Can anyone identify this?
What concerns me is the roo only has 4 hens to service and I notice that the one has lost the feathers on her back. She's a smaller hen compared to the others and he's a big boy. He tends to have a problem keeping his balance on her. So what do I do? Should I add more girls for him to even out the ratio? Or just leave well enough alone?
@galefrances
So good to see you! Been a long time!

I agree w/ @oldhenlikesdogs I think it is just a fluke and you probably won't see that in the eggs consistently. I've seen a bit of tissue like that now and then over the years.
When I had "Mister", there was ONE HEN that lost the feathers on the back consistently. Only one in the whole group. After molt in the fall, they grew back in beautifully, then the next spring, the same thing again. I think it's like you said. It may have just been the way he was mounting her. None of the others had the problem, just this one.
As far as adding hens, I guess you could do that. But if she is prone to losing the feathers there it probably won't make a difference unless you keep him from mating her. I would put one of the "aprons" on this hen just to give her some relief from the sun on bare skin. She looked terrible each summer season that Mister was with us.
Another thing you should know - feathers don't just grow in at random times. They grow in after molt. So don't be alarmed that they aren't coming back in. They will come back in their glory after her molt.