Neck feather loss

[Amymidlife]

My golden wyodonette Lucy has been picked by our other hen in the coop. It started off with a small patch now bigger. I increased their feed with 20%protein feed and giving them more worms. Anything else I can do? Should I separate them? And how long till more feathers come back?
First and second picture is now and third is two weeks ago

 

[oldhenlikesdogs]

There are no pick sprays you can try. You can also try pinless peepers on the ones doing the plucking if you know who they are. Crowding, and boredom are other reason for feather plucking.

As far as growing back they may grow back in right away, or it may take until the fall molt, which generally can start as early as the end of July up through January.