Addition of Macromolecules to PZM-3 Culture Medium on the Development and Hatching of In vitro Porcine Embryos

In this study, we conducted various experiments in order to develop enhanced cultural conditions for in vitro-produced porcine embryos.All embryos were produced by in vitro maturation (IVM) and fertilization (IVF) of immature oocytes from abattoirderived ovaries.In experiment 1, we cultured IVF embryos in 4 different groups, namely, 0% bovine serum albumin (BSA), 3% BSA, 0.05% Polyvinyl alcohol (PVA), and 0.5% Polyvinylpyrrolidone (PVP) added to the basal fluid cultural medium, Porcine zygote medium 3 (PZM-3).The rates of embryo development were higher in the group where the PZM-3 media had been supplemented with 3% BSA than the other groups.While not statistically significant, the percent of blastocysts and hatched blastocytes were 6.9% and 25.0% in the 3% BSA group vs. 1.2-6.4% and 0-16.7% in the other groups, respectively.In experiment 2, we added 10% fetal bovine serum (FBS) to PZM-3 on day 0 of culture and observed the development rate of blastocysts per day of culture from days 0 to 5. The development rate of blastocysts was higher at 15.6% on day 4 than on any other day, and was significantly higher than on day 0 or day 1 (p<0.05).The development rate of hatched blastocysts was 26.7% on day 4, and was higher than on any other day.In experiment 3, we cultured IVF embryos with different fluid culture media, grouped as 1) PZM-3+0.3%BSA (day0-day7); 2) PZM-3+0.3%BSA→(day-4) PZM-3+10% FBS; 3) PZM-3+0.3%BSA→PZM-3+0.3%BSA+(day-4) FBS 10%; and 4) PZM-3+0.3%BSA+10% FBS (day0-day7).The development rates of blastocysts and hatched blastocysts were 21.5% and 53.1% in group 3, respectively, which was significantly higher than group 4 with respect to blastocyst development (5.2%, p<0.05) but not hatched blastocysts (14.3%).The total cell number (TCN) of blastocysts in group 3 was higher at 37.8±16.1 than the other groups at 16.8±4.4-30.1±10.9;however, this was not significantly different.The results of this study showed that PZM-3 containing 0.3% BSA and supplemented with FBS during the later stage of culture on day 4 resulted in better TCNs and an increased rate of hatched blastocysts.(