Equine Embryo Transfer: Is It An Option For You?

The availability of equine embryo transfer is one of the many ways in which raising horses has changed in the modern world. As a horse owner, equine embryo transfer can give you significantly more control over the types of foals that you breed.

Affordability is often a concern with equine embryo transfer. There's no way to entirely avoid the sad possibility that you will spend thousands of dollars on equine embryo transfer and still not end up with a healthy foal, regardless of your efforts. One of the main factors that affects the cost of equine embryo transfer is time. If all goes according to plan and your surrogate mare becomes pregnant on schedule without delays, your costs will probably be relatively low. A small problem with the health of your mare, the surrogate mare, or the stallion could lead to expensive delays.

Why use embryo transfer?

Equine embryo transfer can also help you and your mare overcome some of her potential reproductive problems. If your mare is otherwise healthy and fertile but is unable to sustain a pregnancy for whatever reason, equine embryo transfer enables her to still have a foal safely. Your mare may also be a top performance, or show horse that can't take the time off to be pregnant and raise a foal.

A second advantage is that by performing embryo transfer in the young, competing mare, the interval to the next generation is shortened, whereas traditionally many competition mares are only put in foal once they finish competing.

There are a few key factors to consider if you decide to go down this path. These include the donor mare, the recipient mare and the choice of stallion.

Choosing a recipient mare

The recipient mare (the mare the embryo is transferred into) is easily the most considered factor in an embryo transfer program. Ideally the mare is at least 3 years of age and under 10 years old. Ideally a very similar size as the donor mare, fully vaccinated and not suffering from any aliments that may effect the breeding. To avoid complications, the recipient should previously have carried a foal to term and at no point resorbed a pregnancy.

Choosing a donor mare

The quality of the donor mare must justify the expense of the embryo transfer. The donor mare needs to be of impeccable breeding and temperament, with the aim to obtain high quality foals.

Choosing a stallion

You will need to research your stallion. If you can, see some foals sired by the stallion and learn as much as you can about his history.

The procedure for embryo transfer

Either fresh or chilled semen is best in order to maximise conception rates and increase the chances of recovering an embryo when flushing the donor mare. Although frozen semen may be used, it should be recognized that the likelihood of success may be lower than that of fresh or chilled semen and expectations should be adjusted accordingly. It is very important that the donor mare and the recipient mare are at a similar stage of their estrous cycle so that the embryo is transferred into a uterus very similar to the uterus from which it has been removed. The two mare's estrous cycles must therefore be synchronized. This may be achieved by administering prostaglandin injections to the mares when they are not in season.

Once in season, both mares are closely monitored by ultrasound scanning of their uterus and ovaries. The donor mare is then inseminated at the optimum time to produce a pregnancy; this timing depends on whether fresh, chilled or frozen semen is being used. The recipient mare is given a hormone injection to cause her to ovulate 24-48 hours after the donor mare. The embryo transfer itself is performed 7-8 days after the donor mare has ovulated.

The recipient mare is then scanned 7 days later to confirm if she is pregnant. Your mare will not require any surgery during the actual embryo collection; embryos are retrieved through uterine flushes.

Working with a veterinarian that has a significant amount of experience in performing equine embryo transfers will make it that much more likely that you and your mare will succeed. Transferring embryos is much more difficult than it sounds, and horse owners need to make sure they have secured the services of someone that has spent a long time refining his or her technique. If you are a concerned horse owner, you should still know that the success rate of the surrogate mare successfully receiving your horse's embryo is as high as eighty-five percent. While informed horse owners should be aware of the potential setbacks that can occur, there is no reason for them to become discouraged.