Whenever I give my birds crushed egg shells, they are usually crushed up & included in scrambled eggs or mixed into the various recipes for birdy bread, though the shells from fresh cracked eggs should not pose a problem.....
I think you will find that most listings of egg shells will suggest cooked shells if only that the bird does not get a taste for raw egg, which might lead to breaking & eating its own raw eggs.....
One other reason for feeding crushed egg shells is that the shells came from a bird's body and will be easily absorbed by the bird and easily passed out of the bird's body if it absorbs too much natural calcium, a condition not easily performed when a bird is fed synthetic calcium supplements.....a condition referred to as hypercalcemia occurs, because their body cannot readily void the extra, synthetic supplements they've been fed.....
