A total of 664 foremilk samples from 83 Holstein cows were cultured. Quarter samples were collected at parturition and 7 days post the first parturition. From 664 milk samples examined, 488 (73.50%) were bacteriologically negative and 176 (26.50%) were positive. A high incidence (20.48%) of clinical mastitis was observed. The most frequently encountered isolates were coagulase negative staphylococci (64.20%), coagulase positive staphylococci (8.52%), streptococci (7.96%), Actinomyces pyogenes (4.55%), Mycoplasma bovigenitalium (3.40%) and Escherichia coli (2.84%). The frequency of mastitis pathogen isolation was highest at parturition (17.62%) and decreased markedly during the first week (8.88%).
Bovine; mastitis; primiparous cows; etiology
