Study on bovine mastitis pathogens of yak milk with isolation and identification

Bovine mastitis is considered the major cause of economic loss to milk producers and to the dairy industry through reduced milk yield and quality,cost of drugs and veterinary treatment,discarded milk,and forced culling.It will be significant for improving and enhancing the yield and quality of Yak-milk output if the bovine mastitis pathogens are investigated and the incidence rate of bovine mastitis is controlled.In order to study the diagnosis and treatment methods of the bovine mastitis pathogens on Yak,in the present investigation,major mastitis pathogens are separated and identified from milk samples from Hong-yuan County of Sichuan Province,which relies upon laboratory diagnosis,such as the yak milk samples of somatic cell count,pH determined,streptococcus isolation,culture and biochemical identification,antimicrobial sensitivity,as well as PCR-based methods.Results show that the laboratory procedures,somatic cell count-culture identification-PCR-based methods,are of value in the examination of Yak-milk samples for bovine mastitis pathogens,and also reveal that the vast majority of yarks are subclinical manifestation of mastitis,and the main pathogen implicated are also Streptococcus uberis,Streptococcus dysgalactiae,Streptococcus agalactiae,Escherichia coli,and Staphylococcus aureus