Department of Animal and Poultry Sciences, Virginia Tech, Blacksburg, VA, 24061, USA.
Department of Animal Sciences, Purdue University, West Lafayette, IN, 47907, USA.
Sci Rep. 2022 Feb 21;12(1):2933. doi: 10.1038/s41598-022-06890-5.
Although numerous studies exist relating ruminal volatile fatty acid (VFA) concentrations to diet composition and animal performance, minimal information is available describing how VFA dynamics respond to diets within the context of the whole rumen environment. The objective of this study was to characterize how protein and fiber sources affect dry matter intake, rumen pH, fluid dynamics, fermentation parameters, and epithelial gene expression. Four diet treatments (soybean meal or heat-treated soybean meal and beet pulp or timothy hay) were delivered to 10 wethers. The soybean meals served as crude protein (CP) sources while the beet pulp and timothy hay represented neutral detergent fiber (NDF) sources. Feed intake, rumen pH, fluid pool size, and fluid passage rate were unaffected by treatment. Butyrate synthesis and absorption were greater on the beet pulp treatment whereas synthesis and absorption of other VFA remained unchanged. Both CP and NDF treatment effects were associated with numerous VFA interconversions. Expression levels of rumen epithelial genes were not altered by diet treatment. These results indicate that rumen VFA dynamics are altered by changes in dietary sources of nutrients but that intake, rumen environmental parameters, and the rumen epithelium may be less responsive to such changes.
尽管有许多研究将瘤胃挥发性脂肪酸（VFA）浓度与饮食组成和动物性能联系起来，但关于 VFA 动态如何在整个瘤胃环境的背景下对饮食做出反应的信息却很少。本研究的目的是描述蛋白质和纤维来源如何影响干物质摄入量、瘤胃 pH 值、流体动力学、发酵参数和上皮基因表达。四种日粮处理（豆粕或热处理豆粕以及甜菜浆或梯牧草）用于 10 只绵羊。豆粕作为粗蛋白（CP）来源，而甜菜浆和梯牧草代表中性洗涤纤维（NDF）来源。处理对采食量、瘤胃 pH 值、液体池大小和液体通过速率没有影响。但在甜菜浆处理中丁酸的合成和吸收增加，而其他 VFA 的合成和吸收保持不变。CP 和 NDF 处理效应均与多种 VFA 相互转化有关。瘤胃上皮基因的表达水平不受日粮处理的影响。这些结果表明，瘤胃 VFA 动力学因营养物质的饮食来源变化而改变，但采食量、瘤胃环境参数和瘤胃上皮可能对这些变化的反应较小。
