In vitro production of small ruminant embryos: Latest improvements and further research

This review presents the latest advances in and main obstacles to the application of in vitro embryo production (IVEP) systems in small ruminants. This biotechnology is an extremely important tool for genetic improvement for livestock and is essential for the establishment of other biotechnologies, such as cloning and transgenesis. At present, the IVEP market is almost non-existent for small ruminants, in contrast with the trends observed in cattle. This is probably related to the lower added value of small ruminants, lower commercial demand and fewer qualified professionals interested in this area. Moreover, there are fewer research groups working on small ruminant IVEP than those working with cattle and pigs. The heterogeneity of oocytes collected from growing follicles in live females or from ovaries collected from abattoirs remains a challenge for IVEP dissemination in goats and sheep. Of note, although the logistics of oocyte collection from live small ruminant females are more complex than in the bovine, in general the IVEP outcomes, in terms of blastocyst production, are similar. We anticipate that after appropriate training and repeatable results, the commercial demand for small ruminant in vitro-produced embryos may increase.