Q: What is the difference between genotyping and parentage verification?
A: Genotyping uses a sample of your animal’s DNA to read its genetic fingerprint. It is a DNA profile that identifies your animal. Parentage verification goes a step farther: It compares your animal’s genotype (genetic fingerprint) to those of its sire and dam in order to qualify them as its parents.
Q: What if I’m not sure which are the parents of my calf?
A: Parentage verification can be done for multiple possible sires and even dams. Comparing their genotypes with your calf’s genotype can exclude any sire or dam that could not be a parent of your calf. For the most accurate exclusion, both sire (or sires) and dam (or dams) must have their genotypes included. VGL has an excellent explanation on their website.
Q: All my Dexters are registered. Why should I bother to PV my calves? Their parents are both registered, so they can be registered, too.
A: VGL’s website says: “For over four decades, parentage verification has been utilized in animal registration programs. Breeder experiences have proven that parentage testing, in combination with well run breeding programs, can ensure accurate pedigrees.” A breeder’s integrity and reputation depend on the accuracy of their animals’ pedigrees. When a breeder sells a calf as having a certain pedigree, and subsequent PV by the new owner shows that the pedigree is wrong, the breeder’s breeding practices and even their honesty can be called into question.
Q: But surely such things rarely happen?
A: Just this year (2014), one Dexter owner PV'd two cows they had bought and learned that the prestigious sire on their pedigrees was not, in fact, their sire. With the breeder's cooperation, it was finally determined that two different bulls had actually sired the two cows in question.
At almost the same time, another Dexter owner had the same problem happen with three different cows. Two of the cows eventually had the correct parents identified, but although this owner has been trying for more than seven months to get the breeder to determine the correct sire of the last cow, at this time the sire is still unknown. None of the three cows ended up having the bloodlines for which the owner had bought them. So unfortunately, these kinds of situations are not that uncommon.
Q: If I bred my cow to a registered Dexter bull, isn't the bull already "Sire Qualified" or even "Sire and Dam Qualified?"
A: Not necessarily. The ADCA merely requires all bull calves to be genotyped for registration:
- When registering bull calves, geno lab results must be included with registration.
Of the 34 AI sires listed on the ADCA website, only six are "Sire and Dam Qualified." Twelve are "Sire Qualified," and 16 simply have their genotype on file.
Q: Why do some ADCA AI bulls have a blank next to Genotype?
A: One important consideration for your future success in having your offspring PV'd is where a bull's genotype is on file. Only 9 of the 34 ADCA AI sires state that their genotypes are on file both at TAMU and VGL. Ten have their genotypes on file only at TAMU. Fifteen of the bulls do not have the location of their genotypes specified, leaving a blank next to Genotype. If you have your cows' genotypes on file at one lab and use a bull whose genotype is on file only at the other, it could be more complicated for you to PV your calves, especially if the bull is deceased. You might need to have your cow genotyped at the same lab as the bull to accomplish it.
If your cow and the bull you use are both at TAMU, you can "Sire and Dam Qualify" your calf simply by listing the parents' names on the test form. For VGL, you will need to ask the bull's owner for a Case Number in order to "Sire and Dam Qualify" the calf.
If you are using an AI sire, it would be wise to get an extra semen straw to send to the lab of your choice if the bull is not already on file there. It's worth the extra expense to have the peace of mind that your calves are PV'd.
Q: I’m convinced that I should genotype and PV my animals, but I’m not sure how to do it. Who can help me?
A: Contact your Area Director. There is a list of the Area Directors and their contact info on the ADCA website. They should be able to answer any questions you have.
There are several posts about the process on this blog, and if you still have questions, I would be glad to help. You can contact me using the "Contact Susan" form under the ADCA logo on the upper right hand side of this blog.
Q: I genotype and PV my calves, but the results are my private property. I don’t send results to the ADCA because they are no one’s business but my own. Why should I publicize my animal’s test results?
A: You hurt yourself and your animals by not sending test results to the ADCA. More and more people are buying only "Sire and Dam Qualified" breeding stock, and when people look at your animals' pedigrees, it appears that they have not been tested. With so many sellers offering fully PV'd stock, many buyers will pass you by. However, when you send results to the ADCA that your animals are fully PV’d, you provide a public guarantee of their pedigree to interested buyers.
NOTE: The ADCA Registrar does not make public your animal’s genotype nor your TAMU Accession Number or VGL Case Number. The test results merely serve to authorize the Registrar to designate your animal as “G5” or “Sire and Dam Qualify.”
Hopefully this has helped answer some questions about Parentage Verification. If you have any other questions, please ask them in a comment or through the "Contact Susan" form so I can answer them publicly for the benefit of others. I'll also be glad to email you or call you if you give me your phone number.