Effects of Microchip Technology and Different Sperm Preparation Methods on In vitro Fertilization and Blastocyst Rates in Bovine Embryo Production

This study compared the effects of commonly used sperm preparation methods, Percoll Gradient, Swim-Up, and Brackett & Oliphant (BO), with the increasingly utilized microchip technique on in vitro fertilization and proportion of bovine blastocyst development. Abattoir-derived oocytes were aspirated from 2-8 mm follicles. Grade A and B oocytes were subjected to in vitro maturation in TCM-199 medium for 20-22 hours. The mature oocytes were randomly allocated into four groups, and fertilization was performed using four different sperm separation methods. Following fertilization, presumptive zygotes were cultured separately in CR1aa culture medium according to their experimental groups. The results showed that cleavage rates at 24-48 hours for the Microchip, Brackett & Oliphant, Percoll Gradient, and Swim-Up methods were 57.7%, 35.5%, 23.4%, and 17.1%, respectively, with statistically significant differences among groups (p < 0.05). On day 7 of culture, blastocyst development rates were determined to be 41.02% for the Microchip method, 22.6% for BO washing, 14.3% for the Percoll Gradient, and 15.9% for the Swim-Up method, with statistically significant differences among the groups (p < 0.05). In conclusion, the microchip-based sperm preparation technique was found to be more effective than conventional methods in in vitro bovine embryo production, nearly doubling embryo yield and demonstrating the potential to reduce production costs.