The effects of enzyme supplementation on the performance, yield, and blood profile of broilers fed corn and soybean diets from 1 to 42 days of age were evaluated. A total of 960 male broilers were used, distributed in a completely randomized design, with six treatments and eight replications. Two diets were used: a positive control formulated to meet the birds' nutritional requirements (Diet 1) and a negative control diet with reduction of 150 kcal.kg -1 of metabolizable energy (Diet 2) and 12% amino acid in the initial phase and 18% during the growing and finishing phases. Further diets were based on the negative control with enzymes: enzyme complex 1, composed of 125 g ton -1 protease; enzyme complex 2, composed of 100 g ton -1 amylase, protease, and xylanase; enzyme complex 3, composed of 500 g ton -1 amylase, protease, and xylanase; and enzyme complex 4, composed of 125 g ton -1 protease and 500 g ton -1 beta-mannanase. Enzymatic supplementation did not improve performance during the initial and growing phases due to nutritional imbalance, resulting in the worst weight gain and feed conversion during the finishing phase. Carcass yield, leg yield, abdominal fat, and pancreas were altered by enzymatic supplementation. Triglyceride levels influenced abdominal fat deposition, and the serum levels of albumin and alanine aminotransferase were altered by enzymatic supplementation. Enzymatic supplementation was not effective in restoring broiler performance, carcass yield, and cuts, with changes in the serum biochemical profile of the broiler chickens. Key words: Amylase. Metabolizable energy. Protease. Xylanase.
ResumoEste trabalho foi realizado para avaliar os efeitos da suplementação enzimática sobre o desempenho, rendimento e perfil sanguíneo em frangos de corte alimentados com dietas de milho e soja no período de 1 a 42 dias de idade. Foram utilizados 960 machos, distribuídos em um delineamento inteiramente casualizado com seis dietas e oito repetições, sendo formuladas duas rações, o controle positivo para atender as exigências nutricionais e o controle negativo com redução de 150 kcal kg -1 de energia metabolizável e 12% de aminoácidos nas fases iniciais e 18% nas fases de crescimento e terminação,