I would start feeding them layer feed. But I know alot suggest not to until they start laying. I've always had a mixed group so I'd stop buying 2 seperate feed as soon as I could!!
At that age you should be fine either way. I have a mixed age/species flock so I feed mine gamebird from chick to old biddie and just keep oystershell out freechoice so the ones that are laying can meet their calcium needs.
i have 3 and they have been in with the older flock for 2 weeks now. im sure they have eaten from there feeders of layer mash. i have a little grower mash left didnt want to buy another bag so hope they will be all right on layer from now on.
They are fine on layer now. A lot of the bags say to start feeding at 18 weeks. I started blending left over starter and layer a little earlier in order to use up some of the starter.
My Barred Rock's are 19 weeks, so I purchased a 50 bag of layer feed and have mixed it in with the grower so they transition across to only layer feed once the grower is gone. Also purchased cracked corn and BOSS to mix in to give extra protein for the winter months! Plus they get fresh greens and veggies each day....