What diet can I feed my ex battery hens to help them gain weight? They have lost weight this winter and one has been unwell, although she is progressing nicely now. I feed them layers pellets, porridge and kale every day, and egg yolk on cold days as well. They always seem to leave some food, even though they are pecking around all day. They look well feathered etc. but when handled they are a bit bony. I just want to feed them up so they can tolerate the cold weather better.