Relative Bioavailability of Trace Minerals in Production Animal Nutrition: A Review

SIMPLE SUMMARY: This is a comprehensive review containing the most up-to-date information on the relative bioavailability of selected trace minerals (copper, iron, manganese and zinc) used in ruminant, poultry and swine nutrition. Inorganic and organic forms of the trace minerals are included, and the differences between the product types are highlighted. Building on previously published tables and data, this review incorporates studies on newly developed products and concepts not previously discussed. Extensive data tables are included, providing a valuable reference guide. Methods to calculated relative bioavailability of the minerals are discussed and reasons for potential variance are noted. Detailed background information on uptake mechanisms to aid understanding of mineral transport is also contained in the current review. ABSTRACT: The importance of dietary supplementation of animal feeds with trace minerals is irrefutable, with various forms of both organic and inorganic products commercially available. With advances in research techniques, and data obtained from both in-vitro and in-vivo studies in recent years, differences between inorganic and organic trace minerals have become more apparent. Furthermore, differences between specific organic mineral types can now be identified. Adhering to PRISMA guidelines for systematic reviews, we carried out an extensive literature search on previously published studies detailing performance responses to trace minerals, in addition to their corresponding relative bioavailability values. This review covers four of the main trace minerals included in feed: copper, iron, manganese and zinc, and encompasses the different types of organic and inorganic products commercially available. Their impact from environmental, economic, and nutritional perspectives are discussed, along with the biological availability of various mineral forms in production animals. Species-specific sections cover ruminants, poultry, and swine. Extensive relative bioavailability tables cover values for all trace mineral products commercially available, including those not previously reviewed in earlier studies, thereby providing a comprehensive industry reference guide. Additionally, we examine reasons for variance in reported relative bioavailability values, with an emphasis on accounting for data misinterpretation.