Brief Research Reports
Correspondence: 1Corresponding Author: Jeremy Schefers, University of Minnesota, 1333 Gortner Avenue, St. Paul, MN 55108. firstname.lastname@example.org
The authors propose that screening newborn calves for Bovine viral diarrhea virus (BVDV) antibody prior to colostrum feeding is a useful strategy to detect herds with endemic BVDV infection. In the current study, precolostral serum samples of newborn calves in 2 Minnesota and 2 California dairy farms were examined. Precolostral BVDV antibodies were detected by serum neutralization and enzyme-linked immunosorbent assay in 7.4% (33/446) and 6.2% (32/515) of newborn calves in the California and Minnesota herds, respectively. The serum samples were also tested by reverse transcription polymerase chain reaction (RT-PCR), and BVDV was detected in 1.6% (7/446) and 3.5% (18/515) of newborn calves in the California and Minnesota herds, respectively. The primary advantages of precolostral testing are that calves congenitally infected with BVDV and seropositive at birth represent a larger percentage of calves born than BVDV-viremic calves and that fewer animals would need to be tested with an antibody test than a RT-PCR or antigen detection test to detect endemic BVDV infections at the herd level. Testing for BVDV antibody in calves prior to colostrum feeding detects fetal infections in both late-gestating cows and nonlactating heifers. Precolostral serum antibody detection is not confounded by vaccination and may be a more sensitive screening method than bulk milk RT-PCR and nonvaccinated sentinel calf strategies in large dairy herds.
Key Words: Bovine viral diarrhea virus • dairy herd • herd-level screening • precolostral serum antibody
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Schefers J1, Munoz-Zanzi C, Collins JE, Goyal SG, et al.: J Vet Diagn Invest 20: 625-628, 2008.