Effect Of Exogenous Amylase On In Vitro Nutrient Digestion Of Diets,Growth,and Intestinal Morphology For Broilers

Experiment 1: Effect of exogenous amylase on in vitro nutrient and energy digestibility of broiler dietsThis experiment was conducted to investigate the effect of exogenous amylase supplementation to corn-soybean meal diets on the in vitro nutrient and energy digestibility using a computer-controlled simulated digestion system(SDS—?).The 2×4 factorial arrangement design with 8 treatments and each treatment contained 5 replicates with 1 digestion tube per replicate was adopted in the present study.The control diets were formulated to meet or exceed the nutrient requirements and the test diets were supplemented with 1840,9200,and 18400 U/g exogenous amylase into the control diets,respectively.Dry matter digestibility,crude protein digestibility,starch digestibility,gross energy digestibility and in vitro metabolic energy of the 8 diets were determined using a SDS—?.The results showed as follows: 1)The in vitro gastric DMD and GED of diets increased as the level of exogenous amylase supplementation in the control diets increased(P<0.01).2)In vitro apparent and standardized total tract CPD in the diets with the inclusion 1840 and 9200 U/g amylase were greater in the control diet(P<0.01).3)The effect of diet and amylase on the DMD,GED,CPD,STD and IVME was observed in the present study(P<0.01).It is concluded that there was interaction effect of dietary nutrient level and exogenous amylase on in vitro nutrient and energy digestion.Experiment 2: Effect of exogenous amylase on performance and slaughter performance of broilersThis study was conducted to investigate the exogenous monocomponent amylase on growth performance,organ weight,and carcass traits in a corn-soybean meal diet fed to Arbor Acre broilers.A total of 240 broilers were randomly placed into 48 pens(5 birds/pen)and allocated to 4 treatments with 12 replicates.The control diets were formulated to meet or exceed the nutrient requirements and the test diets were supplemented with 1840,9200,and 18400 U/g exogenous amylase into the control diets,respectively.Following slaughter at the end of 21 and 42 d feeding,organ weight was determined.1)The finishing BW,ADG and ADFI in male birds were greater than in the female birds(P<0.01).2)There was an interaction of the amylase and gender on spleen index for 42 d birds(P=0.02).It is concluded that the effect of exogenous amylase on growth performance of 21 d broilers was better than 42 d.Experiment 3: Effect of exogenous amylase on intestinal morphology in broilersThis study was conducted to investigate the exogenous monocomponent amylase on intestinal histology in a corn-soybean meal diet fed to Arbor Acre broilers.Following slaughter at the end of 21 d and 42 d feeding,duodenum,jejunum and ileum was sampled for histological analysis.1)The amylase increased villus height,crypt depth and the number of goblet cells in the duodenum for 21-d broilers(P<0.01).The 18400 U/g amylase increased the crypt depth,villus height/crypt depth and the number of goblet cells in the jejunum,and villus heigh and crypt depth in the ileum for 21-d birds(P<0.01).2)The 1840 U/g amylase increased the duodenal villus height and crypt depth.The jejunal villus height,crypt depth and the number of goblet cells in the diet with 1840 U/g amylase were greater than in the control diets(P<0.01).It is concluded that amylase affected intestinal histology of birds.Intestinal histology was increased by inclusion of 18400 U/g amylase for 21-d broiler and increased by inclusion of 1840 U/g amylase for 42-d broilers.