.6) 14.2 (3.7)

Auction, sale barn, or 

livestock market 1.6 (0.6) 0.1 (0.1) 0.0 (—) 0.6 (0.2)

Other 2.4 (0.7) 0.7 (0.3) 0.0 (—) 1.1 (0.4)

*From December 1, 2011, through May 31, 2012.
USDA APHIS VS / 83 

Section I: Population Estimates–D. Grower/Finisher Phase

Over three-fourths of all pigs entering the grower/finisher phase came from other sites 

that belonged to the operation.

D.2.b. Percentage of pigs that entered the grower/finisher phase,1 by source of pigs and 

by size of site:

Percent Pigs2

Size of Site (total inventory)

Small 

(fewer 

than 2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Source Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

On-site 18.3 (7.2) 7.3 (2.7) 19.0 (9.9) 13.7 (5.7)

Other sites belonging 

to this operation 65.8 (13.3) 79.0 (7.5) 79.3 (10.2) 77.6 (8.1)

Other sites not 

belonging to this 

operation

13.6 (5.6) 13.1 (5.6) 1.7 (1.0) 8.1 (3.3)

Auction, sale barn, or 

livestock market 0.8 (0.5) 0.0 (0.0) 0.0 (—) 0.1 (0.1)

Other 1.5 (0.8) 0.6 (0.3) 0.0 (—) 0.5 (0.2)

Total 100.0 100.0 100.0 100.0

1

From December 1, 2011, through May 31, 2012.

2

As a percentage of pigs entering the grower/finisher phase.
84 / Swine 2012

Section I: Population Estimates–D. Grower/Finisher Phase

About 80 percent of sites with a grower/finisher phase used an off-site source for pigs. 

Of those sites, about three-fourths used only one off-site source (table D.2.d.). Estimates 

differ slightly from those calculated from table D.2.a. because the two tables are based on 

two different questions, and there were slight differences in the number of respondents 

completing the two questions.

D.2.c. Percentage of sites that used any off-site sources for grower/finisher pigs placed,* 

by size of site:

Percent Sites

Size of Site (total inventory)

Small 

(fewer than 2,000)

Medium

(2,000-4,999)

Large

(5,000 or more) All sites

Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

70.9 (3.8) 87.8 (3.3) 83.9 (6.5) 81.5 (4.1)

*From December 1, 2011, through May 31, 2012.

D.2.d. For sites that used any off-site sources for grower/finisher pigs placed,* 

percentage of sites by number of off-site sources used and by size of site:

Percent Sites

Size of Site (total inventory)

Small 

(fewer 

than 2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Number off-site 

sources Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

1 88.5 (3.0) 76.4 (8.9) 55.2 (9.9) 75.4 (5.6)

2 8.6 (2.5) 15.9 (6.9) 7.1 (4.7) 12.2 (4.7)

3 or more 2.8 (1.3) 7.6 (4.0) 37.7 (10.0) 12.4 (3.1)

Total 100.0 100.0 100.0 100.0

*From December 1, 2011, through May 31, 2012.
USDA APHIS VS / 85 

Section I: Population Estimates–D. Grower/Finisher Phase

A higher percentage of small sites (92.6 percent) than large sites (64.6 percent) used a 

single source for obtaining pigs for the grower/finisher phase.

D.2.e. For grower/finisher pigs placed,1 percentage of sites that commingled (shared 

airspace) pigs from different sources in the same building or area as existing pigs, by size 

of site:

Percent Sites

Size of Site (total inventory)

Small 

(fewer 

than 2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Site type Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Single source2 92.6 (1.8) 79.5 (7.5) 64.6 (9.4) 80.8 (4.2)

Multiple source and 

not commingled 3.7 (1.1) 17.5 (7.3) 26.6 (11.0) 14.8 (3.9)

Multiple source and 

commingled 3.7 (1.3) 3.0 (1.4) 8.8 (4.6) 4.3 (1.4)

Total 100.0 100.0 100.0 100.0

1

From December 1, 2011, through May 31, 2012.

2

Either on-site source or one off-site source.
86 / Swine 2012

Section I: Population Estimates–D. Grower/Finisher Phase

3. Death loss

Of pigs that entered the grower/finisher phase, 4.1 percent died.

D.3.a. Percentage of grower/finisher pigs that died during the grower/finisher phase,1 by 

size of site:

Percent Grower/Finisher Pigs2

Size of Site (total inventory)

Small 

(fewer than 2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

3.5 (0.4) 4.4 (0.5) 4.1 (0.5) 4.1 (0.5)

1

From December 1, 2011, through May 31, 2012.

2

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

Three-fourths of all grower/finisher pig deaths were attributed to respiratory problems. 

D.3.b. Percentage of deaths in the grower/finisher phase,* by producer-identified cause 

and by size of site:

Percent Deaths

Size of Site (total inventory)

Small 

(fewer 

than 2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Cause Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Scours 5.0 (1.6) 3.0 (1.3) 4.1 (2.2) 3.7 (1.6)

Lameness 6.3 (2.8) 4.3 (1.1) 5.2 (0.7) 4.9 (0.9)

Injury 5.0 (2.2) 2.8 (0.7) 3.1 (0.8) 3.2 (0.8)

Respiratory 

problems 71.8 (11.9) 79.8 (6.6) 70.3 (11.4) 75.1 (8.5)

Stress 4.0 (1.7) 1.7 (0.2) 3.1 (0.8) 2.5 (0.5)

Other known 

problems 2.5 (1.4) 3.6 (2.0) 7.0 (5.0) 4.9 (2.8)

Unknown problems 5.4 (2.8) 4.7 (2.0) 7.2 (3.7) 5.8 (2.6)

Total 100.0 100.0 100.0 100.0

*From December 1, 2011, through May 31, 2012.
USDA APHIS VS / 87 

Section I: Population Estimates–D. Grower/Finisher Phase

0

20

40

60

80

Percent

Percentage of deaths in the grower/finisher phase,* by producer-identified cause

Scours Injury Respiratory

problems

Other known

problems

4.9 2.5 3.7 3.2

5.8

Cause

Unknown

problems

75.1

4.9

Lameness Stress

*From December 1, 2011, through May 31, 2012.
88 / Swine 2012

Section I: Population Estimates–D. Grower/Finisher Phase

4. Grower/finisher pig management

On average, pigs left the grower/finisher phase at a substantially younger age on small 

sites (180.6 days) than on large sites (191.8 days). 

D.4.a. Site average age of pigs entering and leaving the grower/finisher phase, by size of 

site:

Site Average Age (days)

Size of Site (total inventory)

Small 

(fewer than 2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error

Entering 67.1 (0.8) 68.5 (1.1) 67.0 (2.4) 67.7 (0.9)

Leaving 180.6 (1.9) 188.2 (2.9) 190.8 (2.7) 185.9 (2.5)

D.4.b. Percentage of sites and percentage of grower/finisher pigs on these sites, by age 

of pigs leaving the grower/finisher phase:

Age (days) Percent sites Std. error Percent pigs Std. error

Less than 160 5.5 (1.7) 2.8 (1.2)

160 to 165 6.5 (1.5) 4.3 (1.7)

166 to 180 33.0 (7.1) 19.7 (7.8)

181 to 209 48.2 (10.1) 63.8 (12.1)

210 or more 6.9 (3.0) 9.5 (5.6)

Total 100.0 100.0
USDA APHIS VS / 89 

Section I: Population Estimates–D. Grower/Finisher Phase

On average, pigs spent about 118.1 days in the grower/finisher phase.

D.4.c. Site average number of days pigs spent in the grower/finisher phase, by size of 

site:

Site Average Number of Days

Size of Site (total inventory)

Small 

(fewer than 2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error

113.5 (1.7) 119.7 (2.6) 123.8 (3.1) 118.1 (2.2)

A higher percentage of small sites than medium and large sites dewormed and 

administered mange/lice treatment to grower/finisher pigs.

D.4.d. Percentage of sites that regularly gave the following treatments to grower/finisher 

pigs,* by size of site:

Percent Sites

Size of Site (total inventory)

Small 

(fewer than 

2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Practice Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Dewormer 30.5 (4.0) 7.5 (2.3) 4.8 (2.2) 14.6 (3.3)

Mange/lice treatment 8.8 (1.6) 1.4 (0.6) 1.6 (0.9) 3.9 (1.0)

*From December 1, 2011, through May 31, 2012.
90 / Swine 2012

Section I: Population Estimates–D. Grower/Finisher Phase

D.4.e. Percentage of all grower/finisher pigs that were on sites that regularly gave the 

following treatments to grower/finisher pigs,1 and by size of site:

Percent Grower/Finisher Pigs2

Size of Site (total inventory)

Small 

(fewer than 

2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Practice Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Dewormer 16.7 (6.6) 4.6 (1.9) 2.7 (1.4) 5.1 (1.9)

Mange/lice treatment 4.2 (1.8) 0.6 (0.3) 0.8 (0.5) 1.1 (0.5)

1

From December 1, 2011, through May 31, 2012.

2

As a percentage of pigs entering the grower/finisher phase.
USDA APHIS VS / 91 

Section I: Population Estimates–E. Wean-to-finish Phase

Percentage of sites that had a wean-to-finish phase,* by size of site:

Percent Sites

Size of Site (total inventory)

Small 

(fewer than 2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

25.0 (3.2) 27.7 (6.3) 15.4 (5.4) 24.4 (4.2)

*From December 1, 2011, through May 31, 2012.

Note: All remaining tables in this section refer to the 24.4 percent of sites with a wean-tofinish phase from December 1, 2011, through May 31, 2012.

1. Facilities and pig flow

Almost one-fourth of all sites had a wean-to-finish phase. Essentially, all medium and 

large sites with a wean-to-finish phase kept pigs in facilities with no outside access, 

compared with almost 80 percent of small sites.

E.1.a. Percentage of sites by primary faciity type used for the wean-to-finish phase, and 

by size of site:

Percent Sites

Size of Site (total inventory)

Small 

(fewer than 

2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Facility type Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Total confinement 50.1 (4.3) 84.2 (4.8) 93.1 (4.5) 71.0 (3.9)

Open building with 

natural ventilation and 

no outside access

29.6 (2.9) 15.6 (4.8) 6.9 (4.5) 20.5 (2.9)

Open building with 

outside access 17.2 (3.1) 0.2 (0.2) 0.0 (—) 7.3 (1.4)

Lot with hut 

or no building 1.5 (0.6) 0.0 (—) 0.0 (—) 0.6 (0.3)

Pasture with hut 

or no building 1.5 (0.7) 0.0 (—) 0.0 (—) 0.6 (0.3)

Total 100.0 100.0 100.0 100.0

E. Wean-to-finish 

Phase
92 / Swine 2012

Section I: Population Estimates–E. Wean-to-finish Phase

Over 98 percent of all wean-to-finish pigs were housed in facilities with no outside 

access. 

E.1.b. Percentage of wean-to-finish pigs by primary facility type used in the wean-to-finish 

phase, and by size of site:

Percent Wean-to-Finish Pigs*

Size of Site (total inventory)

Small 

(fewer than 

2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Facility type Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Total confinement 76.7 (6.1) 86.6 (4.3) 94.9 (3.8) 87.4 (3.1)

Open building with 

natural ventilation and 

no outside access

18.3 (5.3) 12.9 (4.3) 5.1 (3.8) 11.4 (3.0)

Open building with 

outside access 4.5 (1.4) 0.6 (0.6) 0.0 (—) 1.1 (0.4)

Lot with hut 

or no building 0.2 (0.1) 0.0 (—) 0.0 (—) 0.0 (0.0)

Pasture with hut 

or no building 0.3 (0.2) 0.0 (—) 0.0 (—) 0.1 (0.0)

Total 100.0 100.0 100.0 100.0

*As a percentage of pigs entering the wean-to-finish phase.
USDA APHIS VS / 93 

Section I: Population Estimates–E. Wean-to-finish Phase

Almost 90 percent of wean-to-finish sites with indoor-only facilities had completely slatted 

floors. In almost all cases, the slatted floors were concrete.

E.1.c. Percentage of sites by primary flooring type used in the wean-to-finish phase, and 

by type of facility:

Percent Sites

Facility Type

No outside 

access Outside access All sites

Flooring type Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Solid surface 2.2 (1.0) 75.1 (9.7) 3.6 (1.2)

Partial slats 8.5 (2.5) 6.1 (5.2) 8.4 (2.4)

Completely slatted 88.5 (2.7) 0.0 (—) 86.9 (2.8)

Mesh 0.3 (0.2) 0.0 (—) 0.3 (0.2)

Dirt/pasture 0.4 (0.2) 13.6 (8.0) 0.6 (0.3)

Other 0.1 (0.1) 5.2 (4.4) 0.2 (0.1)

Total 100.0 100.0 100.0
94 / Swine 2012

Section I: Population Estimates–E. Wean-to-finish Phase

E.1.d. Percentage of sites by primary slatted flooring material used in the wean-to-finish 

phase, and by type of facility:

Percent Sites

Facility Type

No outside 

access Outside access All sites

Flooring material Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Concrete 96.0 (1.3) * 94.3 (1.6)

Metal 0.2 (0.1) * 0.2 (0.1)

Plastic 0.8 (0.3) * 0.8 (0.3)

No slatted flooring 3.0 (1.2) 93.9 (5.2) 4.6 (1.4)

Total 100.0 100.0 100.0

*Too few observations to report.
USDA APHIS VS / 95 

Section I: Population Estimates–E. Wean-to-finish Phase

Overstocking involves placing large numbers of young pigs in a housing unit designed for 

older, larger pigs so that when the pigs have attained a certain size, some will need to be 

moved as a group—or split—to prevent crowding.

Nearly 75 percent of small sites with a wean-to-finish phase never overstocked, whereas 

almost 60 percent of large sites sometimes or always overstocked. More than half of all 

wean-to-finish sites never overstocked.

E.1.e. Percentage of sites by frequency of overstocking in wean-to-finish phase, and by 

size of site:

Percent Sites

Size of Site (total inventory)

Small 

(fewer than 

2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Frequency Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Always 3.3 (0.9) 5.8 (2.3) 11.1 (5.7) 5.3 (1.4)

Sometimes 23.0 (6.8) 51.0 (9.3) 48.2 (12.0) 38.9 (7.1)

Never 72.6 (6.3) 42.7 (8.4) 40.0 (12.4) 55.0 (6.3)

Don’t know 1.0 (0.5) 0.5 (0.3) 0.7 (0.6) 0.7 (0.3)

Total 100.0 100.0 100.0 100.0
96 / Swine 2012

Section I: Population Estimates–E. Wean-to-finish Phase

Overstocking occurred in the South region on about 10 percent of sites compared with 

about half of sites in the Midwest and East regions.

E.1.f. Percentage of sites by frequency of overstocking in the wean-to-finish phase, and 

by region:

Percent Sites

Region

Midwest East South

Frequency Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Always 4.5 (1.6) 7.9 (3.2) 0.0 (0.0)

Sometimes 38.7 (8.7) 44.0 (13.4) 7.5 (3.8)

Never 56.4 (7.8) 46.8 (11.9) 90.3 (4.2)

Don’t know 0.4 (0.2) 1.2 (0.6) 2.2 (1.9)

Total 100.0 100.0 100.0

Of small sites that overstocked, the highest percentage did so at 150 percent. A higher 

percentage of large sites than small sites double stocked (200 percent).

E.1.h. For sites that overstocked, percentage of sites by amount of overstocking in the 

wean-to-finish phase, and by size of site:

Percent Sites

Size of Site (total inventory)

Small 

(fewer than 

2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Percent 

overstocking Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

150 70.1 (12.2) 38.7 (16.8) 17.3 (8.8) 43.3 (15.2)

200 9.9 (5.1) 53.3 (16.8) 79.4 (9.6) 46.4 (14.7)

Other 20.1 (9.0) 8.0 (4.1) 3.3 (2.0) 10.3 (3.8)

Total 100.0 100.0 100.0 100.0
USDA APHIS VS / 97 

Section I: Population Estimates–E. Wean-to-finish Phase

Over 90 percent of wean-to-finish sites used pit-holding for waste management.

E.1.i. Percentage of sites by primary waste management system used in the wean-tofinish facility, and by size of site:

Percent Sites

Size of Site (total inventory)

Small 

(fewer than 

2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Waste management 

system Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

None 0.9 (0.6) 0.2 (0.2) 0.6 (0.5) 0.5 (0.2)

Pit-holding 85.5 (4.3) 98.2 (0.9) 88.2 (7.8) 93.1 (1.7)

Mechanical scraper/

tractor 6.6 (2.2) 0.6 (0.3) 0.0 (—) 2.3 (0.7)

Hand cleaned 1.1 (0.6) 0.0 (—) 0.0 (—) 0.3 (0.2)

Flush, under slats 4.0 (2.1) 1.0 (0.8) 11.2 (7.9) 3.3 (1.4)

Flush, open gutter 1.0 (0.7) 0.0 (—) 0.0 (—) 0.3 (0.2)

Other 0.8 (0.6) 0.0 (—) 0.0 (—) 0.3 (0.2)

Total 100.0 100.0 100.0 100.0
98 / Swine 2012

Section I: Population Estimates–E. Wean-to-finish Phase

E.1.j. Percentage of sites by primary waste management system used in the wean-tofinish facility, and by region:

Percent Sites

Region

Midwest East South

Waste management system Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

None 0.2 (0.2) 0.3 (0.2) *

Pit-holding 93.1 (2.2) 94.6 (2.3) *

Mechanical scraper/tractor 2.6 (0.9) 1.3 (0.7) *

Hand cleaned 0.2 (0.2) 0.8 (0.5) *

Flush, under slats 3.4 (1.9) 3.1 (1.8) *

Flush, open gutter 0.4 (0.3) 0.0 (—) *

Other 0.2 (0.2) 0.0 (—) *

Total 100.0 100.0

*Too few observations to report.
USDA APHIS VS / 99 

Section I: Population Estimates–E. Wean-to-finish Phase

Almost one-third of small wean-to-finish sites moved pigs all-in/all-out by building, and 

almost one-fourth of small sites managed pigs via continuous flow. Almost half of medium 

wean-to-finish sites managed pigs all-in/all-out by site. Over three-fourths of large weanto-finish sites managed pigs all-in/all-out by room or building.

E.1.k. Percentage of sites by pig-flow management in the wean-to-finish phase, and by 

size of site:

Percent Sites

Size of Site (total inventory)

Small 

(fewer than 

2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Pig-flow 

management Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Continuous flow 23.8 (4.0) 0.7 (0.3) 0.4 (0.4) 10.3 (1.9)

All swine removed 

without cleaning and 

disinfecting room

1.2 (0.5) 0.4 (0.4) 0.0 (—) 0.7 (0.3)

All-in/all-out by room 13.5 (2.6) 24.0 (9.8) 40.1 (16.8) 21.4 (6.5)

All-in/all-out by 

building 32.7 (5.7) 28.6 (7.5) 37.8 (10.3) 31.3 (5.4)

All-in/all-out by site 27.3 (10.7) 46.3 (11.6) 21.7 (14.8) 35.7 (9.7)

NA 1.3 (0.6) 0.0 (—) 0.0 (—) 0.5 (0.2)

Total 100.0 100.0 100.0 100.0
100 / Swine 2012

Section I: Population Estimates–E. Wean-to-finish Phase

Over 98 percent of pigs placed in the wean-to-finish phase were managed all-in/all-out, 

with roughly one-third by room, one-third by building, and one-third by site.

E.1.l. Percentage of pigs by pig-flow management in the wean-to-finish phase, and by 

size of site:

Percent Pigs*

Size of Site (total inventory)

Small 

(fewer than 

2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Pig-flow 

management Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Continuous flow 6.8 (2.1) 0.4 (0.2) 0.5 (0.5) 1.5 (0.4)

All swine removed 

without cleaning and 

disinfecting room

0.3 (0.2) 0.3 (0.3) 0.0 (—) 0.2 (0.2)

All-in/all-out by room 11.2 (4.1) 28.6 (12.9) 39.0 (17.8) 28.9 (11.0)

All-in/all-out by 

building 51.0 (14.7) 25.8 (7.4) 38.6 (9.2) 34.1 (7.0)

All-in/all-out by site 30.5 (13.7) 44.9 (13.1) 21.9 (14.2) 35.3 (10.7)

NA 0.2 (0.1) 0.0 (—) 0.0 (—) 0.0 (0.0)

Total 100.0 100.0 100.0 100.0

*As a percentage of pigs entering the wean-to-finish phase.
USDA APHIS VS / 101 

Section I: Population Estimates–E. Wean-to-finish Phase

2. Sourcing of wean-to-finish pigs

Only 6.0 percent of sites sourced pigs on-site for the wean-to-finish phase. About twothirds of medium and large sites sourced pigs from other sites that belonged to the 

operation, compared with about one-third of small sites. Almost half of small sites sourced 

wean-to-finish pigs from other sites that did not belong to the operation.

E.2.a. Percentage of sites that brought or placed any pigs into the wean-to-finish phase,* 

by source of pigs and by size of site:

Percent Sites

Size of Site (total inventory)

Small 

(fewer than 

2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Source Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

On-site 13.4 (3.9) 1.3 (0.5) 9.4 (4.2) 6.0 (1.4)

Other sites belonging 

to this operation 34.1 (6.5) 63.7 (7.7) 67.7 (12.9) 55.4 (7.3)

Other sites not 

belonging to this 

operation

46.4 (7.3) 35.9 (8.2) 22.9 (10.8) 37.3 (7.0)

Auction, sale barn, or 

livestock market 0.0 (—) 0.0 (—) 0.0 (—) 0.0 (—)

Other 9.9 (4.1) 4.4 (1.9) 0.6 (0.5) 5.5 (1.9)

*From December 1, 2011, through May 31, 2012.
102 / Swine 2012

Section I: Population Estimates–E. Wean-to-finish Phase

E.2.b. Percentage of pigs that entered the wean-to-finish phase,1 by source of pigs and 

by size of site:

Percent Pigs2

Size of Site (total inventory)

Small 

(fewer than 

2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Source Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

On-site 6.4 (3.1) 1.2 (0.6) 16.4 (8.0) 6.8 (2.5)

Other site belonging 

to this operation 31.1 (10.5) 63.9 (8.2) 66.0 (14.1) 59.2 (9.3)

Other site not belonging 

to this operation 51.3 (8.5) 31.6 (7.6) 17.7 (9.2) 30.4 (7.6)

Auction, sale barn, or 

livestock market 0.0 (—) 0.0 (—) 0.0 (—) 0.0 (—)

Other 11.2 (4.1) 3.3 (1.5) 0.0 (0.0) 3.6 (1.4)

Total 100.0 100.0 100.0 100.0

1

From December 1, 2011, through May 31, 2012.

2

As a percentage of pigs entering the wean-to-finish phase.

Nearly 95 percent of sites that had a wean-to-finish phase sourced their pigs off-site, and 

over 90 percent of these sites used only one off-site source.

E.2.c. Percentage of sites that used any off-site source for wean-to-finish pigs placed,* by 

size of site:

Percent Sites

Size of Site (total inventory)

Small 

(fewer than 2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

87.7 (3.7) 98.9 (0.5) 91.2 (4.0) 94.5 (1.4)

*From December 1, 2011, through May 31, 2012.
USDA APHIS VS / 103 

Section I: Population Estimates–E. Wean-to-finish Phase

E.2.d. For sites that used any off-site sources for wean-to-finish pigs placed,* percentage 

of sites by number of off-site sources and by size of site:

Percent Sites

Size of Site (total inventory)

Small 

(fewer than 

2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Number off-site 

sources Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

1 93.7 (4.2) 92.6 (5.0) 98.8 (1.1) 93.7 (3.4)

2 5.8 (4.1) 7.4 (5.0) 0.0 (0.0) 5.9 (3.3)

3 or more 0.5 (0.5) 0.0 (0.0) 1.2 (1.1) 0.3 (0.2)

Total 100.0 100.0 100.0 100.0

*From December 1, 2011, through May 31, 2012.

E.2.e. For wean-to-finish pigs placed,1 percentage of sites that commingled (shared 

airspace) pigs from different sources in the same building or area as existing pigs, by size 

of site:

Percent Sites

Size of Site (total inventory)

Small 

(fewer than 

2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Site type Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Single source2 94.9 (3.3) 93.5 (4.4) 99.1 (0.9) 94.7 (2.8)

Multiple source and 

not commingled 3.6 (2.9) 5.4 (4.4) 0.9 (0.9) 4.2 (2.7)

Multiple source and 

commingled 1.6 (1.5) 1.1 (0.8) 0.0 (—) 1.1 (0.8)

Total 100.0 100.0 100.0 100.0

1

From December 1, 2011, through May 31, 2012.

2

Either on-site or one off-site source.
104 / Swine 2012

Section I: Population Estimates–E. Wean-to-finish Phase

3. Death loss

Just 1.4 percent of wean-to-finish pigs died before the split. Nearly two-thirds of the 

deaths before the split were attributed to respiratory problems. On large sites, more than 

20 percent of deaths prior to the split were attributed to scours.

E.3.a. For sites that overstocked, percentage of wean-to-finish pigs that entered the 

wean-to-finish phase* and died before the split, by size of site:

Percent Wean-to-finish Pigs*

Size of Site (total inventory)

Small 

(fewer than 2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

1.7 (0.2) 1.4 (0.4) 1.3 (0.3) 1.4 (0.3)

*As a percentage of pigs that entered the wean-to-finish phase.
USDA APHIS VS / 105 

Section I: Population Estimates–E. Wean-to-finish Phase

E.3.b. Percentage of deaths in wean-to-finish pigs that occurred before the split, by 

producer-identified cause and by size of site:

Percent Deaths

Size of Site (total inventory)

Small 

(fewer than 

2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Cause Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Scours 5.4 (3.7) 9.1 (5.7) 22.4 (5.0) 12.1 (5.9)

Starvation, 

refusal to eat 6.8 (4.8) 1.8 (1.2) 9.2 (4.5) 4.2 (1.9)

Lameness 1.4 (0.9) 1.3 (1.0) 5.0 (2.7) 2.2 (1.1)

Respiratory 

problems 66.2 (8.4) 67.6 (7.1) 45.7 (10.0) 61.9 (6.8)

CNS/meningitis 9.1 (1.0) 9.0 (1.9) 8.3 (4.4) 8.8 (2.0)

Stress 3.3 (2.3) 2.8 (1.9) 1.0 (0.7) 2.4 (1.5)

Other known 

problems 0.8 (0.8) 1.9 (1.5) 0.7 (0.6) 1.5 (1.0)

Unknown problems 7.0 (2.5) 6.6 (2.4) 7.7 (4.3) 6.9 (2.2)

Total 100.0 100.0 100.0 100.0
106 / Swine 2012

Section I: Population Estimates–E. Wean-to-finish Phase

Overall, 4.2 percent of pigs in the wean-to-finish phase died after the split. Almost 60 

percent of the deaths after the split were attributed to respiratory problems. 

E.3.c. Percentage of wean-to-finish pigs that entered the wean-to-finish phase* and died 

after the split (or during the whole phase if no split) by size of site:

Percent Wean-to-finish Pigs*

Size of Site (total inventory)

Small 

(fewer than 2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

2.4 (0.5) 3.9 (0.5) 5.8 (1.6) 4.2 (0.9)

*As a percentage of pigs that entered the wean-to-finish phase.

E.3.d. Percentage of deaths in wean-to-finish pigs that occurred after the split (or during 

the whole phase if no split), by producer-identified cause and by size of site:

Percent Deaths

Size of Site (total inventory)

Small 

(fewer than 

2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Cause Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Scours 6.6 (2.8) 17.6 (8.9) 7.3 (2.7) 12.2 (3.6)

Starvation, 

efusal to eat 4.8 (1.7) 4.2 (1.2) 0.9 (0.6) 2.9 (0.7)

Lameness 4.7 (1.5) 4.5 (1.5) 3.0 (1.9) 3.9 (1.5)

Injury or trauma 1.7 (0.7) 3.9 (1.6) 0.9 (0.6) 2.4 (1.1)

Respiratory 

problems 54.6 (7.4) 44.6 (5.9) 77.8 (11.4) 59.8 (8.1)

CNS/meningitis 12.3 (3.1) 8.8 (2.3) 3.0 (2.0) 6.6 (2.4)

Stress 2.7 (0.9) 3.9 (1.4) 0.6 (0.4) 2.4 (1.0)

Other known 

problems 2.9 (1.2) 0.9 (0.4) 1.6 (1.3) 1.4 (0.7)

Unknown 

problems 9.7 (2.1) 11.6 (4.0) 4.9 (3.6) 8.6 (3.6)

Total 100.0 100.0 100.0 100.0
USDA APHIS VS / 107 

Section I: Population Estimates–E. Wean-to-finish Phase

0 20 40 60 80

After the split

Before the split

Cause

Percentage of wean-to-finish pig deaths* before and after the split, 

by producer-identified cause

Scours

Failure

to thrive

Lameness

Respiratory

problems

CNS/

meningitis

Stress

Percent

Other known

problems

Unknown

problems

Injury or

trauma

12.1

4.2

2.2

NA

61.9

8.8

2.4

1.5

6.9

12.2

2.9

3.9

2.4

59.8

6.6

2.4

1.4

8.6

*From December 1, 2011, through May 31, 2012.

Died
108 / Swine 2012

Section I: Population Estimates–E. Wean-to-finish Phase

4. Wean-to-finish pig management

The age pigs entered the wean-to-finish unit varied by size of site, ranging from an 

average of almost 28 days of age on small sites to 19 days of age on large sites.

E.4.a. Site average age of pigs entering and leaving the wean-to-finish phase, by size of 

site:

Site Average Age (days)

Size of Site (total inventory)

Small 

(fewer than 2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error

Entering 27.8 (1.4) 20.3 (0.7) 19.3 (0.7) 23.2 (0.8)

Leaving 173.5 (1.7) 172.8 (3.1) 181.2 (3.5) 174.1 (2.2)

E.4.b. Percentage of sites and percentage of wean-to-finish pigs* on these sites, by age 

of pigs leaving the wean-to-finish phase:

Age (days) Percent sites Std. error Percent pigs Std. error

Less than 160 13.2 (4.9) 13.3 (7.8)

160–165 24.2 (7.8) 19.3 (8.5)

166–180 39.7 (6.2) 39.5 (10.7)

181–209 20.9 (7.7) 27.6 (13.6)

210 or more 2.0 (0.6) 0.4 (0.2)

Total 100.0 100.0

*As a percentage of pigs entering the wean-to-finish phase.
USDA APHIS VS / 109 

Section I: Population Estimates–E. Wean-to-finish Phase

E.4.c. Site average number of days pigs spent in the wean-to-finish phase, by size of site:

Site Average Number of Days

Size of Site (total inventory)

Small 

(fewer than 2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error

145.7 (1.2) 152.5 (3.3) 161.9 (4.1) 150.9 (2.5)

For wean-to-finish sites that overstocked, pigs were split at an average age of 59.0 days. 

These pigs were slightly younger than the pigs that left a conventional nursery (67 days 

of age; table C.4.a).

E.4.d. For sites that overstocked, site average age of pigs in the wean-to-finish phase 

when the split occurred, by size of site:

Site Average Age (days)

Size of Site (total inventory)

Small 

(fewer than 2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error Avg.

Std. 

error

61.7 (4.3) 56.3 (3.0) 64.5 (3.2) 59.0 (2.8)
110 / Swine 2012

Section I: Population Estimates–E. Wean-to-finish Phase

A higher percentage of small sites than medium or large sites dewormed pigs and treated 

them for mange/lice while in the wean-to-finish phase. Almost 20 percent of large sites 

provided young pigs with oral vitamin D.

E.4.e. Percentage of sites by treatment used for wean-to-finish pigs,* and by size of site:

Percent Sites

Size of Site (total inventory)

Small 

(fewer than 

2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Treatment Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Dewormer 25.3 (7.0) 6.5 (2.2) 3.8 (1.9) 11.8 (2.8)

Oral vitamin D 

(as young pigs) 6.0 (1.5) 11.2 (6.8) 18.5 (14.1) 9.8 (4.8)

Mange/lice treatment 10.3 (3.3) 1.6 (0.7) 0.0 (—) 4.0 (1.1)

*From December 1, 2011, through May 31, 2012.

E.4.f. Percentage of all wean-to-finish pigs on sites that regularly gave the following 

treatments to wean-to-finish pigs,1 and by size of site:

Percent Wean-to-Finish Pigs2

Size of Site (total inventory)

Small 

(fewer than 

2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Practice Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Dewormer 37.9 (17.3) 6.7 (2.6) 3.1 (1.8) 10.7 (4.7)

Oral vitamin D 

(as young pigs) 3.7 (1.7) 12.9 (9.7) 19.6 (13.3) 13.3 (8.6)

Mange/lice treatment 5.7 (3.1) 1.4 (0.8) 0.0 (—) 1.7 (0.7)

1

From December 1, 2011, through May 31, 2012.

2

As a percentage of pigs entering the wean-to- finish phase.
USDA APHIS VS / 111 

Section I: Population Estimates–F. Biosecurity and Other Farm Characteristics

1. Restrictions to entry

Almost one-fourth of all sites permitted nonbusiness visitors to enter swine facilities.

F.1.a. Percentage of sites by type of visitor allowed to enter pig facilities, and by size of 

site:

Percent Sites

Size of Site (total inventory)

Small 

(fewer than 

2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Visitor type* Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Business 40.4 (4.8) 61.0 (9.0) 65.0 (14.0) 55.0 (7.6)

Nonbusiness 25.7 (6.2) 23.6 (5.3) 23.2 (7.8) 24.2 (4.2)

*Business visitors were those on-site for business purposes, e.g., electrician. Nonbusiness visitors were those 

on-site for other purposes other than business, e.g., education.

The highest percentage of sites required business visitors to change into clean boots and 

coveralls before entering swine facilities. Over two-thirds of large sites required business 

visitors to wait for 24 hours after visiting another swine site before entering their swine 

facilities; 35.0 percent of sites did not allow business visitors.

F.1.b. Percentage of sites by preventive measure required of business visitors before 

entering swine facilities, and by size of site:

Percent Sites

Size of Site (total inventory)

Small 

(fewer than 

2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Preventive measure Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Shower before 

entering site 9.3 (4.7) 25.6 (6.6) 55.0 (13.0) 26.2 (5.6)

Change to clean 

boots and coveralls 35.4 (4.9) 57.9 (8.7) 51.5 (12.2) 49.2 (7.2)

Use the Danish Entry 

(“Bench”) system 1.4 (0.5) 4.0 (1.7) 5.4 (1.8) 3.5 (1.0)

Wait 24 hr or longer 

after visiting another 

swine site

17.5 (4.5) 31.2 (7.1) 45.7 (11.7) 29.6 (5.7)

No business visitors 59.6 (4.8) 39.0 (9.0) 35.0 (14.0) 45.0 (7.6)

F. Biosecurity 

and Other Farm 

Characteristics
112 / Swine 2012

Section I: Population Estimates–F. Biosecurity and Other Farm Characteristics

Over three-fourths of sites did not allow nonbusiness visitors to enter swine facilities. Of 

sites that did allow nonbusiness visitors, 20.7 percent required the visitors to change into 

clean boots and coveralls; 18.9 percent of sites required nonbusiness visitors that had 

visited another swine site to wait at least 24 hours before entering the facility.

F.1.c. Percentage of sites by preventive measure required of nonbusiness visitors before 

entering swine facilities, and by size of site:

Percent Sites

Size of Site (total inventory)

Small 

(fewer than 

2,000)

Medium

(2,000–4,999)

Large

(5,000 or 

more) All sites

Preventive measure Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Shower before 

entering site 6.6 (4.6) 14.3 (5.2) 20.4 (7.6) 13.0 (4.4)

Change to clean 

boots and coveralls 19.8 (6.5) 22.2 (5.3) 18.5 (7.4) 20.7 (4.3)

Use the Danish Entry 

(“Bench”) system 0.7 (0.3) 2.8 (1.5) 1.6 (0.6) 1.8 (0.8)

Wait 24 hr or longer 

after visiting another 

swine site

17.6 (6.7) 19.5 (5.3) 19.5 (7.5) 18.9 (4.4)

No nonbusiness visitors 74.3 (6.2) 76.4 (5.3) 76.8 (7.8) 75.8 (4.2)
USDA APHIS VS / 113 

Section I: Population Estimates–F. Biosecurity and Other Farm Characteristics

More than 80 percent of medium and large sites required employees to change into clean 

boots and coveralls before entering swine facilities. More than half of large sites 

(57.5 percent) required employees to shower before entering swine facilities.

F.1.d. Percentage of sites by preventive measure required of employees before entering 

swine facilities, and by size of site:

Percent Sites

Size of Site (total inventory)

Small 

(fewer than 

2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Preventive measure Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Shower before 

entering site 14.7 (4.7) 26.4 (6.6) 57.5 (13.3) 28.8 (5.7)

Change to clean 

boots and coveralls 68.7 (3.2) 90.0 (2.4) 83.9 (5.4) 81.8 (2.8)

Use the Danish Entry 

(“Bench”) system 5.2 (1.1) 6.0 (1.9) 6.8 (1.9) 5.9 (1.3)

Wait 24 hr or longer 

after visiting another 

swine site

41.1 (5.3) 49.1 (9.0) 48.3 (7.3) 46.3 (6.0)

No employees 11.2 (1.5) 1.8 (0.5) 1.2 (0.7) 4.7 (0.8)
114 / Swine 2012

Section I: Population Estimates–F. Biosecurity and Other Farm Characteristics

2. Trucking

F.2.a. Percentage of sites that allowed trucks or trailers from commercial livestock 

transporters or animal haulers to enter the swine area, by size of site:

Percent Sites

Size of Site (total inventory)

Small 

(fewer than 2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

43.9 (3.6) 73.6 (5.0) 65.3 (10.1) 59.9 (5.0)

About 60 percent of large sites required that the outside of the truck and the animal area 

inside the truck be cleaned and disinfected before coming on-site. Approximately onefourth of small sites had these requirements.

F.2.b. Percentage of sites by required cleaning and disinfecting practices for livestock 

trucks or trailers, and by size of site:

Percent Sites

Size of Site (total inventory)

Small 

(fewer than 

2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Required practices Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Animal area inside 

truck cleaned 31.6 (3.7) 59.6 (7.3) 63.0 (10.4) 48.7 (6.4)

Animal area inside 

truck be disinfected 25.6 (3.9) 52.7 (7.9) 60.2 (10.9) 43.0 (6.9)

Outside of truck 

cleaned 25.8 (3.8) 52.2 (7.9) 59.1 (11.1) 42.6 (6.9)

Outside of truck be 

disinfected 20.6 (4.1) 47.3 (8.5) 56.7 (11.6) 38.0 (7.5)

Trucks/trailers not 

allowed to enter pig 

area

56.1 (3.6) 26.4 (5.0) 34.7 (10.1) 40.1 (5.0)
USDA APHIS VS / 115 

Section I: Population Estimates–F. Biosecurity and Other Farm Characteristics

3. Proximity to other swine sites

More than half the sites in the South region were within a half-mile of another swine site; 

in the East and Midwest regions, only 8.9 and 15.4 percent, respectively, were within a 

half-mile of another swine site.

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

and by region:

Percent Sites

Region

Midwest East South All sites

Distance (miles) Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Less than 0.50 15.4 (1.7) 8.9 (4.0) 53.1 (9.7) 20.6 (4.4)

0.50–0.99 28.6 (2.2) 27.2 (8.4) 23.1 (5.4) 27.1 (3.0)

1.00–2.99 47.2 (2.2) 47.8 (3.8) 13.7 (4.9) 41.0 (3.2)

3.00–4.99 2.8 (0.4) 5.1 (2.2) 1.8 (0.8) 3.3 (0.6)

5.00 or more 6.0 (0.9) 10.9 (4.0) 8.2 (2.9) 7.9 (1.2)

Total 100.0 100.0 100.0 100.0
116 / Swine 2012

Section I: Population Estimates–F. Biosecurity and Other Farm Characteristics

Half the sites in the South region had seven or more swine sites within 3 miles of another 

swine site, compared with less than one-fourth of sites in the Midwest region and less 

than 5 percent in the East region.

F.3.b. Percentage of sites by number of swine sites within 3 miles, and by region:

Percent Sites

Region

Midwest East South All sites

Number of sites Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

0 8.8 (1.1) 16.0 (5.8) 10.0 (3.4) 11.3 (1.6)

1–3 24.9 (2.7) 56.9 (4.7) 23.8 (5.9) 39.5 (4.0)

4–6 32.6 (3.2) 22.9 (5.0) 16.2 (5.0) 26.5 (2.5)

7–9 10.0 (2.0) 2.5 (1.3) 6.1 (3.6) 6.9 (1.5)

10 or more 13.8 (2.0) 1.6 (0.9) 44.0 (9.9) 15.8 (3.9)

Total 100.0 100.0 100.0 100.0
USDA APHIS VS / 117 

Section I: Population Estimates–F. Biosecurity and Other Farm Characteristics

A higher percentage of small sites than medium or large sites had no other swine sites 

within 3 miles. Almost two-thirds of small sites had fewer than four swine sites within 

3 miles.

F.3.c. Percentage of sites by number of swine sites within 3 miles, and by size of site:

Percent Sites

Size of Site (total inventory)

Small 

(fewer than 2,000)

Medium

(2,000–4,999)

Large

(5,000 or more)

Number of sites Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

0 19.8 (1.6) 5.1 (1.3) 6.8 (2.0)

1–3 46.3 (3.3) 33.3 (6.2) 39.1 (6.3)

4–6 18.6 (2.5) 33.2 (4.0) 28.1 (6.3)

7–9 4.9 (1.2) 8.7 (2.3) 7.3 (3.6)

10 or more 10.5 (2.2) 19.6 (6.4) 18.6 (6.7)

Total 100.0 100.0 100.0
118 / Swine 2012

Section I: Population Estimates–F. Biosecurity and Other Farm Characteristics

4. Rodent control

Overall, 95.0 percent of all swine sites used bait or poison to control rodents. Nearly half 

of small sites used cats for rodent control. Cats can spread Toxoplasma gondii to pigs. 

Toxoplasma gondii is a foodborne pathogen with public health consequences. One-fourth 

of large sites used cats for rodent control; however, note the large standard error.

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

Percent Sites

Size of Site (total inventory)

Small 

(fewer than 

2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Rodent control 

method Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Cats 45.0 (3.2) 18.3 (5.3) 25.0 (9.3) 30.4 (4.7)

Dogs 23.8 (2.2) 14.6 (5.1) 22.7 (9.2) 19.8 (4.0)

Traps 28.1 (3.8) 17.6 (5.0) 15.0 (7.0) 21.4 (3.2)

Bait or poison 90.0 (1.0) 98.1 (0.7) 99.4 (0.4) 95.0 (0.8)

Professional 

exterminator 7.4 (2.2) 9.8 (3.1) 12.2 (4.9) 9.2 (2.2)

Other 3.2 (1.5) 4.2 (3.3) 6.1 (3.2) 4.2 (2.4)

Any 98.7 (0.4) 99.9 (0.0) 99.8 (0.2) 99.4 (0.2)
USDA APHIS VS / 119 

Section I: Population Estimates–F. Biosecurity and Other Farm Characteristics

5. Feral swine

Overall, 16.9 percent of sites were in a county where feral swine were present. Almost 

three-fourths of sites in the South region reported that feral swine were in the county. Just 

over 2 percent of sites in the Midwest region reported that feral swine were in the county.

F.5.a. Percentage of sites in counties where feral swine were present (including pigs on 

hunting clubs or captive on farms), by size of site:

Percent Sites

Size of Site (total inventory)

Small 

(fewer than 

2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Feral swine 

present Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Yes 9.2 (1.9) 23.4 (7.8) 19.3 (7.9) 16.9 (4.7)

No 82.4 (2.1) 67.9 (7.8) 66.0 (10.2) 73.5 (5.2)

Don’t know 8.4 (1.4) 8.7 (3.4) 14.7 (6.3) 9.6 (2.5)

F.5.b. Percentage of sites in counties where feral swine were present (including pigs on 

hunting clubs or captive on farms), by region:

Percent Sites

Region

Midwest East South

Feral swine 

present Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Yes 2.3 (0.5) 6.6 (3.1) 74.0 (6.3)

No 87.5 (3.7) 82.0 (7.2) 21.2 (5.7)

Don’t know 10.2 (3.8) 11.5 (5.4) 4.8 (2.2)
120 / Swine 2012

Section I: Population Estimates–F. Biosecurity and Other Farm Characteristics

Feral pigs were seen on less than 1 percent of all sites during the previous 12 months.

F.5.c. Percentage of sites in which feral/wild pigs were seen on-site during the previous 

12 months, by size of site:

Percent Sites

Size of Site (total inventory)

Small 

(fewer than 2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

0.3 (0.1) 0.3 (0.2) 1.8 (1.0) 0.6 (0.2)

F.5.d. Percentage of sites in which feral/wild pigs were seen on-site during the previous 

12 months, by region:

Percent Sites

Region

Midwest East South

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

0.0 (—) 0.1 (0.1) 2.9 (1.4)

For the 3.0 percent of sites in which feral pigs had been seen on-site, over 10 percent 

reported that feral pigs had accessed facilities or feed storage.

F.5.e. For sites in which feral/wild pigs had been seen on-site during the previous 

12 months, percentage of sites in which there was any evidence that feral swine had 

entered or gained access to facilities used to house swine or store feed:

Percent sites Std. error

11.7 (6.7)
USDA APHIS VS / 121 

Section I: Population Estimates–G. General Management

1. Environmental testing

Almost 90 percent of sites had tested the nutrient content of manure at least once during 

the previous 3 years. Of these sites, the majority tested once a year, on average. Just 

14 percent of sites tested air quality, usually only once every 3 years.

G.1. Percentage of sites by number of times the following environmental tests were 

conducted during the previous 3 years:

G. General 

Management

Percent Sites

Number of Tests Conducted

0 1 2 3 4 or more

Tested Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Total

Groundwater1 70.3 (3.9) 16.8 (2.9) 2.3 (0.5) 7.0 (1.9) 3.7 (1.4) 100.0

Nutrient content of 

manure (such as 

nitrogen level)

10.7 (1.8) 7.8 (1.7) 3.8 (1.0) 52.4 (7.3) 25.2 (6.1) 100.0

Air quality2 86.0 (3.7) 11.6 (3.7) 0.8 (0.3) 1.5 (0.6) 0.2 (0.1) 100.0

1

Such as for nitrates or pathogens.

2

Such as ammonia or hydrogen sulfide levels.
122 / Swine 2012

Section I: Population Estimates–G. General Management

2. Carcass disposal

About half the sites with dead preweaned pigs composted the pigs, with the majority 

doing so on-site. More than one-fifth of sites buried dead preweaned pigs, and almost 

half of sites with weaned-pig deaths composted carcasses. When all deaths are 

combined, almost 30 percent of sites had a renderer come on-site to pick up carcasses.

G.2.a. For sites with deaths in preweaned or weaned pigs, percentage of sites by method 

of carcass disposal:

Percent Sites

Pig Type

Preweaned Weaned All deaths

Carcass 

disposal method Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Burial on-site 22.8 (2.0) 10.4 (1.5) 10.8 (1.5)

Burning on-site 10.3 (1.9) 5.1 (1.1) 5.8 (1.2)

Renderer pickup 

on-site 13.4 (3.7) 27.9 (5.0) 29.1 (5.2)

Renderer pickup 

outside site 6.4 (1.0) 11.1 (2.0) 11.2 (2.0)

Composting 

on-site 45.9 (2.8) 39.8 (7.2) 40.9 (7.0)

Composting 

off-site 4.6 (1.0) 5.4 (1.0) 5.4 (1.0)

Other 1.8 (0.4) 1.2 (0.4) 1.2 (0.4)
USDA APHIS VS / 123 

Section I: Population Estimates–G. General Management

Over 40 percent of all dead pigs (43.1 percent) were picked up by a renderer, and a 

similar percentage (45.2 percent) were composted.

G.2.b. Percentage of dead pigs, by pig type and by method of carcass disposal:

Percent Dead Pigs 

Pig Type

Preweaned Weaned All deaths

Carcass 

disposal method Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Burial on-site 2.4 (0.8) 2.4 (1.1) 2.4 (0.6)

Burning on-site 10.3 (4.7) 7.4 (4.5) 9.0 (3.3)

Renderer pickup 

on-site 31.9 (12.8) 32.4 (9.7) 32.1 (8.6)

Renderer pickup 

outside site 10.3 (4.1) 11.8 (4.1) 11.0 (2.9)

Composting 

on-site 38.6 (9.3) 43.5 (14.5) 40.7 (9.1)

Composting 

off-site 6.2 (4.4) 2.4 (0.8) 4.5 (2.6)

Other 0.2 (0.1) 0.2 (0.1) 0.2 (0.1)

Total 100.0 100.0 100.0
124 / Swine 2012

Section I: Population Estimates–G. General Management

3. Use of a veterinarian

More than half of large sites had a veterinarian employed by the operation visit the site 

during the previous 12 months. Almost 60 percent of small sites had a local veterinarian 

visit the site. Overall, three-fourths of all sites were visited by some type of veterinarian.

G.3.a. Percentage of sites in which a veterinarian visited for any purpose during the 

previous 12 months, by type of veterinarian and by size of site:

Percent Sites

Size of Site (total inventory)

Small 

(fewer than 

2,000)

Medium

(2,000–4,999)

Large

(5,000 or more) All sites

Veterinarian Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error

Local practitioner 59.3 (3.5) 35.7 (6.8) 39.1 (7.1) 45.9 (4.2)

Consulting or 

second-opinion 9.2 (1.3) 19.4 (5.1) 23.3 (8.8) 15.9 (3.5)

On-staff 11.9 (3.8) 34.8 (7.9) 52.0 (7.1) 28.2 (4.9)

State or Federal 1.2 (0.3) 0.3 (0.1) 0.7 (0.4) 0.7 (0.2)

Other type 0.5 (0.3) 0.8 (0.3) 2.1 (1.5) 0.9 (0.3)

Any type 73.5 (2.2) 73.5 (9.9) 83.6 (7.8) 75.3 (4.8)
USDA APHIS VS / 125 

Section I: Population Estimates–G. General Management

Over half of sites (55.9 percent) were visited by a veterinarian two or more times during 

the previous 12 months.

G.3.b. Percentage of sites by number of times a veterinarian visited for any purpose 

during the previous 12 months, and by type of veterinarian:

Percent Sites

Number of Visits

0 1 2–4 5 or more

Veterinarian Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Pct.

Std. 

error Total

Local practitioner 54.1 (4.2) 14.9 (2.5) 20.7 (3.0) 10.3 (1.5) 100.0

Consulting or 

second-opinion 84.1 (3.5) 7.3 (2.1) 6.8 (1.4) 1.8 (0.5) 100.0

On-staff 71.8 (4.9) 9.1 (2.3) 14.6 (4.0) 4.5 (1.6) 100.0

State or Federal 99.3 (0.2) 0.5 (0.1) 0.1 (0.0) 0.2 (0.1) 100.0

Other type 99.1 (0.3) 0.2 (0.1) 0.1 (0.1) 0.5 (0.3) 100.0

Any type 24.7 (4.8) 19.4 (2.2) 35.9 (3.7) 20.0 (2.6) 100.0
126 / Swine 2012

Section II: Methodology

NAHMS develops study objectives by exploring existing literature and contacting 

stakeholders about their informational needs and priorities during a needs assessment 

phase. Stakeholders for NAHMS studies include industry members, allied industry 

representatives, government agencies, animal health officials, and many others. The 

purpose of the needs assessment for the NAHMS Swine 2012 study was to collect 

information about the most important swine health and production management 

issues facing the swine industry. A driving force for the needs assessment was for 

NAHMS to receive input from a variety of producers, as well as from industry experts 

and representatives; Federal, State, and private veterinarians; extension specialists; 

universities; and swine organizations. Information was collected via interviews and 

through a needs assessment survey.

Once the most important issues were identified, the study objectives were created by 

prioritizing the needs garnered throughout the needs assessment phase. 

The study objectives for the NAHMS Swine 2012 study were:

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, grower/finisher, and 

wean-to-finish.

2. Describe trends in swine health and management practices.

3. Determine the prevalence and associated risk factors for select respiratory, 

neurologic, gastrointestinal, systemic, and foodborne pathogens found in weaned 

market pigs.

4. Describe antibiotic usage patterns in pigs postweaning to market to control and 

treat disease and promote growth.

5. Evaluate presence of or exposure to select pathogens and characterize isolated 

organisms from biological specimens (feces, sera, feed).

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.

Section II: Methodology

A. Needs 

Assessment and 

Study Objectives
USDA APHIS VS / 127 

Section II: Methodology

1. State selection

The preliminary selection of States to be included in the study was done using the 

NASS 2007 Census of Agriculture and the December 1, 2010, quarterly “Hogs and Pigs” 

report. A goal for NAHMS national studies is to include States that account for at least 

70 percent of the animal and producer populations in the United States. Factors that 

influenced State selection were a high proportion of U.S. farms or animals, demographic 

trends, and regional representation. The 13 States recommended for inclusion in the 

study were: Illinois, Indiana, Iowa, Kansas, Minnesota, Missouri, Nebraska, North 

Carolina, Ohio, Oklahoma, Pennsylvania, South Dakota, and Texas. The selection criteria 

for operations in these States were 100 or more pigs. 

2. Operation selection

The sample design was a multistage design in which the operation was the primary 

sampling unit and the site was the analysis unit. (See “Terms Used in this Report” for a 

definition of operation and site).

The list frame used for sampling operations was provided by NASS. Within each State, a 

stratified random sample was selected in which the size stratum was based on operation 

inventory on the NASS list frame. Size strata were: 100 to 999 head, 1,000 to 1,999 

head, 2,000 to 4,999 head, and 5,000 or more head in total inventory. The sample of 

4,600 operations was drawn in 5 replicates to facilitate mixed-mode data collection, with 

2,000 operations being used for the computer assisted telephone interview (CATI) and 

2,600 operations used for the on-farm personal interview. The CATI sample was chosen 

from operations with fewer than 1,000 pigs (according to the list frame) to minimize the 

number of operations with multiple sites in the CATI sample.

The State-level allocation was based on a weighted percentage of the number of 

operations in the State and the pig inventory relative to the U.S. levels for swine farms 

with 100 or more pigs. The percentage of the 13-State total for the population of 100+ 

swine farms in the State was given a 0.4 weighting and the percentage of pigs was given 

a 0.6 weighting. For example, Iowa had 31.6 percent of pigs and 

34.2 percent of the farms in the United States. Iowa was initially assigned 32.6 percent 

(31.6*0.6+34.2*0.4=32.6) of the sample of 4,600 operations drawn in replicates. The 

allocation was adjusted to move some of the sample from States with a large number of 

operations to other States with fewer operations. Within States, the number of operations 

was allocated to each size stratum using the same strategy as for the State-level 

allocation.

B. Sampling and 

Estimation
128 / Swine 2012

Section II: Methodology

3. Site selection

Some producers on the NASS list frame represented swine operations in which pigs were 

raised on multiple sites. A subsample of sites was selected for operations with multiple 

sites in a State. The number of sites selected depended on the size of the operation. If 

the operation had fewer than 20 sites, 1 sow site and 2 non-sow sites were randomly 

selected. If the operation had 20 to 49 sites, 2 sow sites and 6 nonsow sites were 

randomly selected. If the operation had 50 or more sites, 3 sow sites and 12 nonsow 

sites were randomly selected.

4. Population inferences

Data collected from the sampled producers were used to generate national estimates. 

All respondent data were statistically weighted to reflect the population from which they 

were selected. The inverse of the probability of selection for each operation was the 

initial selection weight. This selection weight was adjusted for nonresponse within each 

State and size group. Site-level weights were then calculated for sow sites and nonsow 

sites, so that sow sites only represented other sites with sows, and nonsow sites only 

represented other sites without sows. The site-level weights were also adjusted for 

nonresponse.

Inferences are to the population of swine operations with 100 or more pigs in the 13 

participating States. According to the 2007 Census of Agriculture, these States accounted 

for 88.9 percent of U.S. swine operations with 100 or more swine and 90.8 percent of 

swine on operations with 100 or more swine. 

Two methods were used to collect data for the Swine 2012 study. For the 2,600 

producers selected to complete the survey via face-to-face interview, producers were 

contacted by a NASS enumerator to set up a convenient time for an on-farm visit. The 

NASS enumerator administered the general swine farm questionnaire (GSFQ) via 

face-to-face interviews conducted from July 16 through August 15, 2012. For the 2,000 

producers selected to complete the survey via CATI, a shorter version of the GSFQ was 

completed during the same time period.

Upon completion of the interviews (CATI and on-farm), respondents with 100 or more 

pigs were asked to sign a consent form allowing NASS to turn their names over to 

APHIS for further consideration in the study, which completed phase I of the study. NASS 

provided the list of producers willing to participate in the study’s second phase to NAHMS 

coordinators in each State. NASS sent a dataset to NAHMS along with completed 

questionnaires via mail. 

C. Data 

Collection
USDA APHIS VS / 129 

Section II: Methodology

Initial data entry and validation were performed in individual NASS State offices for the 

on-farm questionnaire and in a centralized NASS call center for the CATI questionnaire. 

Data were entered into a SAS dataset. NAHMS staff performed additional data validation 

after data from all States were combined.

Data analysis was performed using SAS and SUDAAN software. Responses were 

weighted to make inference back to the population from which the sample was selected. 

Sites were nested within operations and strata to account for clustering. SUDAAN uses a 

Taylor series expansion to estimate appropriate variances for the data that are stratified, 

clustered, and weighted. 

D. Data Analysis
130 / Swine 2012

Section II: Methodology

The purpose of this section is to provide various performance measurement parameters. 

Historically, the term “response rate” was used as a catch-all parameter, but there 

are many ways to define and calculate response rates. Therefore, the following table 

presents an evaluation based upon a number of measurement parameters, which are 

defined with an “x” in categories that contribute to the measurement.

Phase I: General Swine Management Questionnaire

Response 

category

Number 

sites

Percent 

sites Contacts Usable1 Complete2

Survey complete 

and VMO consent 944 18.0 x x x

Survey complete, 

refused VMO 

consent

1,175 22.4 x x x

No hogs on 

June 1, 2012 915 17.5 x x

Out of business 33 0.6 x x

Out of scope 17 0.3

Refusal of GSMQ 908 17.3 x

Office hold (NASS 

elected not to 

contact)

151 2.9

Inaccessible 1,094 20.9

Total 5,237 100.0 3,975 3,067 2,119

Percent of 

total sites 75.9 58.6 40.5

Percent of total 

sites weighted3 71.2 55.5 32.4

1

Usable sites—respondent provided answers to inventory questions for the site (either zero or positive number 

on hand).

2

Survey complete site—respondent provided answers to all or nearly all questions.

3

Weighted response—the rate was calculated using the initial selection weights.

E. Sample 

Evaluation
USDA APHIS VS / 131 

Appendix I: Sample Profile

1. Total inventory

Size of site (total inventory) Number of responding sites

100 to 1,999 1,230

2,000 to 4,999 617

5,000 or more 272

Total 2,119

2. Sow inventory

Size of site (sow inventory) Number of responding sites

No sows or gilts 1,273

1 to 249 501

250 to 499 66

500 or more 279

Total 2,119

3. Region

Region Number of responding sites

Midwest (IA, MN, NE, SD) 1,308

East (IL, IN, OH, PA) 574

South (KS, MO, NC, OK, TX) 237

Total 2,119

Appendix I: Sample Profile

A. Responding 

Sites
132 / Swine 2012

Appendix II: U.S. Swine Inventory and Number of Farms

Number of hogs and pigs Number of farms

Region State All farms

Farms with 

100 or more 

pigs (x1,000) All farms

Farms 

with|100 or 

more pigs

Midwest Iowa 19,295,092 19,256 8,330 6,965

Minnesota 7,652,284 7,623 4,382 2,892

Nebraska 3,268,544 3,251 2,213 1,517

South Dakota 1,490,034 1,481 959 582

Total 31,705,954 31,611 15,884 11,956

East Illinois 4,298,716 4,273 2,864 1,661

Indiana 3,669,057 3,637 3,420 1,581

Ohio 1,831,084 1,797 3,718 1,032

Pennsylvania 1,167,449 1,136 3,637 730

Total 10,966,306 10,843 13,639 5,004

South Kansas 1,885,252 1,867 1,454 466

Missouri 3,101,469 3,067 2,999 965

North Carolina 10,134,004 10,121 2,836 1,741

Oklahoma 2,398,372 2,376 2,702 151

Texas 1,155,790 1,124 4,471 102

Total 18,674,887 18,555 14,462 3,425

Total (13 States) 61,347,147 61,009 43,985 20,385

Total U.S.(50 States) 67,786,318 67,164 75,442 22,921

*NASS 2007 Census of Agriculture.

Appendix II: U.S. Swine Inventory and Number of Farms*
USDA APHIS VS / 133 

Appendix III: 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

• Part II: Reference of Swine Health and Health Management in the United States, 

2012, expected summer 2015

• Reference of Management Practices on Small-enterprise Swine Operations in the 

United States, 2012, February 2014

• Sow Productivity, info sheet, expected spring 2015

• Sow Gestation Housing, info sheet, expected spring 2015

• Biosecurity and Risk Management, info sheet, expected spring 2015

• Wean-to-finish Production, info sheet, expected fall 2015

• Vaccine Use, info sheet, expected fall 2015

• Porcine Reproductive and Respiratory Syndrome (PRRS) Control in Breeding 

Herds, info sheet, expected fall 2015

• Feed Management, info sheet, expected fall 2015

• Vitamin D Supplementation, info sheet, expected fall 2015

2. Describe trends in swine health and management practices.

• Part III: Changes in the U.S. Pork Industry, 1995–2012, expected summer 2015

• Sow Productivity, info sheet, expected spring 2015

• Sow Gestation Housing, info sheet, expected spring 2015

• Biosecurity and Risk Management, info sheet, expected spring 2015

3. Determine the prevalence and associated risk factors for select respiratory, neurologic, 

gastrointestinal, systemic, and foodborne pathogens found in weaned market pigs.

• Swine Dysentery, info sheet, expected fall 2015

• Toxoplasma, info sheet, expected fall 2015

• Trichinae, info sheet, expected fall 2015

• Porcine Reproductive and Respiratory Syndrome (PRRS) Prevalence, info sheet, 

expected fall 2015

• Salmonella, info sheet, expected fall 2015

• Enterococcus, info sheet, expected fall 2015

• Generic E. coli, info sheet, expected fall 2015

Appendix III: Study Objectives and Related Outputs
134 / Swine 2012

Appendix III: Study Objectives and Related Outputs

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, expected summer 2015

• Antibiotic Use, info sheet, expected fall 2015

5. Evaluate presence of or exposure to select pathogens and characterize isolated 

organisms from biological specimens (feces, sera, feed).

• Toxoplasma, info sheet, expected fall 2015

• Trichinae, info sheet, expected fall 2015

• Porcine Reproductive and Respiratory Syndrome (PRRS) Prevalence, info sheet, 

expected fall 2015

• Salmonella, info sheet, expected fall 2015

• Enterococcus, info sheet, expected fall 2015

• Generic E. coli, info sheet, expected fall 2015

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

• Part II: Reference of Swine Health and Health Management in the United States, 

2012, expected summer 2015

• Swine Dysentery, info sheet, expected fall 2015

Table of Contents

Swine 2012 Part I

Introduction 1

Terms Used in This Report 4

Section I: Population Estimates 7

A. Sow and Gilt Management 7

1. Production phases 7

B. Breeding Herd Management and 

Productivity 10

1. Sites with breeding herd 10

2. Replacement gilts and new boars 11

3. Breeding methods 21

4. Gestation housing and pig flow 26

5. Farrowing housing and pig flow 36

6. Farrowoing productivity and 

preweaning death loss 45

 7. Weaning 50

8. Sow and gilt management 51

C. Nursery Phase 59

1. Facilities and pig flow 59

 2. Sourcing of nursery pigs 67

3. Death loss 71

4. Nursery pig management 73

D. Grower/Finisher Phase 75

1. Facilities and pig flow 75

2. Sourcing of grower/finisher pigs 82

3. Death loss 86

4. Grower/finisher pig management 88

E. Wean-to-finish Phase 91

1. Facilities and pig flow 91

2. Sourcing of wean-to-finish pigs 101

3. Death loss 104

4. Wean-to-finish pig management 108

F. Biosecurity and Other Farm 

Characteristics 111

1. Restrictions to entry 111

2. Trucking 114

3. Proximity to other swine sites 115

4. Rodent control 118

5. Feral swine 119

G. General Management 121

1. Environmental testing 121

2. Carcass disposal 122

3. Use of a veterinarian 124

Section II: Methodology 126

A. Needs Assessment and 

Study Objectives 126

B. Sampling and Estimation 127

1. State selection 127

2. Operation selection 127

3. Site selection 128

4. Population inferences 128

C. Data Collection 128

D. Data Analysis 129

E. Sample Evaluation 130

Appendix I: Study Profile 131

Appendix II: U.S. Swine Inventory and 

Number of Farms 132

Appendix III: Study Objectives and 

Related Outputs 133