Effects of dietary zinc, manganese, and copper on tissue accumulation of cadmium by Japanese quail.

The beneficial effects of a combined dietary supplement of Zn, Cu, and Mn in decreasing Cd absorption was previously reported. The purpose of this study was to investigate the individual and combined effects of these three elements. In the first two experiments, day-old Japanese quail were fed basal diets containing either requirement amounts of Zn (30 ppm) and Mn (12 ppm) and slightly above requirement levels of Cu (5 ppm). From Day 7 birds were fed either the basal diet or diets containing combinations at twice these concentrations; a 2 X 2 X 2 factorial design was used. 109Cd content and Cd concentration of these diets were 100 mu Ci and 145 micrograms/kg, respectively. In the third experiment, day-old birds were fed either the basal diet or a basal diet containing 109Cd and single additional supplements of either Zn, Cu, or Mn. All birds were killed at 14 days of age. The Cd concentration was determined for the duodenum, jejunum-ileum, liver, and kidney. When the experimental diets were fed for 7 days, only Zn had a protective effect against Cd. Whereas none of the elements reduced the Cd concentration of the duodenum, Zn reduced the Cd in the jejunum-ileum, liver, and kidney by approximately 66, 21, and 11%, respectively. Cu and Mn caused occasional increases of Cd in some tissues. Feeding the experimental diets for 2 weeks resulted in similar responses. Zn nutrition appears to play an important role in protecting against dietary Cd absorption.