Effect of different activators on development of activated in vitro matured caprine oocytes.

This study was designed to compare the effectiveness of different activation treatments for activation of in vitro matured oocytes and their developmental potency in mCR2aa medium so as to obtain maximum number of embryos. A total of 1090 cumulus oocyte complexes (COC's) were collected from 480 ovaries. In vitro matured oocytes were randomly divided into four groups. Group 1 in vitro matured oocytes (n=226) were exposed to 7% ethanol for 5 min followed by treatment with 2.0 mM DMAP for 4 h in mCR2aa medium. Group 2 in vitro matured oocytes (n=294) were exposed to 7% ethanol for 5 min followed by treatment with 10 µg/ml CHX for 4 h in mCR2aa medium. Group 3 in vitro matured oocytes (n=325) were exposed to 7% ethanol for 5 min followed by treatment with 2.0 mM DMAP and 10 µg/ml CHX for 4 h in mCR2aa medium. Group 4 in vitro matured oocytes (n=108) were cultured for 4 h without any chemical treatment in mCR2aa medium (control). The cleavage rate in groups 1, 2, 3 and 4 was 54.42%, 44.55%, 51.69% and 0.00%, respectively. The percentage of morula and blastocyst production in group 1, group 2 and group 3 was 26.01%, 29.77% and 29.76% and 2.43%, 1.52% and 1.78%, respectively. These results suggest that the activation of in vitro matured oocytes by 7% ethanol for 5 min followed by treatment with 2.0 mM DMAP for 4 h in mCR2aa is most favorable for parthenogenetic caprine embryos production.