Studies on bovine Coccidiosis

The species of Eimeria in cattle were identified for the first timenin Australia. They were E. alabamensis, E. auburnensis, E. bovis, E. brasiliensis, E. brucei, E. bukidnonensis,nE. canadensis, E. cylindrica, E. ellipsoidallis, E. hammondi, E. marquardti, E. smithi, E. subspherica, E. wilsoni, and E. zurnii. Of these, E. brucei, E. hammondi, E.marquardti, and E. wilsoninare described as new species.nSporulation was found to occur in five stages i.e. (1) contractionnof the proptoplasmic mass into a sphere, (2) division of the sphericalnprotoplasm into four sporoblasts, (3) separation of the sporoblasts from thencentral mass, (4) elongation of the sporoblasts, and (5) formation of thensporozoites.nFor critical identification a nd differentiation of the species, thensporulation process (at 22dC) of the oocysts was used for the first time,nin addition to the general morphology of the oocysts and the sporooysts, andnthe sporulation time at 22dC. Three distinct types of morphological changesnwere found to take place during the sporulation process: refractile globulesnwere absent, or they were present and varied in appearance and disposition.nPolar globules were found to be common during sporulation but in most speciesndisappeared before the oocysts had sporulated. Extra-protoplasmio globules,na crescent-shaped refractile structure and a refractile projection werencharacteristic of E. bukidnonensis.nnof E. smithi, and of nE. cylindricanand E. ellipsoidallisnrespectively.nThe endogenous stages of E. alabamensis, E. auburnensis, E. bovis, E. bukidnonensis, E. canadensis, E. cylindrica, E. ellipsoidallis, E. smithi, E. wilsoni, and E. zurnii were studied. Calves were experimentally infectednand were destroyed on the day the oocysts were first shed. n