Effect of Bit Type on Performance Horses Evaluated

With the seemingly endless bit choices available in tack catalogs, choosing the one that best optimizes the horse's performance and welfare can seem like a daunting task. Equitation scientists are now tackling this topic, and they're starting with the traditional single-jointed snaffle bit.

"The traditional (snaffle) bit has hardly changed over the past 3,000 years, and it's time to question whether it's really appropriate for horses in the modern age," said Klaske Van der Horst, MSc, lecturer at University of Applied Sciences HAS Den Bosch in Hertogenbosch, The Netherlands. Together with her colleagues, van der Horst compared performance and welfare criteria between horses ridden with a traditional 18-mm snaffle bit and an 11-mm, two-jointed "Myler" bit with a tongue port.

What they found was that performance stays the same with either bit, but the Myler appears to cause horses less stress, van der Horst said.

Fifteen Dutch Warmblood horses were trained over a period of three weeks by their regular experienced riders, sometimes using their own snaffle bits and sometimes using a Level 2 or Level 3 Myler bit (depending on the shape of the horse's mouth). At the end of the three-week period, each horse performed two dressage tests: one with the traditional bit, and one with the Myler bit. Van der Horst evaluated the horses' heart rate interval variations during movement to evaluate stress levels (the greater the variation, the lower the stress), and she checked for fluctuations in neck positions and observed how much saliva they produced. She also noted the number of times they gaped open their mouths and how often they were on or off the bit.

Horses in the Myler bit showed significantly greater heart rate interval variations during the extended walk, extended trot, and canter phases of the dressage test, meaning they were less stressed than when working these gaits in the traditional bit, van der Horst said. They also bobbed their heads up and down less often during the whole test, "possibly meaning they spent less time avoiding bit pressure," she added.

Five of the horses produced less saliva with the Myler bit than with the snaffle, whereas the other 10 produced comparable amounts of saliva with both bits.

"We aren't sure yet if this means they can swallow more easily or if they just play with the bit less often," she said.

For the other two behavior criteria--mouth gaping and on/off the bit--there were often major differences from one bit to another, but these varied greatly from horse to horse, van der Horst said. Some reacted more to the snaffle, others to the Myler; it seemed to be a question of personal preference for the horse, she noted.

But regardless of the bit used, each horse's performance remained constant in the two dressage tests, according to van der Horst. "So it is possible to ride with a more humane (snaffle) bit without compromising performance," she said.

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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