Follicular growth divergence: effect in the oocyte competence for in vitro embryo production

Abstract

The oocyte growth in the ovarian follicle is determined by several factors which influence its viability and ability for the in vitro development. These factors include: follicular size, estrous cycle day, atresy level and influence of other follicles, such as dominant follicle (DF). The phase of DF selection is visualized by ultrasound as it increases in the diameter of the DF, while other wave follicles stop their growth or undergo regression. These changes that occur in the diameter reflect the important endocrine, paracrines and autocrines alterations that follow or precede this critical moment of the folicle development; in turn, they can influence the oocyte quality and the ability to the in vitro development. The ovum pick-up following in vitro fertilization (IVF) of the oocyte from gotten alive givers and high genetic value has been one of the expanding technique in the world, over all regard to the important genetic increment in the improvement of the flock. However, variability in the results of the in vitro embryo bovine development exists and, in average, only 30% to 40% of the matured oocyte will develop until blastocyst.