DNA analysis can take the guesswork out of the ancient art of producing a champion, says geneticist A British scientist yesterday claimed to have made a "historic breakthrough" in the study of thoroughbred genetics, after a six-year research project produced the first proof of a relationship between specific genes and the individual performances of racehorses. The results of the study by Dr Stephen Harrison, whose company Thoroughbred Genetics is based in Kent, will be published next month in the peer- reviewed journal Mitochondrian It could have considerable implications for international bloodstock business, in which a Derby winner such as Motivator can command a stud fee of many thousands of pounds per cover, but in which young, untried horses are often bought for millions of dollars on little more than a hunch and a prayer. Working with Juan Luiz Turrion-Gomez, Dr Harrison studied eight "athletically-important" genes in samples of mitochondrial DNA (mDNA) taken from 1,000 racehorses, including Classic winners. mDNA is significant because it is inherited solely from the dam side of a horse's pedigree, while the mitochondria in which it is located are important cellular structures linked to energy release and respiration in muscles, and thus, according to Dr Harrison, "have a direct impact on the optimum performance of a racehorse". Dr Harrison has discovered that different combinations of the performance-related genes will give horses different racing aptitudes, particularly with regard to optimum race distance, and the age at which they are likely to perform best. His findings could also provide valuable information to trainers, who often adopt a "try-it-and-see" approach to finding a horse's best trip. Genetic analysis may also help to identify horses that will not stay a certain distance, such as a mile or 12 furlongs, when traditional analysis of their pedigrees suggests that they should. Thoroughbred Genetics now hopes to exploit its findings by offering a genetic testing service to breeders and owners who want to reduce as much of the risk as possible from the bloodstock business. "Breeding racehorses is a high-risk, multimillion-dollar industry," Dr Harrison said yesterday. "A high percentage of racehorse breeders fail to recoup their investments. Many foals produced are bred inappropriately and fetch poor prices at sales, a large proportion fail to reach the racecourse, and the vast majority never win a race. It is estimated that global expenditure on stud fees is $3bn (£2bn) annually, while stallion fees can run as high as $600,000. The odds have for too long been stacked against the breeder, and the use of advanced genetic techniques to modernise traditionally-based breeding programmes can narrow down the quest to produce a truly brilliant horse. Racehorse breeding has effectively been fast-forwarded 200 years." Dr Harrison's work has also highlighted dozens of palpable errors in the General Stud Book, some dating to as recently as the 1970s. He hopes that the research will also lay to rest such beliefs as the idea that a stayer bred to a sprinter will produce a miler, which still have their supporters in some parts of the breeding industry. "That's really like saying that if you take parts from a Formula One car and mix them with bits from a tractor, you'll get a touring car in between," Harrison says. "You are much better off coordinating all your efforts to try to make sure that you have the best genetic chance to start with, and what we want to do now is to develop and provide confirmatory tests that will allow that to happen." Breeding thoroughbreds has often been seen as being as much of an art as a science, while the great Italian breeder Federico Tesio famously commented almost half a century ago that "the thoroughbred racehorse exists because its selection has depended not on experts, technicians or zoologists, but one piece of wood: the winning post of the Epsom Derby." Genetic science, it seems, may be about to prove otherwise.