Antibody levels in milk of vaccinated and unvaccinated cows against organisms of neonatal diarrhoea

Serological, colostral and milk responses of cows vaccinated with a single dose of a combined vaccine against rotavirus, coronavirus and Escherichia coli F5 (K99)

Twenty-five Ayrshire/Friesian cows were vaccinated once with a new combined vaccine against rotavirus, coronavirus and Escherichia coli F5 (K99) or given a saline placebo 31 days before the first expected calving date. Blood samples were taken from the cows at intervals from vaccination until seven days after calving and from their calves up to 28 days after birth, and colostrum and milk samples were collected from the cows at intervals for 28 days after calving. There was a significant increase in the mean specific antibody titre against all three antigens in the serum of the vaccinated animals (even in the presence of pre-existing antibody) which was accompanied by increased levels of protective antibodies to rotavirus, coronavirus and E coli F5 (K99) in their colostrum and milk for at least 28 days.

Lactogenic immunity following vaccination of cattle with bovine coronavirus

In order to investigate the ability of an oil adjuvanted vaccine containing bovine coronavirus antigen to enhance lactogenic immunity in the calf, pregnant cows and heifers were vaccinated and specific virus neutralising antibody levels determined in serum, colostrum and milk. Pre-existing antibody titres (as a result of natural infection) in the serum of these animals were found to be significantly increased as a result of a single shot vaccination carried out between 2 and 12 weeks before calving. This was reflected in a similar increase in the titre and duration of specific antibody in milk and colostrum that was passed on to the calves. The overall response observed was highly dependent on an adequate antigen payload being incorporated within the single dose vaccine. No abnormal local or systemic reactions were observed as a result of vaccination. It is hoped that this approach will lead to the production of a superior commercial vaccine for the protection of neonatal calves against enteric coronavirus infection.

Enhancement of passive immunity with maternal vaccine against newborn calf diarrhea

The effects of a maternal vaccine against newborn calf diarrhea associated with group A bovine rotavirus (BRV), bovine coronavirus (BCV), bovine parvovirus and K99 Escherichia coli (E. coli) were examined on a beef cow-calf herd. After vaccination, serum or colostrum antibody titers to BRV, BCV and E. coli K99 in the vaccinated cows were significantly higher than those in unvaccinated control cows. Serum antibody titers to BRV, BCV and E. coli K99 in calves from the vaccinated cows were also significantly higher than those in calves from the control cows for 3-4 weeks after birth. These results suggested that the immunization of cows with the maternal vaccine enhanced the passive immunity levels in calves against BRV, BCV and K99 E. coli.

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.