Recent developments in in vitro fertilization technologies in livestock

Mammalian oocytes are collected from abattoir-derived ovaries or from live donors using ovum pick-up aspiration. Subsequently, they experience three primary steps of in vitro embryo production: maturation of oocytes; fertilization of matured oocytes with capacitated sperm; and in vitro culture (IVC) of zygotes for one week. The blastocysts formed during this period are transferred to synchronized recipients or are frozen for future use. Although in vitro production (IVP) has been achieved in farm animals, several existing limitations have led to varying degrees of success among different livestock. In order to optimize the efficiency of embryo IVP, along with seeking to improve procedural steps it is a priority to establish the best materials to use. For example, through the exclusive use of a defined in vitro maturation medium it is possible to eliminate the variable effects of the unknown composition of non-defined media supplemented with extracts of animal origin such as serum or follicular fluids. Similarly, while still achieving a desirable outcome IVC requires a specified medium that does not employ the assistance of somatic cells. Further investigation into refining such protocols is needed to establish an effective IVP system for use with a broad range of domestic animals.