The objective of this study was to evaluate the effect of two bovine embryo co-culture systems on calving rates. The embryos were co-cultured with Vero or Vero/BRL cells (mixed co-culture) until the blastocyst stage. A higher percentage of blastocysts was observed on Vero/BRL cells, 42.85%, compared with 30.41% on Vero cells (P≤0.05). The blastocysts from Vero/BRL and Vero cells were transferred to recipients. A higher rate of calving was obtained after transfer of embryos co-cultured with Vero cells (37.50%), compared with Vero/BRL cells (13.16%) (P≤0.01). A greater loss of pregnancy after transfer of embryos co-cultured with Vero/BRL cells was observed between 35 and 65 days. All calves were born naturally, healthy, and with normal weight. Vero cells better support cattle prenatal development than Vero/BRL cells. Probably Vero/BRL cells lead to epigenetic modifications that are responsible for early foetal resorption.