Missing neck feathers on hens

[MamaFox78]

I came out to the coop and discovered two of my sweet Brahma hens are missing big patches of neck feathers!! (Technically I guess they're pullets, they turn 1 in July). This is Hennifer Lopez, and her twin Hennifer Aniston looks the same.

About half a dozen of my 17 girls have huge patches of missing back feathers, and I know it's because of my Brahma cockerel of the same age, Cocky Balboa. He's aggressive with them, often mounting them non-consensually, and aggressive with me and the kids. He doesn't come after me after I set him straight (grabbed him by the feet and held him upside down) but he does chase and attack my 7 & 8yo kids, which is not ok with me. I'm pretty sure he killed one of my hens and my little Silkie rooster, and injured another hen's neck while raping her (it was awful, I saw it). I'm planning to cull him asap, because he's only gotten worse with age.

But I don't know if he did this to the Hennifers, or if it could have been something else? Has anyone else seen this before??

 

[aart]

Guessing that's not from the rooster but other hens 'over-grooming' the neck feathers.
Have seen it here multiple times.

What all and how exactly are you feeding?
How big is your coop and run, in feet by feet?

 

[MamaFox78]

Guessing that's not from the rooster but other hens 'over-grooming' the neck feathers.
Have seen it here multiple times.

What all and how exactly are you feeding?
How big is your coop and run, in feet by feet?

Huh, I've never seen that before!

I'm feeding grower pellets in a big feeder suspended from the ceiling, and I give them a dish of scratch daily (all organic Scratch & Peck feed) plus a side dish of oyster shell for the hens. I toss out kitchen scraps for them to peck at, either in the coop on snowy days or on the ground outside on nice days.

The coop is about 12 x 28'... one room has roosting bars, the other room has nesting boxes and a big dirt floor, and a center area with shelving and storage bins. They have an attached run that's probably 15 x 20', but normally I let them free range.

For the record, I've got 17 hens and 2 roos.

 

[Sueby]

I’ve had bare necks a couple times, one bird over grooms like Aart said & another time it was a sharpish edge on my port feeder.

My over groomer gets separated as soon as I see her do it, once she gets in the habit she won’t stop till I separate her & feathers grow back. Anything out of place on any bird & she starts pulling feathers out. Her favorite target is my bearded EEs with food on their faces.

The port feeder had a sharp edge that was breaking feathers. I had no idea what was happening at first, then I saw a post from someone here with the same feeder. Once I removed the sharp edge all was fine - of course my over groomer had to be separated as she stared pulling more feathers after the feeder damage.

Just a couple things to consider, yours looks like feather plucking. I know pinless peepers can help with that too.