壳聚糖对受免尼罗罗非鱼生长和免疫功能的影响

以初始体重(99.98±2.79) g的尼罗罗非鱼(Oreoehromis niloticus)为研究对象,探讨饲料中添加壳聚糖对其生长和免疫功能的影响。在饲料中添加剂量为0.2%,0.4%,0.6%,0.8%,1.0%的壳聚糖,连续投喂经注射接种嗜水气单胞菌(Aeromonas hydrophila)的尼罗罗非鱼30d后,测定血清中抗体效价,60d后测量其相对增重率、特定生长率、饲料效率、蛋白质效率、酸性磷酸酶活性、溶菌酶活性、超氧化物歧化酶活性以及活菌攻毒后的免疫保护率。结果表明,用添加量为0.6%壳聚糖的饲料投喂受免罗非鱼,不仅可以提高生长速度,还能提高受免罗非鱼对嗜水气单胞菌的免疫应答水平,增强其非特异性免疫力和抵抗嗜水气单胞菌人工感染能力。

Effects of dietary chitosan on growth and immune response of Nile tilapia (Oreoehromis niloticus) inoculated with Aeromonas hydrophila

A feeding experiment was conducted to examine the effects of dietary chitosan on growth, immunity and disease resistance for Nile tilapia, Oreoehromis niloticus with initial weight of (99.98±2.79) g. Nile tilapia (Oreoehromis niloticus) were inoculated with Aeromonas hydrophila and were fed with diets supplemented with appropriate amount of chitosan. 30 days after the inoculation, the agglutinating antibody titer were examined; 60 days after the inoculation, the relative rate of weight gain, specific growth rate, feed efficiency, protein efficiency, acid phosphatase, lysozyme activity and superoxide dismutase activity and bacterial relative percent survival by challenging with live A. hydrophila. The results showed that adding chitosan with a ratio of 0.6% into the diets can promote their growth and enhance the immune response, and chitosan can improve their non-specific defence and the resistance of Nile tilapia to immune response A. hydrophila.