A Revolution in Thoroughbred Sales & Breeding:
Genetic Marker Assisted Selection for Thoroughbred Racing
The modern Thoroughbred racehorse embodies the culmination of selective horse breeding practices developed over several millennia. At each stage of its development this noble creature has proven to be an indispensable asset whether for war or friendly competition. Those who were able to discern the heritability of complex traits – speed, athleticism, bravery, intelligence, trainability -established dominance over their foes as cataloged in the history of our early civilizations. The Bedouins of Arabia originally selected horses of phenomenal speed and endurance for hunting in order to survive the harsh environment of the desert. Here a special breed of horse – the Arabian, was tempered into an agent of war as nomadic tribesman battled for limited resources. The fittest, most brave mares were chosen to breed and each horse’s pedigree recorded in a matrilineal fashion. The early civilizations of Mesopotamia were dependent on the Arabian to hunt and wage war in the Fertile Crescent, but proved useful for everyday tasks given their temperament and intelligence. The Arabian was instrumental in the dominance of the Egyptians, the Huns, and later The Roman and Ottoman Empires. By the 10th century the spread of elite mares and stallions out of Arabia occurred when they were captured in battle, traded along vast commerce routes or offered as gifts. Horsemen in England promptly introduced these traits to the slower English stock by importing (or acquiring) Arabian bloodlines circa 1700. Lighter fleeter horses were produced and soon proved superior to all others on the battlefield and later in race competition. The modern Thoroughbred traces its male roots back to three foundation stallions – the Byerley Turk (1680s), the Darley Arabian (1704), and the Godolphin Arabian (1729) and its female roots back to approximately 70 foundation European mares.
Success in thoroughbred racing came to those who mastered an understanding of thoroughbred bloodlines. In the early years of the 20th century a French officer named Jean-Joseph Vuillier studied the 12 generation pedigrees of horses of his time and devised a “Dosage System” that essentially quantified the “dose” of elite speed and stamina influence in a given pedigree. The work was later used with enormous success by The Aga Khan, who based on this system acquired or bred the likes of Teresina, Mumtaz Mahal, Blenheim II, Gallant Man, Nasrullah and Mahmoud. The concept of a dosage system was later improved by the Italian Dr. Franco Varola and most recently Dr. Steve Romans.
Selective breeding practices have relied mainly on physical assessment and pedigree since that time despite advances in science. Our understanding of the inheritance of traits has evolved over the last two centuries starting with Gregor Mendel’s outstanding study of peas in the mid 1800s. The British biologist William Bateson later coined the word genetics in 1905 to describe heredity in biological terms and in 1910, Thomas Hunt Morgan postulated and later identified the physical element for heredity (genes) were located on chromosomes in the nucleus of cells. The actual molecule responsible for inheritance was discovered 3 decades later by Oswald Theodore Avery, Colin McLeod and Maclyn McCarty when they identified DNA. James D. Watson and Francis Crick finally gave the world the structure of DNA along with a mechanism by which genes are passed from one generation to the next.
Scientists are now able to unlock the secrets trapped within genetic material to estimate risks for health and disease. Major advances have been made in the agricultural practices of plants and animals. Beef and dairy farmers have already seen the benefits of genetic marker assisted selection for beef quality and milk quantity respectively. The sequencing of the entire equine genome was completed in 2007 and since that time revelations regarding the horse’s basic physiology have been made on a consistent basis. In 2009, Dr Emmeline Hill announced the discovery of the “speed gene” when her group discovered a single nucleotide polymorphism in the myostatin gene that conferred speed or stamina in thoroughbred racehorses. Several groups including ours have replicated those findings.
In 2010, LifeLine Labs introduced Pegasus ProfileTM a service powered by our own internally developed software that analyzes a proprietary panel of 40 genetic markers to evaluate horses for racing ability. A horse’s Pegasus ProfileTM is determined by analyzing the DNA sequence at each of those 40 markers and comparing it to a growing database of over 1000 retired thoroughbreds with known performance characteristics and a repository of over 5000 horses. The database is comprised of non-athletes to Eclipse Award winners, claimers to Breeder’s Cup Champions. A Graded Stakes Index (GSI) is determined for the horse in question by comparing its genotype to Graded Stakes caliber horses and normalizing it against the general population. LifeLine Labs also provides a top ten list of horses that compare most favorably to the horse in question. Performance characteristics of the 10 horses (lifetime best Beyer figure, average winning distance, earnings per start, etc) are provided for the client to review.
Knowledge is Power. LifeLine Labs delivers the most comprehensive thoroughbred genetic profile today. This information helps thoroughbred owners and breeders make more informed and confident decisions about breeding, managing and marketing horses at birth and throughout the horse’s lifetime. Join us in ushering in a new era of thoroughbred selection and breeding with Pegasus ProfileTM.