Department of Animal Sciences, University of Illinois, Urbana, IL 61801, USA.
AlzChem Trostberg GmbH, 83308 Trostberg, Bavaria, Germany.
Poult Sci. 2019 Jul 1;98(7):2896-2905. doi: 10.3382/ps/pez036.
Two studies were conducted to test the efficacy of guanidinoacetic acid (GAA) to spare Arg and serve as a precursor of creatine (Cr) by evaluating growth performance and muscle cellular energy homeostasis in broiler chicks. In both studies, 12 replicate pens of 6 chicks received dietary treatments beginning at day 2 post-hatch. At conclusion of each study, muscle biopsy samples were collected within 60 s of euthanasia for analysis of Cr-related energy metabolites. In study 1, Arg-deficient starter and grower basal diets were supplemented with 0 (negative control, NC), 0.06, 0.12, or 0.18% GAA, or supplemental Arg (positive control, PC; 0.37 and 0.32% L-Arg in starter and grower phases, respectively). Dietary GAA elicited graded improvements, with final BW, overall BW gain, and overall G:F being increased (P < 0.05) by 0.12% GAA compared with the NC diet with no difference to PC diet. Increases (P < 0.001) of phosphocreatine (PCr), total Cr (tCr), and glycogen concentrations, as well as the PCr-to-adenosine triphosphate (ATP) and glycogen:ATP ratios, were observed with supplementation of 0.12% GAA compared with the NC diet, even exceeding responses to the PC diet. In study 2, Arg-adequate starter and grower basal diets were supplemented with 0 (negative control, NC), 0.06, or 0.12% GAA, 0.12% Cr monohydrate (PC1), or salmon protein (PC2; containing total Arg concentrations equal to those of the NC diet in each phase and containing similar Cr as in PC1). Overall G:F was increased (P < 0.05) by PC1, but not by PC2, compared with the NC, while GAA supplementation elicited a response intermediate to NC and PC1 diets. However, GAA supplementation increased (P < 0.01) concentrations of tCr and glycogen, as well as the PCr:ATP and glycogen:ATP ratios, when compared with the NC (Arg-adequate) diet. Collectively, these data indicate that GAA can be used to replace Arg in practical, Arg-deficient diets and improve muscle energy homeostasis in broiler chicks receiving either Arg-deficient or Arg-adequate practical diets.
两项研究旨在通过评估肉鸡生长性能和肌肉细胞能量稳态来测试胍基乙酸（GAA）作为精氨酸（Arg）的节约剂和肌酸（Cr）前体的功效。在这两项研究中，12 个重复的 6 只鸡的饲养笼从孵化后第 2 天开始接受饮食处理。在每项研究结束时，安乐死后 60 秒内采集肌肉活检样本，用于分析 Cr 相关能量代谢物。在研究 1 中，Arg 缺乏的起始和生长基础日粮分别添加 0（阴性对照，NC）、0.06、0.12 或 0.18%的 GAA 或补充 Arg（阳性对照，PC；起始和生长阶段分别为 0.37%和 0.32%的 L-Arg）。日粮 GAA 呈梯度改善，最终体重、总体重增重和总增重与饲料比（G：F）均因 0.12%GAA 而增加（P < 0.05），与 PC 日粮无差异。与 NC 日粮相比，添加 0.12%GAA 可增加磷酸肌酸（PCr）、总肌酸（tCr）和糖原浓度，以及 PCr 与三磷酸腺苷（ATP）和糖原：ATP 比值（P < 0.001），甚至超过对 PC 日粮的反应。在研究 2 中，Arg 充足的起始和生长基础日粮分别添加 0（阴性对照，NC）、0.06 或 0.12%的 GAA、0.12%的一水肌酸（PC1）或三文鱼蛋白（PC2；各阶段的总 Arg 浓度与 NC 饮食相同，且含有与 PC1 相同的 Cr）。与 NC 相比，PC1 增加了总增重与饲料比（P < 0.05），但 PC2 没有，而 GAA 补充剂的反应处于 NC 和 PC1 日粮之间。然而，与 NC（Arg 充足）饮食相比，GAA 补充剂增加了 tCr 和糖原浓度，以及 PCr：ATP 和糖原：ATP 比值（P < 0.01）。总的来说，这些数据表明，GAA 可用于替代实用的 Arg 缺乏饮食中的 Arg，并改善接受 Arg 缺乏或 Arg 充足实用饮食的肉鸡肌肉的能量稳态。
