蚕蛹替代鱼粉对吉富罗非鱼生长性能、体成分及血清生化指标的影响

摘要

本试验旨在探讨蚕蛹替代不同比例鱼粉对吉富罗非鱼生长性能、体成分、血清生化指标的影响. 试验以含8%鱼粉的饲料为基础饲料,分别用蚕蛹替代基础饲料中0 (对照)、25%、50%、75%、100%的鱼粉,配制5种等氮(含粗蛋白质32.0%)等脂(含粗脂肪5.5%)的试验饲料(分别命名为SP0、SP25、SP50、SP75、SP100),饲喂初始均重为(44.4±0.41) g吉富罗非鱼幼鱼56 d. 每种饲料设3个重复,每个重复饲喂20尾鱼. 结果表明:1) SP50组的增重率、特定生长率较SP0组分别上升16.18%、8.37%(P<0.05),饲料系数降低3.94%(P<0.05);各组内脏指数无显著差异(P>0.05). 2)SP50 组的全鱼和肝胰脏粗脂肪含量较 SP0 组分别降低6.39%和7.76%(P<0.05),全鱼粗蛋白质和肝胰脏水分含量不受蚕蛹替代比例的显著影响(P>0.05).3)随蚕蛹替代比例的增加,蛋白质效率、蛋白质沉积率均先上升后下降,在SP50组达到最大值,较SP0组分别上升6.48%、13.83%( P<0.05);脂肪沉积率与蛋白质效率、蛋白质沉积率变化趋势相反. 4)蚕蛹替代鱼粉后显著降低了吉富罗非鱼血清总胆固醇、甘油三酯、葡萄糖含量( P<0.05);蚕蛹替代比例为50%时,血清溶菌酶活性最高,但替代比例超过75%时,血清溶菌酶活性显著下降(P<0.05),血清谷草转氨酶、谷丙转氨酶活性均显著上升(P<0.05). 由此得出,蚕蛹替代50%鱼粉可提高吉富罗非鱼的生长性能,促进鱼体蛋白质沉积,提高血清溶菌酶活性,同时还具有降血脂、血糖、肝脂的作用.%This experiment was conducted to investigate the effects of different proportion silkworm pupae ( SP) substitution for fish meal on growth performance, body composition and serum biochemical indices of genetically improved farmed tilapia ( GIFT, Oreochromis niloticus). Five isonitrogenous ( containing 32%crude protein) and isolipidic ( containing 5.5%ether extract) diets were formulated by replacing 0 ( control) , 25%, 50%, 75% and 100% FM with SP on the basis of a basal diet which contained 8% fish meal, and they were named as SP0, SP25, SP50, SP75 and SP100, respectively. Each diet was fed to three replicates of 20 juvenile GIFT with an initial body weight of (44.4±0.41) g for 56 d. The results showed as follows:1) com-pared with SP0 group, weight gain rate and specific growth rate in SP50 group were increased by 16.18% and 8.37% ( P<0.05) , respectively, and feed conversion ratio was decreased by 3.94% ( P<0.05);no difference was found in viscerosomatic index among all groups ( P>0.05) . 2) Whole fish and hepatosomatic ether extract contents in SP50 groups were decreased by 6.39% and 7.76% compared with SP0 group (P<0.05), respec-tively, but whole body crude protein and hepatosomatic mositure contents were not influenced by silkworm pu-pae substitution proportion (P>0.05). 3) Protein efficiency ratio (PER) and protein retention rate (PRR) firstly increased and then decreased with increase of SP substitution proportion, and reached maximum in SP50 group which were increased by 6.48% and 13.83% compared with SP0 group ( P<0.05) , respectively; while lipid retention rate (LRR) followed contrary pattern as that of PER and PRR (P<0.05). 4) Replacement of FM with SP significantly decreased serum total cholesterol, triglyceride and glucose concents ( P<0.05); ser-um lysozyme activity was the highest when the silkworm pupae substitution proportion was 50%, but it signifi-cantly declined when the silkworm pupae substitution proportion was over 75% (P<0.05), concomitantly, it significantly increased serum aspartate transaminase and alanine transaminase activities (P<0.05). In conclu-sion, replacement of 50% fish meal with silkworm pupae can improve growth performance, protein retention rate and serum lysozyme activity of GIFT, and has the functions of decreasing serum lipid,blood glucose and liver lipid.