HOW much is it to lease a recipient mare? What should you look for if you want to buy one yourself? Is just any mare suitable to be a surrogate mare?

Hans Hurkmans, specialises in embryo transplantation and ICSI in horses and cattle. He has a donor station and an IVF lab and transplants numerous embryos in recipient mares. For ‘fresh’ embryos only just flushed, or embryos grown in the lab, he works together with four companies that lease a total of 450 to 500 recipient mares.

Horse Sense (HS): Are there any mares which you would advise against embryo transplantation or ICSI?

Hans Hurkmans (HH): Sure! Last year I used a number of three-year-old mares for ICSI, mares who had never foaled before. I advise against this now, because these horses sometimes get complications from the ovum pick up (OPU). This is because the ovaries of young mares are harder to reach with the OPU-probe, the instrument with which the oocytes (eggs) are harvested. In a mare that has foaled before, everything inside is more loose and you can easily reach the ovaries. But in mares with womb troubles, such as chronic uteritis or a badly closing cervix, embryo transplantation will not always be successful. Fertilisation and flushing can be problematic. Such mares are more suitable for ICSI.

HS: When is an embryo transplanted in a recipient mare?

HH: You can stimulate a recipient mare to get in heat and follow it from the moment she is in heat. In the case of embryo transplantation this has to be closely combined with the cycle of the donor mare. An ICSI embryo can be transplanted on day four or five after the ovulation of the recipient mare, flushed embryos on day five, six or seven after ovulation. The recipient mares can also be used when they are spontaneously in season. Then the frozen embryo can be thawed and transplanted on the desirable day.

HS: How much does it cost to lease a recipient mare?

HH: The prices of leasing a recipient mare varies from 2,000 to 3,000 euro. Generally, a recipient mare is leased as from 45 days of gestation up to four to five months after the birth of the foal. The guarantee will be returned after the recipient mare has returned after weaning the foal. The guarantee also serves to make sure that the mare, if she is for example, sold abroad at an auction, will actually be returned to the owner after weaning.

HS: Are all mares suitable to be recipient mares?

HH: No, not all of them. You need mares with a solid fertility cycle, age three to 15-year-olds. It is also important that the recipient mare is not too small. French trotters are very suitable as recipient mares. They are fertile and have often been used in the sport, so they are easier to handle and to work with.

HS: What should you look for when buying a recipient mare?

HH: It is an advantage when the mare has had a foal before, then you know if she will be a good and careful dam. I advise to have the womb of the recipient mare checked upon purchase. The mare should have been properly vaccinated, have a good condition and have no stable vices.