I have 2 White Leghorns and they both have stopped laying out of 11 others. Basically thier FAT. They all get layer mash then some wet mash with some corn, black sunflower seeds, white millit and some dried mealworms at night. It has been very cold around 15 degrees during the day and then down to -10 at night. I have retro fitted a portion of an old barn we have for my coop. The section is 10ft wide-48ft long and 10 ft tall divided into 3 sections for seperatioins if needed. The hens are able to get to the center of the barn only when the wind dies down and warms up. I have done the best I can in trying to keep the drafts down and heat in. The coop section is usually 10 to 20 degrees warm than the outside temp and the barn isle is around 10 degrees warmer than outside temps as well. Don't know what to do as I have stopped the corn and sunflower as they are blended. Any info would help, PLEASE!!!!!!!!!!