We keep our babies and young adults on starter until they start showing signs of laying an egg. We look for them to molt, the combs/waddles get deeper red, the roo starts taking notice of them, they lay down almost when you pet them or they really start making noise when they walk past a nesting box. I'm guessing this is roughly between 16-18 weeks. When we start seeing these s/s, then we switch them to layer feed. Mind you we always offer grit and oyster shells to everyone no matter what the age is. We are also very fortunate to have found a place 15 miles from us that lets us buy bulk. We go through 100lbs. of feed (50lbs. each of starter & feeder) a week, 5lbs. of grit a week and 25lb. of oyster shell a week. We have 39 chickens and just got 12 baby chicks this morning at the post office. So these numbers haven't included the new babies yet.
We used to pay:
$11 for a 50 lb. bag of feed (starter as well as layer)
$5 for a small 5 lb. bag of grit
$10 for a 50lb. bag of oyster shell
Now we pay:
$10 for 100lb. feed
$6 for 100lb. grit
$6 100lb. oyster shell
Unless my calculations are way way off here is the break down. Since the grit equaled $1.32 for a month, I rounded up from $47.32 to $48 even.
$128 a month on feed, grit and oyster shell before bulk wholesale
$48 a month going bulk wholesale
$80 savings that can go for something else.