No abstract

Inoculation at birth with a live attenuated strain of a bovine rotavirus isolated in the USA (scourvax-reo) induced protection in five gnotobiotic calves seven to 21 days later against a UK isolate of pathogenic bovine rotavirus. However, no protection was induced in three calves challenged three to five days after vaccination. There was a close antigenic relationship demonstrated between the two bovine rotavirus isolates. In contrast only one of three gnotobiotic calves inoculated with foal rotavirus, and one of three with human rotavirus, were protected against bovine rotavirus challenge. Protection in these two calves correlated with high heterologous immunofluorescent antibody titre (320 or greater), although the neutralising antibody titres was less than 20.

Monoclonal antibodies have been produced using two haptens, zeranol-7-hemisuccinate coupled to bovine serum albumin and zeranol-16-carboxypropyl ether coupled to human serum albumin. An assessment of cross-reactivity demonstrated that the monoclonal antibody raised against the 7-hemisuccinate derivative reacted with zeranol (100%), talernol (12%), zearalenone (17%), zearalanone (100%) and alpha- and beta-zearalenol (17% and less than 0.01%, respectively). In contrast the antibodies to the 16-carboxypropyl ether derivative reacted only with zeranol (100%) and also with a alpha-zearalenol (13-16%). All monoclonal antibodies were more specific than the polyclonal antibodies raised to the same haptens by conventional methods using sheep.