Over the years I keep hearing over and over of this study done were shetland mares were bred to draft stallions and the foals were fine. I have never been able to locate this study. If someone has it would you please post it??? Im beginning to think its an urban myth.
The bad thing is so many people believe this and use it as just reason to breed a big stallion to a small mare. You can get lucky and have it work, or you might not.
Heres an excerpt from thehorse.com on this issue
|In regards to the mare size vs stallion size problem, Carla L. Carleton, DVM, MS, Dipl. ACT, an associate professor in equine theriogenology at Michigan State University, says that although a mare has the internal ability to modulate the size of the fetus that's developing in her to some degree, "When you get a discrepancy and the stallion is quite a bit bigger than the mare, the mare's internal control over fetal size may be insufficient to the task. If the fetus' size exceeds that which may easily pass through the mare's birth canal, it will present as a dystocia due to fetal/maternal disproportion.|
No way will I risk the life of my mare to breed a big stallion to a small mare. Just not worth the risk.