Hey John,
Stick with it. I second Brian's suggestion that you keep an eye out for egg-eating behaviour, or for an egg thief, but for the most part, I think James has covered it. And with the amount you've already shelled out and the effort you've already put in, those would be some expensive chicken dinners.
Aren't hens supposed to slow or stop their laying during the shortest days of the year? I know people who freeze their surplus eggs just to get them through the lean/dry time. There are people keeping chickens on this site that do this very thing, because it is usually accepted that in temperate climates these jungle understory birds get the idea that laying is a bad idea when it's cold and dark all the time.
That being the case, we are lucky, or very good at manipulating chickens' laying instincts, if we can get them to keep laying at all when it would otherwise be natural for them to stop.
And have you been hit with the near-record-breaking low temperatures the destabilised polar vortex brought to some of the States, right down to Florida, where it's raining iguanas? Lots of exeptional things are happening. I don't think this season is a good one to be making snap decisions based on winter laying ability.
The only reason to butcher them all would be to find chicken genetics from further north than you are, with harsher conditions, that have a reputation for laying through the winter.
Otherwise, butchering them all would be a waste, and, in my opinion, an overreaction caused by unrealistic expectations of your flock.
Do they have a run around or adjacent to their coop? Is there a possibility to give them a hoop
shelter? I don't know what your circumstances or the availability of resources are, but I would try to provide some kind of hoop or tunnel shelter on some kind of ground, preferably a
garden bed, where you could toss
compost and food scraps. Whatever they consider candy, provide it for them in the space outside their coop.
It's sort of a catch 22 situation, but I think the hermit behaviour is self-encouraging. If there was a way to stimulate daylight activity, preferably of the same sort as they would engage in during warmer weather, that might also get them behaving in a more actively chickeny manner.
As to the pooptacular coop, I like the idea of establishing a deep litter culture whereby I just keep piling on bedding to deal with the accumulation. Some people inoculate the bedding with cultured strains of beneficial bacteria to speed decomposition and keep it from smelling. I like the idea of having some kind of tarp or landscape cloth right under my bedding layer, such that when spring cleaning time comes, all I have to do is open one wall of the coop, pull out the bedding, spray down the landscape cloth, and lay it out in the sun.
So don't kill your chickens. At least don't kill all of them out of hand because you're frustrated by their natural inclination to not lay in the middle of winter. If you notice some that truly don't like the winter, or don't want to leave the coop at all, even when the others are clamouring in their hoop run for the candy you've given them, I would mark them out and keep an eye on them.
It occurs to me that nobody has asked what your long-term goals are with this flock. Were you initially looking to keep them long-term? Did you have any plans to have your hens lay and hatch out their own chicks? In other words, are you looking at your flock in terms of keeping traits you like and eating the eggs from the hens (or even the hens themselves) that exhibit traits that you don't want? In my opinion, that is the real reason to be culling your flock.
That involves intent over time, not reaction to temporary setbacks, and can yield great fruit. You could end up raising your own flock that loves the warm seasons, but still likes a little winter enough that the egg-laying drop-off isn't more than a couple of eggs a hen per week. If you see near-record cold temperatures again, I still wouldn't expect them to keep laying, but rather be surprised and happy that they deigned to think of me at all, if they did. If you get temperatures way lower than what your animals are used to even in winter, you can expect their activity levels to drop. And that would be even for a cold-specialised flock.
So rejoice! You have probably done everything right. This winter has been extreme. Wait until things get back to normal, weather-wise. There is no call for a slaughter, no reason to cull the girls. They'd probably not have much meat anyways.
Good luck, and keep us posted.
-CK
A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects.
-Robert A. Heinlein