We live in vermont, and our chickens need to have everything figured out by dark, or they're out of luck. We don't heat, or use any light (except when we have chickies), even in the dead of winter. we've never lost any to the cold, and though they do stop laying eggs during the holiday season.... halloween-groundhog day, i don't use supplemental lighting because I don't cull them ever... each hen only has a limited number of eggs that she can lay, so the longer she is useful, the happier i am.
