Proteínas de fase aguda e suas relações com o desempenho reprodutivo e produtivo de vacas leiteiras pós-parto.

Abstract

The transition period in dairy cows, characterized by negative energy balance (NEB), where the nutrient demand is greater than the cow intake capacity, has been negatively correlated with the resumption of ovarian activity during postpartum, as well as the cow health, due the inflammatory state generated by the NEB state. Acute phase proteins are nonspecific inflammatory markers and have been used to assess the inflammatory state and the risk of disease occurrence, as they are produced in response to systemic inflammatory. The aim of this study was to evaluate if the postpartum ovulation moment is related with the acute phase proteins release, indicators of lipomobilization and polymorphonuclear (PMN) cell percentage in the endometrial cytology. Holstein multiparous cows (n = 20), were selected by the number of lactations (≥ 3), milk yield in the last lactation (7891 ± 1184/Kg/305 days) and negative history of illness in the last year of production. Blood samples were collected weekly from day -21 relative to calving to 30 days postpartum, and also during the calving day, 3rd, 6th and 9th days postpartum to evaluate the concentration of acute phase proteins: haptoglobin, albumin and paraoxonase, glucose and non-esterified fatty acids (NEFA). To evaluate the cyclicity resumption, blood samples were collected weekly from day 16 to day 44 during the postpartum period to evaluate the concentrations of progesterone. Gynecological and vaginoscopic examinations were performed at the days 18 ± 2, 25 ± 3 and 33 ± 2 during postpartum to evaluation and characterization of uterine secretion. Endometrial cytology was carried out at 37 ± 2 days postpartum, to assess the uterus health, using uterine low volume flushing. Cows were divided according to the postpartum resumption of ovarian activity until 44 ± 2 days in ovulated cows (OV Group = 12, 60%) and cows that did not ovulated (AV = 8, 40%). The cows of the AV group had lower concentrations of albumin during all the pre-partum (P = 0.03) and postpartum period (P = 0.01), higher pre-partum concentrations of haptoglobin (P = 0.04) and tended to have lower postpartum concentrations of paraoxonase than the OV group (P = 0.09). No differences were observed in the concentrations of NEFA and glucose (P> 0.05) between groups. Cows of the OV group has lower PMN cells count in endometrial cytology than cows that did not ovulate (26.3% vs 53.4%, PMN; P = 0.05). At 25 ± 3 days postpartum, only 1 cow in the OV group showed abnormal uterine secretion in vaginoscopy analysis, while 3 cows in the AV group had abnormal secretion (P = 0.07). In conclusion, cows that had earlier postpartum ovarian activity resumption showed a less pronounced systemic inflammatory response, the lipomobilization did not affect and had better uterine health.