Isolation And Identification Of Lactic Acid Bacteria In The Reproductive Tract Of Dairy Cows And Study On Its Microecological Preparation

The dairy cows could not discharge bacteria and other contaminants by themselves during the postpartum recovery period.these leading to endometritis,which seriously damagied the performance of the dairy industry and reducing the useful life of dairy cows.Cause significant economic losses.In recent years,probiotics of green and healthy have gradually become the focus of research.Probiotics are come from biological organism and can be better applied to organism.They are new directions for the prevention and treatment of bacterial diseases.One of the common types of probiotic bacteria in the body of lactic acid bacteria is the normal flora of the mouth,digestive tract and reproductive tract.China has already had the research and application of lactic acid bacteria in the treatment of human digestive tract and reproductive tract diseases,but it has rarely been reported for the prevention and treatment of dairy cow endometritis.To select probiotic strains that can be used to control dairy cow endometritis,serial researches were carried out in this paper:1.Isolation and Identification Lactobacillus from Dairy CowsMucus was collected from the cervix of healthy cows with 30⁶0 days after childbirth to separate and purify lactic acid bacteria.The isolates were identified by biochemical identification and molecular biological identification techniques to obtain 13 of 25 specimen strains of lactic acid bacteria.The probiotic lactic acid bacteria strains with the best antibacterial activity and oil cell adhesion ability were finally screened by the supernatant antibacterial test and cell adhesion test.2.Preparation and Characterization of Lactic Acid Bacteria PreparationThe antibacterial test of the combination of different strains of lactic acid was mixed to find the best antibacterial compound.The antibacterial test of EMB plate showed that there was always competition or antagonism between lactic acid bacteria and Escherichia coli.The main antibacterial components of Lactobacillus and the optimum culture temperature were analyzed by the thermal stability test,the trypsin test,the catalase test,and the pH adjustment of the culture supernatant of the lactic acid bacteria,among which the main inhibition of Lactobacillus mucosae The bacterial components are bacteriocins and organic acids.The most suitable culture temperature is 39°C with strong acid production capacity.The main antibacterial substances of Weissella cibaria bacteria are organic acids,H₂O₂ and proteins.The most suitable culture temperature is 39°C,Under that it has strong acid production capacity;the main antibacterial ingredient of Enterococcus faecalis are organic acids,the optimum temperature is37°C,Its acid prodution capacity is less than that the first two strains.3.Safety evaluation of strains and preparationsLactic acid bacteria were intraperitoneally injected into the abdominal cavity of rabbits and rabbits,and the clinical manifestations such as mental status and body temperature of the animals were observed and recorded,and the pathological conditions of the main organs were observed.The results showed that both the single-bacteria inoculation and the composite lactic acid bacteria strains on the tissues and organs of mice did not cause significant inflammatory reactions in the vagina of rabbits,indicating that the lactic acid bacteria strains and their preparations obtained from the test were safe and can be used for the next step.Clinical trials.