Effects Of Fishmeal Replacement By Defattedsilkworm Pupa Meal On Growth,Hepatopancreas Morphology And Molt Of Litopenaeus Vannamei

A feeding trial was conducted to investigate effects of fishmeal replacement by dietary defatted silkworm pupa meal(DSPM)on growth,hepatopancreas morphology and molt of white shrimp Litopenaeus vannamei.Five experimental diets were formulated using DSPM to replace 0%(control diet,D1),25%(D2),50%(D3),75%(D4)and 100%(D5)fishmeal.Each diet was fed to four replicates of 36 juvenile.The shrimp(initial weight,0.20±0.02 g)were fed with the experimental diets for 56 days.The results showed as follows:1.Effects of fishmeal replacement by DSPM on growth performance,body composition and apparent digestibility of Litopenaeus vannamei.The weight gain rate(WGR),special growth rate(SGR),feed efficiency rate(FER),feeding rate(FR),survival rate(SR)and body composition of shrimp were not significantly affected by fishmeal replacement of DSPM(P>0.05).Replacement of fishmeal with DSPM significantly decreased the contents of Met in whole body(P<0.05)but significantly increased Ca(P<0.05).Apparent digestibility of the dry matter,enegy and P in D5 groups were increased significantly compared with control diet(D1).The apparent digestibility of crude protein was not influenced by DSPM substitution proportion(P>0.05).The apparent digestibility of Ca was decreased significantly with DSPM substitution proportion(P<0.05).It is necessary to supplement calcium source in DSPM diet.No adverse effects of fishmeal replacement by DSPM on growth and body composition Litopenaeus vannamei.2.Effects of fishmeal replacement by DSPM on non-specific immunity and hepatopancreas morphology of Litopenaeus vannamei.The shrimp serum AKP and NOS were not influenced by DSPM substitution ratio(P>0.05).Feeding DSMP diet significantly decreased shrimp serum MDA(P<0.05).The shrimp serum T-AOC in D4 and D5 increased significantly compared with D1(P<0.05).Lipid metabolism: Shrimp serum glucose levels decreased significantly in feeding DSPM diet groups(P<0.05),But serum triglycerides were not significantly different with D1(P>0.05).Total cholesterol,high and low density lipoprotein cholesterol in D5 were decreased significantly with control(P<0.05).There were no adverse effects on hepatopancreas morphology of Litopenaeus vannamei by DSPM replaced 0-75% fishmeal.When DSPM replaced fishmeal up to 100% the structure of the tubules was atrophic,with a complete membrane.The results show that serum alkaline phosphatase activity increased after damage hepatopancreas morphology of Litopenaeus vannamei.Lower cholesterol metabolism and damage hepatopancreas morphology of Litopenaeus vannamei in DSPM 100% replaced fishmeal group.DSPM replaced 75-100% fishmeal significantly increased Litopenaeus vannamei antioxidant ability.3.Effects of fishmeal replacement by DSPM on molt times,chitin deacetylase,?-N-Acetyl-D-glucosaminidase and relative expression of EcR and RXR in hepatopancreas of Litopenaeus vannamei.Relative expression of EcR and RXR were not influenced by DSPM substitution proportion(P>0.05).DSPM replaced 100% fishmeal significantly reduced molt times of Litopenaeus vannamei(P < 0.05).DSPM replaced 100% fishmeal significantly increased thrimp hepatopancreas chitin deacetylase(P<0.05),but not influenced ?-N-Acetyl-D-glucosaminidase(P>0.05).