Sperm Capacitation and in Vitro Fertilization in Cattle

The slaughtered cows or heifers have a large number of immature oocytes within primordial follicles or developing follicles. Therefore, it is useful to aspirate immature oocytes, which would be wasted if left unprocessed, from ovaries; subsequently they are matured in vitro (IVM), fertilized in vitro (IVF), and cultured in vitro (IVC). Also most recently it has been shown that immature oocytes can be collected by repeated Ovum pick-up (OPU) from living cows or heifers with high performances and used for IVF. A large number of normal embryos can be produced in vitro by performing IVM-IVF-IVC. So the improvements of genetics and propagation of livestock are considered to be more efficient by combining IVF technique to OPU and embryo transfer techniques. Thus, the research and development were perused. Currently, there have been considerable improvements in IVM-IVF-IVC and the technique has reached the level of practical use. Moreover, obtaining oocytes as experimental materials from slaughterhouses is easy compared to the collection from experimental animals which require breeding facilities. Therefore, from this regard, oocytes collected from ovaries in slaughtered animals should be used to a great extent as the material for studying mechanisms of maturation, fertilization, and subsequent development. Furthermore, the importance of the role played by IVF as a basic technique for the recent production of cloned cattle is needless to mention. Consequently, in the following, IVF in cattle is described here.