RESUMO
This study was designed to compare the effectiveness of different activation treatments for activation of in vitro matured oocytes and their developmental potency in mCR[2]aa 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 mCR[2]aa medium. Group 2 in vitro matured oocytes [n=294] were exposed to 7% ethanol for 5 min followed by treatment with 10 micro g/ml CHX for 4 h in mCR[2]aa 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 micro g/ml CHX for 4 h in mCR[2]aa medium. Group 4 in vitro matured oocytes [n=108] were cultured for 4 h without any chemical treatment in mCR[2]aa 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 mCR[2]aa is most favorable for parthenogenetic caprine embryos production