EFFECT OF VITAMIN-E AND SELENIUM SUPPLEMENTATION OF COCKEREL DIETS ONGLUTATHIONE-PEROXIDASE ACTIVITY AND LIPID-PEROXIDATION SUSCEPTIBILITYIN SPERM, TESTES, AND LIVER

The phospholipids of avian spermatozoa are characterized by high propo rtions of arachidonic (20:4n-6) and docosatetraenoic (22:4n-6) fatty a cids and are therefore sensitive to lipid peroxidation. alpha-Tocopher ol and glutathione peroxidase [GSH-Px] are believed to be the primary components of the antioxidant system of the spermatozoa. The present s tudy evaluates the effect of vitamin E and vitamin E plus Se supplemen tation of the cockerel diet on GSH-Px activity, vitamin E accumulation , and lipid peroxidation in the spermatozoa, testes, and liver. At the beginning of the experiment 75 Rhode Island Red cockerels were divide d into five groups, kept in individual cages, and fed a wheat-barley-b ased ration balanced in all nutrients. Supplements fed to the differen t groups were as follows: vitamin E, 0, 20, 200, 20, and 200 mg/kg to groups 1-5, respectively, with groups 4 and 5 also receiving 0. 3 mg S e/kg. The vitamin E supplementation produced increased levels of ol-to copherol in semen, testes, and liver. The inclusion of the Se into the cock diet had a significant (P < 0.01)stimulating effect on GSH-Px ac tivity in seminal plasma, spermatozoa, testes, and liver. The increase d vitamin E concentration in the spermatozoa was associated with a red uction in their susceptibility to lipid peroxidation. Similarly, the i ncreased GSH-Px activity provided enhanced protection against lipid pe roxidation.