Wang Xiaodan, Jahagirdar Sanjeevan, Bakker Wouter, Lute Carolien, Kemp Bas, Knegsel Ariette van, Saccenti Edoardo
Adaptation Physiology Group, Department of Animal Sciences, Wageningen University & Research, 6700 AH Wageningen, The Netherlands.
Laboratory of Systems and Synthetic Biology, Wageningen University & Research, 6700 EJ Wageningen, The Netherlands.
Metabolites. 2024 Apr 17;14(4):230. doi: 10.3390/metabo14040230.
During early lactation, dairy cows have a negative energy balance since their energy demands exceed their energy intake: in this study, we aimed to investigate the association between diet and plasma metabolomics profiles and how these relate to energy unbalance of course in the early-lactation stage. Holstein-Friesian cows were randomly assigned to a glucogenic ( = 15) or lipogenic ( = 15) diet in early lactation. Blood was collected in week 2 and week 4 after calving. Plasma metabolite profiles were detected using liquid chromatography-mass spectrometry (LC-MS), and a total of 39 metabolites were identified. Two plasma metabolomic profiles were available every week for each cow. Metabolite abundance and metabolite ratios were used for the analysis using the XGboost algorithm to discriminate between diet treatment and lactation week. Using metabolite ratios resulted in better discrimination performance compared with the metabolite abundances in assigning cows to a lipogenic diet or a glucogenic diet. The quality of the discrimination of performance of lipogenic diet and glucogenic diet effects improved from 0.606 to 0.753 and from 0.696 to 0.842 in week 2 and week 4 (as measured by area under the curve, AUC), when the metabolite abundance ratios were used instead of abundances. The top discriminating ratios for diet were the ratio of arginine to tyrosine and the ratio of aspartic acid to valine in week 2 and week 4, respectively. For cows fed the lipogenic diet, choline and the ratio of creatinine to tryptophan were top features to discriminate cows in week 2 vs. week 4. For cows fed the glucogenic diet, methionine and the ratio of 4-hydroxyproline to choline were top features to discriminate dietary effects in week 2 or week 4. This study shows the added value of using metabolite abundance ratios to discriminate between lipogenic and glucogenic diet and lactation weeks in early-lactation cows when using metabolomics data. The application of this research will help to accurately regulate the nutrition of lactating dairy cows and promote sustainable agricultural development.
在泌乳早期，奶牛处于能量负平衡状态，因为它们的能量需求超过了能量摄入：在本研究中，我们旨在调查日粮与血浆代谢组学图谱之间的关联，以及这些关联如何与泌乳早期阶段的能量失衡相关。荷斯坦 - 弗里生奶牛在泌乳早期被随机分配到生糖日粮组（n = 15）或生脂日粮组（n = 15）。在产犊后第2周和第4周采集血液。使用液相色谱 - 质谱联用仪（LC - MS）检测血浆代谢物谱，共鉴定出39种代谢物。每头奶牛每周有两份血浆代谢组学图谱。使用XGBoost算法，将代谢物丰度和代谢物比率用于分析，以区分日粮处理和泌乳周。与代谢物丰度相比，使用代谢物比率在将奶牛分配到生脂日粮或生糖日粮时具有更好的区分性能。当使用代谢物丰度比率而非丰度时，生脂日粮和生糖日粮效应的区分性能质量在第2周和第4周分别从0.606提高到0.753以及从0.696提高到0.842（通过曲线下面积，AUC衡量）。日粮的顶级区分比率在第2周和第4周分别是精氨酸与酪氨酸的比率以及天冬氨酸与缬氨酸的比率。对于饲喂生脂日粮的奶牛，胆碱以及肌酐与色氨酸的比率是区分第2周和第4周奶牛的顶级特征。对于饲喂生糖日粮的奶牛，蛋氨酸以及4 - 羟基脯氨酸与胆碱的比率是区分第2周或第4周日粮效应的顶级特征。本研究表明，在使用代谢组学数据时，利用代谢物丰度比率区分泌乳早期奶牛的生脂和生糖日粮以及泌乳周具有附加价值。本研究的应用将有助于准确调节泌乳奶牛的营养，促进农业可持续发展。
