layers vrws growers

Sorry to both with more, hopefully last question for a while!

At what age do you change hens over from growers to layers?

They are currently 15wk (light susses and R island red?)

Just check if your growers has any medication in it.  If it's not medicated then it doesn't matter, but if it's medicated you will need to stop feeding it for a couple of weeks before you eat the eggs (because the chicken medication isn't meant to be eaten by humans).

Also make sure you have oyster shell grit available to them.  My Minnie-Rose started eating oyster-shell grit as soon as her comb and wattles started to redden up a bit.  The shell had been available all along, but I only saw her eating it when there were other signs that she might be getting ready to lay.

I've recently changed mine from growers to layers as they show physical signs of maturity, although I will definitely have to wait for another month or so before they lay (we're coming into winter here).