胆汁酸对大菱鲆幼鱼生长、脂肪代谢酶及血清生化的影响

Effects of dietary bile acid on growth performance, fatty enzymatic activities and biochemical indices of turbot Scophthalmus maximus L. junveniles

摘要:

在基础饲料中分别添加0、0.03%、0.06%、0.09%及0.12%的胆汁酸,配制5组等氮等能的实验饲料(D1、D2、D3、D4、D5),投喂体质量为26.5 g的大菱鲆(Scophthalmus maximus)幼鱼56 d,研究胆汁酸对其生长、体组成、脂肪代谢酶活力及血清生化的影响。结果显示:(1)实验鱼的增重率、特定生长率、蛋白质效率及脂肪效率呈先升后平稳的趋势,均在D3组达到最高值。(2)胆汁酸显著降低了全鱼粗脂肪及粗灰分含量,提高了粗蛋白含量(P<0.05);降低了肌肉粗脂肪含量,提高了粗蛋白及粗灰分含量(P<0.05)。(3)脂肪酶及脂蛋白脂酶活力呈先升后平稳的趋势;肝脂酶活力显著升高(P<0.05)。(4)胆汁酸降低了血清谷丙转氨酶及谷草转氨酶活力,提高了碱性磷酸酶活力(P<0.05);总蛋白及白蛋白的含量随胆汁酸含量的增加而升高(P<0.05);甘油三酯、总胆固醇及高低密度脂蛋白胆固醇含量随胆汁酸含量的升高而下降(P<0.05)。(5)鳗弧菌感染48 h后,D3、D4及D5组的累积死亡率显著低于D1组。以增重率为评价指标,经折线回归分析,体质量26.5 g的大菱鲆幼鱼饲料中胆汁酸的适宜添加量为0.09%。

Abstract:

In order to investigate the effects of dietary bile acid on growth, body composition, fatty enzymatic activities and biochemical indices of turbot Scophthalmus maximus L. juveniles, five isonitrogen and isocaloric diets containing graded levels of bile acid(0.00%, 0.03%, 0.06%, 0.09%, and 0.12% of dry matter) were formulated(named D1, D2, D3, D4, and D5, D5 as control group). Each diet was assigned to triplicate tanks of turbot juveniles with initial body weight 26.5 g for 56 days. The results showed that:(1) Growth performance and figure indices were increased by dietary bile acid, and indices of D3, D4, D5 groups were significantly higher than D1 group, but there were no differences among them.(2) Crude lipid and crude ash contents of whole fish were decreased, while crude protein increased by dietary bile acid; Crude lipid of muscle decreased, while crude protein and crude ash increased.(3) Lipase and lipoprotein lipase activities increased at first and kept stable then, but hepatic lipase activities kept increasing.(4) Alanine aminotransferase and asparate aminotransferase activities were decreased while alkaline phosphatase activity was increased by dietary bile acid; total protein and albumin contents increased while triglyceride, total cholesterol, high density lipoprotein cholesterol, and low density lipoprotein cholesterol decreased by dietary bile acid.(5) Cumulative mortalities of D3, D4 and D5 groups were significantly lower than that of D1 group after being infected with Vibrio anguillarum for 48 hours. With WGR as evaluation indicator, broken-line regression analysis showed that the optimum dietary bile acid of turbot with body weight 26.5 g was 0.09%.