New Bolton Researcher Cures $17 Million Stallion's Reluctance to Breed - Pennsylvania Equestrian
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New Bolton Researcher Cures $17 Million Stallion's Reluctance to Breed

by Stephanie Shertzer Lawson

War Emblem, the 2002 winner of the Kentucky Derby and Preakness Stakes, has some amazing genes. To the chagrin of the owners who shelled out $17 million to stand him at stud, he has refused to pass them on.

The 2002 Eclipse Award winner is fertile but completely disinterested in breeding. In five seasons at stud he has produced fewer than 40 offspring.

Those few offspring, however, are stellar. Half of his first small foal crop, now four-year-olds, are stakes winners.

War Emblem, purchased for $17.7 million by the Yoshida family of Shadai Stallion Station in Hokkaido, Japan, has been in contact with hundreds of mares over the past five years but has been persuaded to breed only 70.

His first year at stud produced four foals. After an extended vacation, he produced more than forty foals his second season. The next year, just two. And since then, none.

For two years, hundreds of mares have been introduced to the cranky stallion, who found none of them to his liking.

Dr. Sue McDonnell

Enter Dr. Sue McDonnell. A specialist in stallion behavior and breeding management at Penn Vet's New Bolton Center, she is perhaps the only person in the world who has worked with equine breeding behavior for an entire career. A renowned equine behaviorist, all her academic work focused on stallion behavior and breeding.

Dr. McDonnell and her team flew to Japan in February to meet War Emblem, whose well known problem involved strong preferences. He displayed a near normal response for a small number of mares and lack of interest or aversion with most others.

She collected a history, examined the horse, explored options, and then used her extensive knowledge of how horses breed under natural conditions to develop a treatment plan.


"His behavior suggested he was intimidated and slow to mature sexually," she said. "Young stallions just off the track, housed near experienced stallions, are often intimidated by them. It's similar to the nature of bachelor stallions in the wild."

In nature, a harem stallion will protect his band of mares from bachelor stallions, who live on the periphery. Bachelor stallions risk a beating for attempting to mate with the harem stallion's mares.

Dr. McDonnell suggested changes in housing and management to naturally build maturity and breeding confidence.

Own Band of Mares

War Emblem was moved out of the main stallion station to his own area nearby, where he was the only stallion. He was far enough away so that he could not see, hear or smell the other farm stallions. He was also given his own band of mares.

"We made him a harem stallion by giving him his own mares, who were nearby with safe fence lines," Dr. McDonnell said. "He was able to patrol the fence lines as a harem stallion would. Those were the first ones he started breeding."

Dr. McDonnell also suggested changes in breeding shed handling techniques to maximize response. "When working with a slow, finicky stallion, there are little tricks," she said. "One is to let the mare act as natural as possible."

While a mare's head is usually held straight ahead for breeding, that position can be confusing to an inexperienced stallion. The universal sign that a female quadraped is receptive to breeding is head turned back, one foreleg lifted, Dr. McDonnell said. Allowing the mares to adopt this posture gave the nine-year-old stallion confidence his partner would not kick or run away.

Dr. McDonnell and her team also prescribed some carefully managed hormone supplementation to boost libido and reduce his mare choosiness while his confidence builds.


Since then, Dr. McDonnell sees the stallion daily on video from Japan. "His confidence is building, he's goal directed, blossoming, and breeding," she said. "He hadn't even covered a mare in the past couple years despite many opportunities. Since mid-May, he's bred one or more mares each day and is now responding normally to most mares presented. Those are results beyond our expectations.

"We are confident that he has turned the corner to becoming a normal breeding sire. I sure don't know how horses think about these matters, but observations of his behavior indicate that War Emblem appears to be quite enthused about his new direction."

Dr. Nicholas Mills, of Kent, England, an equine reproduction veterinarian, facilitated the Shadai-Penn Vet connection. The team also includes Penn's stallion handler, Jim Morris.

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