Available Phosphorus and Calcium Reduction in the Finisher Phase and Phytase Utilization on Broilers

Abstract

SUMMARY The objective of this study was to access/identify the effects of phosphorus (P) restriction as a result of non-inclusion of monocalcium phosphate on broiler's diet after 21 d of age and the use of high doses of phytase (PHY). Broilers were divided into 4 treatments: positive control (PC), with phosphate inclusion; with phytase (WPHY), a reduction of 0.15% of available P and calcium (Ca) with the inclusion of 1,000 FYT; and 2 treatments with P restriction starting at 21 d of age: Without phosphate (WoP) and without phosphate supplemented with 4,000 FYT PHY (WoP+4000 FYT). Broilers performance (WG, FI, and FCR) and bone characteristics (bone weight, mineral residue, and Ca and P ratio) were assessed at 41 d of age. In relation to performance, the exclusion of monocalcium phosphate from the diet resulted in worse WG and FCR. However, the inclusion of higher PHY dose (WoP+4000 FYT) overcame the mineral deficiency, and performance was similar to treatments that met bird's mineral requirements (PC and WPHY). The treatment with mineral restriction (WoP) had the worst results in every bone quality assessment. However, broilers of WoP+4000 FYT group had bone parameters similar to PC and WPHY. Therefore, removing phosphate in grower and finishing phases has negative impacts on broiler's performance and bone conformation, but adding high phytase dosage (4,000 FYT) overcome this damages.