My chickens are 13 weeks old (born on the 39 of may) I am currently feeding grower/finisher for my chickens and im getting eager for the first egg! i have a rooster also and i was wondering if i could feed him layer when my hens are laying. What week should i switch to layer? Sorry if this is a little confusing about the questions but this weekend i have to buy their food and i dont want to waste money on a bag of feed they wont even use a quarter of.