DNA Typing and Parentage Verification Explained
Your guide to understanding APHA’s verification system

By Steven Imhof

Have you ever wanted to have more definitive proof that your American Paint Horse’s pedigree is correct as shown on their registration certificate? Or maybe you wish to show your solid Paint-bred horse in the new classes offered at the APHA World Championship Show or APHA Paint Vegas? Parentage verification by DNA testing can help you if your horse’s sire and dam’s DNA is on file with APHA.

What is DNA?
Deoxyribonucleic acid, or DNA, is a nucleic acid that is bound in double helical chains by hydrogen bonds between the bases, forming the basic material in the chromosomes of the cell nucleus. In other words, DNA contains the genetic code that dictates a horse’s physical appearance.

When does APHA require testing?
Not all APHA horses require genetic testing. However, the following instances will necessitate DNA typing or parentage verification:

• All stallions used for breeding must have a DNA type on file before any offspring can be registered.

• Foals that are the result of transported semen or frozen semen breeding are required to be parentage verified. (There is an increased possibility of the wrong stallion’s semen being shipped to the mare owner when multiple stallions are standing at the same location.)

• Foals resulting from embryo transfer must be parentage verified.

• Race horses are required to be parentage verified prior to being tattooed.

• Solid Paint-bred or breeding stock horses competing in the APHA World Championship Show and APHA Paint Vegas must be parentage verified.

APHA may also require a horse to be parentage verified if the color or type does not fall into the acceptable laws of genetics, the dam’s gestation period is out of an acceptable range or a mare was exposed to more than one stallion in a 30-day period. In 1999, APHA also implemented a random parentage verification program, which is done at no cost to the horse owner. This program, in which newly registered horses are chosen at random for testing, helps determine the percentage of error of all new registrations.

It is important to anticipate the need for parentage verification. Generally, the sire will have DNA on file, but many times the dam will not. If the dam dies or becomes unlocatable prior to testing, parentage verification is not possible, which could stop the registration process or halt your plans to race or show your horse.

Almost immediately following the death of a horse, a hair sample is no longer viable. Therefore, it is wise to obtain a hair sample on an old or ailing animal. Hair samples will keep indefinitely in a resealable bag or an envelope. Be certain that roots are attached to the hairs.

The “how to”
To order a DNA kit for a registered horse, you may send a properly completed DNA hair kit order form with a check, money order or Visa/Master Card to the APHA Field Services Department. The form is available on our Web site apha.com, or by calling the Field Services Department at (817) 834-2742, extension 777. The information may also be taken over the phone if paying by credit card. It is important to state the reason you’re testing the horse so APHA knows to ask the laboratory to simply obtain the DNA markers or to conduct parentage verification. Once your request is received by APHA, it generally takes 7-10 business days to process your request. Caution is advised when sending requests with other APHA forms as it may delay processing.

If you want to test a foal that is not yet registered, you must first apply for registration and check the appropriate box on the registration application requesting the DNA kit. The Registration Department will enter the needed information, then forward the file to the Field Services Department to issue the DNA kit. Please keep in mind that turn-around times for new registrations vary throughout the year, so the issuing of your DNA kit may also be delayed.

When you receive your DNA kit in the mail, it is essential to verify that the information on the DNA kit matches the horse you are testing (see sample photo). A registered horse’s name and number will appear on the kit. A foal that is pending registration will receive a UR (un-registered) number for laboratory-tracking purposes that will also list the color, type, sex, year foaled, sire and dam. When testing multiple horses at the same time, it is essential to finish one horse before moving on to the next to avoid mistakes. Many exclusions at the laboratory are caused by these errors and additional re-testing fees may apply.

In obtaining hair samples, mane hair (forward of the withers) is recommended unless you are testing a foal under six months old, which requires tail hair. Mane hair from a young horse is very fine, causing the roots to break off. When tail hair is sampled, the short hair near the base of the tail is best and easiest to obtain. Simply grasp the hairs near the bottom and give a swift pull (see photos). It’s best to try to get the entire sample at once. This procedure causes very little stress to the horse.

Again, make sure the roots are attached. Roots resemble a small bulb and are visible with the naked eye or magnifying glass. Long hair can be trimmed on the non-root end only.

The turn-around time at the laboratory is approximately 2-4 weeks, if everything is correct. Insufficient hair samples will require a new sample, thus delaying the process. When the testing is complete, the laboratory will forward the results electronically to APHA. If you have DNA typed a registered horse (i.e. a stallion to be used for breeding), a post card will be mailed to the owner of record that lists the laboratory case number. This card indicates that the results are on file with APHA. The “results” the card is speaking of are simply the DNA markers.

It is important to note that the testing is exclusively for DNA typing and parentage verification purposes. No other genetic tests are completed. If you wish to test your horse for HYPP, overo lethal white syndrome (OLWS), the various color tests or tobiano zygosity testing, you may contact APHA and we can direct you to the appropriate laboratory for those tests. If parentage verification has been requested, we will issue (or reissue) the registration certificate with a Parentage Verified emblem beside the horse’s photograph.

How long will it take?
If everything goes smoothly, the entire process from ordering the kit to receiving results from the laboratory is approximately 3-6 weeks. Please keep in mind this does not include the time it takes you to submit the hair sample to the lab.

The testing procedures are simple, can add value to the horse and will give you the peace-of-mind that knowing the parentage of your horse is more than just “true and correct to the best of your knowledge.”

References
American Paint Horse Association’s Guide to Breeding brochure
University of California at Davis web site: www.vgl.ucdavis.edu

Genetic DNA lies in the roots of the horse's hair. The roots look like tiny bulbs and are easily visible with a magnifying glass.	When pulling mane hair, be sure to grasp the hair close to the neck. This helps ensure roots will be in the sample.