Eimeria acervulina and Eimeria tenella infections in ochratoxin A-compromised broiler chickens

A 2 x 6 factorial experimental design was used to evaluate the effects of coccidial infections in ochratoxin A-compromised chicks. Ochratoxin A was incorporated into the feed at the dose levels of 0, .5, 1.0, 2.0, 4.0, and 8.0 micrograms/g toxin in feed (ppm), and fed to the birds from 1 day of age. Birds from each treatment were inoculated with either Eimeria acervulina or Eimeria tenella at 14 days of age. Ochratoxin A decreased the severity of lesions caused by both E. acervulina and E. tenella but did not prevent infection. Packed cell volume, hemoglobin concentration, relative weight of the kidney, and plasma protein levels were altered in a manner consistent with the independent effects of ochratoxicosis and coccidiosis. A combination of ochratoxin A and either species of coccidia produced a greater decrease in body weights, increase in feed conversions, and decrease in plasma carotenoid levels than either disease alone. The relative weight of the liver and level of plasma uric acid were altered in a manner that was dependent on the species of coccidia used. These data indicate that ochratoxin A and coccidial infections can interact to limit broiler performance and that some responses are directly related to the species of coccidia.