Studies on Coccidiosis

SINCE it has been demonstrated that an attack of coccidiosis has very definite and prolonged effects on the growth of chickens (Mayhew 1932a and b and 1934a) and that an early severe attack reduces subsequent egg-production (Mayhew, 1934b), an attempt has been made to determine some of the possible causes of these detrimental economic effects with the view of more intelligently seeking methods of treatment of birds sick with the disease. An examination of the post-mortem records of the chickens that had died from the disease during the progress of the experiments carried out at this station shows that the caeca are the regions of the digestive tract most commonly attacked by the coccidia as evidenced by the presence of hemorrhage. The following is a summary of the data: A total of 731 chickens have been inoculated in these experiments from 396 different cultures obtained from a wide variety of . . .