Zhang Ling, Xia Zhenhua, Fu Jicheng, Yang You
College of Animal Science and Technology, Southwest University, Chongqing 400715, China.
College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, China.
Int J Mol Sci. 2025 Mar 13;26(6):2573. doi: 10.3390/ijms26062573.
Increasing the proportion of concentrate in diets can effectively improve ruminant production, and is therefore widely used. However, high-concentrate diets (HCD) enriched with rapidly fermentable carbohydrates can accelerate the production of lactate and short-chain fatty acids (SCFAs). The accumulation of lactate and SCFAs in the rumen leads to a reduction in rumen fluid pH, potentially resulting in subacute rumen acidosis (SARA), which can decrease dry matter intake (DMI), induce local and systemic inflammation, and cause other negative impacts on the host. The substantial prevalence of SARA attributable to long-term HCD causes considerable economic losses, as it can decrease DMI by up to 20%. Understanding its mechanisms and pathogenesis is essential. The rumen epithelium (RE), which is in direct contact with rumen fluid, is an important tissue in the rumen due to its roles in absorption, transport, and barrier functions. The changes that occur in RE under HCD and the subsequent impacts of these changes are worth exploring. In the short term, HCD feeding promotes RE cell proliferation and upregulates the activity of various transporter proteins, enhancing RE absorption and metabolism. However, with prolonged feeding, these functions of RE are negatively affected, accompanied by the development of inflammation. This review elucidates the structure, the functions, and the responses of RE under HCD, providing a detailed analysis of SARA pathogenesis at the cellular and molecular levels.
提高日粮中精饲料的比例可有效提高反刍动物的生产性能，因此被广泛应用。然而，富含快速发酵碳水化合物的高精饲料日粮（HCD）会加速乳酸和短链脂肪酸（SCFA）的产生。瘤胃中乳酸和SCFA的积累会导致瘤胃液pH值降低，可能引发亚急性瘤胃酸中毒（SARA），进而降低干物质采食量（DMI），诱发局部和全身炎症，并对宿主造成其他负面影响。长期HCD导致的SARA大量流行造成了相当大的经济损失，因为它可使DMI降低多达20%。了解其机制和发病机理至关重要。瘤胃上皮（RE）与瘤胃液直接接触，因其在吸收、转运和屏障功能方面的作用，是瘤胃中的重要组织。HCD条件下RE发生的变化以及这些变化随后产生的影响值得探究。短期内，HCD饲喂可促进RE细胞增殖并上调各种转运蛋白的活性，增强RE的吸收和代谢。然而，随着饲喂时间延长，RE的这些功能会受到负面影响，并伴有炎症的发展。本综述阐明了HCD条件下RE的结构、功能及反应，在细胞和分子水平上对SARA发病机理进行了详细分析。
