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.