Exploratory transcriptomic analysis in muscle tissue of broilers fed a phytase‐supplemented diet

Summary The effect of phytase on phosphorus retention, broiler (Gallus gallus) performance and bone mineralization in diets with reduced inorganic phosphate concentration is well documented. Furthermore, so‐called ‘extra‐phosphoric’ effects of phytase have been described in the literature that may be associated with changes in mineral and amino acid partitioning and requirements per se. In particular, the role of myo‐inositol in phytase responses is implied but not well elucidated. It was the purpose of the experiment reported herein to explore the effect of phytase on broiler growth, nutrient digestibility, blood biochemistry and gene expression. A 5‐week broiler floor pen trial was conducted to evaluate the effect of supplementation of a moderately phosphorus‐deficient diet with 1000 U/kg of a 6‐microbial phytase. Parameters measured were growth performance, phosphorus (P), calcium (Ca) and myo‐inositol plasma concentrations, apparent ileal P digestibility, bone mineralization, breast meat weight and Pectoralis major muscle transcriptome. Supplementation of the diet with phytase improved weight gain during the starter period (18%) and the whole period (24%) compared with animals that received the control diet (p