The Purina Layena Pearls Poultry Feed provides the optimal combination of nutrients laying hens need to stay healthy in a highly-digestible, bite-sized pearl. Infused with our exclusive Oyster Strong System, the chicken feed pearls help ensure laying hens receive a consistent supply of calcium through a blend of oyster shell, vitamin D and manganese. The poultry feed utilizes larger particles of oyster shell to provide a steady release of calcium during the night when hens are forming eggshells. Vitamin D is like the taxi that gets the calcium into your hen's bloodstream where it can be transported to where it is needed, while manganese helps strengthen and create the structure of the egg. The Oyster Strong System brings all 3 nutrients together in this chicken feed to help your hens make strong, healthy eggshells. Comes in a 6 lb. bag. Federal regulations prohibit use of added hormones in chicken feed.