FOR LAYING POULTRY: Shell & Bone Builder is an all-natural, premium calcium supplement for laying poultry 18+ weeks of age. Calcium supports strong eggshells and bone health in chickens, ducks, turkeys, and quail. THE RIGHT PARTICLE SIZE: Shell & Bone Builder provides a large, consistent size of calcium carbonate to laying hens. This slow-release form of calcium is highly digestible and allows a hen to process and absorb it when it’s needed most – overnight when the eggshell is being formed. STRONGER EGGSHELLS FOR SAFER EGGS: When it comes to eggshells, stronger means safer. The eggshell is a natural barrier protecting the eggs we eat from harmful contaminants, and calcium is the essential nutrient needed for eggshell formation. Shell & Bone Builder particles support overnight eggshell formation first, and the remaining calcium goes straight to the bones for stronger, healthier birds. NOT ALL CALCIUM IS CREATED EQUAL: Limestone is a natural mineral mined from the earth. Once it hits or goes over 38% calcium, it is called calcium carbonate. The calcium carbonate in Shell & Bone Builder guarantees the highest level of calcium without heavy metal or bacterial contamination that can occur with oyster shells. 100% USA SUPPLY CHAIN: Shell & Bone Builder is a safer, top-quality calcium source for laying poultry harvested in the American Midwest and packaged in Arkansas using Amercan-made recyclable bags.