Role of Some Inducing Additives in in vitro Maturation Environment of Farm Animal's Oocytes: Status Evaluation

Abstract

This review focused on highlighting the importance of the biochemical role of some additives that have a stimulating impact on in vitro maturation (IVM) of farm animal oocytes. The supportive role that these additives played has led to a noticeable increase in embryos yields. Nevertheless, there are some considerations that must be taken into account for the process of producing embryos in vitro to function optimally. Among the hormones, the famous gonadotropic hormones (follicle-stimulating hormone (FSH), luteinizing hormone (LH) and chorionic gonadotropin hormone (CG)), estradiol and growth hormone (GH) occupied a wide area in IVM, but the usage of these hormones still limited to specific concentrations as the increase in their concentrations did not give the desired effect. Due to the historical popularity and the primary role of cysteamine as an antioxidant agent, its usage has increased recently. However, this usage has also remained limited to specific concentrations, as are hormones. Besides, cysteamine was an important reason for obtaining high rates of embryos in the blastocyst stage. Conversely, there was a reservation in the use of follicular fluid (FF) and fetal calf serum (FCS). Although these two elements are rich in hormones, proteins, lipids and various growth factors, FF contains factors that inhibit the maturation of oocytes. Moreover, FCS has a negative role in the quality of resulted embryos because of the high levels of lipids (triglycerides).