School of Life and Environmental Sciences, Faculty of Science, The University of Sydney, Camperdown 2006 NSW, Australia; Poultry Research Foundation, The University of Sydney, Camden 2570 NSW, Australia.
Evonik Operations GmbH, Hanau-Wolfgang 63457, Germany.
Poult Sci. 2022 Dec;101(12):102171. doi: 10.1016/j.psj.2022.102171. Epub 2022 Sep 9.
The present study was designed to re-evaluate the ideal amino acid ratios of total sulphur amino acids (TSAA), Thr, Val, Ile, Trp, and Arg relative to Lys during peak and post-peak production phases in laying hens by using seven independent amino acid assays in similar experimental setting. A total of 348 twenty wk old Isa Brown laying hens were allocated to individual battery cages. Each dietary treatment included 6 replicates with 2 single cages (2 birds) as one replicate. All diets were formulated based on maize, soybean meal, and canola meal to have identical crude protein (120 g/kg) concentrations and energy density (11.9 MJ/kg) but with 5 levels of dietary concentrations of tested amino acids. Hens were offered experimental diets from 27 to 33 wk of age in experiment 1 (Exp. 1) and from 42 to 48 wk of age in experiment 2 (Exp. 2). Daily egg production and weekly egg weights were recorded, and feed intakes were calculated for each experimental period to determine egg production rate, egg mass, and feed conversion ratio (FCR). Linear and quadratic broken line models were used to estimate amino acid requirements on egg production rate, egg mass and FCR. Overall, quadratic broken line models estimated higher amino acid requirements for egg mass, egg production rate and FCR than linear broken line models by 23, 25, and 20%, respectively. The predicted daily Lys intake recommendation was 720 mg/bird/day with linear broken line model and 897 mg/bird/day with quadratic broken line model and the recommended ideal amino acid ratios relative to Lys are 85 for TSAA, 69 for Thr, 83 for Val, 87 for Ile, 22 for Trp, and 82 for Arg based on linear broken line model and 87 for TSAA, 67 for Thr, 83 for Val, 86 for Ile, 22 for Trp, and 78 for Arg based on quadratic broken line model estimations.
本研究旨在通过在类似的实验设置中使用七种独立的氨基酸分析方法，重新评估产蛋高峰期和高峰期后的蛋鸡总含硫氨基酸（TSAA）、苏氨酸（Thr）、缬氨酸（Val）、异亮氨酸（Ile）、色氨酸（Trp）和精氨酸（Arg）与赖（Lys）的理想氨基酸比例。共有 348 只 20 周龄的 Isa Brown 蛋鸡被分配到单独的电池笼中。每个日粮处理包括 6 个重复，每个重复有 2 个单笼（2 只鸡）。所有日粮均以玉米、豆粕和菜粕为基础，粗蛋白（120g/kg）浓度和能量密度（11.9MJ/kg）相同，但含有 5 个水平的测试氨基酸日粮浓度。在实验 1（Exp.1）中，鸡从 27 周到 33 周龄，在实验 2（Exp.2）中从 42 周到 48 周龄时，鸡饲喂实验日粮。记录每个实验期的日蛋产量和周蛋重，并计算饲料摄入量，以确定产蛋率、蛋重和饲料转化率（FCR）。使用线性和二次折线模型估计产蛋率、蛋重和 FCR 的氨基酸需要量。总体而言，二次折线模型比线性折线模型分别高出 23%、25%和 20%，估计蛋重、产蛋率和 FCR 的氨基酸需要量更高。线性折线模型预测每日 Lys 摄入量推荐值为 720mg/只/天，二次折线模型预测为 897mg/只/天，线性折线模型相对 Lys 的理想氨基酸比为 85%TSAA、69%Thr、83%Val、87%Ile、22%Trp 和 82%Arg，二次折线模型估计的理想氨基酸比为 87%TSAA、67%Thr、83%Val、86%Ile、22%Trp 和 78%Arg。
