I don't feed any 'treats', other than unlimited greens and protein meat/egg/cooked dry beans etc, and only in limited amounts, too much protein is a waste.
Hung cabbage in winter is great, keeps them occupied mostly. Funny first time i tried it the birds avoided the hanging cabbage like they were scarred of the strange alien
I haven't harvested them yet but I have good size bed of mammoth red mangel beets, supposed to have the same food quality of grain and like the cabbage stick the beet on a nail in the coop gives the birds something to peck at occupying them in the winter plus saves on feed.
I don't think my birds need anything extra such as corn to keep them warm in winter, plenty of grains in their laying mash anyway. When I process them they are plenty fat so they definitely don't need any more.
We get cold, freezing to below, some stretches of zero F and colder and -20 F windchill.
I have Jersey Giants and Naked Necks, even the nakeds with half the feathers in a sorta hoop coop with a completely open side handle the cold great. The nakeds are the first out of the coop and into the snow, I'm bundled up freezing my butt off and they're laughing at me flapping their wings
Just a thought on those who do like to feed corn for a treat. I'm actually planning on growing some next yr for us and the birds. From what I've read, the colored 'Indian' corn has a higher protein level and is healthier with anti-oxidents, micro nutrients and minerals. And soft starches if you get the flour type. Painted Mountain corn is supposed to be 13%+ protein, regular whole or cracked corn from what I can find is 6-10%
TSC labels theirs at 8%.
Plenty for sale out there right now at farm markets for fall/Halloween/Thanksgiving decorations.