Investigation Of Subclinical Mastitis And Its Identification And Drug Sensitivity Of The Pathogen In Dairy Cow Farm Of Shaanxi Province

Cow mastitis is a frequently encountered disease of cow and causes tremendouseconomic losses.In order to understand the incidence of a recessive mastitis of dairy cows,using LMT to detect subclinical mastitis on165clinical healthy cows,48milk samples withsubclinical mastitis were isolated, biochemical identified, and drug sensitivity was tested.The results showed that the relevance ratio of subclinical mastitis is43.64%(72of165), the positive rate of udder quarter is24.46%(158of646), all of mammary area couldcatch the disease, it’s not significantly different in the detection rate among the4udders based on the χ2test (P>0.05); all parity can catch subclinical mastitis, Thechi-square test confirmed the highly significant difference among the groups（P<0.01）；cowof all age can catch subclinical mastitis. The prevalence rate rises with age, the differenceis significant among the groups（P<0.05）.107strains bacteria were isolated, the main pathogenic bacteria are Staphylococcusaureus，Streptococcus and Escherichia coli. Among the107isolated pathogens, there were32strains of Staphylococcus aureus (29.91%),15strains of Streptococcus (14.02%),14strainsof Escherichia coli (13.08%).3main pathogens were sensitive to Chloramphenicol,Ofloxacin, Amikacin, Ciprofloxacin, and resistant to Streptomycin, Penicillin, Amoxicillinand Ampicillin frequently used. As a consequence,Ofloxacin, Amikacin, Ciprofloxacincould be selected as the candidate drugs for treating the dairy subclinical mastitis in the farm.