Since 2004, Keros has also been offering a complete embryo transfer service, ranging from insemination of the donor mare, uterine lavage, transplantation of the embryo, up to the availability of surrogate mares. Up until now we transplanted over 7500 embryos.
The huge experience and the motivation of our veterinary surgeons allow us to achieve very good results year after year. Up to now, our annual average has always been over 80% (17 days pregnancy). We owe this also, to a large extent, to the strict selection of the surrogate mares.
Since 2005, it has been possible to have the insemination and the uterine lavage carried out in your neighbourhood, and to carry the embryo to Keros for transplantation into the best suitable surrogate mare. Keros collaborates with some 30 veterinary surgeons all over Belgium and its neighbouring countries. The vets have been trained with us in lavage, treatment and preparation of the embryo for transport. They take care that your embryos travel under the best conditions to reach us. The beauty of it all is that the conveyed embryos do not lose any vital power at all and have the same chances of success as embryos that were lavaged and transplanted at Keros’ premises. The transport of embryos is particularly interesting for mares that are actively busy in horse racing so that their training schedule can be continued without interruption.
Embryo transfer means to take away the young embryo from the uterus of the donor mare and to transplant it into the uterus of the surrogate mare. The embryo will then continue to develop in this surrogate mare and is further raised after birth by this surrogate mare.
How does this work out in practice? First of all, the donor mare must be inseminated by a stallion of your choice. The removal of the embryo from the uterus of the donor mare (uterine lavage) is done 7 or 8 days after ovulation. The uterine lavage takes place while the mare is standing upright, occasionally lightly sedated, depending on the mare’s character. A sterile catheter (flexible silicone tube) is carefully introduced through the vagina and cervix into the uterus, after which the uterus is flushed with an appropriate liquid, hence the term “uterine lavage”. The embryo is still very tiny (less than 1 millimetre in diameter) and cannot be observed with the naked eye. The searching for and the manipulation of the embryo occurs under the microscope in a clean area (lab). The embryo is then prepared for immediate transfer into a surrogate mare or for transport to a specialized ET centre (like Keros for instance). The transplantation of the embryo into the surrogate mare looks very much like an insemination with frozen semen. The embryo is placed into a straw which is put into an embryo transfer pipette, then introduced through the vagina and cervix into the uterus of the surrogate mare. Once the transplantation is finished, the embryo continues to grow undisturbed until birth.
You can of course take your donor mare to our insemination centre to be inseminated by the stallion of your choice and to have a uterine lavage carried out (7-8 days after ovulation) in our embryo transfer centre. However, it is also possible to have the mare inseminated in another place (e.g. by your own vet or in another breeding centre) and to make an appointment with Keros for a uterine lavage of your donor mare. Moreover, you can also take advantage of our network of vets, have the donor mare inseminated and the lavage carried out in your neighbourhood. The embryo is then put in a cool box to be taken to our embryo transfer centre in Beselare where it is immediately transplanted into the best suitable surrogate mare.
In order to optimize the chances of success of a uterine lavage, it is important to know the exact date of ovulation. Therefore, it will be necessary that your vet checks the donor mare every day around the insemination, so that he can determine the exact day of ovulation. As soon as the veterinary surgeon has determined the ovulation, contact us THE SAME DAY to make an appointment for the uterine lavage of the donor mare in the embryo transfer centre in Beselare 7 to 8 days later. Uterine lavage takes place by appointment in the afternoon and takes about 30-45 min. The mare can travel home immediately after that. Reservations of surrogate mares must also be made on the same day of the ovulation.
The choice of surrogate mare is very important for the success of the transplantation, the good course of the gestation and the growing up of the foal.
The success of embryo transfer and the number of foals from the same donor mare born in the same year depend to a very large extent on the fertility of the donor mare and the stallion. The success rate of the transplantation of an embryo is practically constant, with chances of up to 80 % (16 days pregnancy) that the surrogate mare is carrying after the embryo transfer. However, the chance that a donor mare produces an embryo is much less predictable and varies from 0 to 80%, depending on the fertility of the donor mare and the stallion. The production of embryos is and remains the most difficult and restrictive step in the whole event. This implies that the chances of a bearing surrogate mare per cycle or uterine lavage are about 33% or in other words, that on average 3 uterine lavages are needed to produce a foal.