The July issue of Equus magazine includes a summary of some research done on twins in horses. The article left me asking a question, so I thought I would look into what I know about Fell Pony twins to follow up.
The research looked at how mares carrying twins responded when one embryo was “pinched off”. (The clinical term is ‘twin reduction.’) The scientists found that mares nine years and older tended to lose the pregnancy. “New research from Kentucky shows that the reduction of a twin pregnancy to a single embryo in a mare age 9 or older is more likely to result in a subsequent miscarriage than is the same procedure in a younger mare.” (1) In addition to the mare’s age, the researchers also looked at location of embryos, month of breeding, and other variables “to identify factors that might influence the likelihood of a live birth.” (2) Mare age was the only factor that showed statistical significance.
This article was of special interest to me first because I’m a breeder and second because I’ve experienced firsthand the fickleness of mares’ reproductive systems. The question that came to mind after reading the article was how older mares would do at carrying twins to term. Is it possible that miscarriage could be avoided by letting nature take its course, either by letting the mare carry the twins to term or perhaps letting one twin outcompete the other? I know of four sets of twins born to Fell Pony mares, so I thought I would look at the ages of those mares at the time of foaling. (3) All but one of the twins survived to weaning.
My study is far from scientific, but I do find it interesting that three of the four Fell Pony mares were nine years of age or older when they gave birth to their sets of twins. More research on nature taking its course in older mares carrying twins would be interesting.
While doing my research, I came upon this quote from Mrs. Newall, breeder of the Dene ponies, about her set of twins in 2003. “We have never had twins before, and I’m especially pleased at this very special double because I bred the mare, her mother, her grandmother and great grandmother!” (4) Having met Mrs. Newall and spoken with her on numerous occasions, I can imagine the delight in her voice when she said this to the reporter. Mrs. Newall told me her ponies were her friends, which I could certainly relate to, so having the depth of history that she did with the twin foals undoubtedly made her delight in them all the deeper.
- Barakat, Christine and Mick McCluskey. “Mare age may affect success of twin reduction,” Equus, issue 430, July 2013, p. 10.
- Same as #1.
- Townend Maddy and Merry were born to Townend Mulberry, age 4. Dene Echo and Epona were born to Dene Eden who was 13. Laurelhighland Venus and Adonis were born to Guards Blossom, who was 9. Restar Mountain Benjamin and Mountain William were born to Townend Mountain Gypsy IV, who was 16.
- Heath, Veronica. “A double celebration at a Northumberland stud,” The Countryman’s Weekly, 1-9-04, courtesy Eddie McDonough.
© Jenifer Morrissey, 2013