Improved in vitro development of porcine embryos with different energy substrates and serum

The effect of replacing 5.5mM glucose in North Carolina State University (NCSU)-23 medium with 0.5mM pyruvate/5.0mM lactate on porcine IVF embryo development was investigated in Experiment 1. Culturing embryos with pyruvate/lactate for 7 days or with pyruvate/lactate from Days 0 to 2, and then glucose from Days 2 to 7 improved cleavage rates. In Experiment 2, embryos were cultured for 7 days in pyruvate/lactate containing NCSU-23 medium supplemented with 0.05% PVA, 0.4% BSA or 10% fetal bovine serum (FBS). The BSA supplement increased the rates of cleavage, blastocyst formation, and the number of total cells in blastocysts. In Experiment 3, embryos were cultured in pyruvate/ lactate containing NCSU-23 medium supplemented with 0.4% BSA for 7 days (BSA-PL), 0.4% BSA from Days 0 to 4 and then 10% FBS from Days 4 to 7 (BSA-PL→F) or 0.4% BSA from Days 0 to 7 with addition of 10% FBS (BSA-PL+F) at Day 4. More blastocysts in BSA-PL→F and hatching or hatched blastocysts in BSA-PL→F and BSA-PL+F were obtained. Total cell number in blastocysts derived from BSA-PL→F and BSA-PL+F were increased. Our results demonstrated that supplementing pyruvate/lactate containing NCSU-23 medium with 0.4% BSA for 4 days and replacing it with 10% FBS for another 3 days improved porcine IVF embryo development.