Persistent infection of calves with bovine viral diarrhea virus on U.S. beef cow-calf operations

2009·0.6 MB·English

Historic, Archive Document
Do not assume content reflects current
scientific knowledge, policies, or practices.

aSF967
.M/8P47 *)
2009
lary Services
or Epidemiology and Animal Health June 2009
Persistent Infection of Calves
with Bovine Viral Diarrhea
Virus on U.S. Beef Cow-calf Testing calf crop for BVDV
Operations
During the Beef 2007-08 study, beef producers who
expected to calve at least 70 percent of their cows and
heifers from November 1, 2007, through June 30, 2008,
The U.S. Department of Agriculture’s National Animal
were encouraged to collect ear notches from their entire
Health Monitoring System conducted the Beef 2007-08
2008 calf crop. Ear notches were subsequently frozen
study, which focused on beef cow-calf health and
dry until tested for indications of persistent infection with
management practices in 24 States divided into three
BVDV.
regions. These major beef cow-calf producing States
At the laboratory, notches were tested using an
represented 79.6 percent of U.S. operations with beef
IDEXX antigen capture enzyme-linked immunosorbent
cows and 87.8 percent of U.S. beef cows.
assay test according to the manufacturer’s instructions.
One of the goals of the Beef 2007-08 study was to
Overall, 205 operations collected ear notches from
estimate the prevalence of calves persistently infected
calves born between November 2007 and June 2008.
with bovine viral diarrhea virus (BVDV) on U.S. beef
The number of notches collected per operation ranged
cow-calf operations.
from 3 to more than 500. A total of 44,150 notches were
Infection with BVDV can affect an animal’s
collected and tested.
reproductive efficiency and cause a variety of conditions,
The prevalence of BVDV among the tested notches
including respiratory and digestive disease.
was 0.12 percent (53/44,150). Within herds, the
Ultimately, bovine fetuses are the source of
prevalence ranged from 0 to 16.0 percent.
persistent infection with BVDV in cattle. Fetuses
Of the 205 operations that submitted ear notches, 18
exposed to the virus between 40 and 120 days of
had 1 or more positive samples, for a herd-level
gestation can become immunotolerant to BVDV and
prevalence of 8.8 percent. Ten operations had only one
shed the virus their entire lives. These persistently
positive sample (1 operation with 1 to 49 cows and 9
infected animals can pass the virus to noninfected cattle,
operations with 200 or more cows), and 1 operation with
which develop clinical disease. If these newly-infected
200 or more cows had 10 positive samples. The
animals are pregnant, they can pass the infection to their
percentages of positive operations were similar across
calves (if the exposure occurs at the right stage of
herd sizes (table 1) and regions (table 2) due to the large
gestation) thereby creating the next generation of
variability in the estimates.
persistently infected calves. Infection with BVDV results
in other effects at other stages of gestation. Vaccination
Table 1. Operations with Samples Positive for BVDV,
can increase resistance to BVDV infection and thus
by Herd Size:
lower the frequency of persistently infected calves.
However, vaccination is not always effective in
eliminating the risk of persistently infected calves. Herd Herd Size (Number of Beef Cows)
BVDV control plans use surveillance, biosecurity, an
All
biocontainment strategies to prevent, reduce, and
200 Opera-
eliminate BVDV. Appropriate testing, targeted
1-49 50-99 100-199 or More tions
vaccination, and management are integral parts of these
Operations
plans.
submitting
samples x | oi 56 85 205
Operations
with
positive
States/Regions
samples 1 0 6 11 18
West: California, Colorado, Idaho, Montana, New Mexico,
Oregon, Wyoming Percent
Central: lowa, Kansas, Missouri, Nebraska, North Dakota, operations
South Dakota with
Southeast: Oklahoma, Texas, Alabama, Arkansas, Florida, Georgia,
positive
Kentucky, Louisiana, Mississippi, Tennessee, Virginia
samples SMe 0.0 TONE 12.9 8.8
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United States Department of Agriculture + Animal and Plant Health Inspection Service * Safeguarding American Agriculture
Table 2. Operations with Samples Positive for BVDV, For more information on BVDV, visit the following Web
by Region:
sites: NATIONAL. AGRICULTURAL LIBRARY
www.bvdinfo.org
Region
www.avc-beef.or 1022545384
Wwww.aabp.org
West Central Southeast
Operations
submitting
samples eS 88 44 For more information, contact:
Operations with
USDA:APHIS:VS:CEAH
positive
NRRC Building B, M.S. 2E7
samples 11.0 peat ieee 13-0
2150 Centre Avenue
Percent
Fort Collins, CO 80526-8117
operations with 970.494.7000
positive E-mail: NAHMS @aphis.usda.gov
samples 8 4 6 http://nahms.aphis.usda.gov
BVDV prevalence was similar across calf-age #551.0609
categories (table 3).
The U.S. Department of Agriculture (USDA) prohibits
Table 3. Percentage of Calves Positive for BVDV, by
discrimination in all its programs and activities on the basis of
Age of Calves:
race, color, national origin, age, disability, and where
applicable, sex, marital status, familial status, parental status,
religion, sexual orientation, genetic information, political beliefs, -
Percent Calves
reprisal, or because all or part of an individual’s income is
derived from any public assistance program. (Not all
Age
prohibited bases apply to all programs.) Persons with
Less Than 3Weeksto Over | Age disabilities who require alternative means for communication of
3Weeks 3Months 3 Months Unknown program information (Braille, large print, audiotape, etc.)
RT KRESS me ae should contact USDA’s TARGET Center at [phone]
(voice and TDD). To file a complaint of discrimination, write to
USDA, Director, Office of Civil Rights, 1400 Independence
Avenue, S.W., Washington, D.C. 20250-9410, or call (800)
Summary 795-3272 (voice) or [phone] (TDD). USDA is an equal
opportunity provider and employer.
The low prevalence of persistent infection with
BVDV in beef calves found in the Beef 2007-08 study is Mention of companies or commercial products does not imply
recommendation or endorsement by the USDA over others not
consistent with findings from other studies. Despite the
mentioned. USDA neither guarantees nor warrants the
low prevalence at the animal level, approximately 1 of 12
standard of any product mentioned. Product names are
operations had at least 1 persistently infected calf,
mentioned solely to report factually on available data and to
suggesting that a number of operations likely have
provide specific information.
BVDV circulating in their herds. Producers should work
with their veterinarian to determine the likelihood that
their herd has an animal persistently infected with BVDV
and, if warranted, develop a surveillance strategy to
determine the BVDV status of their cattle. If persistently
infected animals are discovered, a control or elimination
plan would be advisable, based on the operation’s
specific situation.
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United States Department of Agriculture + Animal and Plant Health Inspection Service + Safeguarding American Agriculture