【作者】 郎海芳；

【导师】 侯明海； 林英庭；

【作者基本信息】 青岛农业大学 ， 动物营养与饲料科学， 2010， 硕士

【摘要】 选取24头年龄和体重相近、采精正常、生理状态基本一致的健康荷斯坦成年种公牛,采用两因子有重复试验设计,根据前期采精记录中射精量、精液密度、鲜精活力等指标进行分组,分别设30、150、300和600 IU/kg4个添加水平和春、(早)夏、秋、冬4个不同季节(阶段),每个处理6个重复,每个重复1头牛。本文研究了VE不同添加水平在不同季节(阶段)对荷斯坦种公牛精液品质、血清抗氧化性能及血液超氧化物歧化酶(SOD)基因mRNA表达的影响。结果表明：1、对精液品质的影响在不同季节(阶段),VE添加水平对种公牛精液品质主要指标的影响有一定的差异。随着添加水平的提高,在春、早夏、秋三个季节(阶段),精液品质显著改善,尤其秋季表现最为明显,精子畸形率极显著下降(P<0.01),鲜精活力显著提高(P<0.05)。VE添加水平对种公牛全年精液品质有着显著的影响,其中对射精量和总精子数影响极显著(P<0.01),对鲜精活力和精液密度影响显著(P<0.05)。本试验条件下,根据拟合曲线模式,VE添加水平在340～380 IU/kg范围时可最大程度地降低因季节因素造成的精液品质下降,使全年精液品质保持较高的水平。2、对血清抗氧化性能的影响VE添加水平可极显著提高种公牛血清中的GSH-Px、T-AOC和抑制·OH能力(P<0.01)、显著提高SOD活性(P<0.05)、极显著降低MDA含量(P<0.01)。MDA含量的变化受季节因素影响较小,主要是VE添加水平的影响；在夏、秋季节,种公牛血清中GSH-Px、SOD活性、T-AOC和抑制·OH能力等抗氧化指标明显高于春、冬季节；根据拟合曲线模式,当VE添加范围为350～410IU/kg时,抗氧化指标受季节因素影响最小,机体抗氧化能力处于较高水平,基本上可满足各季节种公牛对VE的需求。3、对血液SOD基因mRNA表达的影响VE添加水平可极显著提高荷斯坦种公牛春季血液SOD1基因(P<0.01)、显著提高SOD3基因的mRNA表达水平(P<0.05)。随着添加水平的提高,SOD1和SOD3基因的mRNA表达水平呈先升高后下降的趋势。在本试验条件下,根据拟合曲线模式,330～380 IU/kg添加水平时达到高峰。综合分析表明,成年荷斯坦种公牛精料补充料中VE适宜的添加水平为330～410 IU/kg,此时精料补充料中VE水平为385～445IU/kg。更多还原

【Abstract】 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.更多还原