Effect of Inclusion of a Monocomponent Amylase in a Corn-Soybean Meal Diet on Performance and Intestinal Histology in 1- to 21-Day-Old Broilers

A study was conducted the to test the effects of inclusion of an exogenous monocomponent amylase in a corn-soybean meal diet fed to Arbor Acre broilers from 1 to 21 d of age. Broilers were randomly placed into 48 pens (5 birds/pen) and allocated to 4 treatments with 12 replicates. Amylase was added to a corn-soybean meal control diet (22.7% CP, DM basis) with 0 mg/kg, A0; 75 mg/kg, A75; 375 mg/kg, A375; and 750 mg/kg, A750. Growth performance was monitored weekly. Following slaughter at the end of 21 d of feeding (n = 12/treatment), carcass yield, organ weight, and serum biochemical parameters were determined; small intestine was also sampled for histological analysis. No differences in BW, ADF, ADFI, and G:F of birds were observed by inclusion of amylase in the corn-soybean meal diet. There were no differences in dressing weight, half eviscerated weight, eviscerated weight, abdominal fat weight, and thigh meat weight of birds fed the diets with amylase. Relative weight of heart, liver, spleen, lung, and kidneys were not affected by inclusion of amylase in the control diet. Urea nitrogen content was less (P < 0.01) in the A375 and A750 diets than in the A0 and A75 diets. Creatinine content of birds fed the A750 diet was less (P < 0.01) than those fed the A0 diet. Duodenal villus height increased (linear, P < 0.01) as the level of amylase in the diet increased. Villus height in the ileum decreased to reach a minimum at A75 (quadratic, P = 0.08). Crypt depth in the duodenum and jejunum were greater (P < 0.01) in the A750 diet than in the A0 diet, but no difference in crypt depth of the duodenum and jejunum of birds fed the A75, A375, and A0 diets. Villus height/crypt depth in the duodenum increased to reach a maximum in the control diet with 75 mg/kg of amylase (quadratic, P = 0.08), however, the villus height/crypt depth in the jejunum and ileum decreased to reach a minimum in the control diet with 75 mg/kg of amylase (quadratic, P < 0.05). Goblet cells in the duodenum and ileum decreased to reach a minimum in the control diet with 75 mg/kg of amylase (quadratic, P < 0.05). Data provided significant insight on histological profile in the small intestine associated with dietary exogenous monocomponent amylase. Inclusion of exogenous amylase in corn-soybean meal diet can improve the duodenum development of broilers.