yes, I think you are right... if I were you I would try to selectively hatch to identify which hen is throwing the single combs. can be quite complicated to do, I know! you would need to trap nest and mark the egg, then separate the different hen's eggs at hatch time too. OR hatch from only 1 hen at a time.
I would NOT breed the single comb chicks that have hatched, or even sell them personally.. I would cull.
I agree. You could also dye the vents. Sorry about your single comb babies. They're cute, though! :)
In over our head and loving every minute! Currently fancying Old School Rhode Island Reds, Blue Laced Red Wyandottes, Rhodebars, B/B/S Australorps
It's about sewing new seeds and strengthening old roots.