If you have a really valuable mare, or a mare you just like a lot, you may have thought about getting a foal from her before she dies.  When a mare dies, her genetic potential also dies; that potential is important in valuable mares. An older mare may be unable to carry a foal, but she can sometimes be bred and embryo transfer performed.  However, some older mares are not candidates for embryo transfer and we have to consider other options to prevent this loss of genetic potential.  One other option is oocyte transfer after the mare dies.

A study was performed to determine if eggs, or oocytes, from a mare could be harvested and placed in another mare after she dies.  This other mare would be bred and carry the foal to term.  To determine if this was possible, some vets at Colorado State received embryos from mares that had died or were euthanized for various reasons.  Most of these mares had illnesses such as chronic founder or cancer and had to be euthanized.  After euthanasia, the ovaries were removed and either driven or shipped to Colorado State.  Twenty four percent of the mares that were bred with oocytes from mares that were euthanized became pregnant, so it is possible to collect the ovaries after a mare is euthanized and get a pregnancy.  Ovaries that were transported to the lab within an hour of the mare’s death had a greater chance of ending in a pregnancy.  Obviously, this is something that would only be done on very valuable mares.  The procedure is technical and everything has to be ready to go when the mare is euthanized, including a mare to accept the oocyte and semen to fertilize it.  Visit our website at tfbradio.com for the latest animal health information.