The New Age in Breeding: Embryo Transfer

By Debra Ottier, BSc(Agr), MSc

Iron Horse Equine�

Although embryo transfer has been a common practice in the cattle industry for a number of years now, it has only recently gained steam in the equine world. Breed registries have only now begun to allow the use of embryo transfer in the registration of offspring as the development of blood typing and DNA parentage verification can prevent fraud and parentage errors. Thousands of embryos have been collected and transferred into recipient mares since the 1980’s with the future looking towards the importation/exportation of viable embryos, rather than animals. This new age technology will have a tremendous impact on the equine industry today and in building the horse of tomorrow.

Embryo Transfer allows for:

  • mares to continue performance careers,
  • outstanding mares to have more than one offspring per year,
  • obtain foals from problem and aged mares, and
  • immature two year olds to produce offspring.

The requirements are first to select a quality recipient mare to carry the foal to term. This mare needs to have a good reproductive history, be in good health with an adequate plain of nutrition. Both the donor mare and recipient mare need to be synchronized such that ovulation occurs approximately at the same time. This is where most problems arise, as attempts to synchronize both mares precisely can be difficult.

Once the mares are synchronized, the donor mare is impregnated. The embryo is flushed at day 7 after ovulation and transferred into the recipient by a surgical or non-surgical technique. Pregnancy, if established, is confirmed at day 17.

This technique can be quite an expensive undertaking. The costs for drugs for synchronization of ovulation, with professional fees payable to the veterinarian can amount to $2,000. Stabling fees for both the donor and the recipient mares, for a period of approximately 30 days, can add up quite quickly. If one does not have a suitable recipient mare, some practitioners offer mares for lease or purchase. This ranges from $1,500 to $7,500 depending upon the source of the recipient. One must not forget the stud fee which must be taken into account as well. In total, ranges of $4,000 – $12,000 can be expected.

Technology has advanced further such that embryos can be collected and preserved to enable shipping to a central facility which may have a large herd of recipient mares to choose from. In this manner, the donor mares can be collected from on farm and a larger number of recipients are available to synchronize, improving the odds for success.

Although the equine industry is behind in applying the tremendous advances in reproduction already made in other species, the time will eventually come when a catalogue of banked genetic material will be available for breeders to choose their next crop of potential equine athletes.