Precolostral antibody screening gives clear evidence that pregnant cattle are exposed to BVDV and their fetuses are seroconverting. Testing for BVDV antibody in calves prior to colostrum feeding detects fetal infections in both late-gestation cows and non-lactating heifers, says Dr. Jeremy Schefers, University of Minnesota Veterinary Diagnostic Laboratory.

“Precolostral serum antibody detection is not confounded by vaccination and may be a more sensitive screening method than bulk milk RT-PCR, acute and convalescent serology, and non-vaccinated sentinel calves in large dairy herds,” Schefers says. In one Minnesota herd, he notes, whole herd testing followed by removal of PI animals significantly reduced fetal infections and improved herd health.