How DNA parentage verification works
A pedigree is a claim about who the parents are. Parentage verification is the test that checks the claim, and it is the foundation under every number that gets calculated from a pedigree later.
What the lab compares
A parentage test looks at a standard set of DNA markers rather than at any disease variant. At each marker an animal carries two versions, one inherited from each parent. The lab builds a DNA profile for the offspring and for each animal put forward as a parent, then asks whether the offspring’s profile could have come from them.
Labs work from marker panels standardised through the International Society for Animal Genetics (ISAG), which is why a profile issued by one lab can be compared against a profile issued by another.
Two results that are not equally strong
Excluded. At one or more markers, the offspring carries a version the putative parent could not have contributed. That is a Mendelian exclusion, and one clear mismatch is enough. UC Davis’s Veterinary Genetics Laboratory describes parentage exclusions as 100% accurate.
Qualifies. The offspring matches at every marker, so the animal could be the parent. This is a probability rather than a proof, and the strength of it depends on how many markers were read and how common those versions are in the breed. A qualification is stronger when both parents were tested than when only one was, because a single tested parent leaves more of the offspring’s profile unaccounted for.
Verification is much better at ruling a parent out than at ruling one in. Read a qualification as “nothing here contradicts the pedigree”, and read an exclusion as settled.
Test both parents, and every candidate sire
Qualification gets stronger the more of the picture the lab has. Two things follow from that.
- Submit both parents when you can. Testing one side leaves a wider margin.
- Submit every possible sire at the same time. Where more than one male had access, several can qualify against the same offspring, and the lab may need extra markers to separate them. UC Davis asks breeders to send samples from all possible parents on the first request for exactly this reason.
A DNA profile keeps. Once an animal is profiled, that profile is reused for every later mating, which is why registries hold profiles for breeding stock.
When a parent does not qualify
Work through the same order every time, before deciding the pedigree is wrong.
- Check the samples. Who collected them, how they were labelled, and whether the microchip or registration number was checked at collection. A swapped or mislabelled sample is the most common explanation.
- Check the mating records. Dates, and whether another male had access during the window.
- Ask the lab. Additional markers, or a fresh sample collected by a vet who scans the microchip, usually settles it.
- Correct the record. An unresolved parent does not stay contained. Inbreeding coefficients, mate rankings, and every descendant’s pedigree all read from that link.
What to keep
- the parentage report itself, not a note of the outcome;
- the DNA profile or marker report, since it gets reused;
- the identifiers for all three animals, as the lab recorded them;
- the date of the report.
Where AnimalTrace fits
AnimalTrace keeps the lab’s parentage report on the animal’s record, with the lab named as the source and the original attached. The pedigree inbreeding coefficient in breeding checks (Client Pro) counts only the ancestors on record, and the shared ancestors shown next to a COI let you see which link is doing the work. Adding or correcting an animal’s parents isn’t in the app yet.
Working out parentage or relationship from genotypes inside AnimalTrace is planned. Today the app keeps the lab’s verification, and the lab stays the authority on it.