Center of Excellence for Poultry Science, University of Arkansas System Division of Agriculture, Fayetteville, AR 72701, USA.
CJ America, INC, Downers Grove, IL 60515, USA.
Poult Sci. 2022 Sep;101(9):102038. doi: 10.1016/j.psj.2022.102038. Epub 2022 Jun 30.
Two experiments investigated broiler growth performance and processing characteristics when fed increasing Gly concentrations in reduced CP diets fed from 0 to 48 d. In experiment 1, birds were allocated to 1 of 4 dietary treatments: a control (CTL) diet containing feed-grade L-Met, L-Lys, and L-Thr, a reduced CP (RCP) diet with additions of feed-grade L-Val and L-Ile, or the RCP diet with moderate (M Gly) or high Gly (H Gly) inclusion levels to achieve a total Gly + Ser of 100 or 112%, respectively, of the CTL diet. Birds in experiment 2 were assigned to 1 of 6 dietary treatments: a CTL diet, a RCP diet, or a low CP (LCP) diet without or with added Gly to achieve 88, 100, 112, or 124% total Gly + Ser concentrations of the RCP diet. For experiment 1, 0 to 14 d broiler performance was similar (P > 0.05) among dietary treatments. From 0 to 48 d, broilers fed the H Gly diet had the lowest (P = 0.006) body weight gain (BWG) and highest (P = 0.003) feed conversion ratio (FCR). Feeding either the RCP or M Gly diet resulted in similar (P > 0.05) growth and processing characteristics to the CTL. For experiment 2, increasing Gly levels in the LCP diet linearly reduced (P ≤ 0.027) 0 to 14 d FI and FCR. From 0 to 48 d, broilers had similar (P > 0.05) performance when fed the CTL or RCP diet, but had a higher (P < 0.001) FCR when fed the LCP88 diet. Increasing Gly levels linearly reduced (P = 0.033) FCR. Total breast meat yield was negatively affected (P ≤ 0.020) when feeding the LCP88 diet and did not respond to Gly levels. In conclusion, effects of increasing total Gly + Ser levels on 0 to 48 d broiler performance are likely dependent on the content of dietary CP and other potentially interacting nutrients.
两个实验研究了在 0 至 48 日龄期间，肉鸡的生长性能和加工特性，当肉鸡喂食含有不同浓度甘氨酸（Gly）的低蛋白（CP）日粮时。在实验 1 中，将鸡分为 4 种日粮处理组之一：一种含有饲料级 L-蛋氨酸（Met）、L-赖氨酸（Lys）和 L-苏氨酸（Thr）的对照（CTL）日粮，一种添加了饲料级 L-缬氨酸（Val）和 L-异亮氨酸（Ile）的低蛋白（RCP）日粮，或一种含有中量（M Gly）或高量（H Gly）甘氨酸（Gly）的 RCP 日粮，以分别达到对照日粮甘氨酸（Gly）+丝氨酸（Ser）的 100%或 112%。在实验 2 中，鸡被分配到 6 种日粮处理组之一：一种对照（CTL）日粮、一种 RCP 日粮或一种不含或添加甘氨酸以达到 88%、100%、112%或 124%的 RCP 日粮甘氨酸（Gly）+丝氨酸（Ser）总浓度的低蛋白（LCP）日粮。对于实验 1，0 至 14 日龄鸡的生长性能在日粮处理组之间相似（P > 0.05）。0 至 48 日龄时，喂食 H Gly 日粮的鸡的体重增加（BWG）最低（P = 0.006），饲料转化率（FCR）最高（P = 0.003）。饲喂 RCP 或 M Gly 日粮的鸡的生长和加工特性与 CTL 相似（P > 0.05）。对于实验 2，LCP 日粮中甘氨酸（Gly）水平的增加线性降低了 0 至 14 日龄鸡的采食量（FI）和饲料转化率（FCR）（P ≤ 0.027）。0 至 48 日龄时，鸡饲喂 CTL 或 RCP 日粮的生长性能相似（P > 0.05），但饲喂 LCP88 日粮的鸡的饲料转化率（FCR）更高（P < 0.001）。甘氨酸（Gly）水平的增加线性降低了 FCR。胸肉总产量受到负面影响（P ≤ 0.020），当饲喂 LCP88 日粮时，甘氨酸（Gly）水平不再有反应。总之，在 0 至 48 日龄期间，肉鸡总甘氨酸（Gly）+丝氨酸（Ser）水平对生长性能的影响可能取决于日粮 CP 和其他潜在相互作用营养素的含量。
