Department of Animal Sciences, University of Illinois, Urbana-Champaign 61801.
Department of Animal Sciences, University of Illinois, Urbana-Champaign 61801.
J Dairy Sci. 2022 Oct;105(10):8069-8086. doi: 10.3168/jds.2021-21669. Epub 2022 Aug 24.
We determined the effect of prepartum plane of energy intake on liver function and metabolism pre- and postpartum by combining in vivo and in vitro data with mRNA expression data. A subset of multiparous prepartal Holsteins (n = 18) from a previously conducted experiment consumed 1 of 3 amounts of dietary energy intake, relative to their requirements. A diet formulated to allow consumption of ≥150% of net energy requirements during the far-off dry period and the close-up dry period was fed for ad libitum intake (150E) or in restricted amounts so that cows consumed 80% of requirements for energy (80E). A second diet was formulated to include wheat straw (26.1% of dry matter) to limit energy intake to 100% of NRC (2001) requirements for energy when fed ad libitum during the far-off period (100E). In the close-up period, 100E was fed the 150E diet for ad libitum intake. Expression of mRNA for genes related to fatty acid oxidation (PPARA, CPT1A, ACOX1) was greater for 100E cows than 150E cows on d 14 postpartum. These expression patterns were related to in vitro data for conversion of palmitate to CO, acid-soluble products, and esterified products by liver slices. Abundance of mRNA for PC displayed a sharp peak for all groups on d 1 postpartum, but serum glucose did not reflect this peak. The mRNA expression of SREBF1 was greater for 150E and 100E cows prepartum compared with 80E, and was positively related to rate of palmitate esterification postpartum. Expression of NR1H3 (LXRA) mRNA was greater for 100E cows on d 14 postpartum compared with 150E cows, which corresponded to expression of PPARA. An inflammatory response occurred in the liver around the time of parturition for 150E cows, as expression of IL1B was elevated both pre- and postpartum compared with 100E cows. The spike in IL1B expression for 150E cows on d 14 postpartum corresponded to the peak concentration of total lipids in liver tissue for all groups in this experiment. Overconsumption of energy prepartum was detrimental to the expression of important genes related to PPAR and liver function, especially postpartum. Furthermore, results provide evidence for inflammation related to accumulation of lipids in liver and overnutrition prepartum.
我们通过结合体内和体外数据以及 mRNA 表达数据，确定了产前能量摄入水平对产后肝功能和代谢的影响。从先前进行的一项实验中选择了一部分经产荷斯坦奶牛（n=18），它们在远干期和近干期分别摄入了 3 种不同量的日粮能量，相对于其需求。远干期和近干期饲喂的日粮配方允许奶牛消耗≥150%的净能需要量，以供自由采食（150E）或限量摄入，使奶牛消耗 80%的能量需要量（80E）。第二种日粮配方包含小麦秸秆（干物质的 26.1%），当在远干期自由采食时，能量摄入量限制在 NRC（2001）能量需要量的 100%（100E）。在近干期，100E 饲喂 150E 日粮供自由采食。产后第 14 天，100E 奶牛的脂肪酸氧化（PPARA、CPT1A、ACOX1）相关基因的 mRNA 表达高于 150E 奶牛。这些表达模式与肝脏切片将棕榈酸转化为 CO、可溶酸产物和酯化产物的体外数据有关。所有组在产后第 1 天，PC 的 mRNA 丰度都出现了一个急剧的峰值，但血清葡萄糖并没有反映出这一峰值。产前，150E 和 100E 奶牛的 SREBF1mRNA 表达高于 80E，并且与产后棕榈酸酯化率呈正相关。100E 奶牛产后第 14 天的 NR1H3（LXRA）mRNA 表达高于 150E 奶牛，与 PPARA 的表达相对应。150E 奶牛在分娩前后发生了肝内炎症反应，因为与 100E 奶牛相比，IL1B 的表达在产前和产后均升高。150E 奶牛产后第 14 天 IL1B 表达的飙升与该实验中所有组肝脏组织中总脂质浓度的峰值相对应。产前过度摄食能量不利于与 PPAR 和肝功能相关的重要基因的表达，特别是产后。此外，结果为与产前脂质积累和过度营养相关的肝脏炎症提供了证据。
