Karja, N. W. K., K. Kikuchi, M. Fahrudin, M. Ozawa, T. Somfai,K. Ohnuma, J. Noguchi, H. Kaneko and T. Nagai. 2006. Development to the blastocyst stage, the oxidative state, and the quality of early developmental stage of porcine embryos cultured in alteration of glucose concentrations in vitro under different oxygen tensions. Reprod. Biol. Endocrinol. 4:54.