First let me say
.
Second to answer your question as best as I can.
While in the country I had 28 laying hens all Black Austrolorp. The only additional lighting they had was when I went in with a flash light to close things up or open in the morning. I did have a red heat lamp and used it when the temps went below 20 degrees. I saw no drop in egg production in the winter and only a slight drop in the hot part of the summer.
My coop was a converted horse stall in the barn and the roof of the barn was the top of the coop. It got downright cold in there. There were no windows on the barn either so dark was DARK.
Now that I am starting up again with hens in the city I do plan to have some lighting. I want to make sure they all have enough time to eat so I will have dim rope lighting on a timer in both coops and I will only have it on from 7 am to 6 pm.
IMO the lighting is more for us than them. As someone pointed out on another thread, chickens need a break. (not the exact wording)
All animals have the ability to adapt to the changing seasons and I agree that nature needs a break from time to time.
In other words, perhaps it is better for the chickens if we allow their bodies to direct the show.
Maybe not the answer you were looking for but it is the best one I have.
