feeding grit helps with the digestion and also egg shell as it helbs break down the calcium. we use oyster shells for calcium, and it works well, for grit we use \"Grani-Grit\"
One year we got a bag of \"calcium chips\" from the feed store, (I asked for oyster shell, but they gave me that instead, and i never noticed until i got home and opend the bag!) it looked like crushed limestone or some other stone, was deffinately NOT oyster shell. Well sinse we had it, we tried it..but I really did not like the results, made the eggs bumpy with calcium deposits, and seemed to make the shell colors change as well.