基于代谢组学和高通量测序解析硫胺素缓解亚急性瘤胃酸中毒的机制研究

Against the actual problem of subacute rumen acidosis (SARA) frequently occur under the feeding model of high concentrate and low-quality forage in China, as well as the scientific question of the effectiveness and mechanism of thiamine on SARA, the high producing dairy cows with rumen fistula are systematically studied by the technology of metabolomics, high-throughout gene sequencing and Western blot. The following sections are researched: (1) Effects of thiamine supplement levels on lactation performance and the appropriate thiamine supplemental level; (2) Changes of rumen microbial community under SARA and thiamine supplement revealed by high-throughout gene sequencing, and to explicit which microorganism are high related to SARA and thiamine metabolism; (3) The action sites of thiamine in SARA relief and metabolic pathway and regulatory network will be constructed by systematically analyze metabolite of microorganism using metabolomics; (4) The function of thiamine on rumen epithelium function under SARA. Our research findings are believed to reveal the mechanism of thiamine in relieving SARA and enrich the theory of SARA as well as to provide theoretic reference and technical support for prevention and regulation of SARA in ruminant production.

针对当前我国低质饲草加高精料的饲喂模式易诱发奶牛瘤胃酸中毒的实际生产问题，探讨硫胺素缓解亚急性瘤胃酸中毒(SARA)的作用效果及机制这一科学问题，采用代谢组学、高通量测序及Western blot 技术，以易发瘤胃酸中毒的高产荷斯坦奶牛为研究对象，重点研究：(1)不同硫胺素添加量对奶牛泌乳性能的影响，揭示硫胺素的适宜添加量；(2)高通量测序探测SARA及添加硫胺素对微生物区系的影响，明确与SARA和硫胺素代谢相关的微生物种类；(3)利用代谢组学技术分析微生物代谢产物的整体变化，揭示硫胺素调控SARA的作用位点，构建硫胺素代谢调控网络；(4)分析SARA状态下及添加硫胺素对瘤胃上皮组织功能的影响。预期研究结果将从瘤胃微生物构成及其代谢产物的整体变化以及动物机体的应答机制揭示硫胺素缓解亚急性瘤胃酸中毒的作用机制，丰富亚急性瘤胃酸中毒理论，为生产中有效预防和调控SARA提供理论依据和技术指导。

研究针对当前我国低质饲草加高精料的饲喂模式易诱发奶牛瘤胃酸中毒的实际生产问题，探讨硫胺素缓解亚急性瘤胃酸中毒（SARA）的作用效果及机制，研究采用代谢组学、高通量测序、qRT-PCR及western blot技术，以易发瘤胃酸中毒的高产荷斯坦奶牛为研究对象，通过高精料日粮饲喂构建SARA模型，从而确定不同硫胺素添加量对奶牛泌乳性能的影响，添加硫胺素对微生物区系的影响，揭示硫胺素调控SARA的作用位点，并构建硫胺素代谢调控网络。研究表明，高精料饲喂抑制THTR2和MTPPT的表达，进而影响硫胺素的吸收转运，硫胺素可缓解高谷物饲喂条件下的瘤胃上皮炎症反应，其保护作用主要归因于抑制TLR4介导的NF-κB途径。此外，硫胺素添加可调控瘤胃液菌群结构，促进纤维的降解。硫胺素添加物缓解高精料诱导的瘤胃代谢物变化，促进丙酮酸转为乙酸并抑制乳酸的生成而改善瘤胃发酵。硫胺素添加可通过调控瘤胃真菌菌群结构改善瘤胃内环境。硫胺素提高了瘤胃pH，提高了氨利用菌丰度，降低了奇古菌门丰度，降低了瘤胃氨氮的浓度，从而减少N的损失。研究系统阐明了高精料饲喂诱发硫胺素缺乏的判断标准及相关机制，以及硫胺素在提高产奶量及缓解亚急性瘤胃酸中毒的作用途径及机制。并对未来如何制定奶牛硫胺素需要量以及硫胺素对其他营养物质的代谢量的调控作用做出展望。