Figure 1

Effects of medium and embryokine treatments on development of bovine embryos. Cleavage was measured at day 3 (A) and development to the blastocyst stage at day 6 (B,C) and 7 (D,E). Media treatments were no serum, serum replacement (SR) and fetal bovine serum (FBS). Embryokine treatments were added at day 5 and were vehicle, colony stimulating factor 2 (CSF2) and dickopf WNT signaling pathway inhibitor 1 (DKK1). Shown are least-squares means ± SEM. Cleavage rate was affected by medium (P = 0.029) and embryokine (P = 0.008). Using contrasts, cleavage was higher (P = 0.027) for FBS than SR. Cleavage was also lower (P = 0.012) for vehicle than for CSF2 or DKK1. The proportion of embryos that became blastocysts at day 6 (B,C) or day 7 (D,E), whether expressed as the percent of putative zygotes (B,D) or cleaved embryos (C,E), was affected by medium (P < 0.0001). Further analysis using orthogonal contrasts indicated that more embryos became blastocysts in media with SR or FBS than for no serum (P < 0.0001).The total number of putative zygotes/treatment were 945 for no serum—vehicle, 1165 for no serum—CSF2, 1216 for no serum DKK1, 1288 for SR—vehicle, 1416 for SR and CSF2, 1526 for SR and DKK1, 1288 for FBS and vehicle, 1551 for FBS and CSF2, and 1593 for FBS and DKK1.