You could put one of your current pullets, plus one new pullet, in quarantine together, away from the rest of your flock. That does expose one of your current birds to any parasites or diseases that the new bird brings, but it still protects the rest of your flock. Other than that, it gives all...
The test is relatively new. It's been around for at least a year, but I think not more than two or three years from that lab. Sometime before that, a few people were sending feather samples to a lab in Germany to get them tested for that gene (I think that was mostly Ameraucana breeders, who...
There actually is a test for the blue egg gene:
https://iqbirdtesting.com/blueegg
If the pullet has the blue egg gene, she will lay some shade of blue, green, or olive. If she does not have the blue egg gene, she will lay some shade of brown.
I would only bother with the test if it was very...