Effect of the level of sexual receptivity on plasma estradiol and the ovulatory response during the postpartum period in the rabbit

Abstract

The relation between plasma estradiol 17-beta mean levels (E2), sexual receptivity and ovulation response, as well as the evolution of E2 from day 29 of pregnancy until day 11 of postpartum in rabbits, was studied. The results suggest a direct relation between plasma E2 mean levels and high or low sexual receptivity. With a determined plasma E2 concentration was not able to predict sexual receptivity. The best ovulation response was obtained in rabbits of high or medium receptivity treated with 20 micrograms or 40 micrograms of GnRH. High plasma E2 mean concentrations were detected on day 1 and 9 postpartum. The evolution of E2 levels from day 29 of pregnancy until day 11 postpartum suggests that day 9 is the most favorable breeding day, when rabbits are to be submitted to a semi-intensive reproduction management.