Every year your chickens will lose their feathers in what is called a molt. This is normal as they need to replace old with new. More often than not, they will stop laying as well during the molt.
During the molt, and while chickens aren’t laying, they can lose weight which can lead to liver tissue, musculature, and skeletal loss. Strangely, this will improve the quality of the eggs in the years to come.
While in molt, you may want to separate the chickens to keep the others from pecking at it and causing damage to the bird.
In the past, some farmers thought it best to all but starve the chickens during this time, but that didn’t help the poor birds at all, so DON’T DO THAT.
But the feed for chickens in molt will be a little different. You will want to feed them wheat middling and GMO-Free corn, and/or alfalfa. If you are wondering what middlings are, they are also known as millfeed, wheat mill run, or wheat midds. “Middlings can be a good source of protein, fiber, and phosphorus, along with various other nutrients. However, flour milling products arising from a fairly homogeneous parent grain can vary greatly depending upon the objectives of the milling process.” (Wikipedia)
Some think inducing a molt are great because you have all hens molting at the same time, but I believe that you should let things happen naturally in your barnyard.