Chickens off their feed- Cold Weather?

[pfewless]

My girls are very regular in their laying and their feeding. I am concerned. They are not eating much at all today or drinking much. Yesterday instead of getting 5 eggs from 6 hens I got 2 and today I got 4. Is it the cold weather here in SW Michigan causing this? Should I be concerned? Is there something I should be watching for? Something I should be doing? They have heated water but other than that just their hen house and indoor unheated run area which gets 13 hours of light a day with rope light There seem to be no other changes with them other than they do not want to be in the outdoor run with the snow. Any help would be appreciated.
Day two still off the feed. Usually I fill a 2 lb feeder mornign and night with 105 scratch grains 90% layer pellets. They have grit and calcium to free feed on. I also have a cage of fresh greens and one with suet packed with meal worms that hang for them. I have a 2 gallon heated water container that gets a tbsp of ACV in it at every change. I have never had problems getting them to eat or drink and they pick at their cage fod and the free feed grit and calcium. I really am concerned that theyare touching next to nothing. They gave me 5 eggs today so they are back up to par laying. Just not eating. Poop looks normal. I dont knwo what else to check for. Again any hep would be welcome.