The Effect of Cadmium,with and without Supplemental Selenium,on Reproductive Performance in Chickens

The objective of our work was to study the effect of Cd alone and in combination with Se on the reproductive performance of hens, cocks and chicks. Cadmium as Cd chloride (CdCl₂) and Se as sodium selenite (Na₂SeO₃) were added to feed at the following dosages: group 0, control; group 1, 20 mg kg⁻¹ Cd; group 2, 30 mg kg⁻¹ Cd + 4 mg kg⁻¹ Se. The birds were exposed to Cd for 2 months. The following parameters were then evaluated: egg production, fertility, hatchability, and mortality of embryos and chicks of the F1 generation. Cadmium administration at 20 mg kg⁻¹ significantly affected production of eggs after 56 days of the experiment. Significant improvements in egg production in the group receiving 30 mg kg⁻¹ Cd+ 4 mg kg⁻¹ Se in comparison with group receiving 20 mg kg⁻¹ Cd alone and the control group was observed. Fertility and embryo mortality in the 20 mg kg⁻¹ Cd group was not significantly different from controls, whereas both these factors decreased in the group receiving 30 mg kg⁻¹ Cd + 4 mg kg⁻¹ Se. Hatchability in the 20 mg kg⁻¹ Cd group decreased, while this was significantly higher in the group receiving 30 mg kg⁻¹ Cd plus Se than in the group without Se supplementation and the control group. The negative effects of Cd ingestion on egg production can therefore be at least partially ameliorated by supplementation with dietary selenium.