EFECTO DE LA APLICACIÓN DE ESTRADIOL Y PROSTAGLANDINA DURANTE EL POST PARTO SOBRE EL DESEMPEÑO REPRODUCTIVO EN VACAS HOLSTEIN BAJO CRIANZA INTENSIVA

Abstract

After delivery, the process of uterine involution begins, in which a series of changes in the anatomy and histology of the uterus take place and there is a return to cyclical activity of the ovary. The objective was to evaluate the effect of the application of estradiol benzoate and prostaglandin F2α (PGF2α) in the postpartum period on reproductive performance in dairy cows. Six experimental groups were formed in a 2 x 3 factorial arrangement, where a factor determined the administration of estradiol (E2): a) without E2 or b) with E2 (10 mg of estradiol benzoate was applied at 14 days postpartum) ; and another factor determined the administration of PGF2α: a) without PGF2α, b) administration of PGF2α in early postpartum (application of 25 mg of dinoprost at 28 days repeated 14 days later) or c) administration of PGF2α in late postpartum (application of 25 mg dinoprost at 42 days repeated 14 days later). 96 intensively reared Holstein cows were used for the experiment. The variables of interest evaluated were the cumulative pregnancy percentage (PA), the pregnancy rate (TP), the conception rate (TC), the service rate (TS), the first service delivery interval (IP1S) and the interval conception delivery (CPI). For the statistical analysis, the generalized linear model was used. As independent variables in the model, the administration of estradiol, the administration of prostaglandin and the interaction of both factors were analyzed. No significant effect (p> 0.05) of the application of E2 and PGF2α was found on TS, TC, TP and BP. However, a significant effect (p <0.05) of the application of prostaglandin on IP1S and IPC was observed, finding that the administration of PGF2α in the early or late postpartum significantly decreased IP1S. While the CPI was significantly better with the application of PGF2α in the late postpartum period. In conclusion, the application of prostaglandins from day 42 post parturition repeated 14 days later significantly improves the IP1S and IPC in dairy cows.