If polydactyl is a dominant trait, those pullets should give it to about half of their chicks even if the father of the chicks does not have it.Okay, that makes sense, thanks. I have two pullets with polydactyl, and their brother doesn't, so I know he's from a different male. I want to try and keep the polydactyl trait, but the father of those two pullets is absolutely not staying
On the other hand, if the father had just one polydactyl gene, he would give it to half of his chicks--so he could have produced a cockerel without it. If you know the father has two genes for the trait, then I agree the cockerel would have to be from a different father.