Abstract:

Twenty-four breeding Holstein bulls assigned randomly to four groups were conducted to study the effect of different additional levels of vitamin E on semen quality and plasma antioxidant parameters. This experiment involved 4 dietary treatments，consisting of four additional levels of vitamin E which was 30mg/kg, 150mg/kg, 300mg/kg , 600mg/kg within 9 months. The results showed that: Compared with the vitamin E level of 30 mg/kg, sperm concentration and motility in 300 mg/kg level were significantly increased (P<0.05), and sperm abnormalities rate decreased significantly (P<0.01). There were found no significant difference between any of two treatments in ejaculate and freeze-thawed motility (P>0.05). There were extremely significant differences in serum activity of GSH-Px, SOD and T-AOC (P<0.01), and serum contents of ?OH and MDA (P<0.01). It seemed that the optimal additional level of vitamin E of stud Holstein bull was 300 mg/kg.