OMG. I never thought about this. I have been feeding the oyster shells and recycled eggshells as grit for weeks. My eggs are all nice and solid
However, i haven't noticed any change in their digestion or poop. But then I also liberally sprinkle sand into the pen for water dranage/dustbathing/something to make the nosey old women come running over like it's christmas, lol. My habit has been to alternate between granite and oyster shells each time I buy feed. I guess I'll be buying an extra dispenser this week.....
Thanks for the awesome info, even if this IS an ancient thread.