Development of calf diarrhoea vaccines.

Rotavirus and enterotoxigenic E. coli were found to cause approximately three-quarters of the total number of outbreaks of diarrhoea in young calves. Vaccinating pregnant cows with a combined vaccine of K99 antigen from E. coli and inactivated calf rotavirus stimulated secretion of specific antibodies in colostrum and milk. Calves born to vaccinated cows were completely protected against experimental enterotoxigenic colibacillosis. The efficacy of the rotavirus component is being investigated in field trials from which the early results look promising.