Analysis of the Influence of Milk Production and Number of Lactation in Bovine Mastitis Caused by Environmental Pathogens in a Selected Dairy Farm

摘要

Mastitis remains one of the most important diseases among dairy herds despite the use of control programs including techniques such as teat dipping, dry cow therapy, and segregation of infected animals. As a result of control programs for contagious mastitis pathogens (Staphylococcus aureus, Streptococcus agalactiae, Mycoplasma species), mastitis caused by environmental pathogens (coliform bacteria, fecal streptococci, Streptococcus dysgalactiae and S. uheris) is now the primary disease in well managed dairy herds. The control and prevention of environmental mastitis remains a challenge to dairy producers. Actually, the most efficient strategy for controlling environmental mastitis is prevention through appropriate management. Despite extensive research into risk factors for the development of bovine mastitis, recent published works suggest that the mean incidence rate of mastitis is increasing (1). Cow-level risk factors for mastitis include breed, lactation number, leaking milk between milkings,periparturient disease, and cow cleanliness. Quarter-level risk factors reported for mastitis include previous bacterial infection, teat position, and teat-end hyperkeratosis (1). Recent studies have showed that mastitis prevalence differed in association with milk production, somatic cell count (SCC) of the cows milk, and month of lactation in cows with subclinical mastitis (2). The major aim of the present study was to investigate the epidemiology of environmental mastitis bacteria in one selected dairy herd. The hypotheses were that lactation number and milk production would influence in the incidence of environmental mastitis cases.