Abstract

The study of follicular dynamics has been particularly rapid in the last two decades. However,in vitro maturation and fertilization of oocytes results in reduced embryo production, which suggests that not all oocytes have the capacity to mature and to fertilize properly. The efficiency of bovine embryo production in vitro, measured as the blastocyst rate, obtained from oocytes matured and fertilized in vitro, is about 40%. Evidence has demonstrated that oocyte quality depends on the events that occur before germinal vesicle breakdown (GVBD) and has suggested that the oocyte must accumulate the appropriate information for meiotic resumption, fertilization and early embryonic development before chromosome condensation. The reduced blastocyst yield obtained in vitro seems to be related to oocyte source and quality, and the culture system applied. The oocyte quality and protocols of culture are the key factors that determine embryo development, establish a pregnancy and produce healthy offspring.

Key words: Oocyte, in vitro maturation (IVM), vitro fertilization (IVF), in vitro culture (IVC), embryo, bovine.