We investigated changes in rumen fermentation, peripheral blood metabolites and hormones, and hepatic transcriptomic dynamics in Holstein cows with and those without subacute ruminal acidosis (SARA) during the periparturient period. Sixteen multiparous Holstein cows were categorized in the SARA (n-=-8) or non-SARA (n-=-8) groups depending on whether they developed SARA during the 2 weeks after parturition. Reticulo-ruminal pH was measured continuously throughout the study. Rumen fluid, blood, and liver tissue samples were collected at 3 weeks prepartum and 2 and 6 weeks postpartum, with an additional blood sample collected at 0 and 4 weeks postpartum. The 1-h mean pH was depressed postpartum in both groups, whereas depression was more severe in the SARA group simultaneously with significantly longer duration of time (for pH <5.6 and 5.8). Significant expression of differentially expressed genes in liver tissue (DEGs; false discovery rate corrected P-<-0.1) were identified only in the non-SARA group, and were further analyzed by Ingenuity Pathway Analysis software. Among the top expressed DEGs, the hepatic genes encoding lipid and cholesterol secretion (APOA1, APOA4, and G0S2) and gluconeogenesis (PC, G6PC, and PCK1) were upregulated postpartum. In silico analysis revealed the significant postpartum activation of upstream regulators, such as INSR, PPARG, and PPARGC1A. These results suggested that hepatic transcriptomic responsiveness to postpartum metabolic load and hormones were likely discouraged in cows with SARA when compared to the significant activation of genes and signaling pathways for adequate metabolic adaption to postpartum high-grain diet feeding in Holstein cows without SARA.

中文翻译：

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肝脏转录组对围产期激素和代谢变化的反应取决于荷斯坦奶牛产后亚急性瘤胃酸中毒的发生

我们调查了围产期荷斯坦奶牛瘤胃发酵、外周血代谢物和激素以及肝脏转录组动力学的变化，这些奶牛有和没有亚急性瘤胃酸中毒 (SARA) 的。根据分娩后 2 周内是否出现 SARA，将 16 头经产荷斯坦奶牛分为 SARA (n-=-8) 或非 SARA (n-=-8) 组。在整个研究过程中连续测量网状瘤胃 pH 值。在产前 3 周和产后 2 和 6 周采集瘤胃液、血液和肝组织样本，并在产后 0 和 4 周采集额外的血液样本。两组产后 1 小时平均 pH 值均下降，而 SARA 组的抑郁症更严重，同时持续时间显着延长（pH <5.6 和 5.8）。仅在非 SARA 组中鉴定出肝组织中差异表达基因的显着表达（DEGs；校正错误发现率 P-<-0.1），并通过 Ingenuity Pathway Analysis 软件进一步分析。在表达最高的 DEG 中，编码脂质和胆固醇分泌（APOA1、APOA4 和 G0S2）和糖异生（PC、G6PC 和 PCK1）的肝脏基因在产后上调。计算机分析揭示了上游调节因子的显着产后激活，例如 INSR、PPARG 和 PPARGC1A。