Effect of vitamin E supplement in diet on antioxidant ability of testis in Boer goat.

The aim of this study was to evaluate the supplementation of Vitamin E in diet on the antioxidant capacity of testis in Boer goat. Twenty-four healthy, Boer male kids of similar body weight (BW) were selected at 3 months of age from the kid flock. Kids were born from does treated with simultaneous flushing and artificial insemination technology. The Boer kids were divided into four groups randomly, supplemented with 0, 80, 320 and 880 IU kid(-1)d(-1) Vitamin E, which were labeled as Groups 1, 2, 3 and 4, respectively, for 150 days (5 months). Blood samples were collected at the 15th-, 30th-, 60th-, 90th-, 120th-, and 150th-day during the experimental period, and the serums were used to determine Vitamin E content. Three Boer goats in each group were slaughtered at the age of eight months at the end of the experiment. Liver and testis were collected to test the Vitamin E content and the antioxidant capacity of testis. Results showed that the content of Vitamin E in serum, liver and testis increased with the increasing addition of Vitamin E. However, the content of Vitamin E in the serum, liver and testis, in the control, was significantly lower than in Groups 2 and 3, respectively, but there was no significant difference between the control Group and Group 4. When high levels of Vitamin E (880 IU kid(-1)d(-1)) were added, contents of Vitamin E in serum, liver and testis were decreased and compared with the controls. Adding a low level (80 IU kid(-1)d(-1)) of Vitamin E can increase activity of total anti-oxidation competence (T-AOC) and superoxide dismutase (SOD), and decrease content of nitric oxide (NO) in testis. MDA (malondialdehyde) content was decreased significantly in Group 3 (P<0.05). Supplementing a low level (80 IU kid(-1)d(-1)) and middle level (320 IU kid(-1)d(-1)) of Vitamin E decreased activity of nitric oxide syntha (NOS) in testis (P<0.05). Vitamin E can increase activity of GSH-PX (glutathione peroxidase). These results indicate that supplementing Vitamin E protects testis from damage by preoxidation.