Effect of phytase supplementation on performance, fecal excretion, and compost characteristics in broilers fed diets deficient in phosphorus and calcium

This study investigated the effect of dietary supplementation with phytase on growth performance, fecal excretion, and compost nutrition on broilers fed available phosphorus (avP)- and calcium (Ca)-deficient diets. A total of 750 one-day-old broiler chicks were randomly divided into five dietary groups having ten replications in a floor house. Diets of the groups were formulated with positive control (PC), negative control (NC; low avP and Ca), and NC supplemented with phytase levels; 500 (NC500), 1,000 (NC1000), and 1,500 FTU/kg (NC1500). A three-phase feeding program was used in the trial. Average daily gain (ADG) and average daily feed intake (ADFI) in the groups fed diets supplemented with phytase were significantly (<italic>p</italic> &lt; 0.05) higher than those fed NC and the increase was equivalent to those fed PC. Serum levels of Ca and phosphorus (P) were higher (<italic>p</italic> &lt; 0.05) in broilers fed NC1000 and NC1500 than in those fed NC. Interleukin (IL) level was the lowest in the group fed NC. Plasma <italic>myo</italic>-inositol (INS) concentrations in the NC1500 group were higher (<italic>p</italic> &lt; 0.05) than PC, NC, and NC500 groups. Crude protein (CP) excretion was notably (<italic>p</italic> &lt; 0.05) lower in the NC1500 group than in PC and NC groups. A lower (<italic>p</italic> &lt; 0.05) concentration of P₂O₅ was observed in compost from the group fed NC1500 than the groups fed PC and NC. Accordingly, we suggest that phytase supplementation in lower avP and Ca levels of broiler diet can improve their productive performance and reduce environmental pollution.