Efficacy and Metabolizable Energy Equivalence of an α-Amylase-β-Glucanase Complex for Broilers

Abstract

A trial was conducted to evaluate the effects of adding an exogenous α-amylase-β-glucanase complex produced from Bacillus amyloliquefaciens on the growth performance, carcass yield, and relative AME bioequivalence in broilers fed corn-soy diets from 1 to 40 d of age. One thousand seven hundred and fifty one-day-old Cobb x Cobb 500 slow-feathering male broilers were randomly allotted to seven treatments with 10 replicates of 25 birds each as follows: control diet (C); C diet with reduction of 60 (C-60), 90 (C-90), or 120 (C-120) kcal AME/kg; C diet with reduction of 120 kcal AME/kg and supplemented with 200 (C-120-200), 300 (C-120-300), or 400 (C-120-400) mg of the enzyme complex/kg. Each g of the enzyme complex corresponded to 200 kilo-Novo α-amylase and 350 fungal β-glucanase units. On d 40, eight birds were randomly taken from each pen and processed to evaluate carcass and commercial cuts yields. Percent mortality was not affected by the treatments (p > 0.05). Live performance, as indicated by BW gain (BWG) linearly decreased (p < 0.05) and FCR linearly increased with the reduction in AME. Birds fed diets supplemented with the enzyme complex showed weekly improvements in BWG and FCR. There were no effects of the treatments on the yield of the carcass or of commercial cuts; however, abdominal fat was significantly lower (p < 0.0343) in birds fed the C-120-400 compared to the C-120 feeding program (1.67% vs. 1.90%); all other treatments were intermediate. Average AME equivalence of the enzyme complex varied weekly. Estimations for the entire period were 40, 46, and 56 kcal for BWG and 58, 76, and 99 kcal AME/kg for FCR (p < 0.001) for the diets containing 200, 300, and 400 mg enzyme complex/kg, respectively.