IN-VITRO MATURATION AND FERTILIZATION OF BOVINE OOCYTES

Our knowledge of in vitro maturation (IVM) and fertilization (IVF) of bovine oocytes has been expanding rapidly since first applied in the 1 960s and 70s. These techniques are today employed worldwide, although only about 30% of the bovine oocytes matured and fertilized in vitro u sually develop to the morula and blastocyst stages. Although proper cu lture conditions after initial cleavage seem to be essential, the proc esses of oocyte maturation and fertilization also present special requ irements which warrant formation of a zygote. Proper oocyte selection and the need for the development of chemically defined culture media f or IVM are emphasized. Apart from oocyte maturation, the success of IV F depends on the donor of the spermatozoa, the method used for selecti ng motile and morphologically normal spermatozoa, and the method used to enable proper sperm capacitation. This review summarizes the advanc es in research on the IVM and IVF of bovine oocytes; research which at tempts to improve this biotechnology.