Department of Molecular Biology and Genetics, Center for Quantitative Genetics and Genomics, Aarhus University, DK-8830 Tjele, Denmark.
Department of Molecular Biology and Genetics, Center for Quantitative Genetics and Genomics, Aarhus University, DK-8830 Tjele, Denmark.
J Dairy Sci. 2020 Apr;103(4):3334-3348. doi: 10.3168/jds.2018-16057. Epub 2020 Jan 31.
Fourier transform infrared spectral analysis is a cheap and fast method to predict milk composition. A not very well studied milk component is orotic acid. Orotic acid is an intermediate in the biosynthesis pathway of pyrimidine nucleotides and is an indicator for the metabolic cattle disorder deficiency of uridine monophosphate synthase. The function of orotic acid in milk and its effect on calf health, health of humans consuming milk or milk products, manufacturing properties of milk, and its potential as an indicator trait are largely unknown. The aims of this study were to determine if milk orotic acid can be predicted from infrared milk spectra and to perform a large-scale phenotypic and genetic analysis of infrared-predicted milk orotic acid. An infrared prediction model for orotic acid was built using a training population of 292 Danish Holstein and 299 Danish Jersey cows, and a validation population of 381 Danish Holstein cows. Milk orotic acid concentration was determined with nuclear magnetic resonance spectroscopy. For genetic analysis of infrared orotic acid, 3 study populations were used: 3,210 Danish Holstein cows, 3,360 Danish Jersey cows, and 1,349 Dutch Holstein Friesian cows. Using partial least square regression, a prediction model for orotic acid was built with 18 latent variables. The error of the prediction for the infrared model varied from 1.0 to 3.2 mg/L, and the accuracy varied from 0.68 to 0.86. Heritability of infrared orotic acid predicted with the standardized prediction model was 0.18 for Danish Holstein, 0.09 for Danish Jersey, and 0.37 for Dutch Holstein Friesian. We conclude that milk orotic acid can be predicted with moderate to good accuracy based on infrared milk spectra and that infrared-predicted orotic acid is heritable. The availability of a cheap and fast method to predict milk orotic acid opens up possibilities to study the largely unknown functions of milk orotic acid.
傅里叶变换红外光谱分析是一种廉价且快速的预测牛奶成分的方法。一种研究不太充分的牛奶成分是乳清酸。乳清酸是嘧啶核苷酸生物合成途径的中间产物，是尿苷一磷酸合酶代谢牛缺乏的指标。乳清酸在牛奶中的功能及其对犊牛健康、食用牛奶或奶制品的人类健康、牛奶的加工特性以及作为指示性状的潜力在很大程度上尚不清楚。本研究的目的是确定是否可以从红外牛奶光谱中预测乳清酸，并对红外预测乳清酸进行大规模的表型和遗传分析。使用 292 头丹麦荷斯坦奶牛和 299 头丹麦泽西奶牛的训练群体以及 381 头丹麦荷斯坦奶牛的验证群体建立了乳清酸的红外预测模型。使用核磁共振光谱法测定乳清酸浓度。为了对红外乳清酸进行遗传分析，使用了 3 个研究群体：3210 头丹麦荷斯坦奶牛、3360 头丹麦泽西奶牛和 1349 头荷兰荷斯坦弗里斯兰奶牛。使用偏最小二乘回归，建立了 18 个潜在变量的乳清酸预测模型。红外模型的预测误差在 1.0 到 3.2 毫克/升之间，准确性在 0.68 到 0.86 之间。用标准化预测模型预测的丹麦荷斯坦红外乳清酸的遗传力为 0.18，丹麦泽西为 0.09，荷兰荷斯坦弗里斯兰为 0.37。我们得出结论，基于牛奶的红外光谱，可以以中等至良好的精度预测乳清酸，并且可以遗传预测的红外乳清酸。一种廉价且快速的预测牛奶乳清酸的方法的可用性为研究乳清酸的大部分未知功能开辟了可能性。
