RESUMO
BACKGROUND: Mastitis prevalence, milking procedures and management practices were investigated in 25 big dairy herds supplying milk to an Estonian dairy company. The aim of the study was to provide information for the company to be used in their new udder health improvement program to be set up after the completion of this study. METHODS: Quarter milk samples were collected from 3,166 cows for bacterial analysis and SCC (somatic cell counting). During the farm visit the veterinarian filled in a questionnaire about milking procedures and management practices with the help of farm managers. If the milk SCC of a cow or of a quarter exceeded 200,000/ml, the cow was defined as having mastitis. RESULTS: The percentage of cows having inflammation in one or more quarters measured by SCC (200,000/ml) was 52.7%. Corynebacterium bovis, Staphylococcus aureus and coagulase negative staphylococci were the most common bacterial isolates. Women as farm owners, and participating in the milking, were associated with lower mastitis prevalence on the farm. Peat bedding was associated with higher mastitis prevalence. CONCLUSION: We demonstrated relatively high mastitis prevalence in this study. Contagious bacteria (eg. S. aureus, C. bovis, S. agalactiae and coagulase negative staphylococci) caused most of the infections. These infections are usually spread from cow to cow at milking if the milking hygiene is not good enough. The mastitis situation could be improved by improving milking procedures and hygiene.