酵母核苷酸对团头鲂生长性能、抗氧化功能和抗病力的影响

本试验旨在研究饲料中添加酵母核苷酸对团头鲂生长性能、抗氧化功能和抗病力的影响。选择初始体重为（３１．４６±０．０７）ｇ的团头鲂 ３００尾，随机分成 ２组（对照组和核苷酸组），每组 ３个重复，每个重复 ５０尾。对照组试验鱼饲喂基础饲料，核苷酸组试验鱼饲喂在基础饲料中添加 ２００ｍｇ／ｋｇ酵母核苷酸（单体核苷酸与低聚核苷酸总含量为 ７０％）的试验饲料，饲喂５６ｄ后测定鱼体的生长、形体以及血液生理生化指标，并在饲养试验结束后采用嗜水气单胞菌攻毒试验测定鱼体的累积死亡率。结果表明：饲料中添加 ２００ｍｇ／ｋｇ酵母核苷酸显著提高了团头鲂的特定生长率和蛋白质效率（Ｐ＜０．０５），显著降低了饲料系数（Ｐ＜０．０５），但对摄食率、肝体比、内脏比、肥满度和存活率无显著影响（Ｐ＞０．０５）。与对照组相比，核苷酸组血浆中抗超氧阴离子水平显著增加（Ｐ＜０．０５），但碱性磷酸酶活性无显著变化（Ｐ＞０．０５）。饲料中添加 ２００ｍｇ／ｋｇ酵母核苷酸对团头鲂的肝功能以及血脂和血糖指标均无显著影响（Ｐ＞０．０５），但能显著降低嗜水气单胞菌攻毒后 ９６～１６８ｈ的累积死亡率（Ｐ＜０．０５）。由此得出，饲料中添加 ２００ｍｇ／ｋｇ酵母核苷酸能在一定程度上促进团头鲂的生长，增强鱼体的抗氧化功能和抗病力，且不会影响鱼体肝功能以及血脂和血糖代谢。

Effects of Yeast Nucleotide on Growth Performance,Antioxidant Function andDisease Resistance of Bluntnose Black Bream

This experiment was conducted to investigate the effects of a diet supplemented with yeast nucleotides on growth performance,antioxidant function and disease resistance of bluntnose black bream.Three hundred fish with an initial body weight of(31.46±0.07) g were randomly allotted to 2 groups(control group and nucleotide group) and each group included 3 replicates with 50 fish.The fish in the control group were fed a basal diet,and those in the nucleotide group were fed an experimental diet supplemented with 200 mg/kg yeast nucleotide(the total content of single nucleotides and oligonucleotides was 70%).After 56 days feeding,the growth,body and blood physiological and biochemical indices of fish were determined,and the cumulative mortality rate of fish was also be determined for Aeromonas hydrophila challenge test at the end of feeding experiment.The results showed as follows: the diet supplemented with 200 mg/kg yeast nucleotide significantly increased the specific growth rate and protein efficiency ratio(P<0.05),and significantly decreased the feed coefficient ratio(P<0.05),but had no significant effects on the feeding rate,hepatosomatic index,viscerasomatic index,condition factor and survival rate of bluntnose black bream(P>0.05).Compared with the control group,the plasma anti-superoxide anion level in the nucleotide group was significantly increased(P<0.05),but the alkaline phosphatase activity had no significant change(P>0.05).The diet supplemented with 200 mg/kg yeast nucleotide had no significant effects on the liver function,blood lipid and blood glucose indices of bluntnose black bream(P>0.05),but could significantly decrease the cumulative mortality rate after Aeromonas hydrophila challenge 96 to 168 h(P<0.05).It is concluded that the diet supplemented with 200 mg/kg yeast nucleotide can promote the growth,enhance the antioxidant function and disease resistance,but do not affect the liver function,blood lipid and blood glucose metabolism of bluntnose black bream.