DNA Typing and Parentage Verification

Have you ever wanted to have more definitive proof that your American Paint Horse’s pedigree is correct as shown on their Registration Certificate? Parentage verification by DNA testing is an option if the horse’s sire and dam’s DNA markers are 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. Microsatellite markers are the basis for individual identification useful in parentage verification. They are amplified and measured by gel electrophoresis and computer analysis.

When does APHA require testing?
Not all APHA horses require 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, vitrified embryo or oocyte transfer must be parentage verified.
•  Race horses are required to be parentage verified prior to being tattooed.

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.

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 is not locatable prior to testing, parentage verification is not possible, which could stop or delay the process.

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 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 credit card to APHA. The form is available on our website at apha.com, or by calling (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 the request is received by APHA, it generally takes about 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, and 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. 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 and 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 horse to avoid mistakes. Many parentage exclusions at the laboratory are caused by these errors and additional re-test fees may apply.

In obtaining hair samples, mane hair (forward of the withers, see diagram) is recommended unless you are testing a foal under 6 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. 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 is simply the DNA markers. If parentage verification has been requested, we will issue (or reissue) the registration certificate and a Parentage Verified emblem will be present.

What about testing for HYPP, overo lethal white, etc?
APHA is now offering disease diagnostic and coat color testing in addition to DNA testing. Disease Diagnostic testing includes HERDA, HYPP, GBED and OLWS. Coat color tests offered are red factor, agouti, cream, pearl, champagne, dun, silver, gray, tobiano and Sabino 1. Comprehensive packages are available at discounted rates when multiple tests are requested.

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 give you peace-of-mind in 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.