Hi!
The roos are a bit aggressive but no other hen is missing so many feathers - their feathers grow back. My hen Sunshine seems unable to grow back feathers after the mating issues of losing feathers. I put the bluekote on and yet the skin seems just leathery and no feathers... on her back and...
I had exactly the same problem and solution. We have 19 hens. Laying 3 eggs or 0 for days. I had to mix in good expensive stuff to get them to lay again. I thought adding light fixed it. Then I turned off the light and got local feed mill feed. Girls were laying lots even when super cold after...
Yah... it can be the feed. We can prove it by changing feed and the problem is gone. Not all backyard farmers are wrong. For people to actually all talk about it - it isn't business as usual. It is something significant and unusual.
Supposedly, and with 2 months of experience I agree, some feed was causing chickens not to lay. I personally no longer buy Producer's Pride, made by Purina, from Tractor Supply. I buy from a local feed mill, now. With research, you can see this is across brands - not just isolated.