EFFECT OF NATURAL ANTIOXIDANTS ON FROZEN BOVINE SEMEN PRESERVATION

The influence exerted by natural antioxidants (Vitamin E or sodium asc orbate) was studied in various thermal treatments of semen and their e ffect on respiratory activity and membrane integrity during cryopreser vation. Frozen bovine semen samples of diverse quality were employed i n the presence and absence of antioxidants. Both in good-quality sampl es subjected to cold shock and in those of poor-quality standard-coole d, low superoxide dismutase activity was observed concomitantly with h igh malondialdehyde production; as regards oxygen uptake there was no evidence of mitochondrial coupling. In good-quality samples standard-c ooled in the presence of antioxidants, greater superoxide dismutase ac tivity, intact acrosome percentage and mitochondrial coupling were rec orded as well as lower malondialdehyde production than in the controls . Natural antioxidants would seem to exert a protective effect on the membrane of the cryopreserved spermatozoon in samples from good-qualit y semen,