The comparison of three media on the in vitro maturation rate of pig oocytes
In vitro embryo production in pigs remains a challenging obstacle, given the high rate of polyspermy following in vitro fertilization. Improving the efficiency of successful in vitro maturation, which leads to sequential in vitro fertilization and culture, augments the need for modern biotechnologies in pig farming systems, and subsequently conserves germplasm, that is, embryos to be used in future breeding programs. Thus, in this study the effects were compared of North Carolina State University-23 (NCSU-23), North Carolina State University-37 (NCSU-37), and epidermal growth factor (EGF/TCM-199) media on pig oocyte maturation rate and subsequent polar body formations in vitro. Ovaries were collected from a local abattoir in a controlled temperature of 39 °C. The oocytes were aspirated with an 18-gauge needle. Oocytes surrounded by a uniform complex-cumulus mass were selected. A total of 284 oocytes were allocated to the study, and were incubated with 5% CO2 at 39 °C for 48 hours. In vitro maturation rate was observed by checking the presence of expanded cumulus-oocyte complex (COC) and polar body formations under a light microscope. The maturation rate and polar body formations were significantly higher in NCSU-37 with 85.9% and 81.9%, respectively. However, there were no significant differences in EGF and NCSU-23 media as 77.1%; 72.5% and 77.1%; 72.7% were obtained for maturation rate and polar body formations, respectively. In conclusion, EGF and NCSU-23 had lower rates of maturation and meiotic development owing to their dissimilarities in composition. However, NSCU-37 rendered the highest results because the composition of the media contained beneficial constituents, that is, gonadotropins. New assisted reproductive programs may be important for commercial pig farming systems, as this may facilitate innovative ways of production.
Keywords: Embryo production, genetic resources, pig production, reproductive biotechnology