Bovine oocyte development following different oocyte maturation and sperm capacitation procedures

Various procedures have been reported for successful in vitro maturation and in vitro fertilization (IVM/IVF) of bovine follicular oocytes. Direct comparisons of these different recommended procedures have been rare. In this research, involving a total of 5,128 oocytes, a series of experiments were conducted to compare oocyte maturation, fertilization, and development in vitro with 2 maturation systems (with or without added hormones) and 3 types of sperm treatment procedures. Oocytes were collected from ovarian antral follicles (2-7 mm in diameter) within 3 hr after slaughter of cows or heifers. Those with intact or at least 4 layers of cumulus cells were selected for IVM/IVF. Oocytes were incubated for 22 hr in either Medium 199 with 7.5% fetal calf serum (M199 + FCS) alone or M199 + FCS with added hormones (M199 + FCS + H; oFSH 0.5 micrograms/ml, oLH 5.0 micrograms/ml, and E2 1.0 micrograms/ml) at 39 degrees C in 5% CO2 and 95% air. For IVF, frozen-thawed sperm were treated with either 0.1 microM calcium ionophore A23187 (A23187) for 1 min, or 10 or 100 micrograms/ml heparin (H10 or H100) for 15 min.(ABSTRACT TRUNCATED AT 250 WORDS)