I also supplement oyster shell, grit, and birdseed on the side as well. But the flock I referred to never touched the oyster shell or the grit. The grit I wasn't concerned about as they were free range. But them skipping the oyster shell was a bummer. My all time favorite chicken was in that flock. She was a sweet bird, but after failing to break her of eating eggs and laying eggs with paper thin shells I had no other option. :-(
