Biochemical differences between distal limb extensor and flexor tendons among equine breeds selected for racing and sport.

This research study focuses on the comparison of the biochemical properties of tendons in horse breeds traditionally selected for racing or sports performance. It establishes that there are significant biochemical differences in tendon properties between these breeds, which can be linked to their specific locomotor functions.

Objective of the Study

• The primary goal of the research was to investigate the potential biochemical differences between tendons of different horse breeds particularly chosen for racing and sports performance.
• The hypothesis was that racing breeds’ tendons would exhibit properties that increase strength, whereas those in sports-performing breeds would be more elastic.

Methodology

• The researchers conducted an ex vivo tendon tissue study where they compared the tendons from sports horses (specifically, the Friesian and Warmblood horses) and racehorses (the Thoroughbred breed, which is often considered the reference standard).
• The Common Digital Extensor Tendon (CDET) and the Superficial Digital Flexor Tendon (SDFT) of these horses, all of middle age, were harvested and analyzed biochemically.

Findings

• The study revealed that the SDFT of sports horses had a significantly higher water percentage, lower collagen concentrations/glycosaminoglycan content, and higher crosslink concentrations compared to those of racehorses.
• The DNA content was also markedly lower in sports horses than in racehorses.
• Racing breed, Thoroughbreds, were found to rely mostly on extra fibrillar collagen support, while sports breeds, the Friesians and Warmbloods, leaned more toward extra crosslink collagen support.
• These observations pointed toward the racing Thoroughbred having stronger tendons, while the sporting Friesians and Warmbloods utilized less stiff, more elastic tendons.

Conclusion

• The research concludes that significant biochemical differences exist in the properties of tendons between racing and sports horse breeds.
• These differences can largely be correlated to the chosen locomotor performance of each breed; stronger tendons for racing and elasticity for sports performance.
• The findings, however, request further biomechanical and genetic confirmation.