Hen stopped laying

[aart]

They are kept in a chicken tractor that is moved daily. The feed is mixed 50/50.

As per original owner, they should be about 15 weeks now.

So that's about 16% protein(guessing the corn is 10%).
That should be unless they are picking out the corn and not eating the layer with it's added vitamins/minerals/amino acids.

Was thinking may be the pullets are getting close to laying, that can cause some havoc.