The “speed gene” behind Coolmore stud’s renowned racehorse-breeding reputation could trace back to a single mare that lived around 300 years ago, scientists have found.

If it was not for the diminutive Shetland pony, horse racing might well have been a sport for plodders rather than kings, research has revealed.

Nureyev, sire of such stars as Peintre Celebre, Miesque and Spinning World, has died.