Hmmmm
interesting concept, I would say that as long as you can crush it fine enough and you can ingest it, you stomach acids should do their magic to dissolve it for absorption.
Personally I just take pill form 😁 again that lazy thing 😂
Have crushed the egg shells and fed before, but found I was too lazy to do this.... And I didn't eat enough eggs haha!
I buy crushed oyster shells (pullet size) and feed that with Grower ration, much easier to put out a tray of that and also mix with their feed.