Caecal coccidiosis of rather more than usual severity has been found to develop in chicks folded on a stemmy type perennial rye grass pasture at Hanns Hall Farm this season.

Subsequent brooder house experiments have demonstrated that chicks receiving a diet relatively low in protein and fibre content and relatively high in starch content, as cereals, failed to develop coccidiosis when subjected to severe infestation by coccidial oocysts, while the chicks in the same brooder house on a diet containing more roughage developed acute coccidiosis, and other chicks in the same brooder house on a diet containing a relatively high proportion of protein developed chronic coccidiosis.

As these experiments have shown that coccidiosis occurs on diets designed to promote proliferation of anaerobic bacteria in the intestines, and, conversely, does not occur when chicks are fed a diet designed to depress the proliferation of undesirable bacteria in the intestines, it would appear that coccidiosis in chicks is a secondary complaint, the primary aetiological agents being bacteria which proliferate to excess in the presence of roughage or protein.

Attention is drawn to the occurrence of postcoccidial abscesses which may occur after apparent successful treatment with Sulphamezathine for the cure of coccidiosis.