Descriptive statistics of plasma AA concentrations (µmol/L) of calves fed a milk replacer supplemented with different AA combinations

The effects on growth performance of supplementation of four different AA combinations in a milk replacer (MR, 25.4% CP and 20.3% fat) based on skimmed milk powder and whey protein concentrate were evaluated in 76 Holstein male calves (3 ± 1.7 d old). The 4 MR were: CTRL with no AA supplementation; PG supplying additional 0.3% Pro and 0.1% Gly; FY supplying additional 0.2% Phe and 0.2% Tyr; KMT providing additional 0.62% Lys, 0.22% Met, and 0.61% Thr. All calves were fed the same milk allowance program and were weaned at 56 d of study. Concentrate intake was limited to minimize interference of potential differences in solid feed intake among treatments. Animals were weighed weekly, intakes recorded daily, and blood samples obtained at 2, 5, and 7 wk of study to determine serum urea and plasma AA concentrations. The file presents data of the backwards selection process to assess the model that fitted better ADG with the study variables (performance, intake, plasma AA balances). Data was collected at Torre Marimon IRTA calf facilities (Caldes de Montbui, Spain) during 2017.

本研究以76头3±1.7日龄的荷斯坦公犊牛为试验对象，评估了以脱脂奶粉与浓缩乳清蛋白为原料的代乳粉（milk replacer, MR，粗蛋白（crude protein, CP）25.4%、粗脂肪20.3%）中添加四种不同氨基酸组合对其生长性能的影响。四种试验代乳粉处理方案如下：对照组（CTRL）不添加外源氨基酸；PG组额外添加0.3%脯氨酸（Proline, Pro）与0.1%甘氨酸（Glycine, Gly）；FY组额外添加0.2%苯丙氨酸（Phenylalanine, Phe）与0.2%酪氨酸（Tyrosine, Tyr）；KMT组额外添加0.62%赖氨酸（Lysine, Lys）、0.22%蛋氨酸（Methionine, Met）与0.61%苏氨酸（Threonine, Thr）。所有犊牛均采用统一的奶量饲喂规程，并于试验第56天实施断奶。为最小化不同处理组间固体饲料采食量差异可能造成的试验干扰，精料摄入量受到严格限制。试验期间每周对犊牛进行体重称量，每日记录采食量，并于试验第2、5、7周采集血样，用于测定血清尿素氮与血浆氨基酸浓度。本数据集包含基于试验变量（生长性能、采食量、血浆氨基酸平衡）筛选最优平均日增重（average daily gain, ADG）拟合模型的向后逐步选择过程数据。试验于2017年在西班牙卡尔德斯德蒙特布伊（Caldes de Montbui）的Torre Marimon IRTA犊牛养殖设施中完成。