Mares are considered one of the most challenging domestic animals in the fertility department. Management strategies that can lead to successful pregnancies then are of interest to equine breeders. A November 2015 study in the Czech Republic suggests that male companionship after a mare is impregnated either naturally or artificially can increase the chances of the mare settling. (1)
The study found that 100% of mares settled when bred naturally on farm. In comparison, only 46% of mares bred off farm and brought home to a paddock adjacent to males settled successfully. When mares were bred off-site but returned home to a paddock shared with males, the settling rate increased to 78%. In the study, the males that shared the paddock with the mares were geldings. AI rates of settling were consistent with natural cover: mares separated from geldings were eight times more likely to lose their pregnancy.
The researchers cited a mare’s strategies to avoid infanticide as the reason behind the findings. Called the Bruce effect, females including mares will allow multiple matings with males in their environment to confuse the males about who the actual sire is so that the stallion won’t resort to infanticide to preserve his line. By housing mares with males, the mares are allowed to use their anti-infanticide strategy, including flirting with geldings, rather than abort their pregnancy.
I admit to being skeptical upon reading the research findings. I’ve had two Fell Pony mares who have refused to settle when run with a stallion. In one case the mare conceived and then aborted several months later when housed with the stallion. Other Fell Pony mares have refused to allow a stallion to cover them when they have a foal at foot, so there seems to be plenty of Fell Pony evidence to suggest that not all Fell Pony mares prefer male companionship. On the other hand, though, anecdotal evidence suggests that I have a higher fertility rate here with a stallion on-site than one colleague who has no males on their farm. I’ll continue to ponder this study as I work to maximize my mares’ fertility.
- Barakat, Christine, and Mick McCluskey. “A Surprisingly Simple Way to Improve Fertility,” Equus #465, June 2016, p. 18
© Jenifer Morrissey, 2017
The book Fell Ponies: Observations on the Breed, the Breed Standard, and Breeding is full of stories like this one about stewarding Fell Ponies. The book is available internationally by clicking here.