饲料蛋白水平对奥尼罗非鱼(Oreochromisniloticus×O.aureus)生长、免疫功能以及抗病力的影响

EFFECTS OF DIETARY PROTEIN LEVEL ON GROWTH PERFORMANCE, IMMUNITY FUNCTION AND DISEASE RESISTANCE FOR HYBRID TILAPIA (OREOCHROMIS NILOTICUS×O. AUREUS)

采用单因素实验设计方法,进行了饲料蛋白水平对奥尼罗非鱼(Oreochromis niloticus×O.aureus)生长、免疫功能和抗无乳链球菌能力影响的研究。结果表明,饲料蛋白水平对奥尼罗非鱼生长和饲料利用率以及成活率不产生显著影响,蛋白质效率和蛋白质沉积率伴随着蛋白水平的升高显著下降。35%(D35)饲料组奥尼罗非鱼肝脏过氧化氢酶含量显著高于其它饲料组,然而奥尼罗非鱼肝脏溶菌酶、超氧化物歧化酶活性以及丙二醛含量并不受饲料蛋白水平的影响。无乳链球菌攻毒实验结果表明,蛋白水平对奥尼罗非鱼在攻毒后24h和48h后的累积死亡率是不存在显著影响。本实验的结果表明,24.8%(D25)蛋白水平饲料能够满足奥尼罗非鱼正常生长、以及维持机体正常的非特异性免疫功能和抗病力的营养需求。

A one-way analysis model was used to investigate the effects of dietary protein level on the growth per- formance, immune function of hybrid tilapia （Oreochromis niloticus x O. aureus）, as well as defensive ability against Streptococcus agalactiae. The feeding trial results showed that growth performance, feed utilization and survival were not significant affected by dietary protein level, the protein efficiency ratio and protein retention efficiency were significantly decreased with the increase of dietary protein level. Hepatic catalase activity of fish fed 34.9% dietary protein diet （D35） was significantly higher than those of the other diet treatments. However, dietary protein level had no significant effects on hepatic lysozyme activity, superoxide dismutase activity, and hepatic malondialdehyde content of tilapia. The challenge trial results showed that dietary protein level had no significant effects on cumulative mortality rate at 24h and 48h after infection with S. agalactiae. The results of present study indicate that 24.8% （D25） dietary protein level can meet the re- quirements for normal growth, immune function, and disease resistance of hybrid tilapia.