The Jockey Club, the registry for Thoroughbreds, has announced a change in its Stud Book rules that will permit representatives of the organization to physically inspect horses. According to a release, the rule change was made to insure the accurate foaling date of foals listed as born right after the first of the year.

All Thoroughbreds age Jan. 1 each year. Thus a foal born in late December would actually become a yearling when just a few days or weeks old.

The breeding season used to begin Feb. 15, but many farms now open their breeding sheds earlier. With an 11-month gestation period, a foal born just two weeks prematurely could be foaled near the first of the year.

“With these rule revisions, we are reminding North American breeders that Jan. 1 of the year of foaling is the official date of birth for Thoroughbreds,” Jockey Club registrar Rick Bailey said. “Those who choose to breed mares early may risk having foals born prior to Jan. 1. To protect the integrity of The American Stud Book, the enacted rules provide that The Jockey Club may require horses be made available for inspection