Hens go through a pretty amazing process building those eggs, and Oyster shell helps out at a very specific point. The shells are built last, usually overnight – and the process can drain your chicken of Calcium. The calcium in Oyster shell is digested at a different rate than that found in their feed, so they have some extra during those night hours when they are creating shell. Help them out by providing Oyster shell At all times, and they will self-regulate, eating it when they need it. Flaked Oyster & Seashell Mix.**100% satisfaction guarantee**. Promotes healthy plumage of chickens, ducks, other waterfowl. Increases strength of eggshells, making for a healthier bird, and better egg quality. All natural, calcium supplement, leads to stronger shells. Oyster shell supplements calcium for laying hens. Flaked Oyster and Seashell Mix.Best Sellers Rank: See Top 100 in Pet Supplies. Target Species: Bird. Item Weight: 10 Pounds. Brand: Small Pet Select. Country of Origin: USA. : B07R247HPH. Manufacturer: Small Pet Select. Date First Available: April 23, 2019. Item model number: oyster10. Product Dimensions: 23 x 29.21 x 43.18 inches; 10 Pounds.