The aim of the present study was to compare the developmental competence of porcine parthenotes and somatic cell nuclear transfer (SCNT) embryos after day-3 medium change with fresh embryo culture medium to that of embryos that did not have a medium change (monoculture system). The parthenogenetic and SCNT blastocyst formation rates were significantly (P<0.05) higher in the no-medium-change group (43.3±2.3, 18.5±1.1%, respectively) compared with the day-3 medium-change group (35.9±2.4, 7.9±0.9%, respectively). Total cell number in parthenotes and SCNT blastocysts was also significantly (P<0.05) higher in the no-media-change group (92.0±4.2, 66.9±7.7, respectively) compared with the media-change group (81.5±3.1, 46.6±4.9, respectively). No significant difference in cleavage rate was found in either group for parthenotes or SCNT embryos. This result suggests that day-3 medium changes have negative effects on porcine parthenotes and SCNT embryos in vitro.

Key words: Monoculture, Perthenogenesis, Porcine, Somatic cell nuclear transfer