I have three 14 week old pullets - two buff Orps and an EE. I am about to run out of developer feed and can only get a 50 lb bag of it. There is no way I am going to go through a 50 lb bag of it before I need to change feeds. Is it OK to put them on All Flock and then supplement with oyster shell if they start laying? Once I got through the bag of the All Flock, I would switch them to Layer feed. Is this an OK plan? I just do not want to pay out for a huge bag of feed that I might only use a small portion of.