[5] In August 2003, the colt was sent to the Fasig-Tipton sales at Saratoga, where he was bought for $450,000 by Thomas Magnier, acting on behalf of the Coolmore organisation.

[citation needed] Ad Valorem did not race in the spring of 2005 missing an intended run in the Irish 2,000 Guineas.

[12] He did not appear until June, when he contested the St James's Palace Stakes, run that year at York Racecourse.

[13] In July he was made the 6/4 favourite for the Prix Jean Prat at Chantilly Racecourse, but finished fifth of the eight runners behind Turtle Bowl.

In the Group One Sussex Stakes at Goodwood Racecourse, Ad Valorem was tested against older horses for the first time and led for most of the way before finishing third behind Proclamation and Soviet Song.

[14] Ad Valorem returned for a third season, beginning at the Curragh in April when he finished a distant sixth in the Gladness Stakes.

[16] The racecourse stewards called an enquiry into the race, as the winner appeared to have caused interference to both Court Masterpiece and Peeress but although Fallon was given a four-day suspension, the result was allowed to stand.

O'Brien expressed his doubts about running the colt on soft ground[18] and his concerns appeared justified as Ad Valorem finished fifth of the ten runners behind Librettist.

[20] Ad Valorem was retired from racing to become a shuttle stallion, standing at Coolmore's Irish base before spending the southern hemisphere breeding season at the Woodlands Stud.