I'm not sure how it could be from the feeding just being too high in calcium but when watching my birds diet specifically my peafowl, they only eat a lot of oyster shells when the hen is laying and when the peacock is growing his train back in. When they don't need it they won't eat it but eat the rest of the feed in the pan leaving the oyster shells behind.Welcome to Back Yard Chickens !
I never heard of getting to much Calcium.
Hi! I don't think you can kill or damage them by feeding egg shells and yogurt unlless that's all they were offered. . Were you providing free choice oyster shell at that time? Was the hen laying soft shell a new layer? Sometimes it just takes a bit for the factory to run smoothly and there was no deficiency . You're correct to not add egg shells to grower, that kinda makes it layer. Do your 4 RIR's have free choice oyster shell?
