螺旋藻部分替代鱼粉对罗氏沼虾生长性能、养分表观消化率、体组成和血清生化指标的影响

Effects of Partial Replacement of Fish Meal by Spirulina on Growth Performance,Nutrient Apparent Digestibility Coefficients,Whole⁃Body Composition and Serum Biochemical Indices of Macrobrachium rosenbergii

本试验旨在研究螺旋藻部分替代鱼粉对罗氏沼虾(Macrobrachium rosenbergii)生长性能、养分表观消化率、体组成和血清生化指标的影响。基础饲料以红鱼粉和豆粕为主要蛋白质源,鱼油和大豆卵磷脂为主要脂肪源进行配制,在基础饲料中分别用螺旋藻替代0(SP0,作为对照)、20%(SP20)、40%(SP40)、60%(SP60)和80%(SP80)的鱼粉,配制5种等氮等脂的试验饲料。选择体质健康、规格整齐的罗氏沼虾幼苗1125尾,随机分成5组,分别饲喂5种试验饲料,每组设3个重复,每个重复75尾。试验期为60 d。结果表明:1)与对照组相比,螺旋藻替代20%~60%的鱼粉对罗氏沼虾的生长性能指标未产生显著影响(P>0.05),但替代比例达到80%时,罗氏沼虾的终末体重、增重率、特定生长率显著下降(P<0.05),而饲料系数显著升高(P<0.05);SP60组和SP80组罗氏沼虾的肝体比显著低于对照组(P<0.05)。2)干物质表观消化率在各组间无显著差异(P>0.05),SP80组的粗蛋白质表观消化率显著低于其他各组(P<0.05)。3)各组虾体水分、粗蛋白质和粗灰分含量无显著差异(P>0.05),SP40组和SP60组虾体粗脂肪含量显著高于对照组(P<0.05);各组虾体各氨基酸含量无显著差异(P>0.05)。4)罗氏沼虾血清葡萄糖含量各组间无显著差异(P>0.05);SP60组血清总蛋白含量显著低于对照组(P<0.05);SP20组和SP40组血清甘油三酯含量显著高于对照组(P<0.05);血清总胆固醇含量各组间无显著差异(P>0.05);SP60组和SP80组血清谷草转氨酶活性显著高于对照组(P<0.05);SP20组和SP80组血清谷丙转氨酶活性显著高于对照组(P<0.05)。由此得出,在本试验条件下,螺旋藻替代罗氏沼虾饲料中鱼粉的比例不宜超过60%,替代比例过高会导致罗氏沼虾生长性能和粗蛋白质表观消化率的下降,且可能导致肝脏代谢功能异常。

This experiment was conducted to investigate the effects of partial replacement of fish meal by spir⁃ulina on growth performance,nutrient apparent digestibility coefficients,whole⁃body composition and serum biochemical indices of Macrobrachium rosenbergii.The main protein sources in a basal diet were brown fish meal and soybean meal,and the main fat sources were fish oil and soybean lecithin.Five isonitrogenous and isolipidic experimental diets were formulated with different levels of spirulina to replace 0(SP0,as control),20%(SP20),40%(SP40),60%(SP60)and 80%(SP80)fish meal in the basal diet,respectively.A total of healthy 1125 Macrobrachium rosenbergii were selected and randomly divided into 5 groups with 3 replicates per group and 75 shrimp per replicate.The experiment lasted for 60 days.The results showed as follows:1)compared with the control group,growth performance indices were not significantly changed in SP20,SP40 and SP60 groups(P>0.05),but the final body weight,weight gain rate and specific growth rate in SP80 group were significantly decreased(P<0.05),while the feed conversion rate was significantly increased(P<0.05).Hepatosomatic index in SP60 and SP80 groups were significantly lower than that in the control group(P<0.05).2)No significant difference was observed in the apparent digestibility coefficient of dry matter a⁃mong all groups(P>0.05),while the apparent digestibility coefficient of crude protein was significantly de⁃creased in SP80 group compared with other groups(P<0.05).3)The contents of moisture,crude protein and ash in whole⁃body did not significantly differ among all groups(P>0.05).Shrimp in SP40 and SP60 groups showed significantly higher ether extract content in whole⁃body compared with the control group(P<0.05).No significant differences were observed in amino acid contents among all groups(P>0.05).4)No significant difference was observed in the serum glucose content among all groups(P>0.05).Compared with the control group,the serum total protein content was significantly decreased in SP60 group(P<0.05).Shrimp in SP20 and SP40 groups showed significantly higher serum triglyceride content than the control group(P<0.05),and the serum total cholesterol content was not significantly different among all groups(P>0.05).The activity of serum aspartate amino transferase in SP60 and SP80 groups was significantly higher than that in the control group(P<0.05),and shrimp in SP20 and SP80 groups also showed significantly higher serum alanine amino transferase activity than the control group(P<0.05).It is concluded that the optimal replacement proportion of fish meal by spirulina in the diet for Macrobrachium rosenbergii is not more than 60%under the conditions of this experiment.Excessive fish meal replacement with spirulina can lower growth performance and the apparent digestibility coefficient of crude protein,and probably causes abnormal liver metabolism function of Macrobra⁃chium rosenbergii.