Bread is also good for warm mash on very cold mornings....just add bread to your feed with hot water and you can add all sorts of other things like
raisins, nuts, cut up meat leftovers, cracked cortn and other grains, etc..... I do this first thing in the morning when the temps are way low. It gives them a quick heat up.
Feeding them so cracked corn or chicken scratch as a treat at night will also help keep them warm overnight.