In a previous experiment, male Ross 308 broiler chickens were offered dietary treatments with 3 levels of crude protein (222, 193, 165 g/kg) and 3 feed grains (ground maize, ground wheat, whole wheat) from 7 to 35 d post–hatch. Maize-based diets supported superior growth performance in comparison to wheat-based diets. Uric acid concentrations in excreta were retrospectively determined and related to total nitrogen (N) excreta concentrations. Uric acid concentrations ranged from 28.5 to 69.4 mg/g and proportions of uric acid-N to total excreta-N ranged from 27.4% to 42.6% in broiler chickens offered the 3 × 3 factorial array of dietary treatments. Proportions of uric acid-N to total N in excreta in birds offered the 165 g/kg CP, maize-based diet were significantly lower by 10.6 percentage units (27.4% versus 38.0%; P = 0.00057) than their wheat-based counterparts. Total excreta analysed had been collected from 35 to 37 d post–hatch when feed intakes and excreta outputs were monitored. There were linear relationships between proportions of uric acid-N to total N in excreta in birds offered the three 165 g/kg CP diets with weight gain (r = −0.587; P = 0.010), feed intake (r = −0.526; P = 0.025) and feed conversion ratios (r = 0.635; P = 0.005). The possibility that increasing uric acid-N proportions in excreta is indicative of excessive ammonia accumulations compromising growth performance is discussed. The mean proportion of dietary glycine involved in uric acid excretion was 49.2% across all dietary treatments but ranged from 25.0% to 80.9%. Thus, the appropriate amount of dietary glycine is variable and largely dependent on the volume of uric acid synthesised and excreted.

在之前的实验中，雄性 Ross 308 肉鸡在产后 7 至 35 天期间接受了 3 种水平的粗蛋白（222、193、165 g/kg）和 3 种饲料谷物（磨碎的玉米、磨碎的小麦、全麦）的饮食治疗。 -孵化。与以小麦为主的日粮相比，以玉米为主的日粮具有优异的生长性能。回顾性测定排泄物中的尿酸浓度，并将其与总氮 (N) 排泄物浓度相关。在提供 3 × 3 因子阵列的日粮处理中，肉鸡的尿酸浓度范围为 28.5 至 69.4 mg/g，尿酸-N 与总排泄物-N 的比例范围为 27.4% 至 42.6%。提供 165 g/kg CP 的玉米饲料的禽类排泄物中尿酸氮占总氮的比例比小麦饲料显着降低 10.6 个百分点（27.4% 对比 38.0%； P = 0.00057）。孵化后 35 至 37 天期间收集了分析的总排泄物，当时监测了饲料摄入量和排泄物排出量。三种 165 g/kg CP 日粮的禽类排泄物中尿酸氮与总氮的比例与体重增加 ( r = -0.587; P = 0.010)、采食量 ( r = -0.526; P)之间存在线性关系。 = 0.025）和饲料转化率（ r = 0.635； P = 0.005）。讨论了排泄物中尿酸-氮比例增加表明氨积累过多而损害生长性能的可能性。在所有饮食治疗中，参与尿酸排泄的膳食甘氨酸的平均比例为 49.2%，但范围为 25.0% 至 80.9%。 因此，膳食甘氨酸的适当量是可变的，并且很大程度上取决于合成和排泄的尿酸的量。