Each year chickens molt, or lose the older feathers, and grow new ones.
Most hens stop producing eggs until after the molt is completed.
The rate of lay for some hens may not be affected, but their molting time is longer. Late molters are generally the better laying hens and will have a more ragged and tattered covering of feathers. The early molters are generally poorer layers and have a smoother, better-groomed appearance. Early molters drop only a few feathers at a time and may take as long as 4 to 6 months to complete the molt. Early molters are usually poor producers in a flock.