The relationship between management factors, antimicrobial sensitivity and prevalence of staphylococcal mastitis pathogens in a random sample of Prince Edward Island dairy herds

This study, an investigation of coagulase positive (CPS) and coagulase negative (CNS) staphylococcal mastitis in 44 randomly selected dairy herds in Prince Edward Island (REI) had three major objectives. These are: (1) to survey dairy management factors and determine the effect of management factors on the herd prevalence of staphylococcal mastitis pathogens. (2) to survey antimicrobial sensitivity of Staphylococcus isolates from the study herds, and assess which management factors affect sensitivity of staphylococcal mastitis pathogens to these antimicrobials. (3) to determine it significant correlations exist between the prevalence of staphylococcal mastitis pathogens and their in vitro antimicrobial sensitivity.

Adoption rates of 79% and 48% for post-milking teat dipping and dry cow therapy for all cows in a herd were observed. Cloxacillin benthazine and Oxytetracyline hydrochloride were the most widely used dry cow products, on 48% and 32% of farms respectively. Seventy-eight percent of the farms used products containing beta lactams, 48% of these contained Penicillin G.

The association between the proportions of CPS or CNS sensitive to penicillin G and tetracycline in vitro and the herd prevalence were sought after taking into account farm factors using the partial correlation coefficient. No significant associations were found. (Abstract shortened by UMI.).