Also if they are free ranging more ...they may be eating less layer ...Have you changed anything ?
Why eat feed when you can have yummy bugs & grass & stuff ..LOL
We went to Dumor brand feed ...TSC brand ...They laid less with that ..even though it was layer ..
They did great with Purina Layena ..Okay with Agway
They free range ALL day. I feed layena flock raiser FF, and only the odd time throw out oyster shell. All seem healthy, FAT, shiny feathers, etc.