Isolation And Identification Of Pathogenic Bacteria Of Recessive Mastitis In Dairy Goats And Evaluation Of Immune Effect Of Inactivated Vaccine

Dairy goat mastitis is one of the most serious diseases in the process of breeding,which has the most serious influence on milk production and lactation function of dairy goats.It leads to the decline of milk production of the sick mother and livestock,and affects the quality of goat milk.Serious cases may cause systemic symptoms and even death,which is very harmful.Subclinical mastitis is a kind of recessive infection form.The breast and milk of the affected animals have no obvious changes.Under specific conditions,it will turn into clinical mastitis and endanger the health of the mother and lamb.Therefore,early prevention and diagnosis of dairy goats is of great significance to eliminate the potential threat in the process of dairy goat breeding,improve the economic benefits of farmers and create a healthy production environment.In this study,the dairy goat farm in Qianyang County was selected to study the subclinical mastitis of dairy goats,in order to provide theoretical basis for the diagnosis and treatment of dairy goat subclinical mastitis.In this study,milk samples were collected from dairy goats with subclinical mastitis in Qianyang County,Shaanxi Province.The pathogenic bacteria of mastitis were isolated and identified by means of bacterial isolation and purification,morphological observation,physiological and biochemical test,16 S r DNA sequence analysis and PCR amplification.The drug sensitivity test of pathogenic bacteria was carried out.The inactivated vaccine of subclinical mastitis was prepared and used to immunize dairy goats in Qianyang County of Shaanxi Province.The antibody titer was determined by ELISA and the diagnosis of subclinical mastitis was made by mastitis diagnostic fluid to evaluate the immune effect of the vaccine.The research results are as follows:1.The pathogens of recessive mastitis were successfully isolated from dairy goat breeding base in Qianyang County,including Escherichia coli,Staphylococcus aureus and Bacillus cereus.2.The isolated pathogens were moderately resistant to erythromycin and kanamycin,and highly sensitive to chloramphenicol,tetracycline,minocycline and floxacin.3.The inactivated vaccine against subclinical mastitis of dairy goats prepared in this study can stimulate the body to produce high levels of antibodies against pathogenic bacteria.After immunization,the overall incidence of recessive mastitis,the incidence of recessive mastitis +++ and the incidence of recessive mastitis ++ decreased from 49.6%before immunization to 18.3%,23.8% to 12.5%,and 14.8% to 8.7%,respectively,60 days after immunization.The overall incidence of recessive mastitis,recessive mastitis ++ and recessive mastitis ++ had no significant changes in the control group.It is of great significance for the clinical prevention and treatment of recessive mastitis of dairy goats to timely identify the main pathogenic bacteria causing recessive mastitis of dairy goats and grasp the trend of drug resistance,which is conducive to the adjustment of feeding and management methods of dairy goats.