This past year is the first time I have ever had to deal with a hen that pulls out her own feathers and was not broody at all. She was actually still laying eggs but she was looking very ragged. She started plucking the feathers last January/February when we had the snow storm and deep snow, and she never stopped plucking herself. We never needed to pull her out of the flock for broody behavior. Several of the other hens also started to self pluck after she started, but they stopped the plucking behavior after we switched feed. The one hen was the only one left doing it.
Reading more about nutrition, feather plucking and bullying, on a couple of sites, it was recommended that we add kelp meal and some protein to their diet. Rather than just switch all at once, first we stopped using the Layer pellets and went over to the Flock Raiser with more protein but no calcium. We started supplementing with calcium on the side. We had some really crazy extra calcium deposits on the eggs for a while, but that settled down and it rarely happens now. This actually works better because we can have the pullets in the pen at the same time. They do go through a lot more oyster shell/calcium supplement than before, but it is cheap. So that seemed to work for the other few that had also started to eat feather. They stopped pulling out their chest feathers, except for the one hen. So we figured we were on the right track, but was just not enough of something for the one hen.
So the next thing I tried was putting "No Pluck" on her chest. That also helped, but did not stop the behavior all the way. Some of the feathers would grow back in, but the crop area was still bald and bright red.
Eventually, I started adding organic Icelandic kelp meal in July. I read that for poultry, this will add many micronutrients that act as a prebiotic. Another level of nutrients that can help with health and behavior. The recommended amount is 1% to 2% by feed weight. So that would be about 0.24 ounces of kelp meal for each pound of food. We add a small scoop that we measured to match the appropriate amount that we feed the birds a couple times per week. The kelp does not "stick" to the pellets, and basically just collects on the bottom of the feeder but they do eat some of it from the feeder tray.
I don't know if the birds actually get enough of the kelp meal, as recommended, but there is a noticeable change in the feathers coming back in on the one hen who has been bald for so many months. It took several months of the kelp meal supplement, but her feathers are filling in, even though it is moulting time for her. So I'll continue to add the kelp meal. It does not seem to be harming them and their eggs are looking/tasting great.
Plus, now that it is moulting time, I am giving the hens a little extra kitty kibble (fish) and Black Oil Sunflower seeds three times per week to supplement a little extra protein since the nights are getting cooler again. I know that the extra protein is needed for the moulting hens and since we still have layers in the flock, I don't want to change out the feed again since there has been a gradual improvement.
Hopefully, the feathers will continue to fill in before winter sets in. Here is an article about livestock and organic kelp meal with some research links.
11/14/21 Update - While the majority of the feathering has filled back in, there is a vertical strip on the crop that she continues to pick at. I don't know that she will ever stop this behavior. She may simply do it like a person who chews their nails. Such as life.
