Trans-vaginal oocyte retrieval and subsequent in vitro production of embryos from a cow involuntarily culled.
A Holstein cow of high genetic merit, in late lactation (205 days) and diagnosed with salpingitis (after 4 infertile services and veterinary consultation), was subjected to 1 trans-vaginal oocyte collection attempt, prior to slaughter. Of an estimated 10 follicles punctured, a total of 4 cumulus-oocyte complexes were retrieved. These were matured in vitro in a maturation medium for 24 hours. After 24 hours maturation, the oocytes were fertilised in vitro with Percoll-processed frozen/thawed imported semen, of the owner's choice. Fertilisation was achieved in a modified Tyrode's medium. At 18 hours post-insemination, the presumptive zygotes were transferred into culture in vitro in Charles Rosenkran's amino-acid medium and supplemented on Day 4 post-insemination with 10% foetal calf serum. All in vitro procedures were conducted in 50 microl medium droplets, under oil, in a humidified incubator at 38.5 degrees C in 5% CO2 in air. Three of the potential zygotes cleaved and, by Day 7 of culture, these had developed to the morula stage. The embryos were frozen in 1.5 M ethylene glycol and later transferred non-surgically to synchronised Holstein recipient heifers. One morula resulted in the only pregnancy and subsequent birth of a healthy heifer calf. An independent commercial company confirmed parentage through standard blood-typing assays. The genetic salvage of oocytes, for in vitro production of embryos, has potential benefits to the producer.
Shaw
D G
DG
School of Agricultural Sciences and Agribusiness, University of Natal, Pietermaritzburg, South Africa.
Bowles
C M
CM
Raja
K
K
Lishman
A W
AW
D000818:Animals; D002417:Cattle; D004624:Embryo Transfer / Q000662:veterinary*; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods / Q000662:veterinary*; D007247:Infertility, Female / Q000662:veterinary*; D009865:Oocytes / Q000000981:diagnostic imaging / Q000637:transplantation; D010053:Ovary / Q000000981:diagnostic imaging; D011247:Pregnancy; D012488:Salpingitis / Q000175:diagnosis / Q000662:veterinary; D020858:Tissue and Organ Harvesting / Q000379:methods*; D014463:Ultrasonography