Thompson Joshua P, Cristobal-Carballo Omar, Yan Tianhai, Lawther Katie, Dimonaco Nicholas J, Zeller Wayne E, Zhang Zhenbin, Huws Sharon, Safo Laudina, Southam Andrew D, Ludwig Christian, Lloyd Gavin R, Stergiadis Sokratis, Theodoridou Katerina
Institute for Global Food Security, Queen's University Belfast, Northern Ireland, Belfast, UK.
School of Biological Sciences, Queen's University Belfast, Northern Ireland, Belfast, UK.
Anim Microbiome. 2025 Jul 25;7(1):81. doi: 10.1186/s42523-025-00444-6.
Sustainable livestock production is essential for meeting the growing global protein demand while minimising environmental impacts. Exploring alternative forages that enhance nutrient utilisation and reduce reliance on imported feeds is a potential strategy. Condensed tannins (CTs) can bind to proteins in the rumen, protecting them from ruminal degradation resulting in decreased ammoniacal N and enhanced nitrogen uptake in the hindgut. This pioneering research is the first to explore the potential of willow (Salix) as an alternative feed for ruminant nutrition. The study involved feeding ewe hoggets a control grass silage (SIL) or a SIL mix containing a 20% dry matter (DM) dietary inclusion of leaves from two willow varieties to investigate the impact the willow CTs have on rumen fermentation, microbial populations, and metabolomic profiles. Willow treatments: Beagle (BG) and Terra Nova (TN) had an overall CT inclusion (CTI) of 1.1 and 0.1% DM with the control diet containing no CTs in a three-treatment x three-period Latin square design.
Although total dry matter and fibre intake were higher in BG and TN, there was no significant difference in ruminal CH production between the treatments. However, fermentation was affected, with BG and TN showing lower acetate production and reduced total volatile fatty acid production compared to SIL. CTs may have impaired fibre digestion, as SIL had higher Fibrobacter abundance than BG. Heatmap visualisation indicated higher carbohydrate metabolite concentrations in SIL, with reduced metabolism observed in TN and BG. Ruminal ammonia did not differ significantly among treatments, despite higher nitrogen intake in BG and TN treatments. Proteolytic bacteria levels were similar across treatments, but TN and BG had higher ruminal metabolites associated with protein metabolism upon visualisation through heatmap analysis. TN showed higher abundance of Prevotella and Fibrobacter than BG, which had 10 times higher CT content and a greater prodelphinidin proportion.
Feeding CT-containing willow enhanced feed intake, altered rumen microbiome composition and suggested visual changes in the analysis of protein metabolism, offering potential benefits for animal performance. While a reduction in CH was not observed, this study highlights the potential of willow to alter ruminant nutrition while supporting sustainable agricultural practices.
可持续的畜牧生产对于满足全球日益增长的蛋白质需求同时将环境影响降至最低至关重要。探索能够提高养分利用率并减少对进口饲料依赖的替代草料是一种潜在策略。缩合单宁（CTs）可与瘤胃中的蛋白质结合，保护其免受瘤胃降解，从而减少氨态氮并增强后肠对氮的吸收。这项开创性研究首次探索了柳树（柳属）作为反刍动物营养替代饲料的潜力。该研究让青年母羊采食对照青贮草（SIL）或含有20%干物质（DM）的两种柳树品种树叶的SIL混合物，以研究柳树CTs对瘤胃发酵、微生物种群和代谢组学图谱的影响。柳树处理组：比格（BG）和特拉诺瓦（TN）的总CT含量（CTI）分别为1.1%和0.1%DM，对照日粮不含CTs，采用三处理×三期拉丁方设计。
尽管BG和TN组的总干物质和纤维摄入量较高，但各处理间瘤胃甲烷产量无显著差异。然而，发酵受到了影响，与SIL相比，BG和TN组的乙酸盐产量较低，总挥发性脂肪酸产量降低。CTs可能损害了纤维消化，因为SIL组的纤维杆菌丰度高于BG组。热图可视化显示SIL组的碳水化合物代谢物浓度较高，而TN组和BG组的代谢有所减少。尽管BG和TN处理组的氮摄入量较高，但各处理间瘤胃氨含量无显著差异。各处理间蛋白水解细菌水平相似，但通过热图分析可视化显示，TN组和BG组与蛋白质代谢相关的瘤胃代谢物含量较高。TN组的普雷沃氏菌和纤维杆菌丰度高于BG组，BG组的CT含量高10倍，原花色素比例更大。
饲喂含CT的柳树提高了采食量，改变了瘤胃微生物群组成，并在蛋白质代谢分析中显示出明显变化，对动物生产性能具有潜在益处。虽然未观察到甲烷减少，但本研究突出了柳树在改变反刍动物营养同时支持可持续农业实践方面的潜力。
