I have one chicken six weeks old whose back feathers and belly are "stuck" as little pins just sticking out. Fully feathered on wings, neck and head quite nicely feathered, has a nice tail - but the back just stalled out. it doesn't get picked on that I can tell (if anything, it's a bit of a bully, though my buff orp chick puts it in its place). It gets plenty of food and water and is friendly. No raw spots to indicate picking (and given how it pushes its way to the feeders I doubt the other chicks would dare pick a fight with it.) Is there anything I can do to assist the "stuck" feathering? I looked it up and it looks a lot like failure to thrive, except that the chick is good size and according to the meaty scale weighs more than my lightest bird and only a little less than the heaviest.