Manipulation of perinatal diets, such as supplementing feed with rumen-protected glucose (RPG), has been positively regarded as a strategy to improve milking performance. This study was conducted to assess the effects of RPG on the fermentation profiles, resident microbiota and mucosal immunity in the cecum. Ten Holstein dairy cows were randomly assigned to either a 25 g/kg RPG diet (DM basis) or a 11 g/kg coating fat diet (control, CON). Compared with the CON group, the acetate-to-propionate ratio was lower in the RPG group. Gene expression analysis indicated that RPG supplementation tended to upregulate the expression of Na⁺/H⁺ hydrogen exchanger 3 (NHE3) (P = 0.076). RPG supplementation downregulated the expression of genes involved in self-rehabilitation such as matrix metalloproteinase 1 (MMP1), MMP3, MMP9 and MMP13. Additionally, the mRNA expression of genes involved in immunity including Toll-like receptors (TLR4, TLR6 and TLR7) and proinflammatory cytokines (immune interferon gamma [IFNG] and interleukins interleukin 17A [IL17F], IL17A, IL22), was downregulated by RPG supplementation. Nonetheless, no differences existed in the bacterial copy number and beta diversity between the 2 groups. Overall, supplementation with RPG would probably cause a shift towards propionate production in the cecal digesta, and promote the immune homeostasis of the cecal mucosa in transition dairy cows. Our results extended the basic understanding of RPG supplementation and utilization in transition dairy cows in terms of host microbe interplay in the cecum.

控制围产期日粮，例如在饲料中添加瘤胃保护葡萄糖 (RPG)，已被积极视为提高挤奶性能的策略。本研究旨在评估 RPG 对盲肠中发酵曲线、常驻微生物群和粘膜免疫的影响。10 头荷斯坦奶牛被随机分配到 25 g/kg RPG 日粮（DM 基础）或 11 g/kg 涂层脂肪日粮（对照，CON）。与 CON 组相比，RPG 组的醋酸盐/丙酸盐比率较低。基因表达分析表明，补充RPG倾向于上调Na ⁺ /H ⁺氢交换剂3 ( NHE3 ) ( P = 0.076）。RPG 补充剂下调了参与自我康复的基因的表达，例如基质金属蛋白酶 1 ( MMP1 )、MMP3、MMP9和MMP13。此外，免疫相关基因的 mRNA 表达，包括 Toll 样受体（TLR4、TLR6和TLR7）和促炎细胞因子（免疫干扰素 γ [ IFNG ] 和白细胞介素 17A [ IL17F ]、IL17A、IL22）)，被 RPG 补充下调。尽管如此，两组之间的细菌拷贝数和β多样性不存在差异。总体而言，补充 RPG 可能会导致盲肠食糜产生丙酸，并促进过渡奶牛盲肠粘膜的免疫稳态。我们的研究结果扩展了对过渡期奶牛 RPG 补充和利用的基本理解，即盲肠中宿主微生物的相互作用。