The influence of non-bound amino acid inclusions and starch-protein digestive dynamics on growth performance of broiler chickens offered wheat-based diets with two crude protein concentrations  

作　　者：Shemil P.Macelline Michael T.Kidd Peter V.Chrystal Mehdi Toghyani Peter H.Selle Sonia Y.Liu 

机构地区：[1]Poultry Research Foundation,The University of Sydney,Camden NSW 2570,Australia [2]School of Life and Environmental Sciences,Faculty of Science,The University of Sydney,Sydney NSW 2006,Australia [3]Center of Excellence for Poultry Science,University of Arkansas,Fayetteville,AR 72701,USA [4]Complete Feed Solutions,Howick,2145,New Zealand [5]Sydney School of Veterinary Science,The University of Sydney,Sydney NSW 2006,Australia

出　　处：《Animal Nutrition》2023年第4期399-408,共10页动物营养（英文版）

基　　金：AgriFutures Chicken-meat for funding the project “Optimising amino acid profiles and energy in reducedprotein diets”(PRJ010520);the financial support provided by Australian Government Research Training Program Scholarship (RTP) received by PhD student Mr Shemil Macelline

摘　　要：The primary objective of this study was to investigate the influence of high and low inclusions of nonbound amino acid(NBAA)in standard and reduced-crude protein(CP),wheat-based diets on growth performance in broiler chickens.Dietary treatments were formulated to either 210 or 180 g/kg CP.The210 g/kg CP diets contained either 12.1 or 21.1 g/kg NBAA and 180 g/kg CP diets contained either 44.0 or55.5 g/kg NBAA.The formulations also generated different dietary starch:protein ratios which impacted on starch-protein digestive dynamics.Each of the four dietary treatments were offered to 7 replicates of15 birds housed in floor pens from 14 to 35 days post-hatch or a total of 420 male Ross 308 chickens.Growth performance,relative abdominal fat-pad weights,breast muscle and leg shank yields were determined.Ileal starch and protein(N)digestibility coefficients,disappearance rates and starch:protein disappearance rate ratios were defined.Apparent ileal digestibility coefficients and disappearance rates of 16 amino acids were determined at 35 days post-hatch and free concentrations of 20 amino acids in systemic plasma were determined at 34 days post-hatch.The transition from 210 to 180 g/kg CP diets depressed weight gain by 11.3%(1742 versus 1964 g/bird)and FCR by 10.4%(1.606 versus 1.455),although both parameters were subject to treatment interactions.The treatment interaction(P<0.001)observed for FCR was because high NBAA inclusions significantly improved FCR by 4.17%(1.424 versus1.486)in birds offered 210 g/kg CP diets,but significantly depressed FCR by 3.36%(1.632 versus 1.579)in180 g/kg CP diets.A quadratic relationship(r=0.860;P<0.001)between dietary NBAA inclusions and FCR was detected,which indicated that when NBAA inclusions exceed 18.5 g/kg efficiency of feed conversion deteriorated.However,a multiple linear regression(r=0.913;P<0.001)was detected for FCR where both NBAA inclusions and analysed dietary starch:protein ratios were significantly(P<0.001)related to FCR.This relationship indicates that growth performanc

关 键 词：Amino acid BROILER Non-bound amino acid Reduced-crude protein 

分 类 号：S831.5[农业科学—畜牧学]