The transfer of bovine embryos produced by in vitro fertilization (IVF) is widely used in calf production. However, the conception rate of IVF embryos has remained at around 40% for more than 30 years, making improvement of this rate a long-standing technical challenge. The Embryo Production Research Group is developing a new in vitro oocyte maturation culture system that focuses on metabolic changes in the cells surrounding the oocyte, with the aim of improving the quality of oocytes used for IVF. We are also developing a technology for early evaluation of bull fertility using various sperm assessment data, including epigenomic information, to screen out semen of bulls with low fertility, and a new bovine semen cryopreservation method that improves the quality of semen with low IVF capacity. Furthermore, we aim to develop a technology that enables the efficient production of high-quality IVF embryos by improving and integrating two embryo culture systems that we have developed to date.
