Abstract: Canine ovaries collected from slaughterhouse were used, the effects of the different reproductive stage (follicular stage, corpus luteum stage and anestrus stage ) on IVM of canine oocytes were studied. The results showed that the number of A level COCs from follicular stage was 22.67±11.02, significant higher than other groups (P＜0.05). After culture for 48 h, the percentage of oocytes developmented to MⅠ-MⅡ at various stages were 19.2%±15.3%, 26.8%±21.1%, 9.8%±10.4%, there was no significant difference between follicular stage and corpus luteum stage(P＞0.05), but both were significantly higher than anestrus stage (P＜0.05). After culture for 72 h, the percentage of oocytes developmented to MⅠ-MⅡ at various stages were 25.2%±13.5%, 6.6%±6.7% and 9.2%±5.5%, follicular stage significantly higher than other groups(P＜0.05). It was found that different reproductive cycle stages of canine ovaries oocytes had certain influence on IVM, but also related with the culture time.

Key words: canine; reproductive stage; ovary; oocyte; IVM