Alpha-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 < or = 0.05) and feed conversion by 4.2% (P < or = 0.01). At the end of the trial, birds fed the alpha-amylase-supplemented diet ate more and grew faster (P < or = 0.05) and hadbetter feed conversion (P < or = 0.10) than broilers fed the control diet. Also, alpha-amylase supplementation improved apparent fecal digestibility of organic matter and starch (P < or = 0.01) and AMEn of the diet (P < or = 0.001). However, no effects were detected for CP or fat digestibility. Nutrient digestibility and AMEn of the diet increased with age (P < or = 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 < or = 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 < or = 0.001). The data indicated that alpha-amylase supplementation of a corn-soybean meal diet improved digestibility of nutrients and performance of broilers.
Gracia
M I
MI
Departamento de Produccion Animal, Universidad Politécnica de Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain.
Araníbar
M J
MJ
Lázaro
R
R
Medel
P
P
Mateos
G G
GG
D000375:Aging; D000818:Animals; D002645:Chickens / Q000254:growth & development / Q000502:physiology*; D004032:Diet; D004041:Dietary Fats / Q000378:metabolism; D004044:Dietary Proteins / Q000378:metabolism; D019587:Dietary Supplements; D004063:Digestion; D005243:Feces; D005285:Fermentation; D007082:Ileum / Q000378:metabolism; D007422:Intestines / Q000502:physiology; D008297:Male; D009929:Organ Size; D013025:Glycine max; D013213:Starch / Q000378:metabolism; D014783:Viscosity; D015430:Weight Gain; D003313:Zea mays; D000516:alpha-Amylases / Q000008:administration & dosage*
D004041:Dietary Fats; D004044:Dietary Proteins; D013213:Starch; D000516:alpha-Amylases