A long-term feeding study was conducted to determine the effects of dietary β-glucan on the growth performance, non-specific immunity and resistance to Aeromonas hydrophila challenge of carp(Cyprinus carpio).Fish were fed three diets with 0, 0.15% and 0.50% of β-glucan, respectively.The trial lasted for 60 days.The results showed that neither weight gain rate nor feed conversion ratio of the carp fed diets with different doses of β-glucan was significantly different from that of the control group.Hepatopancreas lysozyme and acid phosphatase activities decreased significantly in β-glucan groups compared with the control group, but myeloperoxidase activities in different tissues of carp were not influenced by dietary β-glucan.The survival rates of β-glucan groups were lower than that of the control group after injected Aeromonas.hydrophi-la.In conclusion, β-glucan in the long-term feeding regime exerted no effect on the growth performance, but could reduce the non-specific immune function and disease resistance of carp.%本研究旨在探讨长时间连续投喂β-葡聚糖对鲤生长性能及非特异性免疫功能的影响及嗜水气单胞菌攻毒后的抵抗能力.试验采用初始体重为(61.53±0.34)g的健康鲤(Cyprinus carpio)为研究对象,在饲料中分别添加0、0.15%和0.50%的β-葡聚塘,饲养60 d.结果显示:投喂β-葡聚糖对鲤增重率和饲料系数均没有显著影响(P>0.05);肝胰脏中溶菌酶和酸性磷酸酶活力显著降低于对照组(P<0.05),髓过氧化物酶活力各组之间没有显著差异(P>0.05);攻毒试验结果显示:注射嗜水气单胞菌148 h后试验组鲤存活率明显低于对照组.由此可知,长期投喂β-葡聚糖不影响鲤生长性能,但会降低其非特异性免疫功能及对嗜水气单胞菌攻毒的免疫保护力.
展开▼
