Etiologia das infecções intramamárias em vacas primíparas no período pós-parto Etiology of intramammary infections in primiparous cows at postparturition

Foram analisadas 664 amostras de leite de 83 vacas primíparas da raça Holandesa. As amostras foram colhidas no primeiro e no sétimo dia após o parto. Das 664 amostras analisadas, 488 (73,50%) foram bacteriologicamente negativas e 176 (26,50%), positivas para microrganismos aeróbios. Foi observado um alto índice de mastite clínica (20,48%). Os agentes isolados com maior freqüência foram os Staphylococcus spp coagulase negativo (64,20%), Staphylococcus spp coagulase positivo (8,52%), Streptococcus spp (7,96%), Actinomyces pyogenes (4,55%), Mycoplasma bovigenitalium (3,40%) e Escherichia coli (2,84%). Foi observado um maior índice de isolamento de patógenos no primeiro dia (17,62%) em relação ao sétimo (8,88%).<br>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%)