Impacto da doença uterina clínica pós-parto sobre a biometria e atividade ovariana de vacas leiteiras

Abstract

The objective of this study was to associate the impact of postpartum clinical uterine disease on biometry and the reestablishment of ovarian cyclic activity in dairy cows at two time moments, 21 and 45 days after parturition. The experiment was conducted at the Palmital farm of the Federal University of Lavras. Thirty-four healthy cows were monitored from 14 days before the expected parturition date, D-14, until the fifth day after the farm's voluntary waiting period, D45. On the parturition date, D0, zootechnical information was recorded. The animals were clinically examined by measuring: body weight, body condition score (BCS), rectal temperature (RT), posture and locomotion (P/L), and degree of dehydration (DD) around D-14,D7, D21, and D45. From D3 to D10, the vaginal discharge characteristic was evaluated and assigned a higher score using the Metricheck® device. Reproductive examinations were performed using a Mindray® veterinary ultrasound coupled to a 7.5 MHz rectal transducer, in two periods: D21 and D45. Seven-second videos of each ovary were produced at both moments, in order to obtain and allow calculations of ovarian data, such as: proportion of occurrence of corpus luteum (CL), CL and dominant follicle (DF) volumes, antral follicle count (AFC) and ovarian biometrics. The variables were statistically analyzed using SAS® software. On D10, cows were categorized by clinical variables such as RT, P/L and DD associated with the vaginal discharge score, into two experimental groups: absence of reproductive disease (ARD), defined by animals that did not manifest: alterations at parturition, clinical signs and vaginal discharge, or had mucus with a “gelatinous” consistency, non-fetid; and clinical postpartum uterine disease (CUD), determined by the presence of clinical signs associated with purulent, yellowish-white vaginal discharge that may contain streaks of blood or thin, serous or watery mucus, reddish-brown, with or without parts of necrotic tissue, and fetid. A greater reduction in ECC was observed during the study for animals in the CUD group compared to those in the ARD group. As a result, a greater proportion of animals with CL, larger CL and DF volumes, as well as larger ovarian biometrics were obtained for cows in the ARD group compared to those in the CUD group. Regarding primiparous cows, there was a lower proportion of CL, lower CL and DF volumes, as well as lower ovarian biometrics compared to multiparous cows. The age of the animals showed an effect on AFC and ovarian biometrics. In addition, it was observed on D21 that ovarian volumes were higher for multiparous cows with no reproductive diseases (M-ARD) compared to multiparous cows with clinical postpartum uterine diseases (M-CUD), (p <0.05). However, on D45, ovarian biometrics did not differ between the M-ARD and M-CUD groups, (p = 0.41). Therefore, the study demonstrated that clinical postpartum uterine disease had a negative impact on biometrics and the reestablishment of ovarian cyclic activity in dairycows, only at 21 days postpartum.