酶解大豆分离蛋白替代鱼粉对花鲈生长性能、血清生化指标和脂肪代谢的影响

Effects of Fish Meal Replacement by Enzymatic Hydrolyzed Soybean Protein Isolate on Growth Performance,Serum Biochemical Indices and Lipid Metabolism of Spotted Seabass(Lateolabrax maculatus)

本试验旨在研究酶解大豆分离蛋白替代鱼粉对花鲈生长性能、血清生化指标和脂肪代谢的影响。选择225尾初始体重为(9.0±0.5) g的花鲈,随机分为3个组,每组3重复,每个重复25尾鱼。各组分别饲喂以酶解大豆分离蛋白替代饲料中0(FM组)、25%(ESPI25组)、50%(ESPI50组)鱼粉的等氮(粗蛋白质水平为44%)等脂(粗脂肪水平为11%)试验饲料。试验期8周。结果表明:1) FM组的增重率(WGR)、特定生长率(SGR)和摄食量(FI)显著高于ESPI50组(P<0.05)。2)FM组的粗脂肪表观消化率显著高于EPSI50组(P<0.05)。3) ESPI25组和ESPI50组的血清总胆固醇(TC)、低密度脂蛋白胆固醇(LDL-C)和高密度脂蛋白胆固醇(HDL-C)含量显著低于FM组(P<0.05)。4)ESPI50组的肝脏甘油三酯和总胆固醇含量显著低于FM组(P<0.05)。5)ESPI25组和ESPI50组的肝脏乙酰辅酶A羧化酶1(ACC1)、脂肪酸合成酶(FAS)、固醇调节原件结合蛋白-1c (SREBP-1c)、过氧化物酶体增殖物激活受体γ(PPARγ)、3-羟基-3-甲基戊二酰辅酶A还原酶(HMGCR)、碳水化合物反应元件结合蛋白(ChREBP)的mRNA相对表达量显著低于FM组(P<0.05)。ESPI25组和ESPI50组的肝脏腺苷酸激活蛋白激酶(AMPK)、过氧化物酶体增殖物激活受体α(PPARα)的mRNA相对表达量显著低于FM组(P<0.05)。综上所述,高比例酶解大豆分离蛋白替代鱼粉会导致花鲈的摄食量降低,从而抑制其生长性能。但饲料中酶解大豆分离蛋白替代鱼粉可以通过降低血清和肝脏甘油三酯和总胆固醇含量,抑制脂肪合成基因的表达,从而减少花鲈机体脂肪的沉积。

The experiment was conducted to study the effects of fish meal replacement by enzymatic hydrolyzed soybean protein isolate on growth performance,serum biochemical indices and lipid metabolism of spotted seabass(Lateolabrax maculatus). A total of 225 Lateolabrax maculatus with initial body weight of(9.0±0.5)g were randomly divided into 3 groups with 3 replicates per group and 25 fish per replicate. Fish in three groups were fed with iso-nitrogenous(crude protein level was 44%)and iso-lipidic(crude lipid level was11%)experimental diets which were prepared by using enzymatic hydrolyzed soybean protein isolate instead of fish meal of 0(FM group),25%(ESPI25 group)and 50%(ESPI50 group),respectively. The experimental period was 8 weeks. The results showed as follows:1)the weight gain rate(WGR),specific growth rate(SGR)and food intake(FI)of FM group were significantly higher than those of ESPI50 group(P<0.05).2)The crude lipid apparent digestibility of FM group was significantly higher than that of ESPI50 group(P<0.05). 3)The contents of total cholesterol(TC),low density lipoprotein cholesterol(LDL-C)and high density lipoprotein cholesterol(HDL-C)in serum of ESPI25 group and ESPI50 group were significantly lower than those of FM group(P <0.05). 4)The contents of triglyceride and total cholesterol in liver of ESPI50group were significantly lower than those of FM group(P<0.05). 5)The mRNA expression levels of acetyl CoA carboxylase 1(ACC1),fatty acid synthase(FAS),sterol regulatory element binding protein-1c(SREBP-1c),peroxisome proliferator activated receptorγ(PPARγ),3-hydroxy-3-methylglutaryl CoA reductase(HMGCR)and carbohydrate response element binding protein(ChREBP)in liver of ESPI25 group and ESPI50 group were significantly lower than those of FM group(P<0.05). The mRNA expression levels of adenylate activated protein kinase(AMPK)and peroxisome proliferator activated receptorα(PPARα)in liver of ESPI25 group and ESPI50 group were significantly lower than those of FM group(P<0.05). In summary,the fish meal replacement by high proportion of enzymatically hydrolyzed soybean protein isolate lead to the feed intake decrease of Lateolabrax maculatus,thereby inhibiting its growth performance. However,the replacement of fish meal with enzymatically hydrolyzed soybean protein isolate in diet can inhibit the expression of fat synthesis genes by reducing contents of triglyceride and total cholesterol in serum and liver,thereby reducing the body fat deposition of Lateolabrax maculatus.