structural:scholar_edition, information:filtering, structural:summarization
Crossbreeding

Thoroughbreds are often crossed with horses of other breeds to create new breeds or to enhance or introduce specific qualities into existing ones. They have been influential on many modern riding horse breeds, such as the American Quarter Horse, the Standardbred, and possibly the Morgan, a breed that went on to influence many of the gaited breeds in North America. Other common crosses with the Thoroughbred include crossbreeding with Arabian bloodlines to produce the Anglo-Arabian as well as with the Irish Draught to produce the Irish Sport Horse.

Thoroughbreds have been foundation bloodstock for various Warmblood breeds due to their refinement and performance capabilities. Crossbred horses developed from Thoroughbreds, (informally categorized as "hot bloods" because of temperament) crossed on sturdy draft horse breeds, (classified as "cold bloods" for their more phlegmatic temperament) are known as "warmbloods," which are commonly seen in competitive events such as show jumping and dressage. Examples include the Dutch Warmblood, Hanoverian, and Selle Français. Some warmblood registries note the percentage of Thoroughbred breeding, and many warmblood breeds have an open stud book that continues to allow Thoroughbred crossbreeding.