RISK FACTORS AND PATHOGENS ISOLATED DURING CLINICAL MASTITIS IN DAIRY Cows

摘要

Clinical mastitis is usually caused by environmental microorganisms such as streptococci, coliforms (Escherichia coli, Klebsiella pneumoniae and Enterobacter aerogenes) and enterococci (Enterococcus faecalis and Enterococcus faecium) [1]. The primaryreservoir of environmental pathogens is the dairy cow's environment and the exposure of uninfected udder quarters to environmental pathogens is not limited to the milking process [2]. .Different studies on rates of clinical mastitis in commercial dairies demonstrate parity and lactation period effects [3, 4]. Housing, bedding and season are other factors that influence rate of new infection during both the dry period and lactation [2].