Effects of Age 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 that: (1) The effects of different temperatures (22, 30, 37, 38.5, 40℃) of preserving ovaries on maturation in vitro and developmental potential of porcine oocytes. (2) The effects of periods of preserving ovaries on in vitro maturation and in vitro development of porcine oocytes. (3) The effects of different ages of donors on in vitro maturation and developmental potential of porcine oocytes . The results showed that: (1) There were no statistical differences (P0.05) of the parthenogenetic cleavage rate (79.64% VS 76.18%) and blastocyst rate (18.11% VS 33.82%) between oocytes from ovaries preserved in 38.5℃ and those preserved in 37℃ saline. However, when the preserving temperature was increased to 40℃, the cleavage rate (19.37%) and the blastocyst rate (0) were greatly significant lower than those at 37℃ (P0.01). The cleavage rate (68.60% vs 64.68%) and blastocyst rate (18.30% VS 20.90%) were not different between 30℃ and 37℃(P0.05). When the preserving temperature decreased to 22℃, the rate of cleavage was not different, but the rate of blastocyst was significantly lower than that of 37℃. (2) The rate of cleavage and blastocyst of the porcine oocytes of ovaries preserved in saline at 37℃ collected at 2 or 6 h after cultured in vitro and activated were not different (P0.05). (3) The cleavage rates of oocytes from gilts or sows after in vitro maturation and activation were not different between gilt and sows, but the rate of blastocyst of the sow group was significant higher than that of gilt group (P0.05). The blastocyst cell number of sows and gilt showed no difference (P0.05).