Thoroughbred
The Thoroughbred is a horse breed developed for horse racing. Although the word thoroughbred is sometimes used to refer to any breed of purebred horse, it technically refers only to the Thoroughbred breed. Thoroughbreds are considered "hot-blooded" horses that are known for their agility, speed, and spirit.
The Thoroughbred, as it is known today, was developed in 17th- and 18th-century England, when native mares were crossbred with imported stallions of Arabian, Barb, and Turkoman breeding. All modern Thoroughbreds can trace their pedigrees to three stallions originally imported into England in the 17th and 18th centuries, and to a larger number of foundation mares of mostly English breeding. During the 18th and 19th centuries, the Thoroughbred breed spread throughout the world; they were imported into North America starting in 1730 and into Australia, Europe, Japan and South America during the 19th century. Millions of Thoroughbreds exist today, and around 100,000 foals are registered each year worldwide.
Thoroughbreds are used mainly for racing, but are also bred for other riding disciplines such as show jumping, combined training, dressage, polo, and fox hunting. They are also commonly crossbred to create new breeds or to improve existing ones, and have been influential in the creation of the Quarter Horse, Standardbred, Anglo-Arabian, and various warmblood breeds.
Thoroughbred racehorses perform with maximum exertion, which has resulted in high accident rates and health problems such as bleeding from the lungs. Other health concerns include low fertility, abnormally small hearts, and a small hoof-to-body-mass ratio. There are several theories for the reasons behind the prevalence of accidents and health problems in the Thoroughbred breed, and research on the subject is ongoing.
Breed characteristics
The typical Thoroughbred ranges from high, averaging. They are most often bay, dark bay or brown, chestnut, black, or gray. Less common colors recognized in the United States include roan and palomino. White is very rare, but is a recognized color separate from gray. The face and lower legs may be marked with white, but white will generally not appear on the body. Coat patterns that have more than one color on the body, such as Pinto or Appaloosa, are not recognized by mainstream breed registries. Good-quality Thoroughbreds have a well-chiseled head on a long neck, high withers, a deep chest, a short back, good depth of hindquarters, a lean body, and long legs. Thoroughbreds are classified among the "hot-blooded" breeds, which are animals bred for agility and speed and are generally considered spirited and bold.Thoroughbreds born in the Northern Hemisphere are officially considered a year older on the first of January each year; those born in the Southern Hemisphere officially are one year older on the first of August. These artificial dates have been set to enable the standardization of races and other competitions for horses in certain age groups.
Terminology
The Thoroughbred is a distinct breed of horse, although people sometimes refer to a purebred horse of any breed as a thoroughbred. The term for any horse or other animal derived from a single breed line is purebred. While the term probably came into general use because the English Thoroughbred's General Stud Book was one of the first breed registries created, in modern usage horse breeders consider it incorrect to refer to any animal as a thoroughbred except for horses belonging to the Thoroughbred breed. Nonetheless, breeders of other species of purebred animals may use the two terms interchangeably, though thoroughbred is less often used for describing purebred animals of other species. The term is a proper noun referring to this specific breed, though often not capitalized, especially in non-specialist publications, and outside the US. For example, the Australian Stud Book, The New York Times, and the BBC do not capitalize the word.History
Beginnings in England
Early racing
existed in England by at least 1174, when four-mile races took place at Smithfield, in London. Racing continued at fairs and markets throughout the Middle Ages and into the reign of King James I of England. It was then that handicapping, a system of adding weight to attempt to equalize a horse's chances of winning as well as improved training procedures, began to be used. During the reigns of Charles II, William III, Anne, and George I, the foundation of the Thoroughbred was laid. The term "thro-bred" to describe horses was first used in 1713.Under Charles II, a keen racegoer and owner, and Anne, royal support was given to racing and the breeding of race horses. With royal support, horse racing became popular with the public, and by 1727, a newspaper devoted to racing, the Racing Calendar, was founded. Devoted exclusively to the sport, it recorded race results and advertised upcoming meets.
Foundation stallions
All modern Thoroughbreds trace back to three stallions imported into England from the Middle East in the late 17th and early 18th centuries: the Byerley Turk, the Darley Arabian, and the Godolphin Arabian. Other imported stallions were less influential, but still made noteworthy contributions to the breed. These included the Alcock's Arabian, D'Arcy's White Turk, Leedes Arabian, and Curwen's Bay Barb. Another was the Brownlow Turk, who, among other attributes, is thought to be largely responsible for the gray coat color in Thoroughbreds. In all, about 160 stallions have been traced in the historical record as contributing to the creation of the Thoroughbred. The addition of horses of Eastern bloodlines, whether Arabian, Barb, or Turk, to the native English mares ultimately led to the creation of the General Stud Book in 1791 and the practice of official registration of horses. According to Peter Willett, about 50% of the foundation stallions appear to have been of Arabian bloodlines, with the remainder being evenly divided between Turkoman and Barb breeding.Each of the three major foundation sires was, coincidentally, the ancestor of a grandson or great-great-grandson who was the only male descendant to perpetuate each respective horse's male line: Matchem was the only descendant of his grandsire, the Godolphin Arabian, to maintain a male line to the present; the Byerley Turk's male line was preserved by Herod, a great-great-grandson; and the male line of the Darley Arabian owes its existence to great-great-grandson Eclipse, who was the dominant racehorse of his day and never defeated. One genetic study indicates that 95% of all male Thoroughbreds trace their direct male line to the Darley Arabian.
However, in modern Thoroughbred pedigrees, most horses have more crosses to the Godolphin Arabian than to the Darley Arabian when all lines of descent are considered. Further, as a percentage of contributions to current Thoroughbred bloodlines, Curwen's Bay Barb appears more often than the Byerley Turk. The majority of modern Thoroughbreds alive today trace to a total of only 27 or 28 stallions from the 18th and 19th centuries.
Foundation mares
The mares used as foundation breeding stock came from a variety of breeds, some of which, such as the Irish Hobby, had developed in northern Europe prior to the 13th century. Other mares were of oriental breeding, including Barb, Turk and other bloodlines, although most researchers conclude that the number of Eastern mares imported into England during the 100 years after 1660 was small. The 19th-century researcher Bruce Lowe identified 50 mare "families" in the Thoroughbred breed, later augmented by other researchers to 74. However, it is probable that fewer genetically unique mare lines existed than Lowe identified. Recent studies of the mtDNA of Thoroughbred mares indicate that some of the mare lines thought to be genetically distinct may actually have had a common ancestor; in 19 mare lines studied, the haplotypes revealed that they traced to only 15 unique foundation mares, suggesting either a common ancestor for foundation mares thought to be unrelated or recording errors in the GSB.Later development in Britain
By the end of the 18th century, the English Classic races had been established. These are the St. Leger Stakes, founded in 1776, The Oaks, founded in 1779, and The Derby in 1780. Later, the 2,000 Guineas Stakes and the 1,000 Guineas Stakes were founded in 1809 and 1814. The 1,000 Guineas and the Oaks are restricted to fillies, but the others are open to racehorses of either sex aged three years. The distances of these races, ranging from to, led to a change in breeding practices, as breeders concentrated on producing horses that could race at a younger age than in the past and that had more speed. In the early 18th century, the emphasis had been on longer races, up to, that were run in multiple heats. The older style of race favored older horses, but with the change in distances, younger horses became preferred.Selective breeding for speed and racing ability led to improvements in the size of horses and winning times by the middle of the 19th century. Bay Middleton, a winner of the Epsom Derby, stood over 16 hands high, a full hand higher than the Darley Arabian. Winning times had improved to such a degree that many felt further improvement by adding additional Arabian bloodlines was impossible. This was borne out in 1885, when a race was held between a Thoroughbred, Iambic, considered a mid-grade runner, and the best Arabian of the time, Asil. The race was over, and although Iambic was handicapped by carrying more than Asil, he still managed to beat Asil by 20 lengths. The improvement of the breed for racing in this way was said by noted 19th century racing writer, Nimrod, to have created "the noblest animal in the creation".
An aspect of the modern British breeding establishment is that they breed not only for flat racing, but also for steeplechasing. Up until the end of the 19th century, Thoroughbreds were bred not only for racing but also as saddle horses.
Soon after the start of the 20th century, fears that the English races would be overrun with American-bred Thoroughbreds because of the closing of US racetracks in the early 1910s, led to the Jersey Act of 1913. It prohibited the registration of any horse in the General Stud Book if they could not show that every ancestor traced to the GSB. This excluded most American-bred horses, because the 100-year gap between the founding of the GSB and the American Stud Book meant that most American-bred horses possessed at least one or two crosses to horses not registered in the GSB. The act was not repealed until 1949, after which a horse was only required to show that all its ancestors to the ninth generation were registered in a recognized Stud Book. Many felt that the Jersey Act hampered the development of the British Thoroughbred by preventing breeders in the United Kingdom from using new bloodlines developed outside the British Isles.