Phytate-free nutrition: A new paradigm in monogastric animal production

The statement 'phytic acid is ubiquitously present in non-ruminant animal diets' is often made in scientific manuscripts oriented toward phytase, mineral and amino acid nutrition, monogastric animal performance and skeletal development. However, it is increasingly the case that this statement is at best misleading and at worst entirely incorrect. Phytase bioefficacy is at an unprecedented high in the life cycle of this technology and product cost is at an all-time low, two factors which have contributed to a climb in inclusion concentration and an axiomatic decrease in dietary phytic acid concentration. Though complete dephytinisation of monogastric animal diets may be unrealistic due to the presence of variable concentrations of recalcitrant phytic acid in localized regions of cereals, oilseed meals and grain legumes, the vast majority of reactive phytic acid is rapidly degraded to innocuous lower esters in the proximal GI tract. Thus, the nutritional paradigm has shifted from formulating diets to accommodate the presence of phytase to formulating diets to accommodate the absence of phytic acid. These are not trivial distinctions but may have considerable implications for animal performance and the optimal balance of nutrients in the diet. It is the purpose of the present article to consider the breadth of effect of the ingestion of phytic acid and the likely consequence of an ostensibly dephytinized diet on nutrition and animal performance. The concept of 'phytate-free nutrition' is posited and nutritional strategies to maximise the likelihood of observing measurable benefits from the lack of this nutritional obstacle are discussed around three conceptual pillars: phosphorus, extra-phosphoric effects and myo-inositol.