The minerals present in the mineral block is in the exact amount necessary to nutritionally balance the other foods they eat. 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.