Impact of prepartum administration of a vaccine against infectious calf diarrhea on nonspecific colostral immunoglobulin concentrations of dairy cows.

Unlike human babies, calves do not receive protective immune proteins (immunoglobulins) from the mother before birth, so a sufficient volume of immunoglobulin-rich colostrum of adequate quality must be consumed within hours of birth. It can be a challenge to meet this requirement for all dairy calves. Prior to calving, cows can be vaccinated with a vaccine against specific infectious causes of calf diarrhea to stimulate elevated concentrations of specific immunoglobulins in their colostrum, which is consumed by their calves to protect them until their own immune systems develop. We enrolled cows that were either vaccinated or not with a calf diarrhea vaccine and, using novel laboratory techniques, measured concentrations of immunoglobulin classes A, G, and M in their colostrum. As expected, vaccinated cows had elevated concentrations of vaccine-specific immunoglobulins in their colostrum. However, they also had elevated non-vaccine-specific concentrations of immunoglobulin M. The vaccine may therefore have stimulated a nonspecific increase in colostral immunoglobulin M concentrations. Further research is necessary to confirm the preliminary findings of the present study and determine the mechanism for this apparent nonspecific increase in colostral immunoglobulin M concentrations, whether it may occur in other immunoglobulin classes, and whether it may benefit calf health and growth.