Genes play only small part in racehorse success - study

Spending lots of money on racehorse stud fees may not bring the rewards people might expect, a recent study reveals.

Scientists at the University of Edinburgh have shown that the majority - up to 90 per cent - of a horse's lifetime winnings can be attributed to how the horse is reared, trained and ridden.

Only 10 per cent of a racehorse's winnings can be attributed to its parentage, according to a study published in the journal, Biology Letters.

British researchers compared the stud fees, winnings and lifetime earnings of more than 4000 horses used for racing and breeding since 1922.

They found that although there is genetic variation for how much prize money a horse wins, paying higher stud fees does not necessarily buy access to the best genes around.

Horseracing is a multimillion-dollar industry and the high stakes mean breeders spend vast sums of money trying to buy the best genes for their horses.

Breeders are prepared to pay premium stud fees if a stallion and its offspring have a good reputation.

"The offspring of expensive stallions might tend to win more money, but not necessarily because they have inherited the best genes," said Dr Alastair Wilson, of the University of Edinburgh's School of Biological Sciences, who led the research.

"It is likely that those breeders best able to pay high stud fees are also those who are able to spend more on care of the horse, how it is trained, and who rides it - all of which will contribute more to how much it will win.

"Of course, if every breeder is spending lots on the care of the horse, then the difference between winning or losing will come down to the smaller details, such as who the parents are. So picking the best genes can give an edge, but it's by no means clear that the best genes come with the highest price tag," he said.