饲料中添加雨生红球藻对黄颡鱼生长、抗氧化酶活性、免疫应答及氨氮耐受的影响

为探讨饲料中添加雨生红球藻对黄颡鱼生长、抗氧化酶活性、免疫应答及氨氮耐受的影响。以平均体质量为（5.00±0.85）g的黄颡鱼为研究对象，随机分成4个组，每组3个重复，每个重复30尾鱼，分别投喂添加0.00 %（对照）、0.30 %、0.50 %及1.00 %雨生红球藻的饲料，每天2次表观饱食投喂，实验进行10周。结果显示，饲料中雨生红球藻的添加量大于0.30 %能够显著提高黄颡鱼的增重率和血红蛋白含量，降低饲料系数和白细胞数；饲料中添加0.50 %雨生红球藻能够显著降低黄颡鱼血清超氧化物歧化酶和谷胱甘肽过氧化物酶活性及丙二醛含量，显著提高血清溶菌酶活性；96 h急性氨氮暴露实验表明，摄食0.50 %-1.00 %雨生红球藻饲料的黄颡鱼累积死亡率和血氨含量显著低于对照组；饲料中添加雨生红球藻显著提高了氨氮暴露下黄颡鱼肝脏中氨代谢相关酶含量，其中，氨甲酰磷酸合成酶和精氨酸酶含量随着雨生红球藻含量的升高显著提高。研究表明，饲料中添加大于0.30 %雨生红球藻能够显著提高黄颡鱼的生长性能，改善血液健康状况、氧化损伤及免疫应答能力；饲料中雨生红球藻的添加量超过0.50 %能够显著提高黄颡鱼在氨氮暴露下的存活率。

Effects of dietary Haematococcus pluvialis on growth, antioxidant enzyme activity, immune response and ammonia tolerance in yellow catfish Pelteobagrus fulvidraco

In order to explore effects of dietary Haematococcus pluvialis on growth, antioxidant enzyme activity, immune response and ammonia tolerance in yellow catfish. The four diets were formulated to contain four graded dietary H. pluvialis levels: 0.00 % (control), 0.30 %, 0.50 % and 1.00 %. Each diet was randomly assigned to triplicate groups of 30 fish (5.00±0.85) g twice daily to apparent satiation. The experiment lasted for 10-week. The results indicated that fish fed the diet containing H. pluvialis more than 0.30 % showed the highest weight gain rate and hemoglobin content, and the lowest feed conversion ratio and white blood cell count. Serum superoxide dismutase and glutathione peroxidase activities and malondialdehyde content of fish fed 0.50 % H. pluvialis diet were lower than those of fish fed other diets, but serum lysozyme activity was higher. Cumulative mortality and blood ammonia level in fish fed 0.50 %-1.00 % H. pluvialis were lower than those of fish in control group after were exposed to ammonia at hour 96. Dietary supplementation of H. pluvialis significantly increased the contents of ammonia metabolism enzymes in liver of fish exposed to ammonia, and the contents of carbamyl phosphate synthase and argininase were significantly increased with the increase of the H. pluvialis levels. The results showed that dietary supplementation of more than 0.30 % H. pluvialis could significantly improve the growth, blood health status, oxidative damage and immune response of yellow catfish. The survival rate of yellow catfish exposed to ammonia can be significantly improved by adding more than 0.50 % of H. pluvialis in the diet.