高糖饲料对吉富罗非鱼生长性能、饲料利用和糖脂代谢的影响

为探讨高糖饲料对吉富罗非鱼(GIFT Oreochromis niloticus)生长性能、饲料利用和糖脂代谢的影响,设置糖水平为34%的对照饲料(C组,能量水平13.68 k J·g-1)、糖水平为48%的高糖高能饲料(HCE组,能量水平16.03 k J·g-1)和高糖等能饲料(HE组,能量水平13.81 k J·g-1),在室内循环水系统中饲养初始体质量(20.34±0.42)g的吉富罗非鱼幼鱼60 d。结果表明,HCE组和HE组的增重率、特定生长率、肝脏粗蛋白均显著低于C组(P0.05),饲料系数、肝脏粗脂肪、肝糖原、总糖表观消化率、血清低密度脂蛋白胆固醇和高密度脂蛋白胆固醇均显著高于C组(P0.05);HE组增重率、全鱼粗脂肪、血清甘油三酯和总胆固醇均显著低于HCE组(P0.05);高糖组肝脏葡萄糖激酶显著高于C组,HE组葡萄糖-6-磷酸脱氢酶、苹果酸酶、脂肪酸合成酶活性最高,C组最低(P0.05);由肝脏组织切片看出,高糖饲料引起吉富罗非鱼肝脏细胞肿大变形,出现空泡,HCE组对肝脏损伤更加显著。研究结果表明,吉富罗非鱼能够耐受48%糖水平的饲料,但长期摄食导致鱼体糖脂代谢紊乱,尤其影响脂肪代谢,造成鱼体脂肪蓄积,肝功能损伤,不利于生长与健康。

Effect of high-carbohydrate diet on growth performance,feed utilization,glucose and lipid metabolism of GIFT Oreochromis niloticus

To investigate the effects of high-carbohydrate diet on the growth performance,feed utilization,glucose and lipid metabo lism of GIFT Oreochromis niloticus,we had fed the GIFT juveniles initial body mass (20.34 ±0.42) g] with normal diet (C diet,34％ cholesterol level,dietary energy of 13.68 kJ·g-1),high-carbohydrate and high-energy diet (HCE diet,48％ cholesterol level,dietary energy of 16.03 kJ·g-1) and high-carbohydrate isoenergy diet (HE diet,dietary energy of 13.81 kJ·g-1) in indoor circulating water system for 60 d.The results show that the weight gain rate,specific growth rate,liver crude protein contents of HCE and HE groups were lower than those of C group significantly (P ＜ 0.05);while HCE and HE groups had significantly higher feed conversion ratio,crude fat content and glycogen content of liver,apparent digestibility of carbohydrate,low density lipoprotein cholesterol (LDL-C) and high density lipoprotein cholesterol (HDL-C).The weight gain rate,whole body fat content,serum triglyceride (TG),total cholesterol (T-CHO) of HE group were lower than those of HCE group significantly (P ＜ 0.05).The activities of glucokinase (GK) of HCE and HE group were higher than those of C group,and glucose-6-phosphate dehydrogenase (G-6-PDH),malic enzyme (ME),fatty acid synthase (FAS) of HCE were the highest in the three groups,and those of the C group were the lowest (P ＜ 0.05).High carbohydrate groups induced swelling of liver cells and appearance of vacuoles.Hepatic injury was more serious in HCE group.In conclusion,GIFT can tolerate the feed with 48％ carbohydrate content,but that is not conducive to the growth and health of GIFT,leading to fat accumulation and liver injury,disorder of glucose and lipid metabolism especially fat metabolism.