Replacement of Fish Meal with Plant Protein Mixture in Diets for Pacific White Shrimp (Litopenaeus vannamei)

This experiment was conducted to study the feasibility of replacement of fish meal with plant protein mixture(extruded soybean meal ∶ peanut meal ∶ corn gluten meal=38% ∶ 17% ∶ 45%) in diets for Pacific white shrimp(Litopenaeus vannamei),and to find out the optimal replacement proportion.A total of 720 Pacific white shrimps with an average body weight of(0.52±0.01) g were randomly distributed into 6 groups with 3replicates per group and 40 shrimps per replicate.Six isonitrogenous and isoenergetic diets were formulated with3.91%,7.82%,11.73%,15.64% and 23.46% plant protein mixture to replace 10%,20%,30%,40% and60% fish meal,respectively.The experiment lasted for 56 d.The results showed as follows:different replacement proportions of fish meal with plant protein mixture showed no significant effects on survival rate(SR),hepatopancreas-somatic index and the contents of crude lipid and ash in whole body(P0.05).When the replacement proportion was over 40%,weight gain rate(WGR),specific growth rate(SGR),protein efficiency ratio(PER) and the contents of total protein and glucose in serum were significantly decreased(P0.05),while feed conversion ratio(FCR) was significantly increased(P0.05).When the replacement proportion was over 30%,protein retention ratio(PRR),whole body crude protein content and serum total cholesterol content were significantly decreased(P0.05),while serum triglyceride content was significantly increased(P0.05).Replacement of 30% fish meal with plant protein mixture had no significant effects on the activities of acid phosphatase(ACP),alkaline phosphatase(AKP),surperoxide dismutase(SOD) and nitric oxide synthetase(NOS) in serum(P0.05),while significantly decreased the apparent digestibility of protein,lipid,energy and most of essential amino acids including methionine,phenylalanine,valine,histidine,arginine and threonine(P0.05).Comprehensive analysis of growth,feed utilization and nutrient apparent digestibility,the optimal proportion of plant protein mixture(extruded soybean meal ∶ peanut meal ∶ corn gluten meal =38% ∶ 17% ∶ 45%) to replace fish meal is 20% in the basal diet for Pacific white shrimp,which containing 40%protein and 30% fish meal.