United States Department of Agriculture • Animal and Plant Health Inspection Service • Safeguarding American Agriculture

Veterinary Services

Centers for Epidemiology and Animal Health November 2011

_________________________________________________________________________________________________________________________

Highlights of Health and 

Management Practices on 

Breeder Chicken Farms in the 

United States, 2010

The USDA’s National Animal Health Monitoring System 

(NAHMS) conducted the Poultry 2010 study. One 

objective of the study was to describe farm-level health 

and management practices for chicken primary breeder 

and multiplier flocks. The poultry companies that 

participated in the Poultry 2010 study accounted for 

100.0 percent of primary breeder, 81.2 percent of broiler, 

71.7 percent of table-egg layer, and 81.5 percent of 

turkey production in the United States. Companies that 

had chicken breeder farms (either company owned or 

contract) participated in the breeder farm phase of the 

study, results of which are presented in this report.

Background: poultry industry structure

Breeder farms are comprised of primary breeder 

farms and multiplier farms. The illustration below shows 

how chicken breeder farms in the United States are 

structured (figure 1). Farms with pedigree/elite, greatgrandparent, and/or grandparent birds are considered 

primary breeder farms, all of which produce eggs for 

hatching. The progeny of pedigree flocks form greatgrandparent flocks, and the progeny of greatgrandparent flocks form grandparent flocks, and so on. 

The progeny of multiplier (i.e., parent) flocks become 

production birds on broiler (meat production) or layer 

(table-egg production) farms.

Figure 1. Structure of breeder chicken farms in the 

United States

Breeder farm characteristics

Birds on all primary breeder farms and birds on over

9 of 10 multiplier farms that produced table-egg layers 

were owned by breeder companies. Birds on nearly all 

multiplier farms that produced broilers were owned by 

broiler production companies (table 1). 

Table 1. Percentage of farms by bird ownership and 

by farm type

Percent Farms

Farm Type

Primary 

breeder—

broiler

Primary 

breeder—

table egg

Multiplier

—broiler

Multiplier

—table 

egg

All 

breeder 

farms

Bird 

ownership Pct. Pct. Pct. Pct. Pct.

Breeder 

company

100.0 100.0 1.3 90.9 13.5

Production 

company

0.0 0.0 98.7 9.1 86.5

Total 100.0 100.0 100.0 100.0 100.0

Primary breeder farms had an average of 14,246 

laying hens while multiplier farms had an average of 

19,680 laying hens.

The average ratio of hens to roosters on breeder 

farms was about 11:1. Fertility in breeding flocks 

declines as the flock ages. Young males can be added 

to the breeder flock, which stimulates breeding activity 

through competition between new and established 

males. This practice is called spiking. Nearly all multiplier 

farms (96.7 percent) and 8 of 10 primary breeder farms 

(80.2 percent) had introduced spiking males to stimulate 

breeding activity during the previous 12 months (table 2). 

About one-half of multiplier farms (49.5 percent) but less 

than 1 percent of primary breeder farms (0.6 percent)

that introduced spiking males did so three or more times 

during the previous 12 months. The source of spiking 

males for nearly all farms (99.9 percent) was other farms 

from the same company. Nearly all breeder farms that 

received spiking males from other farms (99.8 percent) 

performed routine testing of the source farms for health 

Primary 

breeder 

Breeder farms

farms
United States Department of Agriculture • Animal and Plant Health Inspection Service • Safeguarding American Agriculture

status (e.g., Mycoplasma or other tests) and 99.4 

percent tested males (e.g., Mycoplasma or other tests) 

before placing them on the farm.

Table 2. Percentage of farms that introduced spiking 

males during the previous 12 months to stimulate 

breeding activity, by farm type

Percent Farms

Farm Type

Primary breeder Multiplier All farms

80.2 96.7 95.0

Breeder farm biosecurity

Controlling access to the farm can prevent 

introduction of disease via people and vehicles. Nearly 

all primary breeder farms had fencing surrounding the 

farm. Signs (e.g., no trespassing) were posted on nearly 

all multiplier farms (95.6 percent) [figure 2]. Additionally, 

88.3 percent of poultry houses had locks on doors, and 

75.1 percent had anterooms that personnel had to pass

through that separated the outside area from the inside 

area. The majority of primary breeder farms (63.4 

percent) had gravel or a hard surface immediately 

surrounding their poultry houses, and the majority of 

multiplier farms (78.9 percent) had short grass

immediately surrounding the houses. No breeder farms

had tall grass or brush immediately surrounding the 

poultry houses.

Employee management is important for the 

prevention of disease introduction and spread. 

Employees worked at another commercial poultry 

production or processing facility for less than 1 percent

of multiplier farms (0.6 percent) and for none of the 

primary breeder farms. All primary breeder farms and 

nearly all multiplier farms (93.0 percent) had written 

biosecurity protocols. Additionally, over 9 of 10 primary 

breeder farms (90.8 percent) conducted formal 

biosecurity training for employees. 

No primary breeder farms allowed employees that 

entered poultry houses to own poultry or other birds, and 

nearly all required that the producer or employees 

shower before entering poultry houses. In addition, all 

primary breeder farms required that the producer and 

employees change clothing, change shoes or use shoe 

covers, and to not have been around poultry at least 24 

hours before entering poultry houses. Over 8 of 10 

multiplier farms required that the producer and 

employees use footwear protection, not be around other 

poultry, and not own poultry or birds (figure 3).

All primary breeder farms and over 90 percent of 

multiplier farms washed and disinfected feeders, flushed 

and disinfected water lines, washed down and 

disinfected the hoses, and cleaned the ventilation 

system after every flock.

Bird health and vaccination

Very few disease problems were reported for 

breeder farms, the most common being E. coli

peritonitis; 22.7 percent of farms reported at least a 

slight problem with E. coli peritonitis in the last 

completed flock (figure 4). None of the breeder farms 

had any history of infectious coryza or avian influenza. 
United States Department of Agriculture • Animal and Plant Health Inspection Service • Safeguarding American Agriculture

All breeder farms participated in the National Poultry 

Improvement Plan (NPIP) avian influenza (AI) program.

All primary breeder farms and more than 85 percent of 

multiplier farms participated in NPIP programs for 

pullorum, Mycoplasma synoviae (MS), and Mycoplasma 

gallisepticum (MG) (table 3). Nearly all breeder farms 

tested their last completed flocks for MS, MG, and AI

(99.7, 99.7, and 99.8 percent of farms, respectively). All 

primary breeder farms and 4 of 10 multiplier farms (40.1 

percent) tested their last completed flock for pullorum 

typhoid. (Note: Flocks may have been tested as pullets 

before coming onto the farm.) None of the farms that 

tested their last completed flocks for pullorum, MG, or AI 

had a positive test result, and less than 1 percent of 

farms had a positive test result for MS (0.9 percent).

Table 3. Percentage of farms that participated in an 

NPIP program for the following diseases, by farm 

type

Percent Farms

Farm Type

Primary 

breeder Multiplier All farms

Disease Pct. Pct. Pct.

Pullorum-typhoid 100.0 95.6 96.1

Mycoplasma 

synoviae (MS) 100.0 85.7 87.1

Mycoplasma 

gallisepticum (MG) 100.0 85.8 87.1

Avian influenza 

(AI) 100.0 100.0 100.0

Primary breeder farms did not vaccinate breeding 

hens while in lay. About one-third of multiplier farms 

vaccinated hens in lay against Newcastle disease and 

infectious bronchitis (31.5 and 31.5 percent, 

respectively). Over 80 percent of primary breeder farms 

and multiplier farms vaccinated pullets against infectious 

laryngotracheitis, Newcastle disease, infectious 

bronchitis, Salmonella, infectious bursal disease, avian 

encephalomyelitis, chicken anemia virus, reovirus, fowl 

pox, and coccidiosis. All primary breeder farms

vaccinated pullets for E. coli, and nearly all multiplier 

farms (98.0 percent) vaccinated pullets for cholera. 

______________________________

For more information, contact:

USDA–APHIS–VS–CEAH

NRRC Building B, M.S. 2E7

2150 Centre Avenue 

Fort Collins, CO 80526-8117 

970.494.7000

Email: NAHMS@aphis.usda.gov

http://nahms.aphis.usda.gov

#635.1111

____________________________________

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