Isolation, Identification And Pharmic Sensitivity Test Of Main Pathogenic Bacteria Causing Subclinical Mastitis In He’nan Province

Subclinical Mastitis of dairy cow is a kind of common and frequently encountered diseasewhich cause the biggist loss in cow industry and restricts the development of the dairy industry.He’nan province is a big agricultural province.In recent years，dairy scale is rapiddevelopment，but the level of management is relatively low；Subclinical Mastitis of dairy cow that is highmorbidity is one of the most important factors which prohibit the development of dairy industry.In order to provide technical support to prevent Subclinical Mastitis of dairy cow，this research inHe’nan investigate its epidemiological conditions，the main pathogenic bacteria species，screening sensitive drugs.The experimental animals are the lactation of the6dairy farms which have been tested byDHI(Dairy herd improvement) in different regions of he’nan.Detect the disease rate and therelationship with the quarter,lactation stage and parity based on the somatic ccell(SCC) providedby DHI; Sample from the milk of Subclinical Mastitis cows implement a series of tests，includingcultivating，isolating and identify bacteria,and measuring its sensitivity against medicine. Then，established a synthetical method to prevent and cure bovine subclinical mastitis combined with thecattle farm management and current situation of prevention and cure for the cattle disease．1. Analyse the SCC of the lactation of the6dairy farms for the whole year2013, totaled7581cows in all.And the result shows,the positive rate of subclinical mastiffs is higher in thesouthern region;the incidence of Subclinical Mastitis is higherWhen cows are in the third and fourth quarter;thel incidence of new infections changes withquarter and the highest incidence occurs in the third quarter;and shows positive correlation withlactation and labour times.2.We collected milk samples from361breast areas of123dairy cattles from the above6scale dairy farms,and positive rate of the samples is60.66%.Isolate from219pairs of bacteriasamples of milk suffered subclinical mastitis．We totally got516isolated strains of bacteria,ofwhich103strains of Staphylococcus aureus, account for19.96%;Streptococcus agalactiae124stains,account for24.03%;Streptococcus dysgalactiae80strains,account for15.50%;Escherichiacoli111strains, account for21.51%,and other bacteria count for18.99%. The main types ofpathogens are Staphylococcus aureus,Staphylococcus epidermidis,Streptococcus dysgalactiae andEscherichia coli is in the second place. 3. Detection pathogen is sensitive to Ceftriaxone，Cefotaxime, Ofloxacin, Ciprofloxacin,Gentamycin, Amoxicillin and Ampicillin.The sensitivity to Tetracycline, Fosfomycin, Neomycin,Terramycin, Polymyxin B is relatively low and showed different degrees of drug resistance toPenicillinG,Erythromycin,and Compound new Ming.