Effect Of Clostridium Butyrate Added To Feed On The Growth And Health Of Eel

In recent years,in order to reduce and replace the use of antibiotics,domestic researchers have carried out a lot of research.Clostridium butyricum,as a new probiotic,grows anaerobically and produce spores.It has the characteristics of heat resistance,acid resistance,alkali resistance and high temperature resistance.It has more development value than additives such as Bacillus and Lactobacillus,which are commonly added at present.It is an ideal strain for feeding probiotics.In this paper,Anguilla anguilla and Anguilla rostrata were selected as the research objects to explore the effect of Clostridium butyrate added to feed on the growth and health of eel,in order to find a cost-effective alternative to antibiotics and promote the healthy growth of cultured animals.The results are as follows:1.To explore the effects of Clostridium butyricum on the growth and health of Anguilla anguilla,and to provide reference for the replacement of antibiotics.Anguilla anguilla,whose initial average weight was about 172.050 g,was randomly stocked in 6 large ponds of 30m~2.They were randomly divided into blank control group(group C,basic diet only)and Clostridium butyricum group(group D,diet supplemented with 1×10~8 cfu/kg Clostridium butyricum).Each group was repeated 3 times for 121 days.The results showed that:(1)The final weight,weight gain rate,specific growth rate and feeding rate of Anguilla anguilla in Clostridium butyricum group increased significantly(P<0.05),but there was no significant effect on the routine body composition,HSI,VSI and CF.(2)Clostridium butyricum significantly increased the activities of serum immune enzymes(ACP,AKP,LYS,ALB)(P<0.05),and decreased the activities of HDL-C and AST(P<0.05).(3)Compared with the control group,Clostridium butyricum significantly increased liver GST,T-SOD,T-AOC activities,significantly decreased liver MDA,ALT and AST activities(P<0.05),but there had no significant effect on liver CAT activities(P>0.05).(4)Clostridium butyricum significantly increased T-AOC,GSH activity,lipase activity,protease activity and intestinal fold length of Anguilla anguilla(P<0.05).(5)Illumina Miseq was used to analyze the structure of intestinal microbiota in two groups of Anguilla anguilla.The average values of Chao1 and Shannon in the two groups showed no significant difference(P>0.05).Spirochaetae,Tenericutes,Firmicutes,Proteobacteria and Bacteroidetes were the main core bacteria in the two groups,and there was no significant difference between the two groups.(P>0.05).2.Histamine,a harmful substance,is easily produced during the long-term storage of feed,which threatens the health of animals.Therefore,this experiment further explored the alleviating effect of Clostridium butyricum on histamine,to provide protection for the healthy growth of animals.Anguilla rostrata with an average weight of 10.987g were randomly divided into 3groups,with 4 replicates in each group.Group C(basic feed),group H(300 mg/kg histamine)and group HD(300 mg/kg histamine+1×10~8 cfu/kg Clostridium butyricum)were recorded respectively.The culture period was 77 days.The results show that:(1)The final weight,WGR and SGR of Anguilla Anguilla in HD group were significantly higher than C group(P<0.05),but there were no significant differences in routine body composition,VSI,HSI and CF.(2)The activities of D-lactic acid,DAO,ALB and LYS activities in serum of group H were significantly lower than those in group C and HD(P<0.05),and the activities of ALT and AST were significantly increased(P<0.05).(3)The liver T-SOD activity in group C was significantly higher than that in group H and HD(P<0.05),CAT activity was significantly higher than that in group H(P<0.05),and there was no significantly in MDA and T-AOC activity between groups(P>0.05).(4)The activities of intestinal CAT,T-SOD and T-AOC in HD group were significantly higher than those in C and H group(P<0.05),and the activities of MDA in HD group were also significantly lower than those in C and H group.Compared with the blank group,histamine significantly increased intestinal MDA activity and T-SOD activity(P<0.05).(5)Compared with group C and H,the activities of intestinal protease and lipase in HD group were significantly increased(P<0.01),and the activities of amylase in HD group were significantly higher than those in group C(P<0.05),but there was no significantly between HD group and H group(P>0.05).(6)Compared with group C,histamine significantly reduced the length of intestinal folds in Anguilla rostrata(P<0.05),and Clostridium butyricum significantly alleviated the shortening of intestinal folds caused by histamine(P<0.01),which was significantly higher than that in group C(P<0.05).(7)Illumina Miseq was used to analyze themicrobiota structure of intestinal contents of three groups of Anguilla rostrata.The results showed that there were no significantly in the abundance(Chao1 index)and diversity(Shannon)of 16S rRNA gene in intestinal contents of Anguilla rostrata among the three groups(P>0.05).However,compared with the blank group,the addition of histamine significantly increased the proportion of Bacillus and Brevundimonas in intestinal contents of Anguilla rostrata(P<0.05).The addition of Clostridium butyrate significantly increased the proportion of Clostridium,Bacillus and Brevundimonas in intestinal contents of Anguilla rostrata(P<0.05)and the proportion of Cetobacterium and Romboutsia is significantly lower than the group C and H(P<0.05).The results showed that the growth performance and anti-oxidative capacity of eel could be significantly improved by adding Clostridium butyricum to feed,and the intestinal health of eel could be maintained.Clostridium butyricum could be used as an effective antibiotic substitute.