R. Bras. Zootec.17/Jul/2026;55:e20250087.
Amylase and xylanase supplementation in broiler diets containing protease and phytase: growth performance and intestinal health
Bárbara Colcetta
, Tânia Luiza Kohler
, Mayara Marisa Tesche Câmara
, Giovanna de Souza Silva
, Débora Piotrowski
, Ana Caroline Hammes
, Cristine Kaufmann
, Nilton Rohloff Junior
, Ricardo Vianna Nunes
, Cristiane Regina do Amaral Duarte
, Cinthia Eyng
ABSTRACT
This study evaluated the effects of xylanase combined with increasing amylase levels in broiler diets containing protease and phytase on performance, intestinal histomorphology, cecal short-chain fatty acid profile, serum interleukin (IL) levels, and economic viability over a 28-d period. A completely randomized experimental design was adopted in a 2 × 3 + 1 factorial arrangement (100 or 200 U kg−1 amylase × 0, 1,000 and 2,000 U kg−1 xylanase + positive control (PC), without enzymes), with seven replicates of 20 birds. Diets with amylase and xylanase also included 2,500 U kg−1 protease, whereas all diets had 500 U kg−1 phytase. Enzyme matrix values accounted for 100 kcal of metabolizable energy and 6% of crude protein and digestible amino acids. At 14 d, broilers receiving xylanase levels presented better feed conversion ratio (FCR) compared with those fed diets without xylanase (P = 0.014). However, regardless of the enzyme supplementation level, FCR was worse compared with PC (P = 0.0001). Diets containing 100 U kg−1 amylase resulted in better histopathology scores (I See Inside®). No difference (P>0.05) was observed between PC and enzyme-supplemented groups for intestinal morphometric parameters, concentrations of acetic, butyric and isovaleric acids, or serum levels of IL-6, IL-10 and IL-16 at 28 d. Feed cost/t of broilers fed 100 U kg−1 of amylase or 1,000 U kg−1 of xylanase was 3.15% and 3.24% lower, respectively, than PC. Although the inclusion of amylase and xylanase in reduced-energy and protein diets containing protease and phytase did not improve the broiler performance and did not match the PC group, it maintained gut health and immunological parameters. The use of 100 U kg−1 of amylase and 1,000 U kg−1 of xylanase enabled an average 3.25% reduction in production cost.