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Breeding a Thoroughbred to a Quarter Horse

How to get your Jockey Club-registered Thoroughbred listed for breeding with AQHA.

American Quarter Horses are extremely versatile horses, very strong and powerful. There's no question about the American Quarter Horse's ability to beat out any other breed in a short-distance race - he's just built for it! But quite some time ago, AQHA's eyes turned to the Jockey Club and the large, long and lean Thoroughbred horses it registers. Thoroughbred (TB) horses succeed in long-distance racing. So, what happens when you mix the sought-after characteristics of the Quarter Horse and the Thoroughbred? You get an Appendix Quarter Horse that will be a powerhouse on the race track, in speed events and much more.

Let's learn more about the Appendix Quarter Horse.

Above all else, AQHA must maintain the integrity of the American Quarter Horse breed. So you have to get a Thoroughbred horse approved before you can breed it to an American Quarter Horse. If you're a Thoroughbred owner, you'll simply submit the following information to AQHA:

    • A front and back photo copy of the Jockey Club certificate showing that you are the owner of the Thoroughbred.
    • A $50 recording fee. ($105 if the owner is not an AQHA member.)
    • A signed statement authorizing AQHA to obtain DNA information (if any) from the Jockey Club. If the DNA type cannot be recorded with AQHA or if the horse does not have DNA on file, a $50 DNA testing fee will need to be submitted and the horse tested before AQHA will approve the horse for breeding.


The horse will be assigned what is called a T-number (ex: T0000000). This serves as the TB's AQHA registration number. A letter is mailed out with this information when the recording is complete. Buyer beware, though! A T-number does not always indicate that a TB has been approved for breeding with AQHA. For example, if the DNA process was never completed, the horse can still be assigned a T-number, but it is not yet approved if we do not have DNA. A bit of TB trivia: AQHA places the year the TB was born at the end of the name. This policy came from the days when names were not eligible to be reused and could not be spelled the same as any other name. Our database requires these additional numbers so the TB names can be added.

If you purchased a Thoroughbred and wonder whether it has been recorded with AQHA, contact us and we'll look the horse up for you. If the horse does have a T-number, simply submit a copy of the Jockey Club certificate and a $20 transfer fee ($75 if you are not an AQHA member), and AQHA will update the ownership record of the horse.

Registering an Appendix

So how does AQHA register half Quarter Horse-half TB offspring? We've created the Appendix Registry. An Appendix Quarter Horse is not limited in any area except for breeding. Appendix horses are only eligible to breed permanent-numbered Quarter Horses. Appendix horses are denoted by an "X" at the beginning of their numbers (Ex: X0000000). So, you cannot breed an "X" with a "T" or an "X" with an  "X."

Appendix horses can advance and become permanent-numbered Quarter Horses. The basic requirement for advancement is a Register of Merit in showing (open division) or racing.