Alpha-amylase supplementation in reduced-energy diets enhances energy efficiency, mineral digestibility and intestinal health in broiler chickens

1. Limited starch digestibility in broiler diets, associated with granule structure and ingredient variability, can reduce energy utilisation and impair performance. Thus, this study aimed to evaluate the effects of alpha-amylase supplementation on performance, carcase yield, nutrient digestibility, intestinal morphology and short-chain fatty acid production.2. A total of 640 male broiler chickens (Cobb 500) were distributed in a completely randomised design with four treatments and eight repetitions of 20 birds each. The treatments: PC: positive control, formulated to meet the nutritional requirements of the birds; NC: negative control with a reduction of 0.25 MJ of metabolisable energy (ME) per kg of diet; NCA100: NC + 100 g alpha-amylase per kg of diet; NCA200; NC + 200 g alpha-amylase per kg of diet.3. At 21 and 42 d, performance was evaluated and, at 42 d, carcase yield and cuts, nutrient digestibility, intestinal morphology and short-chain fatty acid production were assessed in broiler chickens.4. At 21 and 42 d of age, broiler chickens supplemented with NCA200 exhibited improved metabolisable energy (ME) utilisation compared to the PC and NC groups. At 42 d, NCA200 supplementation increased ileal nutrient digestibility, as indicated by both digestible ash and the ash digestibility coefficient. At the same age, broiler chickens supplemented with NCA200 showed enhanced duodenal morphology, with greater villus height and villus-to-crypt ratio, as well as elevated caecal short-chain fatty acid concentrations, including acetic, propanoic and butyric acids, compared to the PC and NC groups.5. In conclusion, supplementation with NCA200 in reduced-energy diets increased mineral digestibility, promoted beneficial changes in intestinal morphology and elevated short-chain fatty acid production, demonstrating its efficacy in broiler diets without affecting performance.