Performance, energy, and nutrient utilization benefits with exogenous enzyme supplementation of wheat-soybean meal-based diets fed to 22-day-old broiler chickens

This study was designed to investigate the performance, bone quality, and nutrient and energy utilization in broiler chickens fed wheat-soybean meal-based diets with a dietary multi-enzyme complex. The positive control (PC) diet met or exceeded energy and nutrient needs, while the negative control (NC) diet was formulated to contain 3.0, 16.7, and 33.3% less of AMEn, Ca, and avP, respectively. Enzyme complex was supplemented to the NC diet at 0, 150, 200, or 250 mg/kg during the pre-starter (d 0-9) and starter (d 9-22) phases. A total of 300 dold male broiler chicks were assigned to the 5 treatments in a randomized complete block design with 10 replicate cages of 6 chicks per cage. Data were analyzed using the GLM procedures of SAS. Birds fed the NC diet had lower (P < 0.01) average daily gain, average daily feed intake, and feed efficiency (FE) compared to those fed the PC diet (d 0-22), while the chickens fed enzyme supplemented diets had similar (P > 0.05) performance to those fed the PC diet. Average daily feed intake (d 9-22 and 0-22) and FE (d 9-22) rose linearly (P < 0.05) with the level of enzyme supplementation. There were linear and quadratic (P < 0.001) relationships for jejunal digesta viscosity, tibia bone breaking strength and tibia ash with enzyme supplementation level. Birds fed the NC diet had lower (P < 0.05) apparent ileal digestibility and utilization of DM, N, digestible energy, and AMEn, but higher (P < 0.05) Ca digestibility and utilization compared with birds fed the PC diet. Higher levels of enzyme supplementation resulted in a quadratic relationship (P = 0.005) with P digestibility and a linear relationship (P < 0.001) with P utilization. Ileal digestibility of nonessential amino acids was quadratically related (P < 0.05) with enzyme supplementation except for Glu and Tyr (P < 0.01). This study showed that growth performance, energy and nutrient utilization, and bone mineralization were maintained with a supplemental multi-enzyme complex in a reduced energy and nutrient wheat-soybean meal-based diet.