by Dr. Barry Ball, DVM
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 carrying a foal to full term is neither desirable or possible
(e.g. younger mares in competition or training as well as mares with other health
concerns that prevent carrying a foal to full term).
Photomicrograph of a Day-7 equine embryo (0.4 mm in diameter).
|
Successful embryo transfer relies 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 Equitainer 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.
To obtain an information packet, please contact Karen Scott at the VMTH at (530)
752-6630 (e-mail kascott@ucdavis.edu).
For more information concerning this program, contact Dr. Mary Scott at (530) 752-6630 (e-mail
mascott@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.
|
