“…Pyruvate and lactate, in the absence of glucose, are able to support in vitro development of bovine embryos (Kim et al, 1993), glucose, however, is widely used as a supplement and is the major energy substrate in most of the culture media. Moreover, it has been demonstrated that inclusion of glucose in culture media affects negatively the development of early-stage embryos in hamsters (Schini & Bavister, 1988;Barnett & Bavister, 1996;Barnett et al, 1997), mice (Chatot et al, 1989;Lawitts and Biggers, 1991;Scott & Whittingham, 1996), rats (Kishi et al, 1991;Miyoshi et al, 1994), cattle (Kim et al, 1993), sheep (Thompson et al, 1992) and humans (Conaghan et al, 1993;Quinn, 1995). Moreover, it has been demonstrated that inclusion of glucose in culture media affects negatively the development of early-stage embryos in hamsters (Schini & Bavister, 1988;Barnett & Bavister, 1996;Barnett et al, 1997), mice (Chatot et al, 1989;Lawitts and Biggers, 1991;Scott & Whittingham, 1996), rats (Kishi et al, 1991;Miyoshi et al, 1994), cattle (Kim et al, 1993), sheep (Thompson et al, 1992) and humans (Conaghan et al, 1993;Quinn, 1995).…”