Experimental infections of the domestic fowl with a variant of Eimeria praecox from the Ceylon jungle fowl

Abstract

A species of Eimeria from the Ceylon jungle fowl (Gallus lafayetti), at first thought to be a new species of Eimeria, has been identified as a strain of E. praecox. Oocysts of this jungle fowl strain were slightly larger than those of E. praecox, being 23·2 × 19·9 μm, but the endogenous stages were similar. The strain reproduced poorly in the domestic fowl but oocyst production was improved by treating the chickens with beta-methasone. A single infection of chickens with the strain of jungle fowl origin protected against challenge with the original culture and E. praecox, but did not cross-protect against E. acervulina. The name E. praecox var. ceylonensis is proposed for this strain of Eimeria.The criteria used to identify new species of Eimeria are discussed.