Our results showed that the donor cell type can significantly affect embryo development in vitro as well as in vivo. Cumulus cells proved to be the most effective cell type for somatic cloning according to both the in vitro development test as well as full-term survival. These results suggest that DNA from cumulus cells is more effectively reprogrammed following nuclear transfer. Our results agreed with those obtained in mice [57] where they compared the nuclear transfer efficiency of neuronal, Sertoli and cumulus cells, and obtained the best live birth rate from cumulus cell-derived cloned embryos. Furthermore, it was reported that cumulus cell-derived cloned mice do not have widespread dysregulation of imprinting [23]. Kato et al. [15,36] compared cells from the liver, testis, skin, ear, along with cumulus and oviductal cells and concluded that cumulus and oviduct epithelial cells are the most suitable for nuclear donors. Evidence supporting the superiority of cumulus cells for nuclear transfer also comes from the study of Forsberg et al. [58] who conducted large numbers of embryo transfer in cattle. It was shown that cumulus cells gave an overall 15.2% calving rate, while fetal genital ridge cells, and fibroblast cells produced a 9% calving rate. Adult fibroblast cells, in this study, gave the lowest calving rate of only 5%.