Effect of irradiation (gamma rays) on the biology of Eimeria tenella oocysts.

Effect of gamma rays on the biology of the progeny of the irradiated Eimeria tenella oocysts was investigated. The parent inoculum of sporulated oocysts was exposed to 5 to 60 kR (gamma rays). These oocysts were fed to chicks. The oocysts voided by the chicks were collected and sporulated. The sporulation rate, pathogenicity, immunogenicity and reproduction potential of these oocysts--the progeny of the irradiated oocysts--were compared with those of the unirradiated oocysts. It was observed that increase of irradiation dose caused progressive decrease in the pathogenicity of the oocyst suspension. The oocysts exposed to 30 and 40 kR produced only mild infections whereas those exposed to 50 kR and above, were noninfective. No difference in pathogenicity, immunogenicity and reproduction potential of unirradiated oocysts and the oocysts progeny of the irradiated oocysts, was seen. It was concluded, therefore, that the effect of irradiation was limited to the inoculum exposed to it, and was not transmissible to the progeny of the irradiated oocysts.