The Effect Of Lactobacillus Plantarum And Fermented Soybean Meal On Juvenile Coho Salmon(Oncorhynchus Kisutch)

This paper aims to study the biological characteristics research of a strain of Lactobacillus plantarum,the effects of dietary L.plantarum on juvenile coho salmon and the effects of fermented soybean meal of L.plantarum on juvenile coho salmon(Oncorhynchus kisutch).It is mainly divided into the following three parts:1.Biological characteristics research of L.plantarum.The study is that eleven strains of Lactobacillus were screened from the intestine of coho salmon.Finally,L.plantarum with fast growth and high acid yield was selected for testing.The result indicates that L.plantarum can grow slowly at low temperature,and can tolerate no more than 60℃.Can tolerate the growth of p H 3-9 culture environment;It had better survival rate in simulated gastric fluid and simulated intestinal fluid.Can use a variety of carbon sources for growth;Have good adhesion ability;Tolerance to some drugs;Safe for fish.Therefore,the L.plantarum can be applied to subsequent experiments.2.The effects of dietary L.plantarum on juvenile coho salmon.This study was designed to investigate the effects of dietary L.plantarum on growth performance,muscle composition,intestinal digestive enzyme activities and tissue morphology,hematology and liver gene m RNA expression of juvenile coho salmon.Four groups of the juveniles(initial weight(101.56±0.51 g))in triplicate were fed for 10 weeks on four different concentrations of L.plantarum experimental diets,which were received 10~5 cfu/g(T1),received 10~7 cfu/g(T2),received 10~9 cfu/g(T3)and untreated feed used control group(CK).The main results were as follows:compared with the CK diet,the T2 diets can significantly(P<0.05)influence specific growth rate,weight gain rate,feed conversion ratio,moisture and crude protein in muscle composition,pepsin,α-amylase and villi height of intestine,glucose,total protein,superoxide dismutase,catalase,glutathione peroxidase and malondialdehyde in serum and the gene m RNA expression of pi3k,akt,mtor,g6pd,sod 3,cat and gpx 2 in liver.However,there was no significant effect(P>0.05)on condition factor,hepatosomatic index,survival,ash and crude lipid in muscle composition,lipase,villi width and wall thickness of the intestine,total cholesterol,triglyceride,aspartate aminotransferase and alanine transaminase in serum.In conclusion,the diets received 10~7 cfu/g L.plantarum could significantly increase the growth performance,protein content in muscle,intestinal health,antioxidant and their related gene expression of the juveniles.3.The effect of fermented soybean meal and soybean meal replace partial fish meal on juvenile coho salmon.In order to explore the effect of fermented soybean meal and soybean meal replacing part of fish meal on the growth performance,hematology,liver antioxidant activities and immune related gene m RNA expression of juveniles coho salmon,four kinds of iso-nitrogen and iso-lipid and iso-energy feeds were set up in this experiment(crude protein is about 42%and crude lipid is about 15%).The control group was fed with 41%fish meal(FM)(fish meal protein accounts for 27%);the experimental groups were replacement of partial fish meal by soybean meal in the FM diets(SM)(soybean meal protein accounts for 10%and fish meal protein accounts for 17%),replacement of partial fish meal by soybean meal and fermented soybean meal in the FM diets(FSM5)(soybean meal protein accounts for 5%,fermented soybean meal protein accounts for 5%and fish meal protein accounts for17%)and replacement of partial fish meal by fermented soybean meal in the FM diets(FSM10)(fermented soybean meal protein accounts for 10%and fish meal protein accounts for 17%).Those feeds used to feed juvenile coho salmon with an initial weight of(102.25±0.24)g for10-weeks and the results indicated that there were no significant differences(P>0.05)in the weight gain rate(WGR),specific growth rate(SGR),daily growth rate(DGR)and condition factor(CF)between the FSM10 and FM diets,the WGR,SGR and DGR of the FSM5 diets were significantly lower(P<0.05)than the FM control groups but significantly higher than the SM diets and there were no significant differences(P>0.05)in hepatosomatic index(HSI),viscerosomatic index(VSI)and survival rate among groups.There was no significant difference(P>0.05)in moisture,crude ash,crude protein among groups,but the crude lipid of the SM diets was significantly lower(P<0.05)than that of the FM control groups.There were no significant differences(P>0.05)in the glucose(GLU),total cholesterol(T-CHO),albumin(ALB)and total protein(TP)between the FSM10 and FM diets and there were nosignificant differences(P>0.05)in alkaline phosphatase(AKP),aspartate aminotransferase(GOT)and alanine aminotransferase(GPT)among groups,but the GLU,ALB,TP of the FSM5 diets were significantly lower(P<0.05)than the FM control diets but higher(P<0.05)than the SM diets.The activities of superoxide dismutase(SOD)and catalasehe(CAT)of the FSM10 diets were significantly higher(P<0.05)than that of the FM control groups and there was no significant difference(P>0.05)in glutathione(G-SH)between the FSM10 and FM diets.The malondialdehyde(MAD)of the FSM10 diets were significantly lower(P<0.05)than that of the FM control groups.The CAT and G-SH of FSM5 diets were higher(P<0.05)than the SM diets but the MAD was lower than it.The SOD of the FSM5 diets was significantly lower(P<0.05)than the FSM10 diets but have not significant differences(P>0.05)with the FM control diets.The relative m RNA expression of gene sod-3,lyz,tlr-3 and c3αof the FSM10 diets were significantly higher(P<0.05)than that of the FM control groups(P<0.05),and there were no significant differences(P>0.05)in the relative m RNA expression of gene tlr-7 between the FSM10 and FM diets.There were no significant differences(P>0.05)in the relative m RNA expression of gene il-6 and hsp-70 among groups(P>0.05).The relative m RNA expresion of gene lyz and tlr-3 of the FSM5 diets were significantly higher(P<0.05)than the SM diets.Overall,under the experimental conditions,using fermented soybean meal replace 10%fish meal protein had no significant differences on growth performance and hematology of juvenile coho salmon,but had positive effect on liver antioxidant capacity and immune related gene m RNA expression.Therefore,fermented soybean meal could be used instead of 10%fish meal protein in juvenile coho salmon diets.