Table_2_Differences of serum glucose and lipid metabolism and immune parameters and blood metabolomics regarding the transition cows in the antepartum and postpartum period.docx

This study aims to investigate differences in metabolism regarding the transition cows. Eight cows were selected for the test. Serum was collected on antepartum days 14th (ap14) and 7th (ap7) and postpartum days 1st (pp1), 7th (pp7), and 14th (pp14) to detect biochemical parameters. The experiment screened out differential metabolites in the antepartum (ap) and postpartum (pp) periods and combined with metabolic pathway analysis to study the relationship and role between metabolites and metabolic abnormalities. Results: (1) The glucose (Glu) levels in ap7 were significantly higher than the other groups (p < 0.01). The insulin (Ins) levels of ap7 were significantly higher than pp7 (p = 0.028) and pp14 (p < 0.01), and pp1 was also significantly higher than pp14 (p = 0.016). The insulin resistance (HOMA-IR) levels of ap7 were significantly higher than ap14, pp7, and pp14 (p < 0.01). The cholestenone (CHO) levels of ap14 and pp14 were significantly higher than pp1 (p < 0.01). The CHO levels of pp14 were significantly higher than pp7 (p < 0.01). The high density lipoprotein cholesterol (DHDL) levels of pp1 were significantly lower than ap14 (p = 0.04), pp7 (p < 0.01), and pp14 (p < 0.01), and pp14 was also significantly higher than ap14 and ap7 (p < 0.01). (2) The interferon-gamma (IFN-γ) and tumor necrosis factor α (TNF-α) levels of ap7 were significantly higher than pp1 and pp7 (p < 0.01); the immunoglobulin A (IgA) levels of pp1 were significantly higher than ap7 and pp7 (p < 0.01); the interleukin-4 (IL-4) levels of pp7 were significantly higher than ap7 and pp1 (p < 0.01), the interleukin-6 (IL-6) levels of ap7 and pp1 were significantly higher than pp7 (p < 0.01). (3) Metabolomics identified differential metabolites mainly involved in metabolic pathways, such as tryptophan metabolism, alpha-linolenic acid metabolism, tyrosine metabolism, and lysine degradation. The main relevant metabolism was concentrated in lipid and lipid-like molecules, organic heterocyclic compounds, organic acids, and their derivatives. The results displayed the metabolic changes in the transition period, which laid a foundation for further exploring the mechanism of metabolic abnormalities in dairy cows in the transition period.

本研究旨在探究围产期奶牛的代谢差异。本试验选取8头奶牛作为受试对象。分别于产前14天（ap14）、产前7天（ap7）以及产后1天（pp1）、产后7天（pp7）、产后14天（pp14）采集血清以检测生化指标。本实验筛选出产前（ap）与产后（pp）时期的差异代谢物，并结合代谢通路分析，探究代谢物与代谢异常之间的关联及作用机制。结果如下：(1) 产前7天（ap7）组的葡萄糖（Glu）水平显著高于其余各组（p<0.01）。ap7组的胰岛素（Ins）水平显著高于产后7天（pp7）组（p=0.028）与产后14天（pp14）组（p<0.01），且产后1天（pp1）组的胰岛素水平亦显著高于pp14组（p=0.016）。ap7组的胰岛素抵抗指数（HOMA-IR）显著高于产前14天（ap14）、pp7及pp14组（p<0.01）。产前14天（ap14）与产后14天（pp14）组的胆甾酮（CHO）水平显著高于pp1组（p<0.01）；pp14组的CHO水平亦显著高于pp7组（p<0.01）。pp1组的高密度脂蛋白胆固醇（DHDL）水平显著低于ap14组（p=0.04）、pp7组（p<0.01）及pp14组（p<0.01），且pp14组的DHDL水平显著高于ap14与ap7组（p<0.01）。(2) ap7组的γ-干扰素（IFN-γ）与肿瘤坏死因子α（TNF-α）水平显著高于pp1组与pp7组（p<0.01）；pp1组的免疫球蛋白A（IgA）水平显著高于ap7组与pp7组（p<0.01）；pp7组的白细胞介素-4（IL-4）水平显著高于ap7组与pp1组（p<0.01）；ap7组与pp1组的白细胞介素-6（IL-6）水平显著高于pp7组（p<0.01）。(3) 代谢组学鉴定得到的差异代谢物主要参与色氨酸代谢、α-亚麻酸代谢、酪氨酸代谢及赖氨酸降解等代谢通路。相关核心代谢物主要集中于脂质及类脂质分子、有机杂环化合物、有机酸及其衍生物类。本研究结果揭示了围产期奶牛的代谢变化规律，为进一步探究围产期奶牛代谢异常的发生机制奠定了坚实的研究基础。