Copro-antibody in calves from dams vaccinated against Salmonella typhimurium.

Calves received colostrum either with (positive colostrum) or without (negative colostrum) anti-Salmonella typhimurium antibodies. Regarding the detectability of copro-antibodies, the following observations have been made. In calves that had been given positive colostrum on day 4 post natum (p.n.), copro-antibodies were detectable over 7 days, while in those that had received positive colostrum on day 1 p.n. copro-antibodies were detectable over 45 days. After supplying highly positive colostrum, copro-antibodies were found over a period of 8 weeks, and after supplying weakly positive colostrum, they were found over a period of 5 weeks. It is concluded that serum antibodies are transferred to the intestine for maximum local protection, and that there exists a preference for the intestinal system regarding the distribution of salmonella antibodies. Challenge infection on day 5 p.n. of calves that had received highly positive colostrum resulted in a copro-antibody gap that reached the limit of detectability in two calves that were excreting salmonellas. Challenge infection of calves that had received negative colostrum provoked a local IgM and IgA antibody response.