“GAIT KEEPER” GENETICS
Previously, this series has analyzed the contributions of non-Thoroughbreds in the pedigree of foundational American Standardbred sire Rysdyk’s Hambletonian (through the rest of this article, we’ll call him “RH”). The most important of these ancestors was Bellfounder, an imported Norfolk Trotter, but his pedigree also contains a good deal of Thoroughbred.
Why then do Standardbreds both trot and pace? It’s a question worth asking because Bellfounder was a trotter---and the Thoroughbred as we know the breed today is never a pacer. Yet both made significant contributions to the breed now known as the American Standardbred.
Join me now in a fascinating quest to find the pacing ghost in what is fundamentally a trotting machine.
THE SPECTRUM OF LATERAL GAITS
“Lateral” limb coordinations are not all strictly lateral. The extreme form is the pace, in which the lateral pairs of limbs work in perfect unison; when this is the case, the left hind and left fore (and right hind and right fore) alternate in striking the ground simultaneously, thus producing two sounded beats per stride. However, it is possible for a horse to coordinate its limbs in such a manner that lateral pairs do not move in perfect unison, in which case there will be four sounded beats per stride. The time interval or “spacing” between the four footfalls can range from near-unison (producing a syncopated ta-ta ---ta-ta rhythm), to near isochronality (which produces a rhythm close to an evenly spaced ta---ta---ta---ta).
Attempting to name gaits on this spectrum is a real can of worms. The term for a particular gait is often culturally determined, with different regions and countries having their own traditional naming systems. Confusingly, the same gait may be called by a different name in different
