Desempenho reprodutivo pós-parto de vacas de corte submetidas a indução/sincronização de cio

Abstract

To assess the reproductive performance of beef cows submitted to estrus induction/synchronization, 42 Aberdeen Angus cows with body condition 3 (1-5 scale) under extensive management were used. The milk production was estimated through the weight-suckling-weight method. For gynecological examinations, ultrasound equipment and trans-rectal palpation were used. The milk production level (above and below the average production of cows), pregnancy, prebreeding reproductive condition (CRPA), surface anoestrus (uterine tone, follicles > 10 mm and absence of CL) and deep anoestrus (no uterine tone, follicles <10 mm and absence of CL) and the estrus induction/synchronization response (RISC) were considered as constant factors. The variables analyzed were the pre-delivery, delivery weight, mating and conception weights, weaning weight, the average daily weight gain from birth to weaning and total milk production. The prebreeding reproductive condition influenced the pre-birth and birth weights, showing that the better pre-birth and birth performance favors the restoration of reproductive activity in cows with moderate body condition (CC) in the post-partum period. The classification of the pre-breeding reproductive condition in beef cows can be a resource to determine the reproductive performance of beef cows submitted to estrus induction/synchronization, since cows in surface anoestrus tend to have better response to the protocol. In beef cows with moderate body condition, the pre-birth weight performance affects the prebreeding reproductive condition, increasing the likelihood of better reproductive performance. © 2009 Sociedade Brasileira de Zootecnia.