Effects Of Different Additional Levels Of Vitamin E On Semen Quality, Serum Antioxidant Properties, Cloning And MRNA Expression Of SOD Gene In Holstein Bulls

Twenty-four breeding Holstein bulls assigned randomly to four groups were conducted to study the effects of different additional levels of vitamin E on semen quality, serum antioxidant properties and cloning and mRNA expression of SOD gene in Holstein bulls. The experimental bulls were divided into in 4 dietary treatments by two factors design, consisting of four additional levels of vitamin E which was 30, 150,300,600 IU/kg within 12 months. Each group included four stages for spring, (early) summer, autumn and winter. It showed that:1 The effects on semen qualityThe effects of different additional levels of vitamin E on semen quality in different stages were significant. With the increase of additional levels of vitamin E, semen quality in spring, early summer and autumn were significantly improved(P<0.05). And the greater improvement of semen quality was showed in autumn than the orther seasons. Sperm abnormalities rate decreased significantly(P<0.01), motility increased significantly(P<0.05) in autumn. According to quadratic curve fitting models, the optimal additional level of vitamin E to semen quality was 340～380 IU/kg in this experiment. In this additional level, it had the higher levels of semen quality the whole year and the low lost because of the season.2 The effects on serum antioxidant propertiesIn different additional levels of vitamin E, it showed the extremely significant difference in serum GSH-Px, T-AOC, inhibiting OH ability and MDA(P<0.01), and significant in SOD(P<0.05). The main effect of MDA parameter was the different additional levels of vitamin E, not the season. Other antioxidant parameters including GSH-Px, T-AOC, SOD, inhibiting OH ability in summer and autumn were higher than in spring and winter. According to quadratic curve fitting models, in 350～410 IU/kg additional level of vitamin E, it could keep serum antioxidant capacity at a high level, and could meet the Stud bulls' requirement for whole year.3 The effects of cloning and expression of SOD gene in bloodThe supplemental of vitamin E could enhance the mRNA expression of SOD1 extremely (P<0.01), and SOD3 significantly(P<0.05) in Holstein bulls blood in spring. As the additional level added, the mRNA expression of SOD1 and SOD3 were both increased firstly and then decreased. According to quadratic curve fitting models, the mRNA expression of SOD1 and SOD3 gene were both reached the peak in 330～380 IU/kg additional level in this experiment.It seemed that the optimal additional level of vitamin E of Holstein bulls was 330-410 IU/kg in this experiment.Total levels of vitamin E in the concentrate supplement is 385～445 IU/kg.