High amylose to amylopectin ratios in nitrogen-free diets decrease the ileal endogenous amino acid losses of broiler chickens  

作　　者：Huajin Zhou Tahir Mahmood Wei Wu Yanhong Chen Yao Yu Jianmin Yuan 

机构地区：[1]State Key Laboratory of Animal Nutrition,College of Animal Science and Technology,China Agricultural University,Beijing 100193,China [2]Adisseo Animal Nutrition,DMCC,Dubai 00000,United Arab Emirates

出　　处：《Animal Nutrition》2023年第3期111-120,共10页动物营养（英文版）

基　　金：supported by the National Natural Science Foundation of China(No.31772620)。

摘　　要：This study explored the variation of ileal endogenous amino acid(IEAA)losses and its influencing factors in chickens offered nitrogen-free diets(NFD)containing different ratios of amylose to amylopectin(AM/AP).A total of 252 broiler chickens at 28 d old were randomly allocated into 7 treatment groups for a 3-d trial.The dietary treatments included a basal diet(control),a NFD containing corn starch(CS),and 5NFD with AM/AP ratios of 0.20,0.40,0.60,0.80,and 1.00,respectively.As the AM/AP ratio increased,the IEAA losses of all AAs,starch digestibility and maltase activity linearly decreased(P<0.05),but the DM digestibility linearly and quadratically decreased(P<0.05).Compared with the control,the NFD increased the number of goblet cells and its regulatory genes mucin-2 and krüppel-like factor 4(KLF-4)while decreasing serum glucagon and thyroxine concentrations,ileal villus height,and crypt depth(P<0.05).Additionally,NFD with lower AM/AP ratios(0.20 and 0.40)decreased the ileal microbiota species richness(P<0.05).In all NFD groups,the number of Proteobacteria increased whereas the abundance of Firmicutes dropped(P<0.05).However,the broilers in the AM/AP 0.60 group were closer to the digestive physiological state of chickens fed the control diet,with no significant change in maltase activity and mucin-2 expression(P<0.05).In conclusion,increasing AM/AP ratio in a NFD decreased the IEAA losses and the apparent ileal digestibility of starch but inevitably resulted in malnutrition and disruption of gut microbiota homeostasis.This study recommends AM/AP in NFD at 0.60 to measure IEAA of broiler chickens.

关 键 词：Broiler chicken Endogenous amino acid losses Nitrogen-free diet AMYLOSE AMYLOPECTIN Goblet cells 

分 类 号：S83[农业科学—畜牧学]