α-Amylase supplementation of broiler diets based on corn

A 42-d trial was conducted to study the influence of exogenous alpha-amylase on digestive and performance traits in broilers fed a corn-soybean meal diet. There were two treatments (control and alpha-amylase supplemented diet) and six replicates (14 Cobb male chicks caged together) per treatment. At 7 d of age, alpha-amylase supplementation improved daily gain by 9.4% (P less than or equal to 0.05) and feed conversion by 4.2% (P less than or equal to 0.01). At the end of the trial, birds fed the alpha-amylase-supplemented diet ate more and grew faster (P less than or equal to 0.05) and had better feed conversion (P less than or equal to 0.10) than broilers fed the control diet. Also, alpha-amylase supplementation improved apparent fecal digestibility of organic matter and starch (P less than or equal to 0.01) and AME(n) Of the diet (P less than or equal to 0.001). However, no effects were detected for CP or fat digestibility. Nutrient digestibility and AMEn of the diet increased with age (P less than or equal to 0.001); however, no interactions of alpha-amylase x age were observed for any trait. Coefficients of apparent ileal and fecal digestibility of starch at 28 d of age were similar, which indicated that most of the undigested starch, was not fermented in the hindgut of the chick. alpha-Amylase supplementation reduced relative pancreas weight (P less than or equal to 0.001) but did not affect the weight of the remaining organs. Age consistently reduced intestinal viscosity and relative weights of all the organs (P less than or equal to 0.001). The data indicated that alpha-amylase supplementation of a corn-soybean meal diet improved digestibility of nutrients and performance of broilers.