Na Sang Weon, Guan Le Luo
Department of Agricultural, Food & Nutritional Science, University of Alberta, Edmonton, Alberta, Canada.
Anim Nutr. 2022 Apr 16;10:41-53. doi: 10.1016/j.aninu.2022.04.002. eCollection 2022 Sep.
Feed efficiency is one of the economically important traits for the cattle industry that affects profit (feed costs) and the environment (production of manure and methane). Due to that feed efficiency is driven by multi-factors, mechanisms contributing to the animal to animal variation in this trait have not been well defined, limiting the development of precision feeding strategies to improve the herd production efficiency. Rumen microbial fermentation and volatile fatty acids (VFA) production have been recently reported to be associated with cattle feed efficiency, however the roles of rumen epithelial function in feed efficiency are less studied although the rumen epithelium has an important function in VFA absorption and metabolism which can affect host feed efficiency. Rumen epithelium is colonized with a diverse microbial population, termed epimural microbiota, which has proposed functions in tissue development, barrier and inflammation, urea transport, and oxygen scavenging, suggesting that they can affect rumen epithelial functions and subsequently cattle feed efficiency. Especially, prospective functions of epimural microbiota, enhanced rumen immunity and increased rumen epithelial thickness, might contribute to less nutritional requirement for tissue recuperation. Thus, the understanding of the functions of rumen epithelium, epimural microbiota, and rumen epithelial host-microbe interactions is essential to identify their roles in contributing to feed efficiency. In this review, we will focus on to date research findings on the structure of rumen epithelium, epimural microbiota, and epithelial host-microbe interactions together with their functions and how these are associated with feed efficiency, aiming to provide insights on future directions to study rumen epithelial host-microbe interactions and improve the rumen functions in cattle.
饲料效率是养牛业中一个具有重要经济意义的性状，它会影响利润（饲料成本）和环境（粪便及甲烷排放）。由于饲料效率受多种因素驱动，导致该性状在个体间存在差异的机制尚未明确，这限制了精准饲养策略的发展，不利于提高牛群的生产效率。最近有报道称瘤胃微生物发酵和挥发性脂肪酸（VFA）生成与牛的饲料效率相关，然而瘤胃上皮功能在饲料效率方面的作用却鲜少被研究，尽管瘤胃上皮在VFA吸收和代谢中具有重要功能，而这会影响宿主的饲料效率。瘤胃上皮定植着多种微生物群体，称为壁周微生物群，它们在组织发育、屏障与炎症、尿素转运及氧气清除等方面具有潜在功能，这表明它们可能会影响瘤胃上皮功能，进而影响牛的饲料效率。特别是，壁周微生物群的潜在功能，如增强瘤胃免疫力和增加瘤胃上皮厚度，可能有助于减少组织修复所需的营养。因此，了解瘤胃上皮、壁周微生物群的功能以及瘤胃上皮宿主与微生物之间的相互作用，对于确定它们在饲料效率方面的作用至关重要。在这篇综述中，我们将聚焦于目前关于瘤胃上皮结构、壁周微生物群以及上皮宿主与微生物相互作用的研究结果，以及它们的功能，以及这些与饲料效率的关联，旨在为未来研究瘤胃上皮宿主与微生物相互作用及改善牛的瘤胃功能提供方向。
