Xie X, Wang J K, Liu J X, Guan L L, Neves A L A
School of Marine Sciences, Ningbo University, 315832, Ningbo, People's Republic of China.
Institute of Dairy Science, College of Animal Sciences, Zhejiang University, 310058, Hangzhou, People's Republic of China.
Anim Microbiome. 2025 May 12;7(1):46. doi: 10.1186/s42523-025-00407-x.
The rumen is one of the four compartments of the ruminant stomach and houses a diverse array of anaerobic microbes that play a crucial role in feed digestion and volatile fatty acid (VFA) production. The aim of this study was to explore how two different in vivo rumen environmental conditions, AHR (created from sheep-fed alfalfa hay) and CSR (created from sheep-fed corn stover), affect fiber digestion and rumen bacterial colonization in relation to two types of forage, alfalfa hay (AH) and corn stover (CS). Both AH and CS forages were subjected to in-sacco incubation in AHR and CSR conditions for a period of 48 h. The results revealed that CSR exhibited a less variant pH, lower total VFA concentration, and higher acetate-to-propionate ratio than AHR. CSR significantly enhanced the degradation of neutral detergent fiber and acid detergent fiber in both incubated forages (AH and CS). Although CSR did not improve the degradation of dry matter (DM) or crude protein (CP) on AH, it improved the degradation of DM and CP on CS. Both CS and AH incubated under CSR were found to have a greater abundance of fibrolytic bacteria (e.g., Fibrobacter and Butyrivibrio 2) compared to the same forage incubated under AHR, especially during the initial stages of incubation. However, CS and AH incubated under AHR were colonized by bacteria specialized in breaking down soluble carbohydrates (e.g., Prevotella and Succinivibrio). Compared with AHR, CSR enhanced the degradation rates of both incubated forages (CS and AH). These findings underscore the role of the rumen microenvironment in affecting the composition of adherent microbial communities and enhancing the breakdown of forages. Therefore, optimizing the rumen microenvironment to promote the attachment of fibrolytic bacteria during the early fermentation stages while minimizing hydrogen accumulation to stabilize the pH could lead to improved forage fermentation and animal performance.
瘤胃是反刍动物胃的四个腔室之一，容纳了各种各样的厌氧微生物，这些微生物在饲料消化和挥发性脂肪酸（VFA）产生中起着至关重要的作用。本研究的目的是探讨两种不同的体内瘤胃环境条件，即AHR（由饲喂苜蓿干草的绵羊产生）和CSR（由饲喂玉米秸秆的绵羊产生），相对于两种类型的饲料苜蓿干草（AH）和玉米秸秆（CS），如何影响纤维消化和瘤胃细菌定植。将AH和CS两种饲料在AHR和CSR条件下进行瘤胃袋培养48小时。结果表明，与AHR相比，CSR的pH值变化较小，总VFA浓度较低，乙酸与丙酸的比例较高。CSR显著提高了两种培养饲料（AH和CS）中中性洗涤纤维和酸性洗涤纤维的降解率。虽然CSR没有提高AH上干物质（DM）或粗蛋白（CP）的降解率，但提高了CS上DM和CP的降解率。与在AHR条件下培养的相同饲料相比，在CSR条件下培养的CS和AH都有更丰富的纤维分解菌（如纤维杆菌属和丁酸弧菌属2），尤其是在培养初期。然而，在AHR条件下培养的CS和AH被专门分解可溶性碳水化合物的细菌（如普雷沃氏菌属和琥珀酸弧菌属）定植。与AHR相比，CSR提高了两种培养饲料（CS和AH）的降解率。这些发现强调了瘤胃微环境在影响附着微生物群落组成和增强饲料分解方面的作用。因此，优化瘤胃微环境，在早期发酵阶段促进纤维分解菌的附着，同时尽量减少氢气积累以稳定pH值，可能会改善饲料发酵和动物性能。
