'Motivator Gene' Linked to Horses and Their Race Careers
Genes associated with behavior might play as big a role as a horse’s physical attributes in determining whether a Thoroughbred makes it to the races.

In previous studies, researchers have shown that fewer than half of Thoroughbred foals born actually race, with durability–the horse’s ability to withstand the rigors of training—seen as a critical factor.

New peer-reviewed research by scientists at University College Dublin (UCD) and equine science company Plusvital has established a genetic contribution to whether a horse is likely to race and has identified genes associated with behavior that might be key influencers. One of these genes is PRCP, which, based on these results, which researchers are calling the “motivator gene.”

Emmeline Hill, PhD, UCD professor of equine science and chief science officer with Plusvital, said the high proportion of Thoroughbred foals that don’t make a race start, despite being bred for this purpose, has a major economic impact not just on the owner but on the racing industry as a whole. She said the identification of key genes has opened exciting possibilities for the sector.

“Our study of 4,500 horses, some that raced and some that did not, has established a measurable genetic link to future racing potential and identified several genes of particular importance,” said Hill. “The most important genes appear to be involved in neurological or behavioral traits. This is fascinating in the context of trainers’ assessments that a horse’s ‘attitude’ to their exercise regime is among the most important aspects to a positive outcome on the racetrack.

“One of the genes, known as PRCP, has previously been shown to be associated with voluntary wheel running in mice,” she continued. “Our findings support the theory that, just as with humans, motivation to exercise may be a critical factor in maintaining a training regime and achieving a high level of fitness. Some horses are just naturally keener for their job than others. This may manifest directly in the training environment, but it is also possible there are more subtle effects from a younger age.

“The more naturally active foal or yearling in a paddock is likely to strengthen better than others that are less naturally motivated to play and move around, and this could have knock-on effects later in life,” she said.

In addition to establishing a genetic link, the scientists developed a predictive test for determining a Thoroughbred’s chances of making a start in their 2- and 3-year-old racing seasons.

“The prediction model analyzes the DNA of a horse and then categorizes them as having a high, medium, or low chance of making a racecourse start,” Hill said. “Horses categorized as high are more likely to have a racecourse start, more likely to run in more races, more likely to have higher earnings, but curiously do not have a significantly different sales price. This is, therefore, valuable information that even the most astute in the market currently cannot assess from the pedigree or by physical assessment of the horse.

“Of course, genetics cannot on its own replace the current tools,” she added. “There are many other reasons a horse may not progress to race, through injury or the presence of performance-limiting disorders. But while there are veterinary screening tools for those, there is currently no other means to determine a young horse’s motivation to exercise other than long-tern observation, and by then it may be too late to get the best out of them.”