不同蛋白质源部分替代鱼粉对褐点石斑鱼幼鱼生长性能、体组成以及血清生化指标的影响

本试验旨在研究不同蛋白质源部分替代鱼粉对褐点石斑鱼幼鱼生长性能、体组成以及血清生化指标的影响。配制5组等氮等能饲料,对照组饲料(D1)含68%的鱼粉,试验组饲料(D2～D5)是在对照组饲料的基础上分别用豆粕替代10%的鱼粉、豆粕替代20%的鱼粉、啤酒酵母替代10%的鱼粉、玉米蛋白粉替代10%的鱼粉。选取体重在15 g左右的褐点石斑鱼幼鱼180尾,随机分为5组,每组3个重复,每个重复12尾。试验期为8周。结果表明:在生长性能方面,与对照组相比,D2、D3组的增重率、摄食率、特定生长率、粗蛋白质表观消化率差异不显著(P>0.05),而D4、D5组的上述指标均显著降低(P<0.05)。与D2、D3组相比,D4组的特定生长率显著降低(P<0.05),肝体指数显著升高(P<0.05);D5组的摄食率、特定生长率、蛋白质效率和粗蛋白质表观消化率显著降低(P<0.05),饲料系数、肝体指数显著升高(P<0.05)。在体组成方面,D5组全鱼和肌肉中粗蛋白质含量显著低于对照组和D2、D3组(P<0.05);D4组肌肉中粗脂肪含量显著低于对照组和D2组(P<0.05)。在血清生化指标方面,D3组血清总蛋白、球蛋白、葡萄糖含量显著低于对照组(P<0.05),而白球比显著高于对照组(P<0.05);对照组、D4组血清甘油三酯含量显著高于D3、D5组(P<0.05);各组间血清谷丙转氨酶和谷草转氨酶活性没有显著差异(P>0.05)。由此得出,作为鱼粉的替代品,豆粕比啤酒酵母和玉米蛋白粉能更好地满足褐点石斑鱼幼鱼的营养需求;从主要生长指标不受影响的角度考虑,褐点石斑鱼幼鱼饲料中可以用豆粕替代20%的鱼粉。

Influence of Partial Replacement of Fish Meal by Different Protein Sources on Growth Performance,Body Composition and Serum Biochemical Indices of Juvenile Epinephelus fuscoguttatus

An 8-week feeding experiment was conducted to evaluate the influence of partial replacement of fish meal by different protein sources on growth performance,body composition and serum biochemical indices of juvenile Epinephelus fuscoguttatus.Five isonitrogenous and isoenergetic diets were formulated.The diet containing 68% fish meal was used as a control diet(D1).On the basis of the control diet,the experimental diets(D2 to D5) were prepared as follows: soybean meal was used to replace 10% fish meal,soybean meal was used to replace 20% fish meal,beer yeast was used to replace 10% fish meal,and corn gluten meal was used to replace 10% fish meal,respectively.A total of 180 juvenile Epinephelus fuscoguttatus with body weight about 15 g were randomly divided into 5 groups with 3 replicates per group,and each replicate contained 12 fish.The results showed as follows: on the aspect of growth performance,no significant differences in weight gain rate,feeding rate,specific growth rate and apparent digestibility of crude protein were found between the control group and group D2 or D3(P>0.05),while the above indices in the groups D4 and D5 were significantly decreased compared with the control group(P<0.05).Compared with the groups D2 and D3,the specific growth rate in the group D4 was significantly decreased(P<0.05),while the hepaticsomatic index was significantly increased(P<0.05);the feeding rate,specific growth rate,protein efficiency rate and apparent digestibility of crude protein in the group D5 were significantly decreased(P<0.05),while the feed conversion ratio and hepaticsomatic index were significantly increased(P<0.05).On the aspect of body composition,the crude protein content in whole fish and muscle in the group D5 was significantly lower than that in the control group,groups D2 and D3(P<0.05);the muscle crude lipid content in the group D4 was significantly lower than that in the control group and group D2(P<0.05).On the aspect of serum biochemical indices,the contents of total protein,globulin and glucose in serum in the group D3 were significantly lower than those in the control group(P<0.05),while the albumin/globulin was significantly higher than that in the control group(P<0.05);the serum triglyceride content in the control group and group D4 was significantly higher than that in the groups D3 and D5(P<0.05);no significant differences in activities of alanine aminotransferase(ALT) and aspartate aminotransferase(AST) were found among all groups(P>0.05).The results indicate that soybean meal as the substitute of fish meal can satisfy the nutritional requirements of juvenile Epinephelus fuscoguttatus,and the replacement effect is better than beer yeast and corn gluten meal.Taking no influence on primary indices of growth into consideration,20% fish meal in juvenile Epinephelus fuscoguttatus diets can be replaced by soybean meal.