[joyfull]

Hi do you know how old and what breed the white ones are? If your girls are in a run then try adding things like cabbages hung up so they have to stretch up to get them. Also have logs and perches in their run and possibly put feed up on top so they are more active. Layers pellets/mash should be available all the time and if necessary cut down or withdraw any mixed corn as this can be fattening.
Meat birds will just sit and eat all day so wondered if this is what your white ones are whereas the others could be an egg laying breed (meat birds will also lay eggs but pile on the weight when young).

[Dave W]

Hi Joyful, I think you're right. The white ones come from a big barn and were due for execution until they made a bid for freedom, they have now ended up in my run. Better to be in the garden than a pot noodle. The run has alsorts hanging around in it, it is a large fenced off area that gets moved a couple of times a year; the birds have the opportunity to do stuff, its just getting the motivation to do it! sounds familiar........

Dave.