Embryo transfer available through UC Davis

Established in 1996 at the UC Davis Veterinary Medical Teaching Hospital (VMTH), the Equine Assisted Reproduction Program provides mare and stallion owners access to the latest techniques to enhance the reproductive efficiency of horses. The success and widespread utilization of technologies such as embryo transfer and semen preservation offer many advantages to both mare and stallion owners. The reproduction program at the VMTH offers these services to horse owners.

Embryo transfer offers distinct advantages to mare owners who wish to maximize the number of foals from a particular mare. In addition, embryo transfer may be useful for mares when cmaying a foal to full term is neither desirable nor possible (e.g., younger mares in competition or training as well as mares with other health concerns that prevent carrying a foal to flail term).

Successful embryo transfer reties on careful and accurate reproductive management of both the donor mare, from whom the embryo will be collected, as well as the recipient mare that will carry the resulting pregnancy to term. The donor mare requires daily examination during estrus to accurately time insemination and ovulation and the recipient mare's cycle needs to be synchronized with the donor mare. This reproductive management can be handled either by your veterinarian or at the VMTH. At seven or eight days after ovulation, the embryo is collected from the donor mare using a noninvasive procedure that flushes the embryo from the donor mare's uterus. After recovery, the embryo is transferred into the recipient mare's uterus.

A large band of healthy and reproductively sound recipient mares is critical to the success of equine embryo transfer. The VMTH maintains a band of recipient mares that serve as surrogates to carry the pregnancy resulting from an embryo transfer. Each of these mare's reproductive health is carefully screened prior to acceptance into the recipient mare band. To assure accurate synchronization with the donor mare's estrous cycle, the recipient mare's cycle is monitored on a daily basis.

During the past two years, the Equine Assisted Reproduction Program also established a transported embryo service. With this service, the embryo is collected on the farm and then packaged and chilled in an Equltainer for transport via courier to the VMTH for transfer into a recipient mare. The transported embryo service avoids the need to bring the donor mare to the VMTH for embryo collection. Success rates using transported, chilled embryos are comparable to those obtained when embryos are transferred immediately after collection; therefore, the popularity of this procedure is increasing dramatically. In addition to embryo transfer, the Equine Assisted Reproduction Program also offers both chilled and cryopreserved semen preservation for stallion owners. For mare owners, the program offers breeding management services with both chilled and frozen semen.

The mare is inherently fertile

Speaking at the Bluegrass Equine Reproduction Symposium last year, Dr. Dan Sharp asserted that the mare is an inherently fertile animal, and does not deserve the often unjust o r inappropriate reputation of being difficult to breed. He said there is a fine irony here, as many commercial breeding farms brag about their high "conception rates,', when, in fact, the conception per estrus is reported to be 40-50%. The high "conception rates" which are commonly heard discussed likely represent cumulative pregnancy rates over the entire breeding season, often spiced with a sense of omission of mares from the records that they "knew wouldn't get bred anyway." He went on to explain how breeding procedures and practices lead to inefficiencies. WEJ

From The Horse Report by Dr. Barry Ball

Photomicrograph of a Day-7 equine embryo (0.4 mm in diameter).

To obtain an information packet, please contact Karen Scott at the VMTH at (530), 752-6630 (email kascott @ ucdavis.edu). For more information concerning this program, contact Dr. Nick Carney at (530) 752-6630 (e-mail njcarney@vmth.ucdavis.edu) or Drs. Barry Ball (e-mail: baball @ ucdavis.edu) or Irwin Liu (e-mail: ikliu@ucdavis.edu) at the VMTH (530) 752-0292.

A copy of the Bluegrass Equine Reproduction Symposium can be obtained from: Hagyard, Davidson, McGee Assoc., 4250 Iron Works Pike, Lexington, KY 40511-8412.

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