高脂饲料中添加胆汁酸对齐口裂腹鱼幼鱼生长性能、肌肉营养成分含量、消化酶活性及血清生化指标的影响

Effects of High-Lipid Diet Supplemented with Bile Acid on Growth Performance,Muscle Nutritional Component Contents,Digestive Enzyme Activities and Serum Biochemical Indices of Juvenile Schizothorax prenanti

本试验旨在研究高脂饲料中添加胆汁酸对齐口裂腹鱼幼鱼生长性能、肌肉营养成分含量、消化酶活性及血清生化指标的影响。以360尾初始体质量为(12.74±0.14)g的健康齐口裂腹鱼幼鱼为试验对象,随机分为4组(每组3个重复,每个重复30尾),分别投喂在高脂饲料中添加0(对照)、75、150和300 mg/kg胆汁酸的4种试验饲料,养殖时间为70 d。结果显示:齐口裂腹鱼幼鱼的增重率(WGR)、特定生长率(SGR)和蛋白质效率(PER)均随胆汁酸添加水平的升高呈先升高后降低的变化趋势,且均在150 mg/kg胆汁酸组达到最大值,分别为263.52%、1.84%/d和2.09%,并显著高于其余各组(P<0.05);齐口裂腹鱼幼鱼的饲料系数(FCR)则随胆汁酸添加水平的升高呈先降低后升高的变化趋势,在150 mg/kg胆汁酸组达到最低值,为1.23,且显著低于对照组和75 mg/kg胆汁酸组(P<0.05);随着胆汁酸添加水平的升高,齐口裂腹鱼幼鱼的肥满度(CF)、脏体比(VSI)和肝体比(HSI)呈先降低后趋于稳定的变化趋势,150和300 mg/kg胆汁酸组显著低于对照组和75 mg/kg胆汁酸组(P<0.05);随着胆汁酸添加水平的升高,齐口裂腹鱼幼鱼肌肉中粗蛋白质的含量呈逐渐升高最后趋于稳定的变化趋势,150和300 mg/kg胆汁酸组显著高于对照组和75 mg/kg胆汁酸组(P<0.05);齐口裂腹鱼幼鱼肌肉中粗脂肪的含量则随着胆汁酸添加水平的升高而呈先降低而后趋于稳定的变化趋势,75、150和300 mg/kg胆汁酸组均显著低于对照组(P<0.05);各组齐口裂腹鱼幼鱼肌肉中水分、粗灰分含量则无显著变化(P>0.05);随着胆汁酸添加水平的升高,齐口裂腹鱼幼鱼肝胰脏中蛋白酶的活性呈先升高后降低的变化趋势,前肠及中肠中蛋白酶的活性则均呈逐渐升高的变化趋势,肝胰脏及前肠中脂肪酶的活性呈先升高后降低的变化趋势,中肠中脂肪酶活性则呈逐渐升高的变化趋势;胆汁酸添加水平对齐口裂腹鱼幼鱼后肠中蛋白酶、脂肪酶及肝胰脏、前肠、中肠及后肠中淀粉酶活性无显著影响(P>0.05);随着胆汁酸添加水平的升高,齐口裂腹鱼幼鱼血清甘油三酯(TG)、胆固醇(CHO)含量均呈逐渐升高的变化趋势,而低密度脂蛋白胆固醇(LDL-C)含量则呈逐渐降低的变化趋势,且上述指标各组间差异显著(P<0.05)。综上,本试验条件下,在高脂饲料中添加胆汁酸可有效地增强齐口裂腹鱼幼鱼对高脂饲料的消化利用能力,促进生长,减少脂肪的沉积,改善肌肉品质。综合各项指标得出,齐口裂腹鱼幼鱼高脂饲料中胆汁酸的适宜添加水平为150 mg/kg。

This experiment was conducted to study the effects of effects of high-lipid diet supplemented with bile acid on growth performance,muscle nutritional component contents,digestive enzyme activities and serum biochemical indices of juvenile Schizothorax prenanti.A total of 360 juvenile Schizothorax prenanti with an average body weight of(12.74±0.14)g were randomly divided into 4 groups with 3 replicates per group and 30 fish per replicate.The high lipid diets with different bile acid supplemental levels(0,75,150 and 300 mg/kg)were fed to juvenile Schizothorax prenanti for 70 days.The results showed that the weight gain rate(WGR),specific growth rate(SGR),protein efficiency ratio(PER)initially increased and then decreased with bile acid supplemental level raising.Conversely,the feed conversation ratio(FCR)firstly decreased and then increased with bile acid supplemental level raising.The WGR,SGR and PER were all the highest(263.52%,1.84%/d and 2.09%,respectively)when the bile acid supplemental level was 150 mg/kg,and those in 150 mg/kg bile acid group were significantly higher than those in other groups(P<0.05);at the same time,the FCR was the lowest(1.23),and it in 150 mg/kg bile acid group was significantly lower than that in control group and 75 mg/kg bile acid group(P<0.05).With bile acid supplemental level raising,the condition factor(CF),hepatosomatic index(HSI)and viscerosomatic index(VSI)were initially increased and then to stabilization,and those in 150 and 300 mg/kg bile acid groups were significantly lower than those in control group and 75 mg/kg bile acid group(P<0.05).The crude protein content in muscle was initially increased and then to stabilization with bile acid supplemental level raising,while the crude lipid content in muscle was initially decreased and then leveled off.The muscle crude protein content in 150 and 300 mg/kg bile acid groups was significantly higher than that in control group and 75 mg/kg bile acid group(P<0.05),and the muscle crude lipid content in 75,150 and 300 mg/kg bile acid groups was significantly lower than that in control group(P<0.05).There were no significant differences in moisture and crude ash contents in muscle among all groups(P>0.05).With bile acid supplemental level raising,the protease activity in hepatopancreas and the lipase activity in hepatopancreas and foregut initially increased and then decreased,at the same time,the protease activity in foregut and midgut,the lipase activity in midgut was increased gradually.Bile acid supplemental level had no significant effects on the protease and lipase activities in hindgut and the amylase activity in foregut,midgut,hindgut and hepatopancreas(P>0.05).With bile acid level raising,the serum cholesterol(CHO)and triglyceride(TG)contents increased gradually,at the same time,while the serum low density lipoprotein cholesterol(LDL-C)content decreased gradually,and there were significant differences in above indices among all groups(P<0.05).The results of above indicate that bile acid supplementation in the high-lipid diet can effectively enhance the digestion and utilization abilities,promote the growth,reduce the fat deposition,and improve the muscle quality of juvenile Schizothorax prenanti under those experimental conditions.Comprehensive analysis of various indices,the optimal supplemental level of bile acid in the high-lipid diet of juvenile Schizothorax prenanti is 150 mg/kg.