Regulation Of Mongolian Veterinary Medicine Babu-7 Component Compound On Intestinal Health And Function Of E.coli O1 Diarrhea Calves

Pathogenic Escherichia coli is the main pathogen causing diarrhea in newborn calves,and its strong infectivity and high lethality cause serious economic losses to the breeding industry.Preliminary studies have shown that Mongolian veterinary drug Babu-7 can regulate intestinal flora and has a good therapeutic effect on calves with E.coli O1 diarrhea.Therefore,in order to understand the mechanism of Mongolian veterinary medicine Babu-7 in the treatment of calf diarrhea,the orthogonal design compound of its active ingredients: Mongolian veterinary medicine Babu-7 active ingredient compound(Effective ingredients compound of Babu seven,BSEIC)was compared with the calves with diarrhea caused by E.coli O1 are used as model animals,and early intervention treatment is carried out to deeply explore the effect of the compound on calves with diarrhea and the mechanism of regulating intestinal flora and improving intestinal barrier function,so as to promote the development and utilization of TCM resources.Provide new ideas and new ways.The experimental design is as follows:48 newborn Holstein calves with similar body condition were randomly divided into 6 groups: blank control group(NC,normal saline,n=8),infection group(EC,normal saline+E.coli O1,n=8),antibiotic group(CIP,ciprofloxacin+E.coli O1,n=8)),Mongolian veterinary medicine Babu-7 active ingredient compound low-dose group(BSEIC-L,low-dose+E.coli O1,n=8),medium-dose group(BSEIC-M,medium-dose+E.coli O1,n= 8),high-dose group(BSEIC-H,high-dose+E.coli O1,n=8),continuous injection for 7 days,2 times/d,the other five groups except the NC group were orally administered before the morning feeding on the 5th day Pathogenic E.coli O1(2.50×1011CFU/m L,100 m L/head).The body weight was weighed on the 1st day before the test and before the morning feeding on the 7th day of the test;the diarrhea situation was recorded every day,the stool index was counted,and the diarrhea rate was calculated;the contents of whole blood,serum,intestinal tissue and colon were measured 1 hour after the last administration on the 7th day.material sample collection.The test methods and results are as follows:Experiment 1 To study the effect of BSEIC on calf colonic gut microbiota:16s RNA gene sequencing analysis method was used to detect the calf colonic gut microbiota structure.The results showed that the invasion of E.coli O1 would lead to the imbalance of intestinal flora in calf colon and the damage of biological barrier function.BSEIC-M and BSEIC-H groups can significantly increase species richness and diversity by reducing Simpson index,increasing shannon,Ace and Chao index(P<0.05);reducing the relative relationship between Proteobacteria,Enterobacter and Faecalibacterium.Abundance(P<0.05);at the microbial phylum level,the dominant bacterial phylum was significantly increased: Firmicutes(P<0.05)and the relative abundance of Bacteroidetes,and at the family level,Lactobacillus,Ruminococcus and Bifidobacterium were increased.The relative abundance of Bacillus can significantly increase the relative abundance of Lactobacillus,Bacteroides(P<0.05),Brautia,Bifidobacterium and Butyricoccus at the genus level.Experiment 2 To study the effect of BSEIC on the growth performance of diarrhea calves: record the diarrhea rate,body weight and average daily weight gain of the experimental calves,and conduct blood physiological and biochemical indicators detection.The results showed:(1)Compared with the EC group,the BSEIC-M and BSEIC-H groups could effectively maintain and increase body weight and reduce the diarrhea rate(P>0.05),while the CIP group had the effect of reducing the diarrhea rate(P<0.05).,but the body weight of calves decreased significantly(P<0.05,P<0.01);(2)Compared with the EC group,the blood routine indexes of each BSEIC group were within the normal range and were equal to those of the NC group(P>0.05);(3)Compared with the EC group,the biochemical indexes of each BSEIC group were within the normal range and were equal to those of the NC group(P>0.05).Experiment 3 To study the effect of BSEIC on the intestinal mechanical barrier of calves with diarrhea: HE pathological examination of calf small intestine tissue,transmission electron microscope TJ ultrastructure observation of calf jejunum,and immunohistochemical method to calculate the positive expression of these proteins in jejunum tissue The level of tight junction protein in small intestine was detected by ELISA.The results showed that:(1)After infection with E.coli O1,calf intestinal villi and microvilli were damaged,the intestinal mucosa TJ was damaged,and the tight junction cell space increased,while the BSEIC groups restored the intestinal structure damaged by E.coli O1.(2)E.coli O1 significantly decreased the level of tight junction protein in the intestine(P<0.05),while BSEIC-M and BSEIC-H groups could significantly increase the level of tight junction protein compared with the EC group(P<0.05).Experiment 4 To study the opsonizing effect of BSEIC on the immune function of calves with diarrhea: flow cytometry was used to detect the percentage of lymphocytes in the peripheral blood of calves,and ELISA was used to detect the levels of serum anti-inflammatory immune factors and intestinal neurotransmitters.The results showed that:(1)BSEIC groups could significantly increase the ratio of CD3~+T,CD4~+T,CD21+B and CD4+/CD8~+T in peripheral blood of diarrhea calves(P<0.05),and CD8~+T and CD14+ single The level of nuclear cells was significantly decreased(P<0.05)and was close to the normal level of the NC group(P>0.05);(2)The levels of TNF-α,IL-1and IL-6 in the serum of the calves in the EC group were significantly higher than those in the NC group.The contents of IFN-γ,IL-2 and IL-4 were significantly decreased(P<0.05),while the BSEIC-M and BSEIC-H groups were comparable to the NC group(P>0.05);(3)calves in the EC group The levels of Ach and 5-HT in bovine small intestine were significantly increased,and the level of DA was significantly decreased(P<0.05).However,the BSEIC-M group could correct the abnormal intestinal neurotransmitter caused by pathogenic E.coli O1,which was significantly different from that of the EC group(P<0.05),and could be the same as the normal group(P>0.05).Conclusion: BSEIC can effectively inhibit the reproduction of enteropathogenic Escherichia coli based on the original antibacterial properties.By increasing the abundance of beneficial bacteria in the colon,it can improve the protective function of the intestinal mucosal barrier,reduce the rate of diarrhea,and ensure the nutritional intake of calves.Conducive to the maintenance and increase of body weight,showing good effect on the early intervention treatment of diarrhea calves.To provide reference for Mongolian medicine and its component compound to replace antibiotics and to treat calf diarrhea.