Day-3 Medium Changes can Affect Developmental Potential of Porcine Somatic Cell Nuclear Transfer and Parthenogenesis Embryos In Vitro

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-mediumchange 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 nomedia- change group (92.0±4.2, 66.9±7.7, respectively) compared with the mediachange 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.