Nutrena NatureWise Oyster Shell Poultry Supplement, 7-lb bag

Product is mostly calcium carbonate. I was expecting oyster shell. I already had a giant bag of calcium carbonate that my chickens will not eat so now I have this useless bag of calcium carbonate that was advertised as oyster shell

If your hens are laying soft or pimply eggs, stop reading and buy this. Nutrena’s oyster shell is the gold standard for calcium supplementation. It’s clean, perfectly sized, and practically dust-free.

Chickens should have extra calcium available when they reach laying age (20 weeks). This supplement should not be added to their food, but be available to them. They will take a little themselves on a as needed basis. The purpose is to harden the egg shells and replace calcium used when they reach egg producing age.

My chickens won't eat it. It has a very strong smell of rancid oil. I feed the chickens with "wet" feed (cooked corn kernels). I mix the food with powdered calcium (I grind calcium pills into powder with a coffee bean grinder). Usually them fight for it and finish it in no time. I then grind some of this oyser shell and mix with the (wet) food. The chickens eat a little bit of it and then leave it alone. Apparently the smell of the rancid oil puts them off.