What is this?

[Wyorp Rock]

I would leave her with the hens and separate the rooster from the hens inside a dog crate with food and water. He probably is overmating her. The damage is on her neck and wings. Watch to see the hens are not pecking her. I have used BluKote spray on bare spots to discourage pecking. Pine tar or Nustock cream work work as well. How much room do they have? Are they getting outside to roam daily? You might want to increase their protein in their feed to 20%. A bit of scrambled egg divided can be good as well.

This
Move the rooster, not the hen.
Feather loss/damage to the back of the head, wings and back are usually signs of being mated quite a bit.
Feather loss under the neck and along the breast, can be overgrooming from another hen/her picking at her own feathers, etc.

Remember, you are not punishing the rooster. If he's young, he's likely over zealous and roosters mate a lot during the day, especially the first year or so and in the spring...LOL

Why you want to remove the rooster, is he will be much much easier to just re-integrate back into a flock of hens than it would be to remove 1 hen, then put her back with the group. Roosters just waltz in for the most part. A hen has to fight her way back in.

I agree, I'd cut back on the corn and increase feed protein to around 20%.

 

[Coffetym]

I have almost the exact same issue & I’m presently trying to identify what is causing this. Out of our 16 hens only 5 seem to be affected. It started with one pullet with a vertical bare strip on her throat that has slowly increased in size.
A good while after our roo started mounting the girls, a few of them started showing some feather loss just in front of the base of their tails.
I have put the Roo up for about a month now & the problem has seemed to get worse. I have applied Blu Kote to the bare skin & surrounding feathers to help prevent picking. The only picking I have seen is the girls picking/preening themselves.
I know that there are mites that destroy & cause irritation to the quill of the feathers but haven’t seen any evidence or been able to identify anything showing this as the problem.
Any help would be greatly appreciated.

 

[Wyorp Rock]

I have almost the exact same issue & I’m presently trying to identify what is causing this. Out of our 16 hens only 5 seem to be affected. It started with one pullet with a vertical bare strip on her throat that has slowly increased in size.
A good while after our roo started mounting the girls, a few of them started showing some feather loss just in front of the base of their tails.
I have put the Roo up for about a month now & the problem has seemed to get worse. I have applied Blu Kote to the bare skin & surrounding feathers to help prevent picking. The only picking I have seen is the girls picking/preening themselves.
I know that there are mites that destroy & cause irritation to the quill of the feathers but haven’t seen any evidence or been able to identify anything showing this as the problem.
Any help would be greatly appreciated.

Do you have photos?

Loss of feathers on the throat is likely due to picking/plucking.

The loss on the back sounds typical from mating/mounting. If you removed the rooster, you may have a hen that is mounting the others, it happens.

Not likely Feather/Depluming mites, the hens would be digging at their skin constantly and they would be stripping the feathers out/plucking themselves bald.

 

[Coffetym]

Do you have photos?

Loss of feathers on the throat is likely due to picking/plucking.

The loss on the back sounds typical from mating/mounting. If you removed the rooster, you may have a hen that is mounting the others, it happens.

Not likely Feather/Depluming mites, the hens would be digging at their skin constantly and they would be stripping the feathers out/plucking themselves bald.

I will get & post pics tomorrow!

 

[Coffetym]

Do you have photos?

Loss of feathers on the throat is likely due to picking/plucking.

The loss on the back sounds typical from mating/mounting. If you removed the rooster, you may have a hen that is mounting the others, it happens.

Not likely Feather/Depluming mites, the hens would be digging at their skin constantly and they would be stripping the feathers out/plucking themselves bald.

Hopefully these pics will help shed some light on the situation.

 

[Wyorp Rock]

Hopefully these pics will help shed some light on the situation.

Looks like typical loss from mating/being mounted.

The broken feathers will not be replaced until the hens go through a molt, so they may be bare until late summer/early fall depending on how old they are.