饲料中添加谷胱甘肽对凡纳滨对虾肝胰腺抗氧化指标和脂质过氧化物含量的影响

Effects of dietary glutathione level on growth performance,antioxidant indexes and lipid peroxide content of hepatopancreas in Litopenaeus vannamei

采用1种对照饲料和5种添加不同水平还原型谷胱甘肽(GSH)(添加量分别为60、120、180、240和300mg.kg-1)的试验饲料,饲喂初始体重约为1.12g的凡纳滨对虾(Litopenaeusvannamei),分别命名为G0、G60、G120、G180、G240和G300组,经8周饲养后,观察饲料中不同浓度的GSH对凡纳滨对虾生长性能、肝胰腺抗氧化指标和脂质过氧化物含量的影响。结果表明,南美白对虾的增重率随着饲料中GSH添加量的增加而增加,在G180组达到高峰,但随着GSH添加量的进一步增加,增重率呈下降趋势(P<0.05);饲料转化率随饲料中GSH添加量的升高而显著升高,在G240组达到最高(P<0.05);成活率随饲料中GSH添加量的增加而显著提高,提高幅度为8.53%-31.69%。饲料中添加GSH能不同程度地提高凡纳滨对虾肝胰腺中抗氧化酶活力(P<0.05),其中G60、G120组的谷胱甘肽还原酶,G120、G180和G300组的超氧化物歧化酶,G120、G180和G240组的谷胱甘肽过氧化物酶活力,分别显著高于对照组G0(P<0.05)。各试验组肝胰腺中GSH含量和总抗氧化能力比对照组G0分别提高了8.93%-52.57%和3.02%-37.03%,且呈剂量??效应关系。对虾肝胰腺中的活性氧含量随着日粮中GSH添加量的增加呈现下降的趋势,其中G180、G240组显著低于对照组(P<0.05);与对照组相比,试验各组肝胰腺丙二醛含量显著降低(P<0.05),抗O2-能力升高,在G120、G180、G240和G300组达到显著水平(P<0.05)。研究结果初步表明,饲料中添加一定量的GSH能提高凡纳滨对虾生长性能和肝胰腺抗氧化能力并降低脂质过氧化物含量。

A feeding experiment was conducted to determine the effects of dietary glutathione （GSH） on growth performance, antioxidant indexes and lipid peroxide content of hepatopancreas in Litopenaeus vannamei. The shrimp, initially weighing about 1. 12 g, were fed a control diet （G0） and five treatment diets supplemented with 60, 120, 180, 240 and 300 mg · kg^-1 GSH （Gro, G120, G180, G240 and G300） respectively. After a 8-week feeding trial, the results showed that, with the increasing of dietary GSH level, weight gain rate （WGR） of the shrimp increased, reaching the highest level at G180, then significantly decreased at a higher level （ P 〈 0.05 ）. Feed conversion efficiency （FCE） increased significantly with the dietary GSH level increasing, reaching the hightest at G240. The shrimp survival rate of experimental groups significantly increased in comparison with that of control. Dietary GSH had a significantly effect on the activity of antioxidant enzymes in hepatopancreas ： the activity of GR at Gro and G120 , SOD at G120 , G180 and G300, GSH - PX at G120, G180 and G240 were significantly higher than that of control （P 〈 0.05）. The content of GSH and the total antioxidant ability （T-AOC） in hepatopancreas showed a dose-dependent relationship with dietary GSH level, 8. 93% - 52. 57% and 3. 02% - 37. 03% being increased of experimental groups compared with control. With dietary GSH increasing, ROS level in hepatopancreas tends to decrease, showing significant decrease at Group G240 and G300 （ P 〈 0.05 ）, MDA content of each experimental groups was significantly lower than that of control （P 〈 0.05 ）. Dietary GSH significantly improved anti-O2^- ability of group G120,G180 and G240 （P 〈 0.05）. The results of this study suggested that dietary GSH might help to improve growth performance, raise antioxidant indexes, and decrease lipid peroxide content in hepatopancreas of Litopenaeus vannamei.