Pregnancies established in cattle by transfer of fresh and frozen embryos derived from in vitro maturation and fertilization of oocytes and their subsequent culture in vitro

P~~~~CI~S ESTRRLISIIEDXV CATTLE BY TRRHSPER DP FRESH A&D PROEEI EHBRYOS DERIVED FROH IH VITRO MRTURATfOllRRD PRRTILIZATIOP OF OOCTTRS AND TREIR SUBSEQURRT CULTURE xl?VITRO K, H, Lul=3, H. S. Jiang1*2*3, W. L. Wangl~2~3& I.Gordon2 OVAMASS Ltd.,Fethard,C!o.Tipperary,Ireland. :: Department of hgricu~ture,Univers~~y College Dublin. 3. Animal Reproduction Laboratory,Guangxi Agricultural College, panning, Guangxi, China. It was previously reported that Normal pregnancies had been established in cattle by transfer of fresh and frozen embryos derived from in vitro maturatfon,fertilization and their subsequent culture in vivo in the sheep oviductfLu et al, 1987, Vet, Rec. 121,259; Lu et a1,1988,11th Congr. of Anix. Reprod. and AI, Dublin,Vo1.3:3421.In the present from bovine oocytes which had been study,pregnancies matured and fertilized and developed in vitro have been obtained. ovaries obtained at a local Oocytes . aspirated from abattoir were matured and fertilized in vitro.At 44-48 h cocell) were after insemination,early embryos(2-8 cultured for 5-7 days by utilizing two co-culture systems with granulosa and oviduct cells previously described by Jiang and Wang et al(1989, Y. Reprod. Fert.,Absract Series ova developed to No.3, 89, SO).The percentage of blastocysts was 25-303.Eabryos harvested on layers at 7-8 days after inseaination were frozen according to the laethod reported by Lu et al (1988‘11th Congr. of Rnim. Reprod. and AI . Dublin, Vol.3 :342). In the further evaluation of enbryos(blastocysts),the viability of embryos developed in vitro has been verified by embryo transfer to cattle recipients.Xn the first trial,8 beef heifers were used as recipients and the frozen-thawed embryos were transferred on day 7 or day 8 of the oestrous cycle.In the second trial,24 beef heifers and friesian cows were used for fresh embryo transfer.The erabryos were transferred no-surgically in pairs to the ipsilateral horn of the uterus. Pregnancy diagnosis of the recipients revealed'that 4 out of 8( 50% ) were pregnant in the first trial with frozen embryos{ 180 days of gestation),and 14 out of 24f 58.3% ) were pregnant in the second trial with fresh embryosf90 days of gestation). In conclusion,pregnancies have been established in cattle by transfer of either fresh or frozen embryos derived from oocytes matured , fertilized and their subsequent culture in vitro.

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JANUARY 1990 VOt. 33 NO. 1