Tolerance of the chick to excess dietary cadmium as influenced by dietary cysteine and by experimental infection with Eimeria acervulina.

Three experiments were conducted with 9-d-old crossbred chicks to determine the effect of supplemental L-cysteine.HCl.H2O on tolerance to excess dietary Cd. Cd levels of 30 or 60 mg/kg added to a fully fortified corn-soybean meal diet depressed both body weight gain and gain:feed ratio and increased kidney Cd concentration. Supplemental cysteine (i.e., .59% L-cysteine.HCl.H2O) did not alleviate the depression of weight gain or gain:feed ratio due to Cd feeding but did decrease kidney Cd accumulation. Eimeria acervulina infection (i.e., duodenal coccidiosis) depressed rate and efficiency of weight gain and resulted in increased Cd concentrations in kidney tissue. Cystein supplementation increased kidney cadmium concentration even further in E. acervulina-infected birds.