LEXINGTON, Ky. - Brownell Alexander is an exercise rider, but her job is quite different from that of her peers at the racetrack. Alexander, 49, works at one of the nation's premier farms, Gainsborough Stud in Lexington, Ky., where she does something many horsemen wouldn't dare to do: She rides stallions, including 2004's leading general sire, Elusive Quality.