Development of immunity to porcine rotavirus in piglets protected from disease by bovine colostrum.
Bovine colostrum with rotavirus-neutralizing activity was fed for 10 days to two groups of piglets, one of which was inoculated intranasally with a rotavirus of porcine origin. A third group, which did not receive colostrum, was also inoculated with the virus, and these piglets developed diarrhea, excreted rotavirus in the feces, and died 6 days after infection. In contrast, the infected piglets fed with bovine colostrum remained healthy, although they developed antibody to rotavirus. Twenty-seven days after the primary inoculation, piglets in the colostrum-fed groups were inoculated intranasally with virus. Those in the previously unexposed group became clinically ill and excreted rotavirus, whereas those which had experienced a previous subclinical infection (the colostrum-fed, virus-inoculated group) remained healthy. It was concluded that bovine colostrum protected piglets from the clinical effects of a porcine rotavirus and that these animals developed an immunity which prevented subsequent disease.