Mixed Flock Starting to Lay...Feeding Advice?

So I have a mixed flock of 6 Red Ranger hens (meat birds) that are all transitioning from pullet to hen, 2 DP (a SLW and a PR) that are not, and 3 Cayuga ducks.

No roosters.

All were born on 7/7/14, so all of them are same age of 22 Weeks old.

I have been feeding them Nutrena All Flock Grower at 18% protein. They spend from sun up to sun down freeranging in my backyard.

The meat birds being meat birds are all full grown over my Wyandotte and Rock, and I just got my first egg from one of the Red Ranger ladies! She's been doing The Squat (mating position) for me for the last couple of weeks, and we got our first egg on Saturday!
She's laying beautiful, perfect little brown eggs. I'm so proud of her. ^_^



Anyway, the other Rangers are moving into maturity now and I'm getting surrounded by horny hens as 4 of the 6 are now figuring out their new "adult" feelings and instincts. Their combs are reddening and growing bigger, and they are starting to do The Squat for me, and the ducks (1 drake, 2 hens) are now practicing mating.

So, my feeding question: I'm still working through their last batch of Grower and they all eat the same thing so I just dump their feed and go. Is it OK to start buying Layer feed and Oyster shell now? Can I just set it out? Or do you guys recommend I figure out some seperate feeding schedules for either my DP's or my ducks?