Purina® Organic Layer Crumbles with the Oyster Strong® System provide a balanced and complete diet with 16% protein for feeding organic laying hens. This product has been certified organic by the USDA. It is made with non-GMO ingredients that have been grown without the use of pesticides and fertilizers. Our layer feeds include the Oyster Strong® System, which is an exclusive blend of oyster shell and key vitamins and minerals, like vitamin D and manganese, ensuring a supply of calcium will be available at night when your hens are forming eggs.