If I did that outside of my main 3 months, I'd just be constantly buying extra feed. I have tiny clutches of chicks all throughout the year and I don't trust keeping a single bag open more than a month.You should just buy a large bag of starter-grower which will be something you should feed them from day 1-week 20 (or until the first egg appears) I only had 4 chicks this summer and they they went through a 40 pound bag of starter-grower in 13 weeks! You’d be surprised that they could go through a bag that size
I'll just stick with mash or crumbles layer feed for my chicks