Impact of hormonal modulation at proestrus on ovarian responses and uterine gene expression of suckled anestrous beef cows.

Background: This study evaluated the impact of hormonal modulation at the onset of proestrus on ovarian response and uterine gene expression of beef cows.

Methods: A total of 172 anestrous beef cows were assigned to one of four groups according to the treatment with estradiol cypionate (ECP) and/or equine chorionic gonadotropin (eCG) [CON ( = 43), ECP (n = 43), eCG ( = 44) and ECP + eCG ( = 42)].

Results: ECP-treated cows (ECP and ECP + eCG groups) presented greater occurrence of estrus (44.

Regulation of the polyamine metabolic pathway in the endometrium of cows during early diestrus.

The timing and magnitude of exposure to preovulatory estradiol followed by post-ovulatory progesterone (periovulatory endocrine milieu) in cattle modulate endometrial gene expression, histotroph composition, and conceptus development, but the mechanisms underlying this regulation remain unknown. Using an experimental model based on the modulation of follicle growth, this work aimed to evaluate if the polyamine metabolic pathway is regulated by the periovulatory endocrine milieu. Nelore cows were manipulated to ovulate small (n = 15) or large (n = 15) follicles, then the profiles of polyamines and their synthetic enzymes were compared between groups.