Iron forms part of the haemoglobin molecule that transports the oxygen around the body. Where there is a deficiency causing anaemia the oxygen carrying capacity of the blood is greatly reduced. All pig diets should be supplemented with iron. Anaemia due to a primary deficiency of iron is unusual in pigs over six weeks of age unless they have not been administered iron in the first one to two weeks of life and had no access to a supplemented creep diet. It is usual to administer iron to the piglet by intramuscular or subcutaneous injections of 100-200mg of iron dextran between days 3 and 7 of age.