The methodology of in vitro embryo production in ovine requires the development of maturation, fertilization and culture media, in order to increase cleavage and development rates. This, in turn, would improve the implement of biotechnological programs for commercial purposes, as well as the use of this technique for cloning and transgenesis in this species. From the point of view of research, the oocytes can be obtained by puncture or slicing of ovaries collected from abattoirs, or by laparospic follicular aspiration (LOPU). One of the advantages of the LOPU is allowing the use of the same hormonally stimulated donor several times in periodic intervals. This could be extremely important, for instance, when using the ovine as a biological model for the production of biodrugs, as long as animals are submitted to a strict sanitary control. On the other hand, in Brazil, due to their improved productivity or high commercial value, there is a demand for animals of high genetic value, which requires the development, adaptation and maximization of the different methodologies designed throughout the last years in reference laboratories worldwide. In this context, the perfect knowledge of the ovine physiology, especially from the breeds raised in Brazil, as well as the problems of the ovine in vitro embryo production are becoming more and more important. Therefore, it is fundamental to create protocols to allow not only the increase on the population of oocytes with enough quality to undergo in vitro maturation, but competence to reach the blastocyst stage, or alternatively, the transference of early stages embryos to the recipients, avoiding the common embryo losses during the in vitro development and the low rates of full-term pregnancies, with healthy lambs. The first results of this challenge are already being observed in Brazil, not only in the in vitro embryo production for commercial purposes, but in programs of cloning and transgenesis.
embryo; in vitro fertilization; oocyte; ovine