Birth of calves after in vivo fertilisation of oocytes removed from follicles and matured in vitro
Newcomb, R.; Christie, W.B.; Rowson, L.E.
Veterinary Record 102(21): 461-462
1978
ISSN/ISBN: 0042-4900 PMID: 664199 Document Number: 128205
Ovaries were removed from cattle about 40 min after slaughter, and the contents of follicles 2-5 mm in diameter were aspirated into 10-ml syringes. The syringes were cooled to 20 deg -25 deg C during transport to the laboratory. Oocytes with a compact cumulus were cultured at 37 deg , and most reached metaphase II within 22-24 h. A total of 135 such oocytes was surgically transferred to 3 inseminated heifers, being placed in the oviduct opposite to the ovary that had recently ovulated. The heifers were inseminated again soon after the operation. Seven days after transfer, the heifers were killed. Of the 60 oocytes recovered from the recipient oviduct, 50% were still at the 1-cell stage and 23.3% were at or beyond the 8- to 16-cell stage. When similar transfers were made to non-inseminated, control heifers, cleavage beyond the 8-cell stage was not observed. Two blastocysts from the recipient oviduct of one of the inseminated heifers were surgically transferred (1 to each uterine horn) to another recipient on the 8th day after oestrus. This recipient gave birth to normal twin bull calves 277 days after the oestrus preceding egg transfer.