Occurrence of mastitis pathogens at dry off period and after calving in dairy cows

Abstract

The aim of the work was to study the occurrence of mastitis pathogens before and after calving in the same dairy cows. The Holstein cows suspicious on subclinical mastitis (positive California Mastitis Test) were sampled at quarter level under practical farm with high level of milk yield (11,278 kg). The cows were treated with antibiotics (Cefquinomum) before drying. In total 84 samples before drying and 107 samples after calving from the same dairy cows were collected. The samples were cultured on blood agar (MkB Test as, Rosina, SR). MALDI-TOF MS (Bruker Daltonics, Germany) was used to identify mastitis pathogens. Bacteriologically positive (BP) samples from dairy cows before drying were found in 35% of the milk samples. The most frequent pathogens in BP milk samples were coagulase-negative staphylococci (CNS) (77.38%). The most common CNS was Staphylococcus (S.) xylosus (32.14%). S. aureus was detected in 5.95% of BP samples. After calving, we found BP samples in 14.02% of dairy cows. The most common pathogens in milk samples were CNS (10.39%). S. aureus was detected in 0.94% of BP samples. Antibiotic treatment during the drying period clearly reduced the occurrence of CNS and S. aureus in dairy cows at the beginning of lactation.