中文摘要：

酵母硒和茶多酚都是优质的天然抗氧化剂。酵母硒作为有机硒源,兼有抗氧化和免疫增强的双重功效。茶多酚是茶叶中多酚类物质的总称,具有清除体内自由基、抗菌消炎和免疫调节等多种功效。为探讨酵母硒和茶多酚及其配伍对团头鲂（Megalobrama amblycephala）组织硒沉积量,肝中抗氧化酶活性及其基因m RNA表达的影响,本试验采用二因素三水平设计,在团头鲂幼鱼基础饲料中分别添加酵母硒（按硒计）3个水平（分别为0,0.25 mg/kg,0.50 mg/kg）,茶多酚3个水平（分别为0,50 mg/kg,100 mg/kg）,进行排列组合后得到9组日粮。选用体重为（1.75±0.01）g团头鲂1 350尾,随机分为9组,每组3个重复,每个重复50尾,进行为期8周的饲养试验。结果表明：1）日粮中添加酵母硒和茶多酚均能显著提高团头鲂幼鱼的增重率和特定生长率（P〈0.05）,当日粮中硒缺乏时,两者互作效应显著（P〈0.05）;而当硒适量或过量时,两者交互作用不显著（P〉0.05）。2）日粮中单独添加酵母硒能显著提高团头鲂肌肉和肝中硒含量（P〈0.01）,而茶多酚对组织硒含量无显著影响（P〉0.05）,两者对硒在肝中沉积的交互作用显著（P〈0.05）。3）酵母硒和茶多酚均能够通过诱导抗氧化酶基因表达来提高机体抗氧化酶性能,不同的是酵母硒主要上调Ma GPx1和Ma Cu/Zn-SOD基因m RNA表达,茶多酚主要上调Ma CAT基因。4）酵母硒和茶多酚具有协同抗氧化作用,两者配伍上调了Ma GPx1基因m RNA表达量（P〈0.05）,对Ma Cu/Zn-SOD和Ma CAT基因表达有促进作用,结果两者配伍显著提高了肝总抗氧化能力（T-AOC）而显著降低肝丙二醛（MDA）含量（P〈0.05）。综合分析,建议当基础日粮中添加0.50 mg/kg酵母硒和50 mg/kg茶多酚时,即在提高生长指标的同时较好的提高各抗氧化物酶的活性,降低肝中MDA的含量。

英文摘要：

Selenium yeast（SY） and tea polyphenols（TP） belong to high-quality natural antioxidants. As an organic selenium source, SP has the effects of both antioxidant and immune-enhancer. Tea polyphenols（TP） is a term for polyphenols in tea, which is helpful to free radicals scavenging, anti-bacterial and anti-inflammatory actions, immunomodulatory effects and so on. In the present study, a two-factorial and three-level experiment was designed to evaluate the effects of dietary SP and TP on selenium deposition in the muscle and liver, the activities and m RNA levels of antioxidant enzymes in the liver of juvenile Wuchang bream, Megalobrama amblycephala（mean weight 1.75 g±0.01 g）. Totally nine semi-purified diets were formulated to provide graded levels of Se（0, 0.25 mg/kg, 0.50 mg/kg） and TP（0, 50 mg/kg, 100 mg/kg）. After 8 weeks of feeding trial, the results showed that：（1） Both dietary SY and TP significantly enhanced the weight gain rate（WGR） and specific gain rate（SGR） in juvenile Wuchang bream（P〈0.05）. Only when dietary SY was lack（P〉0.05） are there significant interaction effects of dietary SY and TP on WGR and SGR.（2） Dietary SY significantly enhanced selenium contents in the muscle and liver（P〈0.01）, whereas there was no significant effect of dietary TP on selenium deposition（P〉0.05）, and the interaction effect of dietary SY and TP on selenium deposition was significant in liver（P〈0.05）.（3） Both dietary SY and TP significantly enhanced the activities of glutathione peroxidase（GPX）, superoxide dismutase（SOD）, catalase（CAT） by upregulating the expression of these antioxidant enzyme genes. The difference is that SY upregulated m RNA expression of Ma GPx1 and Ma Cu/Zn-SOD significantly（P〈0.05）, whereas TP raised the transcription of Ma CAT.（4） The combination of SP and TP has synergistic antioxidant effects by upregulating Ma GPx1 gene expression significantly and promoting the transcription of Ma Cu/Zn-SOD and Ma CAT. A