School of Environmental and Rural Science, University of New England, Armidale, New South Wales 2351, Australia.
Feedworks Pty Ltd, Romsey, Victoria 3434, Australia.
Poult Sci. 2022 Apr;101(4):101692. doi: 10.1016/j.psj.2021.101692. Epub 2021 Dec 30.
Guanidinoacetic acid (GAA) is the direct precursor of creatine and can spare arginine (Arg) for creatine synthesis in low crude protein (CP) broiler diets. This study aimed to determine the extent GAA could spare Arg in broilers offered low CP diets and if supplemental betaine provides additional benefits. Seven hundred twenty-day-old Ross 308 male broilers were assigned into 9 dietary treatments with 8 replicates of 10 birds each. The treatments were; normal CP diet, a low CP (-15 g/kg) diet deficient in Arg, a low CP diet sufficient in Arg, and low CP diets with GAA, where 0.1% added L-Arg was spared by GAA at 50, 100, and 150% with and without 0.1% betaine. The treatments were offered during grower (d 10-24) and finisher (d 25-42) phases. The birds offered a low CP Arg deficient diet had 7.8% lower weight gain, 10 points higher FCR, 8.5% lower breast meat yield, 27.2% lower breast meat creatine concentration and 30.4% more abdominal fat pad compared to those offered a normal CP diet. When Arg was added back to the Arg deficient diet, growth performance, breast meat yield and creatine concentration loss were restored. When GAA spared Arg at 150%, feed intake, weight gain, FCR, breast and abdominal fat yields, breast meat moisture, drip loss, and breast meat creatine concentration became comparable to Arg sufficient low CP and normal CP treatments. When GAA spared Arg at 100 and 50%, FCR was 3 and 5 points lower than the normal CP treatment. Breast meat creatine concentration was positively correlated to feed efficiency (r = 0.70, P < 0.001) and breast meat moisture (r = 0.33, P < 0.01), and negatively correlated to relative weight of abdominal fat (r = -0.37, P < 0.01) and breast meat pH (r = -0.49, P < 0.001). There were no benefits of adding betaine with GAA on the parameters measured but the results with GAA were consistent in the presence or absence of betaine.
胍基乙酸（GAA）是肌酸的直接前体，可在低粗蛋白（CP）肉鸡日粮中节省精氨酸（Arg）用于肌酸合成。本研究旨在确定 GAA 在提供低 CP 日粮的肉鸡中可节省 Arg 的程度，以及补充甜菜碱是否提供额外的益处。720 日龄 Ross 308 雄性肉鸡被分配到 9 种饲粮处理中，每个处理有 8 个重复，每个重复有 10 只鸡。处理包括：正常 CP 日粮、低 CP（-15g/kg）日粮缺乏 Arg、低 CP 日粮 Arg 充足和低 CP 日粮加 GAA，其中 0.1%添加 L-Arg 由 50、100 和 150%的 GAA 替代，添加或不添加 0.1%甜菜碱。处理在生长期（d 10-24）和育肥期（d 25-42）提供。与提供正常 CP 日粮的肉鸡相比，提供低 CP Arg 缺乏日粮的肉鸡体重增重降低 7.8%，FCR 高 10 点，胸肉产量降低 8.5%，胸肉肌酸浓度降低 27.2%，腹部脂肪垫增加 30.4%。当 Arg 被添加回 Arg 缺乏日粮时，生长性能、胸肉产量和肌酸浓度损失得到恢复。当 GAA 替代 150%的 Arg 时，采食量、体重增重、FCR、胸腹部脂肪产量、胸肉水分、滴水损失和胸肉肌酸浓度与 Arg 充足的低 CP 和正常 CP 处理相当。当 GAA 替代 100%和 50%的 Arg 时，FCR 比正常 CP 处理低 3 点和 5 点。胸肉肌酸浓度与饲料效率（r=0.70，P<0.001）和胸肉水分（r=0.33，P<0.01）呈正相关，与腹部脂肪相对重量（r=-0.37，P<0.01）和胸肉 pH（r=-0.49，P<0.001）呈负相关。添加甜菜碱与 GAA 联合使用对所测参数没有益处，但在存在或不存在甜菜碱的情况下，GAA 的结果是一致的。
