If you are feeding your hens Purina® Layena® or Purina® Layena® Plus Omega-3 layer feed, you should not need to supplement with oyster shells. These two feeds include Oyster Strong™ System, so the added calcium is included right in the feed. However, there are a few times when oyster shell supplement should be offered: - During warm temperatures or if hens have decreased feed consumption: If hens are not eating their entire allotment of complete layer feed, offer oyster shell supplement to ensure they receive the calcium that they need. - During molt: Hens in molt require higher protein levels and do not need the added calcium. During this annual event, switch your laying hens from a complete layer feed to a high-protein feed, like Purina® Flock Raiser® crumbles. Offer hens a dish of oyster shell. When they prepare to return to laying, they will start eating oyster shell and you can then transition back to a complete layer feed. Once they are finished molting and back to their usual Purina® Layena® or Purina® Layena® Plus Omega-3 layer feed, you can remove the dish of oyster shell. - Organic flocks: Purina® Organic layer feed does not include Oyster Strong™ System. However, the amount of calcium in Purina® Organic meets the needs of those birds for strong shells and egg production. Have you tried a feed that includes Oyster Strong™ System? What results have you seen?