Hello! I've read how some people feed their chickens corn during the winter.....I have been giving my 5 big girls a handful of Black sunflower seeds while they were moulting recently and occasionally toss a handful of scratch on the coop floor. Will this help with putting on weight for winter? Or should I buy some corn to give them at night for warmth? IF so, should it be whole or cracked? Any other supplements I should give them? (besides grit and oystershell available). They haveen getting apples, tomatoes, and whatever other scraps available (watermelon) here and there. Do I need to buy some of this when our garden is done for the winter? Thanks in advance!