background: the differential efficacy between long gnrh agonist with antagonist can partly be due to the preexisting differences in the early antral follicles before ovarian stimulation. objective: to compare the effect of pretreatment by estradiol with gnrh antagonist on antral follicular size coordination and basal hormone levels in gnrh antagonist protocol. materials and methods: on cycle da...

Background: The objectives of a series of studies undertaken was to improve farm animal reproductive efficiency in terms of embryo production efficiency, conception rate and litter size by immunoneutralization of inhibin in conjunction with other conventional reproductive techniques. Materials and Methods: A recombinant porcine inhibin alpha-subunit mature peptide was produced by mass scale and...

Ovulation induction (OI) is a cornerstone of human assisted reproduction treatments (ART). Current OI protocols are based on the human follicular dynamics model known as propitious moment theory (PMT), by which follicles continuously grow from the primordial pool without any pattern, and follicular fate depend on the occurrence of a gonadotropin surge. Recently, a new paradigm of human follicul...

To evaluate multiple follicular development synchronization after estrogen stimulation in prepubertal mice, follicular responsiveness to gonadotropin superovulation, the prospective reproductive potential and ovarian polycystic ovary syndrome (PCOS)-like symptoms at adulthood, prepubertal mice were intraperitoneally injected with estrogen to establish an animal model with solvent as control. Wh...

The effects of estrus synchronization with prostaglandin F(2α) (PGF(2α)) and Controlled Internal Drug Release Device (CIDR) on ensuing antral follicular development were documented and compared to natural estrous cycles of non-seasonal tropical goats. Two to six follicular waves were observed, with the three-follicular wave pattern being most frequently observed (58%), followed by four follicul...

American Society of Animal Science members, publishing in Journal of Animal Science (JAS), completed research that resulted in understanding the estrous cycle of cattle, which led to the ability to inseminate cattle on a given day with pregnancy rates similar to those achieved by 21-d breeding by a fertile and sound bull. Research published in JAS led to understanding estrus, ovulation, the est...

The study of follicular dynamics began in the mid-20th century, but progress has been particularly rapid in the last two decades through the use of tools that have enabled serial, non-invasive examination. A brief overview of early oogenesis and folliculogenesis is provided as a backdrop to the evolution of our understanding of follicular dynamics during the bovine estrous cycle. Studies to dat...

Oestrous synchronization involves synchronization of ovarian follicular turnover, new wave emergence, and finally induction of ovulation. The final step can be synchronized by the parenteral administration of either GnRH or oestradiol benzoate. This study investigated corpus luteum and follicular emergence after ovulation had been induced by the administration of either GnRH or oestradiol benzo...

McKenzie’s laboratory (U. MO; 1930s) described the estrous cycle of domestic animals. Brownell (Cornell; 1936) reported AI and bull bred pregnancy rates were similar. Between 1938 (first, EJ Perry, NJ) and 1940, 54 AI organizations in 21 states were formed. Ulberg, Christian and Casida (1951) controlled time of ovulation in cows with progesterone (P) injected daily. Trimberger and Hansel (1955)...