RESUMO
To eliminate cytotoxic effects of colostrum on cells, a modified virus neutralization test (VNT) for the detection of Bovine viral diarrhea virus-specific neutralizing antibodies in colostrum was developed. The new test was compared to the World Organization for Animal Health-recommended VNT and the results evaluated. The agreement of the new test compared to the standard VNT was determined to be 98%, whereas sensitivity and specificity of the modified VNT compared to the standard VNT were 100%. Bovine viral diarrhea virus-specific antibodies were detected in 42 sera samples and 38 colostrum samples. The antibody titers in serum and colostrum showed a high correlation (n = 56, r = 0.9719, P < 0.001). The modified virus neutralization technique described herein succeeds in eliminating cytotoxic effects and can be readily applied for the detection of specific antibodies against other infectious agents in colostrum.