Serological, colostral and milk responses of cows vaccinated with a singledose 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 gi ven 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 col ostrum and milk samples were collected from the cows at intervals for 28 da ys after calving. There was a significant increase in the mean specific ant ibody titre against all three antigens in the serum of the vaccinated anima ls (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.