Abstract: To examine the effects of epidermal growth factor (EGF) on the nuclear and cytoplasm maturation of buffalo oocytes in vitro culture. After the buffalo oocytes were matured in vitro for 24~26 h in TCM199 control medium supplied with EGF（0, 10, 25, 50, 100 ng/ml）, the first polar body (PB1) formation was assessed, then the oocytes were activated by 6dimethylaminopurine combined with ionomycin, examining the cleavage rate、blastocyst development rate and the number of blastocyst by staining with Hoechst33342. Adding EGF to the culture medium improved the nuclear maturation rate of buffalo oocytes significantly (P<0.05). The cleavage rate, blastocyst development rate and blastocyst hatching rate adding 25 ng/ml EGF to medium group were significantly higher than those in control group; but there were no significant difference in the number of cells of blastocyst. EGF can improve the effect of maturation of nuclear and cytoplasm of buffalo oocytes in vitro culture, and the best concentration of EGF was 25 ng/ml.

Key words: epidermal growth factor( EGF); buffalo; oocyte; in vitro maturation