I've seen the suggestion thrown around a few times over the past few years that winter chicks don't reach their full potential size-wise because they have to spend energy not only for growing, but for keeping warm too.
As I said in my first post, MOST HENS that are going to go broody will go broody in the spring and summer. I know it's possible for them to go broody at any time in the year, but the major outbreaks of broodiness tend to run spring through summer. I myself had a winter broody hen that hatched her chicks in February. The difference being, she was keeping them warm and taking care of them, not me. Her more sensible sisters waited till spring.
As I said in my first post, MOST HENS that are going to go broody will go broody in the spring and summer. I know it's possible for them to go broody at any time in the year, but the major outbreaks of broodiness tend to run spring through summer. I myself had a winter broody hen that hatched her chicks in February. The difference being, she was keeping them warm and taking care of them, not me. Her more sensible sisters waited till spring.