A review of the iron requirements and its determination in commercial poultry

). The poor bioavailability of inorganic Fe has led to increased interest in alternative organic Fe sources, such Fe-amino acid chelates and Fe proteinates, with higher absorption efficiency at lower active inclusion levels. Iron absorption is also dictated by interactions with anti-nutrients, notably phytic acid and mineral antagonists. There is considerable variation in recommended supplemental Fe levels for poultry across published guidelines, feeding standards and scientific articles. For example, in broilers and broiler breeders recommended total Fe ranges from 20 to 110 mg/kg and in laying hens from 30 to 80 mg/kg. Advances in feed formulation, including use of organic sources of Fe, reduced concentration of antagonistic trace minerals and phytase supplementation, has enhanced bioavailability of Fe, indicating that commercial poultry may now be over-supplemented with Fe. Updated and context-specific Fe recommendations are essential for optimising poultry productivity. This review examines how to assess Fe utilisation in poultry, including methods for determining Fe status, proposes Fe recommendations for broilers, broiler breeders and laying hens based on outputs from research trials, and explores how Fe interacts with other nutrients and the microbiota.