The aim of the present study was to develop a treatment protocol for the precise synchronization of oestrus that would avoid the development of persistent dominant ovarian follicles. Bos indicus heifers, in which oestrous cycles had been presynchronized, were allocated randomly, according to the day of their oestrous cycle, to one of five treatment groups. All heifers received a subcutaneous ea...

The objective of this study was to determine the effect on pregnancy outcome of either inseminating heifers twice (at 48 and 72 hours after withdrawal of a controlled internal drug release insert (CIDR) containing progesterone) or once (56 hours after CIDR withdrawal) following a seven-day CIDR synchronisation protocol. Dairy heifers (n=267) from five farms, with an age range of 388-736 days, w...

The objective of our study was to compare the characteristics of the corpus luteum (CL) formed after ovulation of the dominant follicle (DF) of the first follicular wave (W1) and those of the CL formed after ovulation of the DF of the second (induced) follicular wave (W2). Non-lactating Holstein cows were used for this study. In Experiment 1, cows were treated with PGF2α and GnRH on days 6 and ...

Regulation of human ovarian steroidogenesis differs from other species and precise knowledge on how human small antral follicles (hSAF) develop and acquire competence for continued growth and steroid output is still incomplete. The present study has characterized almost 1,000 normal hSAF collected in connection with cryopreservation of ovarian tissue for fertility preservation. The antral folli...

BACKGROUND Polycystic ovary syndrome (PCOS) is highly associated with an ovulatory infertility, features of the metabolic syndrome, including obesity, insulin resistance and dyslipidemia. Serum concentrations of high sensitive C-reactive protein (hs-CRP) were significantly higher in obese than in non-obese PCOS patients at baseline, suggesting a relationship between elevated hs-CRP levels and o...

BACKGROUND The intracellular signalling mechanisms that regulate ovarian follicle development are unclear; however, we have recently shown differences in the Akt and Erk signalling pathways in dominant compared to subordinate follicles. The aim of this study was to investigate the effects of inhibiting Akt and Erk phosphorylation on IGF- and gonadotropin- stimulated granulosa and theca cell fun...

We tested the hypothesis that a small dose of estradiol benzoate (EB) at the midstage of the estrous cycle in cattle would synchronize the subsequent pattern of ovarian follicular development, estrus, and ovulation. Nonlactating Friesian cows received either 1 mg of EB i.m. on d 13 of the estrous cycle (T; n = 12; estrus = d0) or served as untreated controls (C; n = 12). Their ovaries were exam...