Incidence of cytological endometritis and its effects on reproductive performance in Nelore beef cows

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, and with a body condition score above 2.5 were used. Ultrasound examination was performed to evaluate the uterine wall and ovarian activity. The cytological diagnosis of endometritis was done by uterine lavage, and endometritis was considering cases of >= 5% neutrophils in each blade. The incidence of cytological endometritis in the herd was 22%, and did not differ between the categories analyzed (primiparous versus multiparous) (P>0.05), and the conception rate for first insemination was also similar between primiparous versus multiparous (P>0.05). However, the pregnancy rate at the end of BS was higher in multiparous cows (83.8%) when compared to primiparous (50.0%) cows (P<0.05). The presence or absence of cytological endometritis did not influence the conception rate (P>0.05) nor pregnancy rate at the end of the BS (P>0.05). Therefore, it can be concluded that the use of endometrial cytological cannot be justified as a diagnostic tool in Nelore beef cows.