Effects Of Dietary Amylose/Amylopectin Ratio And Amylase On Growth Performance Of Broilers And Their Interaction Effects

The purpose of this experiment was to study the effects of amylose /amylopectin ratio and amylase on growth performance,nutrient digestibility,serum biochemical parameters and endogenous digestive enzyme activities of broilers.The experiment used 4×3 factor design,and 960 1 day old Arbor Acres(AA)white feather broilers were randomly divided into 12 treatment groups,each treatment was 5 replicates,and each repetition of 16 broilers,each treatment group was I(amylose /amylopectin ratio 0.11+0 U/Kg amylase),II(amylose /amylopectin ratio 0.11+3000 U/Kg amylase),III(amylose /amylopectin ratio 0.11+6000U/Kg amylase),IV(amylose /amylopectin ratio 0.23+0 U/Kg amylase),V(amylose /amylopectin ratio 0.23+3000 U/Kg amylase),VI(amylose /amylopectin ratio 0.23+6000U/Kg amylase),VII(amylose /amylopectin ratio 0.35+0 U/Kg amylase),VIII(amylose /amylopectin ratio 0.35+3000 U/Kg amylase),IX(amylose /amylopectin ratio 0.35+6000 U/Kg amylase),X(amylose /amylopectin ratio 0.47+0 U/Kg amylase)),XI(amylose /amylopectin ratio 0.47+3000 U/Kg amylase),XII(amylose /amylopectin ratio 0.47+6000 U/Kg amylase).The test period was 21 d,and the growth performance,nutrient digestibility and endogenous digestive enzyme activity of broilers were determined.The results showed that:(1)The diet with a amylose /amylopectin ratio of 0.23 could significantly increase the average daily gain of broilers(P<0.05),and the F/G of amylose/amylopectin was the highest in group 0.47(P < 0.05);the addition of 6000U/Kg amylase in the diet significantly reduced the average daily gain of broilers(P<0.05).(2)The utilization rates of energy,protein,dry matter,crude fat and calcium were highest in the diet group with a amylose /amylopectin ratio of 0.11(P<0.05),and the diet with a amylose /amylopectin ratio of 0.47 was the lowest group(P<0.05);the interaction between amylose/amylopectin ratio and amylase had a significant effect on nutrient digestibility(P<0.05);The energy digestibility at the end of the ileum decreased significantly with the increase of the amylose/amylopectin ratio of the diet(P<0.05).The addition of 6000 U/Kg exogenous amylase significantly reduced the energy digestibility(P<0.05),and both The interaction effect significantly affected the energy digestibility of the terminal ileum;the starch digestibility also decreased significantly with the increase of the linear/amylopectin ratio of the diet(P<0.05),and 3000 U/Kg significantly decreased the starch digestibility.High doses(6000 U/Kg)increase starch digestibility.(3)Groups I and III had the fastest rise in blood glucose,reaching 15.87 mmol/L and 15.88 mmol/L,respectively,followed by groups IV,V and VIII,followed by groups II and VII,followed by VI,IX,XI and XII,X group had the smallest change in blood glucose.The interaction between amylose /amylopectin ratio and amylase in diet significantly affected lactic acid content(P<0.05);insulin content was highest in group II,lowest in group VII and XII,and amylose /amylopectin ratio in diet The insulin content was significantly affected(P<0.05),and the insulin content decreased significantly with the increase of amylose /amylopectin ratio(P<0.05).Amylase significantly affected insulin content(P<0.05),The interaction between amylose /amylopectin ratio and amylase in diet significantly affected the insulin content(P<0.05).(4)The addition of amylase in diet could significantly increase the activity of α-amylase(P<0.05);the interaction between the two had significant effects on invertase and maltase(P<0.05).(5)Feeding the amylose /amylopectin ratio of 0.47 diet group significantly increased the activity of pancreatic α-amylase in broiler chickens(P<0.05).Conclusion: Feeding a amylose /amylopectin ratio of 0.23 and an amylase supplement of 3000 U/Kg can improve the growth performance of broilers.