When I read about this horrific practice, it made me ill. Thankfully, I know what happens to my hens in the backyard. Nothing cruel or inhumane happens here.
Egg producers withhold food from hens from 5-38 days in order to force hens to molt. During this time, hens lose their feathers and the hen ceases to lay eggs. Once the period of starvation is over, the hens lay more and larger eggs. All this boils down to greater profit for egg producers. The length of starvation varies.
The other way a molt is forced is to feed hens foods with little nutritional value. The hens don't starve; they are just malnourished. Malnutrition can lead to pecking, feather eating and further diminish the welfare of the flock.
Yes, chickens do die during this starvation. Chickens die every day in commercial chicken houses, but the starvation period multiplies the number of hens that die.
As for the period of starvation or malnutrition, depending on the method used, the time varies. I am quite sure that no hen is starved for 38 days, so this might be the period of diminished nutrition.
Since I have not yet found the way to copy and paste in 10, I cannot give you a link. The best was about.com. I did read Wikipedia, too, for information.
I need to go hug my hens.
Have you ever heard of "forced molt?" Does it make you ill to think of starving an animal to increase profit?