| Abstract: | Duration of active and colostrum-derived passive antibodies to bovine viral diarrhea virus was studied in 14 calves. Five calves born with actively induced antibodies to bovine viral diarrhea virus retained high titers during the year of observation. Colostrum-derived antibodies to bovine viral diarrhea virus in nine calves declined at an expected rate for the first four to six months of age. However, titers of six of these calves increased at five to eight months of age and either remained constant or increased through one year of age. Bovine viral diarrhea virus antibody titers of the other three calves declined at a constant rate to less than 1:4 by nine to 12 months of age. |
