Abstract
The present study was carried out to evalute the effect of glucose and lactate on in vitro produced bovine embryos using m-SOF medium. In the first and second experiments, cumulus oocyte complexes (COCs) were matured (22 h), fertilized (5 h) and cultured (9 days) in medium containing 0, 3.3, 5, 10, 15 mM lactate or 0, 1.5, 3, 5 mM glucose in m-SOF for in vitro production of embryos. In the third experiment, 1.5 mM of glucose was suspended in m-SOF at 0, 48, 72, 96 and 120 h after IVF. The cleavage rates of embryos were not significantly different among the concentrations of lactate, however the blastocyst production rate was significantly higher (p<0.05) with a concentration of 3.3 mM (34.8%) than those of 10 and 15 mM (18.9 and 15.7%, respectively). The cleavage rate of embryos was significantly higher (p<0.02) with a concentration of 0 mM of glucose (66.9%) than those of 1.5, 3, and 5 mM (41.2, 46.5 and 40.3%, respectively). The blastocyst production rate was significantly higher (p<0.02) with concentration of 0 mM (35.6%) than those of 3 and 5 mM (16.7 and 19.6%, respectively). When the embryos were cultured in m-SOF suspended with 1.5 mM of glucose at 48, 72, 96 and 120 h after IVF, the blastocyst production rates were significantly higher (p<0.05) at 96 and 120 h (51.6 and 50.8%) than those of 48 and 72 h (32.0 and 33.3%). These results indicate that 3.3 mM of lactate was more effective than that of other concentrations for in vitro embryo production, and that glucose inhibited embryonic development in early stage embryos, but sustained their post-morula stage.
