Scientists Discover Trotting Ability is Genetic

A groundbreaking study in the field of genetics has revealed that some horses are not able to trot or pace, regardless of their training, while for others trotting is a breeze. The discovery could have far-reaching implications for an industry that spends huge amounts of time and resources training horses for …

harness racing. By identifying the gene, which scientists have dubbed DMRT3, in a horse at birth or before purchasing it trainers will know whether they can expect results on the racetrack.

Lead researcher of the project at Sweden’s Uppsala University, Professor of Functional Genomics Leif Andersson, has called the discovery “sensational”, and revealed in a published interview that researchers started their investigation with Icelandic horses in January 2011. Known for their ambling gait, referred to as a Tölt in Sweden, it was noted that some could pace and others could not. Scientists wanted to pinpoint why this was the case. Their research led to a single gene which divided horses of the same breed into pacers and non-pacers. Having established this, they tested other breeds for the gene, including the South American Paso Fino and the Tennessee walking horse, and found the same result.

Researchers then tested trotters in Sweden and found the presence of the gene which inhibits a horse from transitioning from trot to gallop at high speeds. Next, a field test was conducted on 61 horses owned by Swedish scientist and entrepreneur Bengt Agerup and trained by Daniel Reden. Among the horses were a few that were unable to keep their trot, despite intensive training. The identity and number of these horses was withheld from scientists. After running DNA tests on hair samples, the scientists correctly identified the two horses that were unable to perform.

Tests on standardbreds in the United States revealed that all 57 tested had the proper genetic mutation, which is seen as evidence of successful breeding in the sport’s 300-year history. Researchers also discovered that up to 95 percent of Swedish horses tested had the DMRT3 gene, whereas up to half of the trotters in Sweden imported from France did not, which explained the reputation these horses have for breaking their gait. Andersson noted that breeding select French trotters, with trotters from the United States would be an excellent pairing.