I've had three black sex links in my coop for a few months now - they belong to my neighbour and are the only survivors of a raccoon attack. One has not laid an egg since she got here although she seems to be all healed up and happy now. The other two each produce an egg a day without fail. The temperatures are dropping to freezing overnight now, they are in the middle of a moult (1.5 years old), there is no supplemental lighting, and still those two lay an egg every day. They are egg-laying machines! I know that I will have two extra large brown eggs in the nest box every morning even though I'm only getting one egg from my 6 young EEs (I was getting 3-4 blue eggs a day but they seem to have gone on strike lately).