I opened the crop of the last one and it was full of straw. We are removing the straw and feeding them more (they are free range.) The other chickens seem fine, but I'm afraid they might be partially impacted too from eating straw. I'm guessing straw stays in the crop forever? What should we do in terms of determining if the other chickens might be developing a problem and is there anything we can give them (I read about mineral oil) to get the straw that they might have in their crop to pass.