Fattening them up for the winter?

[ChickenCrazy8]

I have found that my chickens look on the skinny side. And am going to up the food I am giving them. Also, I was wondering what I could give them (outside of normal feed) to help them pack on a bit more weight for the winter???
Thanks in advance,
Zoë

 

[salt and pepper]

I would just give them free access to food, and scratch, or cracked corn is great to give them in the winter.