Breeding Dummy Design

Breeding Dummy Design

For almost all stallions, a barrel length (from front to tail) of 60 inches is ample. It doesn't hurt for it to be longer, but it is not needed.

Photo: Anne M. Eberhardt/The Horse

Q. We have a Quarter Horse stallion that we will be starting in a shipped semen program this year. All of us—the stallion, our veterinarian, and our farm personnel—are new at collecting semen. We are in the planning stages for our breeding room and trying to make decisions on a dummy mount. Our vet said that you gave a talk on dummy mounts at the American Association of Equine Practitioners meeting and would be able to advise us on dimensions for our dummy mount. We have only this one stallion, at least for the first year. He is 15.2, with a very long body for a Quarter Horse, and he is very athletic. We would appreciate any recommendations on how big we should make the dummy for this stallion.

Cathy, via e-mail


 For fit of a breeding dummy, consider:

  • The dummy's barrel length from shoulder to tail;
  • The dummy's height at the tail; and
  • The girth of the barrel, or barrel diameter.

For almost all stallions, a barrel length (from front to tail) of 60 inches is ample. It doesn't hurt for it to be longer, but it is not needed. You want to keep your stallion nicely squared up at the back of the dummy as he would be with a mare, rather than advancing up the side of the dummy.

Concerning girth, for Quarter Horse stallions, a barrel diameter of 20 inches almost always works. A good starting height for a stallion of 15.2 hands would be about 55-58 inches from the floor to the top of the barrel at the tail for a level dummy, and an inch or so lower if the dummy body is angled. Since your horse is long in the body, you might want to go a bit higher than average. If he is athletic, it is probably better to go on the higher rather than the lower range. This will stretch him out and encourage him to stay coupled up squarely at the rear rather than advancing up the side of the dummy as he thrusts.

Another big design question is whether to buy or build a dummy with one fixed height or to go for an adjustable-height dummy. Like almost everything, each has advantages and disadvantages.

One of the most important features of a dummy is sturdy, solid construction. Whenever you make it adjustable, you run the risk of introducing jiggle and rattle that can distract certain stallions that would otherwise do well with a more solid, quiet design. For farms with plans for one breed with fairly uniform height, it's often most practical to choose one fixed-height dummy, and to design it on the high side. If for some horses you need it lower, the height can be effectively reduced by placing thick mats, such as cocoa mats, around the dummy for the stallion to stand on.

For further tips on dummy mount features and fit, as well as recommendations on starting and handling stallions on dummy mounts, check out "Stallion Handling for Dummies" on the University of Pennsylvania website.

Recommended Breeding Dummy Size
Breeding Phantom diagram
Light Horses


About the Author

Sue McDonnell, PhD, Certified AAB

Sue M. McDonnell, PhD, is a certified applied animal behaviorist and the founding head of the equine behavior program at the University of Pennsylvania's School of Veterinary Medicine. She is also the author of numerous books and articles about horse behavior and management.

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