You may be wondering what makes DNA based avian sexing so accurate. The answer to this question can be found in the technology underling this approach. Advances in molecular diagnostics have brought a technique known as PCR to the forefront of DNA diagnostics. Using PCR, differences in the DNA of male and female birds can be amplified and detected in the laboratory. Here’s how it works. DNA based avian sexing utilizes the fact that male and female birds have different genes or chromosomes, much like mammals. The only difference is that the female bird (carrying a ZW chromosome pair) determines the sex of the offspring, since the male (carrying a ZZ chromosome pair) can only contribute a ‘Z’ chromosome (this is just the opposite of what occurs in humans). Using PCR in the laboratory, a region of DNA that differs in size between the Z and W chromosomes is amplified. Thus, this method yields one PCR product for males and two PCR products for females, making visual detection in the laboratory easy.
offers bird owners two options with regards to submitting samples for sexing. These options include feather sexing or blood sexing. It is a common misconception that blood samples are more accurate then feather samples for determining sex. In reality, blood sexing and feather sexing are 100% identical with regards to accuracy. Since both procedures ultimately result in isolating and analyzing DNA, the source of the DNA (whether it’s from blood or feather cells) has no impact on the final results of this test. Instructions for submitting either blood or feather samples are included on the last page of this newsletter. Also, HealthGene provides free sample collection kits, complete with instructions, for those interested in submitting blood samples. Although HealthGene accepts feather and blood samples, blood samples are preferred since they ensure a result. Again, there is no difference in the accuracy of the final result; however, feather samples may have to be resubmitted if not enough cells are present for analysis. Alternatively, eggshells may be used to determine sex if the inner membrane is still present and intact. Turnaround times for this particular test range from 1-2 business days.
Avian Sample Collection Kits
Kit Contents
The avian Sample Collection Kit contains a blood card, a submission form and a return envelope.Collecting Sample
Avian DNA Samples can be submitted in one of two ways: blood or feather.Blood Sample:
- Wipe the bird’s nail with an alcohol swab and let dry(5-10 seconds) and ensure that the toenail clipper is thoroughly cleaned between birds.
- Clip the nail short enough to allow bleeding (avoid clipping too high since this may be uncomfortable for the bird). If blood is not present, gently squeeze the toe until blood appears.
- Allow a small amount of blood to bead up and carefully touch the corner of the card to the blood bead (only one or two drops is required).
- Allow the car to dry and place it into the envelope provided.
- Select only medium sized feathers for plucking. The feather must be physically plucked (molted feathers cannot be used for this test). Very small feathers located under the wing are not recommended.
- Pluck 4-6 medium sized feathers from the chest area of the bird and place them in a zip-lock bag. Ensure the feather tip, which is attached to the skin, is present (white coloration). Large feathers may contain some blood, which should be left on the feather.
Note:
Sample only 1 bird’s feather at a time and put each bird’s feathers into a separate container.Some bird owners say that it is better to allow a third party (someone that the bird in not familiar with) to perform this type of collection.