Avaliação do edema e tônus uterinos em éguas acíclicas tratadas com cipionato de estradiol e progesterona

Abstract

The use of acyclic recipient mares in the execution of embryo transfer programs is a growing and greatly important practice, given the differences between donor and recipient mares reproductive cyclicity and economic interest in the athletic performance of foals born early in the foaling season. Several protocols using two or more estradiol applications prior to progesterone administration have been described for preparing acyclic recipients. Furthermore, the exposure time of the endometrium to estradiol has been being associated with better pregnancy rates. In view of these aspects and considering previous studies that described the behavior of estradiol cypionate in mares, the present study aimed to evaluate uterine edema and tone of acyclic mares after exposure to estradiol cypionate for three or six days prior to long acting progesterone administration. For this, two groups of five mares in seasonal anestrous were selected, which received the same dose of estradiol cypionate, prior to progesterone administration, also in equal doses. Evaluations were performed by daily rectal palpations and ultrasound examinations. The group exposed to estradiol for a longer period showed gradual reduction in the edema score before progesterone administration, differently from the group shorter exposed. Uterine tone was not different between the groups. Thus, it was concluded that the group with longer exposure exhibited an uterine edema profile close to that observed in cyclic mares, although the expression of tone was not altered by the duration of the estrogenic domain.