Sometimes even the most eager stallion requires a little motivation when it comes to semen collection for artificial insemination. Thus, most breeding facilities employ the help of a live "stimulus" mare to put him in the mood. Not just any mare, however, will do for all stallions.

Kristina Janson Whitesell, DVM, a reproduction resident and research fellow in the Havemeyer Equine Behavior Program at the University of Pennsylvania's New Bolton Center in Kennett Square, described the ideal stimulus mare candidate and how to prepare her at the 2013 American Association of Equine Practitioners' Convention, held Dec. 7-11, in Nashville, Tenn.

"A stimulus/mount mare that is an easy keeper, sound, and reliably attractive and receptive to most stallions, as well as comfortable with her work and easy to handle, is invaluable to a breeding facility," said Whitesell.

"A cycling mare in natural estrus close to ovulation is typically the most stimulating to stallions," she said. And on farms with large herds of mares from which to select on any given day, a naturally cycling mare is often a good choice. But for many facilities the choice is to prepare one or more ovariectomized (with ovaries removed) mares that can be used year-round as a stimulus/mount mare for semen collection