Effects of Ages of Donors and Conditions of Preserving Ovaries on Porcine Oocytes Maturation in vitro and Efficiency of Parthenogenetic Activation

Effects of different ages of donors and different conditions of preserving ovaries on porcine oocytes maturation in vitro and efficiency of parthenogenetic activation were studied. The experiments included: 1) effects of different temperatures (22, 30, 37, 38.5and 40℃) of preserving ovaries on porcine oocytes maturation in vitro and developmental potential; 2) effects of periods of preserving ovaries on porcine oocytes maturation in vitro and development in vitro; 3) effects of different ages of donors on porcine oocytes maturation in vitro and developmental potential. The results of the experiment showed:1) There were no statistical differences (p＞0.05) of the parthenogenetic cleavage rate (79.64% vs 76.18%) and blastocyst rate (18.11% vs 33.82%) between oocytes from ovaries preserved at 38.5℃ and those preserved at 37℃. When the preserving temperature was increased to 40℃, the cleavage rate (21.68%) and the blastocyst rate (0) were great significantly lower than those at 37℃(p＜0.01). The cleavage rate (80.79% vs 76.18%) and blastocyst rate (29.61% vs 33.82%) were not different between 30 and 37℃(p＞ 0.05). When the preserving temperature was decreased to 22℃, the rate of cleavage was not different,but the rate of blastocyst was significantly lower, compared with that at 37℃; 2) The cleavage and blastocyst rates of the porcine oocytes collected after slaughter 2 or 6h were not different (p＞0.05); 3) The cleavage rate of oocytes from gilts and sows after maturation was not different, but the blastocyst rate of the sow group was significantly higher than that of gilt group (p＜ 0.05). The blastocyst cell number of sows and gilt showed no difference (p＞0.05).