Equine Body Type's Effect on Endurance Performance Studied

Equine Body Type's Effect on Endurance Performance Studied

Horses with good thermoregulation are able to exert themselves for longer periods of time, and those with good biomechanics are more likely to stay sound, travel longer distances, and be more efficient in their physical efforts, Robert said.

Photo: Anne M. Eberhardt/The Horse

If you think there’s a perfect body type for a successful endurance horse, think again. French researchers recently concluded that the precise morphology (form and structure) of typical endurance horses has little to do with their racing success.

“There are few morphological criteria that are associated with performance, and the correlations with that performance are weak,” said Céline Robert, PhD, DVM, lecturer and researcher at the National Veterinary School of Maisons-Alfort, and researcher at the French National Agricultural Research Institute in Jouy-en-Josas. Robert presented her research during the 2014 French Research Day held March 18 in Paris.

As part of their larger “GenEndurance” project, Robert and colleagues measured 54 conformational traits—body lengths, angles, slopes, thicknesses—on 367 endurance horses. All the horses were at least seven years old, had at least one Arabian parent, and were qualified for 90-kilometer (60-mile) races.

“The qualification status itself did narrow down the kinds of morphology we were comparing,” Robert said. “The basic morphology of the standard endurance horse is better adapted to long-distance racing than that of the standard show jumper, for example. Our goal was to fine-tune the morphological comparisons within the select group of endurance horses itself.”

They ultimately concluded that “performance is influenced by numerous other factors, such as training, genetics, and breeding farm management and methods,” Robert said.

Still, some morphological criteria—specifically, body length, skin thickness, the slope of the femur, and stifle angle—did seem to affect thermoregulation and biomechanics, she said. Horses with good thermoregulation have a better self-cooling system that enables them to exert themselves for longer periods of time. Horses with good biomechanics are more likely to stay sound, travel longer distances, and be more efficient in their physical efforts. Consequently, these conformational traits seemed to have a slight effect on performance.

In particular, they found associations—albeit weak ones—between performance and morphology, including:

  • Long-bodied horses tended to rank better in longer distance rides, probably because they have longer strides and their bodies have more surface area, allowing them to cool themselves better, Robert said.
  • A more horizontally sloped femur improved rankings, as it provides greater propulsion, better balance, and fewer musculoskeletal disorders, she said.
  • High-ranking horses over the longest distances had smaller stifle angles, which contribute to more efficient propulsion and more muscle relaxation, Robert said.
  • Well-ranked horses over longer distances had thinner skin, mostly likely due to the body’s facilitated capacity to evacuate heat, she said. Robert also noted that the conformational traits associated with performance were, in fact, in line with the judging criteria used in breeding championships.

“Conformation alone is not a performance predictor, even though it can contribute to performance,” she concluded.

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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