The experiment was conducted to evaluate the effect of enzyme efficiency in diets with and without nutrient reduction on the performance of broilers. Thousand and hundred forty male broiler chicks (Cobb 500®) were distributed in a completely randomized design with 4 treatments in a factorial 2x2 (two diets with different nutrient densities, with and without enzyme) with 8 replications of 45 birds. The diets were: positive control (normal) and a negative control (with a reduction of 4.3% and 4.5% of metabolizable energy, 16.7% and 17.7% of calcium and 35% and 42.7% of phosphorus, in initial and growth phases, respectively). The enzyme supplementation consisted of a combination of phytase enzyme (100g t-1) and amylase, xylanase and protease (500g t-1). It was evaluated the performance of birds in phases 1 to 21 and 1 to 42 days old. In the total period, the birds fed with negative control diet with added enzyme had feed intake (5.97%), body weight (8.47%), body weight gain (8.64%) and feed conversion (2.92%) higher (P<0.05) than compared to birds fed with negative control diet without enzyme supplementation. In addition, birds fed with control diet with added enzyme showed negative feed intake, average live weight and body weight gain similar (P>0.05) to the group fed with positive control diet with or without enzyme. It is concluded that the addition of exogenous enzymes in diets with reduced metabolizable energy, calcium and phosphorus, providing a feed intake, average live weight and weight gain similar to a diet with adequate levels for broiler.
poultry; phytase; amylase; protease; xilanase
