Birth of live calves by in vitro embryo production of slaughtered cows in a commercial herd in South Africa.

In vitro fertilisation (IVF) has become a useful breeding tool in most of the developed world. In this paper the success of bovine IVF and the birth of live calves under typical South African conditions is reported. Oocytes for IVF were collected from the ovaries of 6 slaughtered Bovelder beef cows. On average, 36.2 oocytes per donor were retrieved. From these oocytes, 43 blastocysts were produced from 5 of the donors by IVF with frozen Bovelder semen. The best 11 of these embryos were transferred into oestrous, synchronised Bovelder recipients in the same herd. As a result, 7 calves were born (a 64% calving rate) from 4 of the original donors. The calves had a normal birth mass, but the mean gestation length of the male calves was significantly longer than the herd average (291.6 versus 285.2 days respectively). No calving difficulties were encountered. In summary, it was shown that IVF for bovine embryo production and transfer is possible on a commercial basis in South Africa.