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

Veterinary Services 

Centers for Epidemiology and Animal Health December 2009 

_________________________________________________________________________________________________________________________ 

Biosecurity on U.S. Beef 

Cow-calf Operations 

The U.S. Department of Agriculture’s National Animal 

Health Monitoring System (NAHMS) conducted the Beef 

2007–08 study, which focused on beef cow-calf health 

and management practices in 24 States.*

 These States 

represented 79.6 percent of U.S. operations with beef 

cows and 87.8 percent of U.S. beef cows. 

An objective of the Beef 2007–08 study was to 

describe current biosecurity practices on cow-calf 

operations. Biosecurity involves the use of certain 

management practices designed to prevent the 

introduction of disease to a premises. Examples of these 

practices include: limitations on new animal sources, 

quarantine and testing of new animal additions, rodent 

control and control of other animals that may serve as 

vectors for infectious agents, control of fence-line 

contact with outside cattle and other animals, and 

monitoring and controlling human and vehicle traffic on 

the operation. Usually, a comprehensive biosecurity plan 

also includes measures to increase the animals’ 

resistance to disease (e.g., vaccination). 

Herd additions

Herd additions can be a source of disease 

introduction. Producers were asked about the addition of 

cattle during the previous 12 months and during the 

previous 3 years. The percentage of operations that 

added any cattle during the previous 12 months 

increased as herd size increased, from 27.6 percent of 

operations with 1 to 49 beef cows to 69.9 percent of 

operations with 200 or more beef cows. During the 

previous 3 years, 67.8 percent of operations added 

cattle (table 1). 

 

*

States 

Alabama, Arkansas, California, Colorado, Florida, Georgia, Idaho, 

Iowa, Kansas, Kentucky, Louisiana, Mississippi, Missouri, Montana, 

Nebraska, New Mexico, North Dakota, Oklahoma, Oregon, South 

Dakota, Tennessee, Texas, Virginia, and Wyoming. 

Table 1. Percentage of Operations that Brought New 

Cattle onto the Operation During the Following Time 

Periods, by Herd Size 

 Percent Operations 

Herd Size (Number of Beef Cows)

Cattle 

added 

during... 1-49 50-99 100-199

200 or 

More 

All 

Operations 

Previous 

12 months 27.6 43.0 58.0 69.9 34.5 

Previous 

3 years 58.6 88.3 88.1 89.2 67.8 

The level of risk for introducing a disease to an 

operation varies depending on the source and type of 

new cattle. For instance, the risk of adding an animal 

from a herd of known health status (e.g., negative for 

Johne’s disease) would be lower than the risk of adding 

an animal obtained from a herd of unknown status. The 

most common sources for herd additions on operations 

that brought on new cattle were another beef operation 

(70.3 percent of operations) and sale barn/auction 

(34.8 percent of operations). 

The most common classes of cattle brought on 

during the previous 12 months were weaned beef bulls 

(19.5 percent of operations) and pregnant beef cows 

(9.2 percent of operations). 

Quarantine of new arrivals

 Isolation of new animals is one way to decrease the 

risk of introducing new disease agents into the herd. 

New additions can be monitored for disease symptoms 

while in isolation; the isolation period should be long 

enough to allow recently infected animals to begin to 

show signs of disease. Almost two-thirds of operations 

that added cattle during the previous 12 months 

did not quarantine any of the new cattle (figure 1).
United States Department of Agriculture • Animal and Plant Health Inspection Service • Safeguarding American Agriculture 

None

Some

All

Figure 1. For Operations that Brought New Cattle onto 

the Operation During the Previous 12 Months, 

Percentage of Operations that Quarantined or 

Separated All, Some, or None of the New Additions

28.0%

5.7%

66.3%

Testing new arrivals

Another strategy to reduce the chance of introducing 

infectious pathogens is to require testing of newly 

acquired cattle for diseases before bringing them onto 

the operation. Some disease agents, such as bovine 

viral diarrhea (BVD) virus and the bacterium that causes 

Johne’s disease, can be carried by cattle with no 

outward signs. Almost one of four operations that 

brought cattle 2 years of age or older onto the operation 

during the previous 3 years (24.1 percent) required that 

these animals be tested for brucellosis. About 1 of 20 

operations that brought cattle onto the operation during 

the previous 3 years required testing for BVD (4.5 

percent) or bovine tuberculosis (5.4 percent), and only 1 

of 50 operations (2.1 percent) required testing for 

Johne’s disease (figure 2). 

0 5 10 15 20 25

Brucellosis for

animals 2 years

of age or older*

Johne's

disease

BVD

Bovine

Tuberculosis

Anything

else

24.1

2.1

4.5

5.4

2.7

Percent

Figure 2. For Operations that Added Cattle During the 

Previous 3 Years, Percentage of Operations that 

Normally Required Tests for the Following Diseases 

Before Bringing Cattle onto the Operation

Disease

*Excludes operations that brought on only cattle less than 2 years of age.

Bulls used for breeding

The percentages of operations that purchased, 

leased, or borrowed bulls for the last breeding season 

increased as herd size increased, ranging from 

25.1 percent of operations with 1 to 49 beef cows to 

68.2 percent of operations with 200 or more beef cows 

(figure 3). 

0

20

40

60

80

Percent

Figure 3. Percentage of Operations that Purchased, 

Leased, or Borrowed Bulls in Preparation for the 

Last Breeding Season, by Herd Size

25.1

34.3

49.1

68.2

30.7

1-49 50-99 100-199 200 or

more

All

operations

Herd Size (Number of Beef Cows)

The addition of bulls for breeding can introduce 

venereally transmitted diseases such as Tritrichomonas 

fetus. Tritrichomonas can cause economic losses due to 

infertility and abortions. Testing for Tritrichomonas is 

recommended for all new bulls over 18 months of age or 

no longer considered virgin. Bulls should be tested three 

times at weekly intervals prior to being introduced to the 

herd, and positive bulls should be sent to slaughter. Just 

over one of three operations (34.4 percent) that 

purchased, leased, or borrowed bulls over 18 months of 

age or no longer considered virgin had all these bulls 

cultured for Tritrichomonas. A higher percentage of 

operations with 200 or more cows tested all these bulls 

than operations with fewer than 200 cows (figure 4). For 

comparison, in 1992 only 4.4 percent of operations that 

introduced bulls over 18 months of age or no longer 

considered virgin had all these bulls tested for 

Tritrichomonas.

 1

 

1

Cow Health and Productivity Audit 1992/93 Part 3, Population: 

spring calving operations with 5 or more cows in 18 States. 
United States Department of Agriculture • Animal and Plant Health Inspection Service • Safeguarding American Agriculture 

0

20

40

60

80

Percent

Figure 4. For Operations that Introduced Bulls Older 

than 18 Months or No Longer Considered Virgin, 

Percentage of Operations that Cultured All These 

Bulls for Tritrichomonas fetus, by Herd Size

1-49 50-99 100-199 200 or

more

All

operations

Herd Size (Number of Beef Cows)

34.0

28.6 26.4

58.5

34.4

Cattle that leave the operation and then return

Animals that leave the operation to attend an event 

and return represent another avenue for introducing 

disease agents. Only 5.4 percent of operations had any 

cattle that left the operation to go to a show, fair, rodeo, 

or other event and then return during the previous 12 

months (table 2). Of operations in which any cattle left 

the operation, had contact with other cattle, and then 

returned during the previous 12 months, over one-half 

(53.6 percent) routinely isolated cattle when they 

returned. 

Table 2. Percentage of Operations in which Any 

Cattle Left the Operation to Attend a Show, Fair, 

Rodeo, or Other Event and Returned During the 

Previous 12 Months, by Herd Size 

Percent Operations 

Herd Size (Number of Beef Cows)

1-49 50-99 100-199 

200 or 

More 

All 

Operations

4.3 6.2 9.5 12.0 5.4 

Visits to the operation

Visitors can carry disease agents from one operation 

to another. Producers were asked about the number of 

visits to the operation during an average month, 

including visits by employees, veterinarians, neighbors, 

nutritionists, commercial haulers, etc. Overall, 29.4 

percent of operations had 10 or more visits in a month 

(fig. 5). Operations with 200 or more cows were more 

likely to have 10 or more visits a month than operations 

with fewer than 200 cows. Over one-half of operations 

with 200 or more cows (51.4 percent) had 10 or more 

visits in a month. 

10 or more

6-9

3-5

1-2

0

Figure 5. Percentage of Operations by Number of Visits

to the Operation During an Average Month, Including

Visits by Employees, Veterinarians, Neighbors,

Nutritionists, Commercial Haulers, etc.

17.9%

24.7%

29.4%

21.1%

Number Visits 6.9%

Contact with other animals

Some diseases can be transmitted to cattle from 

other animal species. For example, deer can transmit 

bovine tuberculosis to cattle. Also, foot-and-mouth 

disease can be passed among cattle, sheep, pigs, and a 

number of other species. Awareness of contact between 

cattle and other animal species can lead to a more 

timely response to a disease outbreak. During the 

previous 12 months, wild cervids (e.g., elk, deer) had 

fence-line contact or commingled with beef cattle on 

72.6 percent of operations. Other species that had direct 

contact with beef cattle included horses (44.5 percent of 

operations), pigs (12.1 percent of operations), goats (9.6 

percent of operations), dogs (69.7 percent of 

operations), and cats (55.4 percent of operations). Beef 

cattle had direct contact with dairy cattle on 3.1 percent 

of operations, and had direct contact with cattle of 

Mexican origin on only 1.0 percent of operations. 
United States Department of Agriculture • Animal and Plant Health Inspection Service • Safeguarding American Agriculture 

Rodents and insects can serve as reservoirs or can 

mechanically carry the agents for various cattle 

diseases. About 8 of 10 operations (82.0 percent) used 

fly control during the previous 12 months, and 

65.0 percent routinely used some type of rodent control 

during the previous 12 months.

Summary 

A number of management practices can reduce the 

risk of introducing disease to an operation. Each 

operation should develop a customized biosecurity plan 

based on the specific risks of the operation and on the 

diseases targeted for control. The biosecurity plan will 

likely include some combination of management 

practices and the judicious use of vaccines. Employee 

training and annual review of the biosecurity plan are 

important aspects of maintaining a successful plan. 

Further information on biosecurity can be found in 

the Bovine Alliance on Management and Nutrition’s “An 

introduction to infectious disease control on farms 

(biosecurity).” See reference below. 

Reference 

Bovine Alliance on Management and Nutrition. “An 

Introduction to Infectious Disease Control on Farms 

(Biosecurity) 2001. For copies, contact: AFIA, Rich 

Sellers, 1501 Wilson Blvd., Suite 1100, Arlington, VA 

22209. 

http://nahms.aphis.usda.gov/dairy/bamn/BAMNBiosIntro.

pdf

___________________________ 

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 

E-mail: NAHMS@aphis.usda.gov 

http://nahms.aphis.usda.gov

#557.0509 

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