Note to Editors: Photos of mare and foal are available to download from the News and Information website. Contact Karen Wheeler at the above-mentioned telephone or e-mail.
Thanks to Colorado State University researchers, Heaven Only Knows is the first foal born from oocytes harvested from the ovaries of a mare and shipped across the country from Virginia to Colorado for transfer into a surrogate.
"The ability to successfully obtain viable oocytes from transported ovaries means we can offer breeders a lot more options when dealing with the death of a valuable mare," said Ed Squires, Director of the Animal Reproduction and Biotechnology Laboratory at Colorado State University. "We’ve been able to make amazing strides in reproductive science over the past decade and this is just one of our successes."
The process of obtaining and transferring oocytes, which consist of a single cell, from one mare’s ovaries to another is a delicate operation in and of itself, without even factoring in the hazards of shipping from Virginia to Colorado.
At the time the ovaries were harvested, the mare, Jaguars Bar Bee Doll, had been dead for several hours. However, the veterinarian, Dr. Vito Del Vento, a Colorado State graduate, recalled that the Animal Reproduction Laboratory at CSU has been doing extensive research into oocyte transfer and he made a call.
The ovaries were shipped the same day, and were delivered to Drs. Lisa MacLellan and Marco Coutinho da Silva at CSU at about 1:30 a.m. Oocyte recovery began immediately by carefully scraping the ovaries, then culturing the six oocytes they were able to retrieve and allowing them to mature overnight in an incubator. The next day, five of the six were transferred into a recipient mare from the CSU herd.
Although the conception rate for immature oocytes is only 10-20 percent, eleven months later, Heaven Only Knows was successfully delivered on the Hylton Farm in northern Virginia.
Shipping ovaries is not like shipping semen, which is a procedure pioneered at CSU’s Animal Reproduction Laboratory. As Squires points out, there are a thousand sperm in a shipment of semen, but there are a limited number of oocytes in a mare’s ovaries and they are much more fragile.
Researchers are not even certain of the optimum temperature at which to store the ovaries for shipping. In this case, the ovaries were not refrigerated or cryogenically preserved.
"We are still working out the best method for shipping the ovaries, including developing appropriate containers, method of transportation, etc.," said Dr. Elaine Carnevale, a lead researcher with Colorado State’s Animal Reproduction Laboratory.
"One day, we hope to be able to offer breeders the option of shipping ovaries to us for egg recovery and be able to mature them and transfer them immediately, or, freeze them for transfer at a later date."
Last year, the ARBL team made an important breakthrough when they successfully delivered twin foals, Vitreous and Ethyl, from oocytes frozen then thawed and transferred to two different recipient mares.