It’s early morning in the “Princess
Barn” and the residents are waking
up, softly whinnying to each other
while waiting for breakfast to be served.
These ladies in waiting are treated like
royalty and Dr. Elaine Carnevale makes
no apologies for that.
The mares are her
charges and she wants to make sure they
get only the very best.
The mares are at the Equine Reproduction
Laboratory for reproductive
assistance, whether to increase reproductive
success in older or problem mares, or
to obtain a pregnancy from a stallion
with limited or poor quality sperm.
Whatever the problem, Dr. Carnevale, an
Assistant Professor in the Department of
Biomedical Sciences, helps to find a solution
to safeguard the mare’s lineage and
ensure her valuable genetic material will
be conserved.
“Fertility starts to decline in mares in their teen years,” said Dr. Carnevale, who is a member of the research team at the Equine Reproduction Laboratory. “Many of our assisted reproduction techniques help prolong the reproductive life of the mare by using such technologies as oocyte transfer, embryo transfer, and sperm injection. We also are working to understand how aging affects reproduction. It’s all about optimization.”
When Dr. Carnevale came to Colorado State University in 1998, she began a clinical oocyte (egg) transfer program to obtain pregnancies from mares that were no longer able to get pregnant or provide embryos. This evolved to include the collection of oocytes from the ovaries of valuable mares after they had died. Work done lately includes sperm injections (an assisted test-tube fertilization to obtain foals from subfertile stallions) where sperm is injected into the eggs of mares to improve conception rates.
Dr. Carnevale’s clinical program is based on referrals so horses of all breeds come from across the United States (and some from other parts of the world) for treatment. The mares usually stay about six months out of the year, in the “Princess Barn,” with the clinical team working to ensure the highest level of care and the best possible reproductive outcome. Dr. Carnevale works with mares of all ages, often as old as 25 years. The reason being, she notes, is that mares are limited in the number of foals they can produce, and their value may take a number of years to establish.
“The mare may be older by the time her value as a broodmare is recognized,” said Dr. Carnevale. “We work with a lot of very good mares that are old and have compromised reproduction. Many horses will continue to perform in events, such as cutting, reining, racing, and jumping, until they are older and their reproductive capacity is limited. Most of the mares in our program have proven their value as performers or producers, but they now have reproductive problems. Our goal is a healthy pregnancy and a healthy foal.”
In her research program, Dr. Carnevale and her team continue to improve the science behind using sperm injections to artificially fertilize eggs. In another research project they are studying the egg and its interactions with the follicle. This would include the signals between the egg and follicle that result in egg maturation (preparation for fertilizations) and ovulation. An important component of the work is how these signals differ in old and young mares.
“One interesting aspect of our work with older mares is how it relates to fertility in humans,” said Dr. Carnevale. “A lot of the same things that happen in the horse happen in the woman, including a long follicular phase, one ovulation, and a similar length of time for the egg to mature before ovulation. Some of the reproductive problems we see are also similar, as many women wait until they are older to have children. Mares will probably make an excellent model forhuman reproductive studies and the information we gain can be used to benefit both species.”
Dr. Carnevale, who is originally from Trinidad, Colorado, decided in the first grade that she wanted to be a horse doctor. She attended Colorado State University where she received her DVM and master’s degree in equine reproduction. She spent a few years working in the breeding industries in New Zealand, Ireland, and Australia, before returning to the United States to the University of Wisconsin where she received her PhD in reproductive physiology. She studied with Dr. O.J. Ginther, internationally considered one of the leading authorities in equine reproduction.
Dr. Carnevale joined the faculty at Southern Illinois University, before returning to private practice for a year and then joining the faculty at Colorado State University. In addition to her research, Dr. Carnevale helps teach undergraduate, graduate, and veterinary students at the Equine Reproduction Laboratory. She also teaches short courses for veterinarians, horse owners and breeding farm managers.
