Effects of cadmium and zinc on the quality of quail's eggs

We report the effects of cadmium (Cd) and zinc (Zn) on the quality of Japanese quail's eggs. For this study, 60 birds were divided into 3 groups of 20 subjects each. The animals in group 1 received 4 mg Zn/d, whereas those in group 2 were given a combination of 4 mg Zn/d and 0.12 mg Cd/d. The quails in group 3 were not given any supplements, acting as controls. The distribution of Cd and Zn in the eggs, the eggs' mass, and the strength and thickness of the shells were determined after 35 and 58 d of supplementation. Zinc showed a positive effect on the mass of eggs and accumulated mainly in the egg white. The content of Cd was significantly lower in the egg yolk of birds in group 1 (p<0.001), whereas those in group 2 had decreased eggshell thickness and strength in comparison to groups 1 and 3 (p<0.001). These results suggest that the adverse effects of Cd on the quality parameters of eggs from commercially important bird species can be, at least in part, counteracted by Zn supplementation.