I have a very reliable and lovely hen who has always laid regularly, even when whe was being picked on by some of the other birds. I am not sure what variety she is, but she is over 3 years old and has never moulted. Some of her wing and tail feathers are very degraded and just spikes really and she looks like she could really do with a lovely new coat! She is capable of growing new feathers as I had to isolate her for a while to regrow some shoulder feathers that had been pecked off by the others. Do some chickens simply never moult? I had a chicken of the same age unfortunatly die earlier this year and she too had never moulted. This is in contrast to another one of my hens who first moulted at 9 months and now has about 2 broody sessions a year that last for months that are followed by a full moult! Crazy creatures!
Most chickens will molt - but some lose so few feathers you would never know. I have a couple nearly naked buff orps right now & others have hardly lost a feather. It is possible to force a molt but its very stressful for the bird & not recommended. Especially for a 3 year old.
My wife fav hen is molting.She is naked necked,naked belly,and her wing pins are a-showing..poor sad looking thing,but shes about 18 months so she is due up for new feathers.
I found this article on molting interesting: http://msucares.com/poultry/management/poultry_feathers.html It talks about how some chickens stretch a molt over 4-6 months, so you really never notice the change, while others do a fast molt and look raggedy for a short period. Gives pros/cons over the type of molt...
As the post from teach1rusl indicates there are several ways of molting. There is the blow all my feathers at once and look like a porcupine molt (resulting in a miserable chicken) and the gradual several feathers at a time molt.
Thanks very much for the info - didn't realise that some could moult over such a long period of time and this must be the answer (though she looks like she could still do with some new ones!). She is certainly a much happier chicken than my little 'throw them all out at one go' bird, who has chosen to do this now, in the sub-zero temperatures...again!
Our Rhode Island Red have done a very slow (over months) molting. They started a couple months ago and still are at it. I am very thankful for this as the combination of wind and rain we get here probably would have killed them otherwise. Crystal, thank you for posting that link