Eimeria mitis: immunogenicity and cross immunity of two isolates

The ability of two isolates of Eimeria mitis to provide protection against homologous or heterologous challenge was examined. Based on weight gain and feed efficiency of male chickens, the B4 and C2 isolates protected against both homologous and heterologous challenge. The unprotected chickens suffered severe growth depression and impairment of feed utilization. Birds were inoculated with a series of increasing immunizing doses and became immune by the sixth dose. The C2 isolate (strain) appeared to be more immunogenic than the B4 isolate (strain).