Where are all of Their Feathers?

Chickens grow rapidly. By the time they are three weeks of age, the chick's yellow down has been replaced by feathers and the heat in the barn has been gradually reduced to 22 degrees Celsius.

These chickens are now 3.5 weeks of age. As you can see, they have lost their yellow down and are beginning to grow their adult feathers. They'll have all of their feathers in another week or two.