Manna Pro Oyster Shell Poultry Treat, 50 lb., at ...
· Product Details. The Manna Pro Oyster Shell Poultry Treat provides a good source of calcium that builds strong eggshells for your birds. The oyster shell poultry treat is also heattreated for purity. This poultry treat is the perfect addition to your chicken feed supplies. Pelletsize crushed oyster shell.