The on-gel culture system enables bovine blastocysts to complete cell segregation events at day (D) 10 following in vitro culture [Left panel: Epiblast marker SOX2 (Yellow), Primitive endoderm marker SOX17 (Magenta), DNA marker Hoechst (Cyan)]. This study demonstrated full-term development of D10 mature blastocysts produced using an on-gel culture system (Saito et al. Generation of viable calves derived from developmentally mature blastocysts produced by on-gel culture, pp. 330–334). This confirms that the on-gel culture system recapitulates preimplantation development to D10 and that the in vitro production of D10 blastocysts for cattle production is feasible. Two calves derived from on-gel–cultured embryos were vaginally born. Birth and placental weight were normal for both calves, and no obvious morphological abnormalities were evident. As of August 30, 2022, the calves are still alive and healthy (Right panel). The ability of the on-gel culture system to recapitulate bovine preimplantation development until D10 could contribute to studies on efficient animal production and preimplantation development in cattle.