If a barred rooster always passes on the barring, how did I get my black hen?
There were 3 hens and 1 rooster in my flock and yet I got a black hen out of the mating.
For the purpose of my earlier response to the original person, I felt like it would be too much to give all the info at once if it wasn't needed. It can make things more confusing than it needs to be.
But here's more info.
Female chickens (pullet/hen) can carry up to 1 copy of barring.
She can only receive barring from her dad, and can only pass on her barring gene to sons.
Male chickens (cockerel/rooster) can carry up to 2 copies of the barring gene.
In order to be double barred, he needs to inherit one copy from each parent.
If he's double barred, all of his offspring will inherit 1 copy from him (daughters and sons).
If he is single barred, he could have inherited that from either parent.
A single barred rooster can randomly pass on his barring to any of his offspring. Some might inherit, some might not. It doesn't matter if it's daughters and sons.
If there's a barred hen, and a single barred rooster, you could end up with any possibility. Single barred sons, double barred sons, barred daughters, and no-bar daughters.
If there's been another rooster/cockerel in with the flock within a few weeks of that egg being collected to incubate, that could be a potential father.
So for your specific question- either your rooster is single barred, or he is not the father.