phosphorus, digestibility, broiler


Accurately meeting the dietary P needs of broilers is critical to ensure optimal bird performance, health, and welfare without causing undue environmental burdens associated with excess dietary P excretion. Phosphorus is commonly supplied in broiler diets from inorganic phosphates derived from non-renewable sources, but it has been estimated that peak P production will occur between 2030-2040 and that the global supply of P could be depleted within this century (Cordell and Drangert, 2009; Nest and Cordell, 2012). To address these concerns, inorganic P use in agriculture, including use in broiler diet formulation, requires careful stewardship. To this end, the dietary inclusion of animal protein meals can help reduce or eliminate the need for inorganic phosphate use, especially when paired with phytase (van Harn et al., 2017). However, the proportion of P available to the bird within commonly used inorganic phosphate and animal protein sources is often not well-defined.With increasing adoption of ileal digestibility of P in feed formulation, additional data are needed to develop robust databases for commonly used and important sources of P. Therefore, the aim of this study was to generate values of AID and SID of P for different inorganic phosphates and meat and bone meal sources using the direct method. In addition, relative P digestibility of these sources was determined using monosodium phosphate as the reference ingredient to provide a basis for comparing quantitative digestibility results with relative values.