Abstract
Bovine cumulus-oocyte complexes were inseminated in fertilization medium, mBO medium including caffeine (5 mM), heparin (10 μg/ml) and bovine serum albumin (BSA; 10 mg/ml) with or without glucose (13.9 mM). Oocytes were freed from cumulus cells 8 h post-insemination and transferred into culture medium, mTCM-199 supplemented with BSA (3 mg/ml) and with or without glucose (5.56 mM). When oocytes were examined 24 and 72 h post-insemination, high proportions of oocytes were penetrated (88-92%) and cleaved to more than the 2-cell stage (68-71%), respectively, regardless of the presence or absence of glucose during fertilization and/or further culture without cumulus cells. At 144 and 192 h post-insemination, however, the proportions of oocytes developed to the morula and blastocyst stages, respectively, were significantly (P<0.01) higher in culture medium without than with glucose regardless of the presence of glucose during fertilization. In addition, significantly (P<0.05) higher proportions of oocytes developed to the morula (23 vs. 40%) and blastocyst (5 vs. 12%) stages when they were cultured in glucose-free medium after fertilization in medium without than with glucose. When glucose was added in culture medium 120 or 144 h post-insemination, 23 to 24% of inseminated oocytes developed to the early or expanded blastocyst stage 192 h post-insemination.
