Effect of Dietary Vitamin E, Selenium and Their Combination on Concentration of Selenium, MDA, and Antioxidant Enzyme Activities in Some Tissues of Laying Hens

This experiment was conducted to investigate the effects of dietary vitamin-E (alpha-tocopherol acetate), selenium (selenomethionine) and their combination on Se concentration in liver, heart, kidney and breast muscle. In addition, malondialdehyde (MDA) concentration and enzyme activities of glutathioneperoxidase (GSH-Px), superoxide dismutase (SOD) and catalase (CAT) in liver, heart, breast and thigh tissues of laying hens were determined in present study. A total of 96 White Lohman laying hens, aged 24 weeks, were randomly divided into 4 groups (n=24), each of which was composed of 6 subgroups. The control group received the basal diet (T-1), treatment groups were fed on the the basal diet plus the three experimental diets included one of the followings: 125 mg/kg vitamin E + basal diet (T-2); 0.5 mg/kg Selenium + basal diet (T-3) and 125 mg/kg vitamin E plus 0.5 mg/kg selenium + basal diet (T-4), respectively. Experiment lasted for 12 weeks. In this study, supplementation of diets with Vit-E, selenium (Se) and their combination significantly increased Se concentration in all examined tissues of treatment groups when compared to the control group. Supplementation of Vit-E, Se and their combination significantly (P<0.05) decreased the concentration of MDA, but, significantly (P<0.05) incrased GSH-Px, SOD and CAT activities in treatment groups. In conclusion, results indicated that Vitamin E and selenium supplementation of laying hen diets could protect these animals from detrimental effect of free radicals by increasing activity of antioxidant enzymes.