"Pedigree, conformation, and the racing performance of siblings are the main selection criteria utilized by buyers to evaluate the athletic potential of Thoroughbred yearlings," said Dr. Joe Pagan, president of Kentucky Equine Research in Versailles, Ky., during the Equine Science Society meeting May 31-June 3 in Tucson, Ariz. However, he also noted a positive correlation between size of a yearling and selling price at the Keeneland September yearling sales.
Body weight, wither height, and body condition score measurements were taken in late August and early September from 630 yearlings (332 colts and 298 fillies) that were entered in the auction.
"Of the studied yearlings, 79% (495) were listed as sold and 21% (135) were listed as RNA (reserve not attained)," he explained. The average selling price was $93,922, and the median selling price was $35,000. The average age of the yearlings at sale time was 544 (+/- 37) days. On average the colts were heavier than fillies (1,014 pounds vs. 974 pounds, or 461 kg vs. 443 kg.) and taller (15.3 hands vs. 15.1 hands).
Yearlings that brought bids above the session median were significantly heavier than those below the median (1,005 pounds vs. 986 pounds, or 457 kg vs. 448 kg.) and taller (15.2 hands vs. 15.15 hands).
"Data from this study clearly shows that selling price is influenced by body size," said Pagan. "Size does matter. Yearlings that commanded higher bids than the median session price tended to be higher at the withers and had a higher body weight, but were not fatter."