Chicken with feather loss?

  I have an Ameracuana chicken about one year old that has lost most of its feathers and is being picked on by the other chickens it lives with. It grew up with the other chickens that are also the same age and they never pecked her like this before since after she lost her feathers. At first i thought it was molting because it didn't seem bad but then it worsened. She's doesnt lay eggs anymore, and tries to stay away from the other chickens, who are all normal and have been healthy . Whats wrong with my chicken?
Your birds Need their feathers for protection, insulation. flight (as little as it may be), with feather loss this may cause injury or tissue damage the bird will use more body energy to produce more feathers. it will also use more energy to stay warm as well. can have infections, bruising as well as any open sores from the attacks she is getting when her feathers are being pulled out.

Feather pulling/snatching is caused by poor nutrition. If inadequate foods are given the birds will find what they need and this is pulling feathers from other birds.This may be done by 1 or several birds its a bad habit and if others catch on then its really bad since they all will attack one bird.Its a behavior problem .... You may have to watch your flock and see who is being the star bully and who follows, Then you might try isolation for the peckers and pullers.This poor bird may be at the bottom of the order as well So may wish to put her up for a spell till she gets some more feathers in and healthy again. pets question and answers,www.5d2d.com

Any of this can cause feather loss as well, stress, parasites cleanliness or disease.

Chickens can be come distressed if are to cold or to hot for prolonged periods. Bullying, aggressiveness, chickens are in fear constantly of predators. Stress, unhealthy birds loose feathers. Ck for mites, lice, sickness or disease. Best to place her alone in a quiet spot wher she can rest and have her peace give her foods and water and watch her for illness or see if she get her feathers back sooner .....