Crooked toes can be caused by a vitamin deficiency too, it's not always genetic, or incubation error.Yep, that hen (pullet) has a crooked toe. I’m going to have to make a hard decision now. I cull crooked toed birds across all my lines, and it rarely happens anyhow. It more happens with my guineas because the eggs are usually old when I find the nests. The incubation of the BF was odd in that I had some non-related American crosses come out crooked toe and the incubation period ran a day late. So I’m not sure if this is a genetic issue or an incubation issue.