EFFECT OF THE ENZYME PHYTASE ADDITION ON DIETS FOR BROILER CHICKEN WITH REDUCTION THE LEVELS OF PHOSPHORUS IN THE DIFFERENT PHASES OF CREATION

Abstract

Four hundred one-day-old male chicks were distributed at random in four treatments, with four repetitions of 25 birds per treatment. Treatments were constituted by different levels of available phosphorus (Pd) on different phases. In the control treatment (T1), the levels of Pd in the initial, growth and final phases were 0.45; 0.41 and 0.38%, respectively. In the treatments 2, 3 and 4 the reductions occurred respectively, in the final phase (0.14%Pd), in the growth and final phases (0.17 and 0.14%Pd), and in all phases (0.21; 0.17 and 0.14%Pd). When reduction of Pd levels occurred in the different phases, diets were supplemented with the phytase enzyme (500 FTU/kg of diet). In the different phases of production the reduction of Pd levels, using phytase, had effect upon the performance, the poultry litter and bone characteristics. In the growth phase, the reduction of Pd level from 0.41 to 0.17%, using phytase worsened feed conversion and the productivity efficiency index. However, on the final phase the reduction of Pd level from 0.38 to 0.14% with the inclusion of phytase, established similar performance and bone characteristics to the control treatment. KEY-WORDS: Coefficient of residue, performance, poultry litter.