All nine minerals are needed by birds to stay healthy. Here is the list of ingredients in the Manu Mineral Block: Calcium: Needed for strong bones, proper muscle function, and eggshell production. Min. 18% Copper: Helps keep blood vessels flexible for good circulation and promotes healing. Min. .002% Iron: Carries oxygen in the blood and needed by hens for egg production. Min. 1.8% Magnesium: Activates enzymes for absorption and transportation of nutrients. Min. .85% Manganese: Required for metabolism of fats and sugars: Improves hatch-ability. Min. .10% Phosphorus: Releases energy from carbohydrates, fats and proteins. Min. .20% Potassium: Needed for normal heart and muscle activity. Min. .10% Sodium: Aids protein absorption and maintains ionic strength of body fluids. Min. 1.2% Zinc: Needed for sexual maturity in males; involved in formation of feathers. Min. .01% Ingredients: calcium sulfate, iron oxide, bentonite clay, sodium chloride, magnesium oxide, potassium chloride, dicalcium phosphate, zinc sulfate,copper sulfate, ferrous sulfate, and manganese oxide.