A REALLY high-class sprinter who was a group winner and beaten a short head by Twilight Son in the Group 1 Betfred Sprint Cup, Strath Burn has retired to stud this year. He is the first son of the dual Group 1 sprinting star Equiano to go to stud and has already had his first mares tested in foal, including a half-sister to the Group 1 Nunthorpe Stakes heroine Margot Did.