The effects of supplementing sodium selenite and selenized yeast to the diet for laying hens on the quality and mineral content of eggs

In this experiment the effects of supplementing the diet for laying liens with sodium selenite (SS) or selenized yeast (SY) on the quality and content of some minerals of eggs were studied. Hy-Line Brown chickens were randomly divided on the day of hatching into 4 groups (12 birds per group). The birds were fed from day I of life to 9 months of age with diets differing in amounts and/or forms of selenium. The control group received a basal diet (BD) containing selenium naturally occurring in feeds (0.1 mg Se/kg of dry matter (DM)). The first and second experimental groups were fed the same BD enriched with Se at a dose of 0.4 mg/kg DM from sodium selenite or selenized yeast, respectively. The feed for the third experimental group consisted of BD supplemented with selenized yeast to a final selenium content of 1.0 mg/kg DM. The results showed that supplementation of SY to the diet significantly affected egg weight, egg yolk weight, egg albumen weight and Haugh units. Significantly lower egg shell weights and egg shell ratios were found in the experimental group with sodium selenite. Also, the concentration of Se in blood as well as that of some trace- and macroelements in eggs of laying liens appeared to be significantly influenced by selenium supplementation.