Cadmium and the laying hen: apparent absorption, tissue distribution and virtual absence of transfer into eggs.

After being given a single oral dose of 40 muCi. of 109CdCl2, laying hens were fed a practical type ration to which 0 or 60 p.p.m. cadmium (Cd, as CdCl2) was added. On the basis of 109Cd in excrement, apparent absorption of the isotope averaged less than 10% of the dose for both diets. Less than 4% of the dose was retained in total body tissue 23 days after dosing. Dietary Cd level did not significantly influence excretion of 109Cd by hens, but hens fed 60 p.p.m. Cd retained a significantly higher proportion of 109Cd dose in liver, kidneys and whole body than did control hens. 109Cd was only detected in blood 48 hours after dosing and more than 75% of radioactivity in the blood occurred in plasma. Hens fed 60 p.p.m. Cd consumed less feed and produced less eggs than control hens. 109Cd was found infrequently at very low levels in yolks of eggs produced by hens fed 60 p.p.m. Cd. No radioactivity was detected in any egg whites, or in yolks of eggs produced by control hens.