Ok so I have a coop of free range chickens. They are strictly my egg layers and some of the kids 4H chickens when they arent getting in shape (feather wise) for show. My freerange birds are HUGE heavy and healthy . Last spring we started buying different breeds and eggs to hatch. We have a bunch. But I have noticed that most of the birds are lighter and not as heavy as they should be. We have had freerange chickens for a long time. Never had any problems with weight most are actually quite plump. The chickens in the coops are not starving but I am having a hard time getting them to fill in all the way. I figured that would be true for the really heavy chickens as the Giant Cochins are not something that we have ever had before. I imagine even freeranging they would eat alot . But even the Polish seem a little lighter than normal and the others. They are all over 6 mos and we are feeding them Flock Raiser by Purina. I am staying away from the corn because a few of the girls chickens started to get that yellow tint to thier feathers. We also give them cut grass each coop usually once every week to week and a half. (A full lawnmower bag I am semi lazy there . ) We had a suggestion from the kids 4H leaders to give them horse poo. So once to twice a week they get a good scoop or two of horse poo. Thanks for any and all extra help !!