Two of my hens died, so I only have my RIR rooster and hen left now (not counting my chicks : ), and I think both started molting about a month ago, but the rooster had "pins" that filled back in already. My hens back (always thin on fearhers from the rooster) is now completely bare for the first time. It didn't look red or scratched, so I think it is mostly from molting, but it could be from the busy rooster. Okay, so my questions are: 1) Should I switch to starter feed? 2) Should I get a shield for her back? 3) Do I need to add heat to the coop because her back has a bare patch the size of a hand? I heard no heat was necessary, but without feathers I don't see how she can stay warm. Here in Indiana it's about to be in the low 30's all next week. It is a tractor coop design, and I am venting out the top for the winter, but the roosts are only inches from the vents because the area is only like 3sq ft.
A bare back I think is far more likely to be due to the rooster's attention than molting. I would switch to starter or maybe game bird or part game bird, for the protein. And I would put a shield on her bare back til she feathers back in. Besides the skin getting injured from the rooster's attention, they can actually get sunburned. Heat is always a problem, though, if only becuase it is so dangerous to have them acclimated to heat, then lose it in a power outage. I believe I would find a way to avoid having their backs so close to the ventilation. Perhaps you can lower the roost somehow. It's difficult to make suggestions without knowing more about your setup, but I agree, there is concern over a draft on her back, even with cloth covering it. Maybe you will find this link helpful: https://www.backyardchickens.com/a/patterns-chicken-saddles