Studies on Electrical Activation of Porcine Oocytes Matured in vitro and Embryo Culture Systems

Conditions for electrical parthenogenetic activation of porcine oocytes matured in vitro and in vitro culture systems of porcine embryo were studied. The best results were achieved under the conditions of electrical field strength and the pulse duration at 130Vmm-1/80 μs, with a blastocyst development rate of (20.12 ± 8.18)% (P ＞ 0.05). No significant difference was found between treatments of multiple pulses and a single pulse ( P ＞ 0.05). Parthenogenetic embryos were cultured with different methods and air conditions for 7 days in vitro, blastocyst development rate of embryos with changed culture media [ (26.44 ± 8.35)% ] or changed media with 10% fetal bovine serum (FBS) [ (17.68 ± 5.39)% ] on the fifth day showing no significant difference from that of embryos without change of culture media [ (25.30 ± 7.55) %, P ＞ 0.05 ], while cell numbers of blastocysts from embryos with changed culture media (15.78 ± 5.46 and 14.55 ± 4.81) were significantly lower than number of blastocysts from embryos without change of culture media (18.01 ± 6.79,P ＜ 0.01 ). Blastocyst development rate and blastocyst cell number of embryos cultured in lower O2 (5 % CO2:7%O2:88%N2) also showed no significant difference from those in high O2 (5% CO2 in air) [ (20.78 ± 8.80) % and 17.00 ± 6.12 vs. (25.30 ± 7.55) % and 18.01 ± 6.79, P ＞ 0.05 ]. It is concluded that change of culture media with the same new one or changing over to media with 10% fetal bovine serum (FBS) on the fifth day and low O2 environment are not necessary for porcine embryos development.