I have chickens in two separate coops and runs. They are never mingled. I have noticed that most (but not all) of my chickens in both coops have lost weight. So much so that I can feel their keel bone. We live in the mid-south on the coastal plain. Our temps have been in the 50's during the day and in the low 30's at night. With the occasional warmer day or night. I don't suppliment the coops with additional heat all night long. We do have lamps with 150 watt bulbs that are one for about 3 hours each evening. They give off some heat but are mostly there for the light and egg production. As far as I can see they are eating well. Maybe not quite the quantity that they were in the summer but eating. I have been feeding them private label, high quality layer crumbles from a local milling company. Into the feed I also mix alfalfa meal and turmeric and oyster shell. Several times a week I make them a mash with hard boiled egg or oatmeal in it. Poos seem to be normal. I'm not much for treats but I have given them a small sprinkling of scratch and crimped oats in the runs, every other day. Mostly to give them something for which they can peck around. Any thoughts, please.