铬对凡纳滨对虾生长性能、血清生化指标及非特异性免疫酶活性的影响

Effects of Chromium on Growth Performance,Serum Biochemical Indices and Non-Specific Immune Enzyme Activities of Litopenaeus vannamei

本试验旨在研究铬对凡纳滨对虾生长性能、血清生化指标及非特异性免疫酶活性的影响。试验配制7种等氮等能饲料,其铬(吡啶甲酸铬形式)添加水平分别为0、0.4、0.8、1.2、1.6、2.0和5.0 mg/kg。选择初始体重为(0.310±0.001)g的凡纳滨对虾虾苗840尾,随机分配到21个0.38 m3的玻璃纤维钢桶中,每桶40尾虾,每3桶饲喂1种饲料。试验期为56 d。结果表明:以1.6 mg/kg组增重率和特定生长率最高,饲料系数最低,显著高于或低于0、0.4和5.0 mg/kg组(P<0.05),与1.2 mg/kg组差异不显著(P>0.05)。蛋白质效率和蛋白质沉积率均以2.0 mg/kg组最高,但与1.6 mg/kg组差异不显著(P>0.05)。饲料铬添加水平对凡纳滨对虾全虾水分、粗脂肪和粗灰分含量有显著影响(P<0.05),但对全虾粗蛋白质含量无显著影响(P>0.05)。凡纳滨对虾血清总蛋白、葡萄糖和总胆固醇含量分别在铬添加水平为5.0 mg/kg、1.2～1.6 mg/kg、0.4 mg/kg时显著升高(P<0.05)。血清碱性磷酸酶、总超氧化物歧化酶、酚氧化物酶活性均以1.6 mg/kg组为最高,血清谷草转氨酶活性以1.2 mg/kg组为最高,血清谷丙转氨酶活性以2.0 mg/kg组为最高,并均显著高于0 mg/kg组(P<0.05)。饲料铬添加水平对凡纳滨对虾血清甘油三酯含量和酸性磷酸酶活性未产生显著影响(P>0.05)。综合考虑生长性能、血清生化指标以及非特异性免疫酶活性,对于0.31～8.50 g的凡纳滨对虾,在饲料中以吡啶甲酸铬形式添加1.2～1.6 mg/kg的铬为宜。

This experiment was conducted to study the effects of chromium on growth performance, serum biochemical indices and non-specific immune enzyme activities of Litopenaeus vannamei. Seven isonitrogenous and isoenergetic diets were prepared with the chromium （the form of chromium picolinate） supplemental levels of 0, 0.4, 0.8, 1.2, 1.6, 2.0 and 5.0 mg/kg, respectively. A total of 840 shrimp with an initial body weight of （0.310？0.001） g were randomly distributed into twenty-one 0.38 m3 fiberglass tanks with 40 shrimp per tank and 3 tanks per diet. The feeding experiment lasted for 56 d. The results showed as follows： the highest weight grain rate, specific growth rate and the lowest feed convention ratio were all found in 1.6 mg/kg group, and significantly higher or lower than those in 0, 0.4 and 5.0 mg/kg groups （P〈0.05）, but there were no significant differences compared with 1.2 mg/kg group （P〈0.05）. The 2.0 mg/kg group had the highest protein efficiency ratio and protein deposition rate, but there were no significant differences compared with 1.6 mg/kg group （P〈0.05）. Chromium supplemental level had significant effects on the moisture, crude lipid and crude ash contents in whole body （P〈0.05）, but had no significant effects on the crude protein content in whole body （P〉0.05）. Serum total protein, glucose and total cholesterol contents were significantly increased when chromium supplemental levels were 5.0 mg/kg, 1.2 to 1.6 mg/kg and 0.4 mg/kg, respectively （P〈0.05）. The highest serum alkaline phosphatase, total superoxide dismutase and phenoloxidase activities were found in 1.6 mg/kg group, the highest serum glutamic-oxalacetic transaminase activity was found in 1.2 mg/kg group, and the highest serum glutamic-pyruvic transaminase activity was found in 2.0 mg/kg group, which were all significantly higher than those in 0 mg/kg group （P〈0.05）. Serum triglyceride content and acid phosphatase activity were not significantly affected by chromium supplemental level （P〈0.05）. Based on the growth performance, serum biochemical indices and non-specific immune enzyme activities, the optimal supplemental level of chromium （the form of chromium picolinate） for 0.31 to 8.50 g Litopenaeus vannamei is 1.2 to 1.6 mg/kg.