Experimental infection of newborn calves with coccidia and reinfection after weaning.

摘要: Four newborn Hereford calves were orally inoculated five times with 100 sporulated oocysts of coccidia, predominantly Eimeria zurnii. Each calf was kept isolated its dam until weaned at the age 13 weeks. Three other similarly but not experimentally infected. The then challenged 300,000 five, seven and nine months. previously unexposed developed marked clinical coccidiosis after first challenge, resisted second third challenge. neonatally exposed susceptible to infection challenge as well next two challenges months age, signs following last milder than those These findings suggest that under conditions where become infected coccidia when very young, such may, by shedding in large numbers for long periods, be a continuing source coccidial infections animals.