I know that they need more fatty food in winter to keep them warm, but I would never use an extra heat for chicken. When they are outside it is cold too. My chicken get a lot of extra food in winter too. I hope the winter will not be so cold !That explains why when it's too cold for them and not enough heat and light and food they reserve their resources and stop laying, id give them extra food to help them gain some winter weight and give them a heat soure They will soon start to lay again.. . It's the most natural thing for a healthy bird to lay eggs... I give my rabbits and hens lots of extra food to fatten up over winter ( it's what they do in the wild) after all fat is there to keep us all warm... it's not about giving them a break from laying it's a simple case of they are cold and need extra heat and food... give it a go no harm will come of it as it's a bitter winter this year ❤