蛹肽蛋白替代鱼粉对大菱鲆(Scophthalmus maximus L.)幼鱼生长、饲料利用、消化代谢酶及免疫性能的影响

Effects of Dietary Substitution of Fishmeal by Fermented Silkworm Pupae on the Growth, Feed Intake, Digestion and Immunity of Juvenile Turbot (Scophthalmus maximus L.)

关键词:  蛹肽蛋白  大菱鲆  蛋白源  替代

Key words:  Fermented silkworm pupae  Turbot (Scophthalmus maximus L.)  Protein source  Substitution

摘要:

选取蛹肽蛋白分别替代大菱鲆幼鱼配合饲料中0、15%、30%、45%、60%、75%的鱼粉，配制成6种等氮等能的饲料饲喂大菱鲆幼鱼(19.84±0.04 g) 56 d，以研究蛹肽蛋白替代鱼粉的效果。结果显示，大菱鲆幼鱼的特定生长率、饲料效率随替代水平的升高而降低，30%及以上替代组显著低于对照组(P<0.05)；鱼体粗蛋白、粗脂肪水平随替代水平的升高而降低，分别在75%和30%及以上替代组显著降低，鱼体水分和灰分含量随替代的升高而升高，分别在75%和30%及以上替代组显著升高(P<0.05)。摄食率随替代水平升高呈先上升后下降的趋势，在30%替代组呈现出最高的摄食率，且显著高于对照组(P<0.05)。饲料干物质的表观消化率在42.53%−54.36%之间，且当替代水平达到75%时显著低于对照组(P<0.05)；而蛋白质表观消化率在71.67%−86.89%之间，仅45%和75%替代组显著低于对照组(P<0.05)。各替代组肝脏超氧化物歧化酶活性均高于对照组，在45%和60%替代组出现显著性差异(P<0.05)。综上所述，蛹肽蛋白可以替代大菱鲆幼鱼饲料中15%的鱼粉而不影响其生长摄食、饲料利用以及与消化、代谢、免疫相关的酶的活性。

Abstract:

Fish meal is a major protein source in aquafeeds especially for carnivous fish species. Increasing demand, unstable supply and high price of fish meal with expansion of aquaculture made it necessary to search for alternative protein source. Fermented silkworm pupae is a compound protein of both silkworm pupae and some plant proteins and was a promising substitute for fish meal. To evaluate fermented silkworm pupae as an alternative for fish meal, a 56-day feeding trial in an in-door seawater recirculating system was conducted to investigate the effects of fishmeal replacement by fermented silkworm pupae (FSP) on growth performance, feed utilization blood physiology and enzymatic activities of juvenile turbot with initial average weight of (19.84±0.04 g). Six isonitrogenous and isocaloric practical diets were formulated to replace fishmeal at 0%, 15%, 30%, 45%, 60%, and 75% levels with FSP. Each diet was randomly fed to quadruplicate groups of fish. With the increasing FSP level, the specific growth rate (SGR) and feed efficiency (FE) decreased and was significantly different at over 30% replacement levels (P<0.05). Whole body protein and lipid content decreased with the increasing FSP substitution level, and was significantly different at 75% and 30% replacement level respectively (P<0.05). However, whole body moisture and ash content increased with the increasing fishmeal replacement level, and significant difference was shown at 75% and 30% replacement level respectively (P<0.05). ADC of dry matter (42.53%−54.36%) was significantly lower than the control at 75% replacement level (P<0.05); while ADC of protein (71.67%−86.89%) decreased significantly only when 45% or 75% fish meal was replaced by FSP (P<0.05). Hepatic SOD activity in all treatments was higher than the control and was significantly different at 45% and 60% replacement levels (P<0.05). Results of the present study indicated that FSP could replace 15% fish meal in the diets of juvenile turbot without compromising growth performance, feed utilization, blood parameters and enzymatic activities.