Preliminary Study On The Effect Of Bacillus Amvloliquefaciens GBacillus-9 Preparation On The Prevention And Treatment Of Diarrhea In Lambs

In order to improve the therapeutic effect of diseases in animals,antibiotics are widely used in the breeding industry.However,the ban on the use of antibiotics in livestock production is an inevitable trend,so the development of economic and effective antibiotic substitutes is imminent.Some probiotics can balance the intestinal microbes of animals and enhance immunity,providing an important path for the development of antibiotic alternatives.Bacillus amyloliquefaciens-9(GBacillus-9)has strong environmental adaptability and can secrete a variety of digestive enzymes to inhibit the growth of pathogenic bacteria.The purpose of this paper is to optimize the preparation process of Bacillus amyloliquefaciens GBacillus-9 preparation,and systematically study the prevention and treatment effect of the bacteria preparation on lamb diarrhea.The main results are as follows:(1)Preparation of bacterial preparation:The optimal fermentation medium M9(X,Na2HPO4,K2HPO4,M2SO4,NH4Cl,NaCl)of GBacillus-9 was selected by medium screening,and the single factor test combined with Central Composite Design(CCD)was used to determine the culture.The optimum ratio of the components(X 46.8 g/L,Na2HPO4 8.5 g/L,K2HPO4 3 g/L,NH4Cl 1.4 g/L,NaCl 0.5 g/L,M2SO4 0.08 g/L);fermentation conditions(temperature,pH,inoculum size,rotation speed,and optimization(36?,pH 7.0,5%inoculum,180 rpm,10 h),the preparation route of the bacteria preparation was established by small-scale fermentation and spray drying.(2)Preliminary study on the control effect of GBacillus-9 preparation on lamb diarrhea:24 lamb were selected in the experiment,12 in each group,divided into control group(feeding goat milk+3 ‰ starch)and experimental group(feeding goat milk+3‰microecological preparations).Free drinking water,feeding for 15 days,the test results are as follows:? Lamb diarrhea prevention and treatment effect:After 15 days of feeding,the diarrhea symptoms of the diarrhea lambs in the experimental group were all cured,and the diarrhea rate of the control group lambs decreased by 57%;the incidence rate of diarrhea in the healthy lambs in the experimental group was 11%,and that in the control group was 44%.The results showed that the preparation of GBacillus-9 had obvious control effects on the symptoms of diarrhea in lambs.? Effects of GBacillus-9 on serum physiological,biochemical and immune-related factors in lambs:After 15 days of feeding,The serum immune indexes IgA,IgG and IgM of the experimental group increased,and the contents of IgA and IgG changed significantly(P<0.05);The levels of IL-2,IL-4 and IL-6 were increased,and the levels of IL-4 and IL-6 were significantly increased(P<0.05).The serum levels of TG and GPT in the experimental group were significantly increased(P<0.05).The serum levels of SOD,NO and LZM in the experimental group were not significantly different(P>0.05).The results revealed that the GBacillus-9 preparation can improve the serum immunity of the lamb.?Effects of GBacillus-9 preparations on the microbial community structure of gastrointestinal tract of lambs:After 15 days of feeding,The microbial community composition of the gastrointestinal tract of the two groups of lambs was compared.It was found that the microbial diversity of the gastrointestinal tract was not significantly different between the experimental group and the control group(Pshannon>0.05),and the microbial community structure was similar.At the level of the Phylum,the bacterial preparation could reduce the ratio of the gastrointestinal tract Firmicutes and the Bacteroides,and The genus level can significantly increase the relative abundance of beneficial bacteria such as Collinsella,Bifidobacterium,Acetitomaculum,Prevotella,etc.,reduces the relative abundance of inflammatory genus and pathogenic bacteria of rumen Blautia,Tyzzerella-4.Spearman analysis revealed the correlation between microbes and immunity in the gastrointestinal tract of lambs,and established a potential link between bacterial genus and immunoglobulins IgA,IgG,IgM and immune cytokines IL-2,IL-4,IL-6.The subordinate level explained that the GBacillus-9 bacteria preparation can effectively improve the microbial flora structure of the gastrointestinal tract by regulating the microbial community structure of the gastrointestinal tract,thereby significantly preventing the diarrhea of the lamb.