In dairy cattle, uterine infections are not life threatening and often unavoidable; however, they reduce fertility and increase the production costs of properties. The aim of this study was to evaluate the incidence of subclinical endometritis from 32 to 70 days in milk (DIM) and its effects on the reproductive performance of crossbred dairy cows. Lactating cows (Holstein/Gir; n = 172), with no history of retained placenta, without clinical signs of uterine infection were used. The body condition score (BCS) was evaluated on a scale from 1 to 5. Ultrasound examination was performed to evaluate uterine lining and ovarian activity, while vaginal mucus was analyzed by gloved hand. The diagnosis of subclinical endometritis was performed by endometrial cytobrush technique. The samples were collected, stained, and examined microscopically; positive cases for subclinical endometritis were considered with the presence of ≥5 % of neutrophils. Later, the cows were submitted to conventional artificial insemination or timed artificial insemination. The incidence of subclinical endometritis in the herd was 26 %, and this was not affected by the season of calving, presence of corpus luteum, DIM, and parity. Cows with a BCS ≤2.50 had a higher incidence of subclinical endometritis. The conception rate to first insemination and pregnancy rate at 150 days postpartum were not influenced by the presence of subclinical endometritis in crossbred dairy cows.

RESUMOAvaliaram-se a incidência de endometrite citológica dos 29 aos 90 dias pós-parto e seus efeitos sobre o desempenho reprodutivo de vacas de corte Nelore submetidas a uma estação de monta (EM) de 90 dias. Foram utilizadas 49 matrizes Nelores, sem histórico de retenção de placenta, sem a presença de uma infecção uterina clínica, e com escore de condição corporal acima de 2,5. Realizou-se exame ultrassonográfico para avaliar a parede uterina e a atividade ovariana. O diagnóstico de endometrite citológica foi feito pela técnica de lavagem uterina, considerando-se caso de endometrite ≥5% de neutrófilos em cada lâmina. A incidência de endometrite citológica do rebanho foi de 22%, não diferindo entre as categorias analisadas (primíparas versus multíparas) (P>0,05), a taxa de concepção à primeira inseminação também foi semelhante entre primíparas versus multíparas (P>0,05), porém a taxa de gestação ao final da EM foi maior nas vacas multíparas (83,8%) quando comparadas às primíparas (50,0%) (P<0,05). A presença ou ausência da endometrite citológica não influenciou a taxa de concepção (P>0,05), tampouco a taxa de gestação ao final da EM (P>0,05). Conclui-se que o uso da citologia endometrial não se justifica como ferramenta de diagnóstico em vacas de corte Nelore.Palavras-chave: lavado uterino, neutrófilos, reprodução, sincronização do estro ABSTRACT Were evaluated the incidence of cytological endometritis from 29 to 90 days postpartum and its effect on the reproductive performance of Nelore beef cows submitted to a breeding season (BS) for 90 days. A total of 49 cows, with no history of retained placenta, without the presence of a clinic uterine infection