Is Sustainability a Heritable Trait in Thoroughbreds?

Is Sustainability a Heritable Trait in Thoroughbreds?

Researchers have determined that sustainability (how long the horse can keep racing without illness or injury) is just as heritable a trait as performance.

Photo: Erica Larson, News Editor

Breeding for speed? New research shows that, for better welfare—and for better economics—you might also want to breed for sustainability in your Thoroughbreds.

Australian and Swedish researchers have determined that sustainability (how long the horse can keep racing without illness or injury) is just as heritable a trait as performance. And while environmental factors, such as nutrition and training, also shape sustainability and performance, the genetic influences are there, said Brandon D. Velie, BSc, MSc, PhD, a researcher in the Department of Animal Breeding and Genetics at the Swedish University of Agricultural Sciences, in Uppsala, who was previously with the University of Sydney, in Australia.

“I don’t know of anyone in the industry who doesn’t think winning performance is heritable, and sustainability is no more complex than winning performance,” Velie said. “The industry has had great success with breeding for performance and, if united in their effort, would likely be just as successful in improving the sustainability of the breed.”

Velie and colleagues at the University of Sydney examined the racing records and bloodlines of 168,993 horses racing in Australia and Hong Kong. They looked at the heritability of several elements related to sustainability, such as the length of the horse’s racing career (longevity), the number of events the horse raced in (persistence), and how many spells (breaks of longer than 90 days between performance events) the horse had.

They found that racing longevity, racing persistence, racing frequency, spells per year, spells per 10 starts, and the variation of days between races were all significantly heritable traits, Velie said.

The results give support for “the successful and practical application of genetic selection methodologies” that could improve the lives of racehorses, their report concluded.

Some breeders are already practicing the science of breeding to eliminate the risk for certain injuries or illnesses, Velie said. But an overall sustainability approach makes more sense, as it’s obviously better for equine welfare. Horses that succumb to the physical and emotional stress of racing are often very young, usually no more than 6 years old, and sometimes never fully recover, he said. Better sustainability keeps them healthier longer and gives them the chance for a second career in leisure or sport once their racing careers are over.

Breeding for sustainability in addition to performance also keeps horses on the track longer—which is better for the owner’s investment, Velie added.

“If I were a breeder, I’d be seriously considering sustainability (in addition to speed, of course) in my breeding decisions,” he said. “After all, how many breeders can say that on average every horse that they have bred races for at least three, four, or perhaps even five years?”

In fact, aiming for sustainability in racehorses could on a broader scale help the industry’s image as a whole, said Velie, pointing to the darling of the U.S. Thoroughbred industry as an example.

“Longer careers for horses (even if only by six months) will likely increase field sizes, and, as we’ve seen with American Pharoah, the longer a horse is around, the more likely the industry will recruit new fans,” said Velie.

“While American Pharoah isn’t very old, he clearly demonstrates what can happen when a country gets captivated by a single horse,” Velie said.

Photo: Courtesy Keeneland

In 2015, the now 4-year-old colt became the first Triple Crown winner in 37 years and the first horse to win the “Grand Slam”—the Triple Crown plus the Breeders’ Cup Classic in the same year.

“While American Pharoah isn’t very old, he clearly demonstrates what can happen when a country gets captivated by a single horse,” Velie said. “That’s very hard to do with very short racing careers and even more difficult to do when injured horses are what comes to mind when the average person thinks of the racing industry.”

Equine sustainability and further genetic research are keys to the future of Thoroughbred breeding, for welfare, economics, and the sustainability of horse racing in general, Velie relayed.

“We need to remain open-minded about what genetic research can do for the horse racing industry,” he said. “Genetic and genomic technologies are continuing to advance at an incredibly fast rate, and those industries who remain closed off to genetic research are undoubtedly going to be left behind.”

The study, “Heritability of racing durability traits in the Australian and Hong Kong Thoroughbred racing populations,” will appear in an upcoming issue of the Equine Veterinary Journal

About the Author

Christa Lesté-Lasserre, MA

Christa Lesté-Lasserre is a freelance writer based in France. A native of Dallas, Texas, Lesté-Lasserre grew up riding Quarter Horses, Appaloosas, and Shetland Ponies. She holds a master’s degree in English, specializing in creative writing, from the University of Mississippi in Oxford and earned a bachelor's in journalism and creative writing with a minor in sciences from Baylor University in Waco, Texas. She currently keeps her two Trakehners at home near Paris. Follow Lesté-Lasserre on Twitter @christalestelas.

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