吡啶甲酸铬对吉富罗非鱼生长、饲料利用和非特异性免疫功能的影响

Effects of chromium picolinate on growth performance,feed utilization and non-specific immunity in juvenile hybrid tilapia (Oreochromis niloticus)

本试验研究饲料不同水平吡啶甲酸铬对其生长、饲料利用,体成分、血液生化指标和非特异性免疫功能的影响。600尾吉富罗非鱼分为5个处理组,每个处理各设4个重复,每重复30尾鱼。每个处理铬添加量分别为0、0.4、0.8、1.2 mg/kg和10.0 mg/kg,在0.38 m3玻璃纤维钢桶中用开放式流水养殖,饲养8周。结果表明,饲料中添加吡啶甲酸铬对吉富罗非鱼的增重率、特异生长率、饲料系数、蛋白效率及蛋白质沉积率均有显著影响(P<0.05)。当铬添加量为0～0.8 mg/kg时,随着添加量增加,可显著提高吉富罗非鱼增重率、特定生长率、蛋白质效率和蛋白质沉积率(P<0.05),显著降低饲料系数(P<0.05),但对成活率和肝体比无显著影响(P>0.05);当饲料中添加为1.2 mg/kg～10.0 mg/kg时并未能进一步提高罗非鱼的生长和饲料利用。同时,铬添加水平为0～0.8 mg/kg,随着添加水平增加,显著提高吉富罗非鱼全鱼的蛋白质和磷含量(P<0.05),显著降低全鱼水分、脂肪和灰分含量(P<0.05),并显著提高吉富罗非鱼血清总蛋白含量以及肝胰脏AKP、ACP和LZM的活性(P<0.05),显著降低血清葡萄糖含量(P<0.05),但对血清胆固醇和甘油三酯含量及肝胰脏T-SOD活性无显著影响(P>0.05)。当饲料中添加铬1.2 mg/kg和10.0 mg/kg,除了显著降低肝胰脏AKP活性外(P<0.05),对血清生化指标和肝胰脏非特异性免疫酶活性无显著影响(P>0.05)。综合生长、饲料利用、体组成成分、血液生化指标和肝胰脏非特异性免疫酶活性的影响结果表明,对于0.91～4.93 g吉富罗非鱼,饲料中以吡啶甲酸铬的形式添加0.8～1.2 mg/kg铬为宜。

The trial was conducted to determine the effects of chromium picolinate with dietary different supplementation levels （Chromium Cr was 0,0.4,0.8,1.2 mg/kg and 10.0 mg/kg,respectively） on growth performance,feed utilization,body composition,blood biochemical index and non-specific immunity of juvenile hybrid tilapia （Oreochromis niloticus） for 8 weeks.Five kinds of iso-nitrogenous and iso-energies diets were formulated as experimental diets.A total of 600 fish were randomly distributed into twenty 0.38m3 fiberglass tanks with 30 fish per tank and 4 tanks per diet.The results showed that in 8-weeks feeding trial,the diet with 0 - 0.8mg/kg Cr supplementation could significantly increase the weight grain （WG）, specific growth rate （SGR）,protein efficiency ratio （PER） and productive protein value （PPV） of juvenile hybrid tilapia （P 〈 0.05）,and significantly decrease feed convention ratio （FCR） （P 〈 0.05）,while the survival rate and hepatopancreas somatic index （HSI） were not significantly affected （P 〉 0.05）.The whole boby crude protein and phosphorous（P） content were significantly increase by the diets with 0 -0.8mg/kg Cr supplementation levels （P 〈 0.05）, whereas the effects on moisture,crude lipid and crude ash content in whole body.As the same time,the diet with 1.2mg/kg or 10.0 mg/kg Cr supplementation could not significantly increase the growth and feed utilization of the fish than those of the diet with 0.8mg/kg Cr supplementation levels （P 〉 0.05）.Activities of hepatopancreas total superoxide dismutase （T- SOD） and the content of cholesterol and triglyceride in serum,was not significantly affected by the dietary Cr supplementation levels （P 〉 O.05）.Except of the activity of hepatopancreas acid phosphatase （ACP） ,activities of alkaline phosphatase （AKP） and lysozyme （LZM） in hepatopancreas and the contents of total protein and glucose in serum decreased significantly （P 〈 0.05）,when the dietary without Cr supplementation or excess of 0.8mg/kg supplementation.Based on weight gain rate,feed utilization, body conposition, blood biochemical index and the non-specfic immunity,the optimal dietary supplementation levels of Cr （the form of chromium picolinate） for the tilapia diet formulation was 0.8 mg/kg.