AMBLING VS. TROTTING THOROUGHBREDS

So important has the Thoroughbred been as an “improver” in the development of other breeds that it is useful to look in more detail at the three major families which comprise the breed. The acknowledged “foundation” horses are the Byerly stallion, a Circassian-type Turkmene; the Darley stallion, a Yomud-type Turkmene carrying a dash of Asil Arabian; and the Godolphin stallion, representing a threeway cross between Hobby, Barb and Turkmene but with Hobby predominating. During the early 18th century, all three families went through what biologists consider “breeding bottlenecks,” so that most post 18th-century horses that trace back in sire line to the Byerly stallion, for example, do so through Herod. The situation is similar with respect to the Darley and Godolphin.

Notice the conformation of these horses. The Byerly indeed looks like the Turkmene he was, but the Darley’s more level croup, smaller size and more shapely neck reflect his Arabian ancestry, which may have been as much as 25 percent. The Godolphin’s conformation is not at all like a Turk’s; his size, still smaller than the Darley, probably not more than 14:1 hands, the enormous hindquarters, broad back, heavily crested neck and wedge-shaped head with markedly undulating facial profile reveal his mostly Hobby ancestry.

It then becomes very interesting to compare the conformation of the “second founders” depicted to the right of the arrows. Herod’s pedigree reveals 46.8 percent Turkmene ancestry, 40.4 percent Hobby and 12.8 percent Barb; Eclipse’s consists of 47.8 percent Turkmene, 47.1 percent Hobby and 5.1 percent Barb; while Matchem’s consists of 33.3 percent Turkmene, 39.4 percent Hobby and 27.3 percent Barb. Thus Herod and Eclipse have similar “dosages” of Turkmene, Hobby and Barb in their pedigrees, yet their conformation differs. Matchem’s “dosages” are an almost even split, yet his conformation resembles Herod’s.

Variability in conformation—as well as in temperament, way of going, and physiological or athletic capabilities—is exactly what is to be expected when breeds, like the Thoroughbred, are created by outcrossing. The primary criterion that drove mares to the cover of Herod, Eclipse and Matchem—and which thus saved the male lines of the Byerley, Darley and Godolphin stallions from extinction—was their ability to win under the rules of “King’s Plate” heatracing. In short, all three “foundation” Thoroughbreds had “stayer” physiology and were in addition efficient movers, game and sound, characteristics which allowed them to become champions under those conditions.

History shows us, however, that conditions did not remain the same. As I demonstrate in “Eclipse on Top” (EQUUS 451), the rules and conditions for Thoroughbred racing have changed from the 17th century to the present day. Heat-racing under the old King’s Plate rules ended in England in the early years of the 19th century; it hung on in modified form in America for about another 50 years, until the beginning of the Civil War.

Since 1800, Thoroughbred flat-track races have gotten progressively shorter and shorter so that today even the “classic distance” races of 1 to 1.5 miles are becoming less common; the majority of contests span a mere five to seven furlongs, barely more distance than required of Quarter Horse sprint-racers. As “selective conditions” have changed, there has been a strong shift to horses of the Eclipse family, so that those descended from Herod or Matchem are now rarely represented in the winner’s circle. Breeding for shorter races has also driven Thoroughbred conformation toward that of the Quarter Horse, so that in many cases the two are now indistinguishable.

The Quarter Horse ancestors Printer and Steel Dust lived in the first half of the 19th century, the same period during which Thoroughbred racing changed from the old King’s Plate protocol, which favored the “stayer,” to shorter races that favor “sprinters.” We should thus expect to see changes in conformation, and the map survey presented here highlights two types of Thoroughbred: the ambler-galloper, typified by the Quarter Horse ancestor imported Little Janus (and his English sire, Janus), and the trotter-galloper, typified by the enormously influential American-bred Sir Archy.

It comes as a surprise to most horse fanciers today to learn that the majority of 17th and 18th century Thoroughbreds ambled, but considering that their ancestry is based on Hobby, this should not be surprising. Many Turkmene horses are also ambler-gallopers, so the early Thoroughbred had more than one source from which to inherit the gene complex that conveys the knack for “easy gaits.”

As the emphasis in Thoroughbred racing shifted from heat-racing to classic distances, English Thoroughbreds like *Diomed proved fastest. In England, precisely because he trotted rather than ambled, *Diomed was considered nearly worthless—trainers there believed that to develop top racing speed, the horse needed to be worked at the rack. No such idea dominated American thinking, so upon his arrival here *Diomed was put to a full book of elite-quality mares including *Castianira, dam of Sir Archy. Sir Archy in turn is the sire-line as well as the mare-line ancestor of Lexington (1850), the last and one of the greatest heat-racers, but also the sire and grandsire of hundreds of classicdistance winners.

For full detail of the Thoroughbred story go to EQUUS issues 448, 449, 451, 452, 453, 458. “America’s Major Horse Breeds Emerge” (EQUUS 473) provides more information and images of amblergalloper Thoroughbreds as well as on the origin of the related Hackney.