Livestock has a significant contribution to methane emission as a portion of their ingested energy, which is wasted in the form of methane (2–15%), and ammonia (75–95%). Microbial fermentation in ruminants results in the loss of energy in methanogenesis and protein via ammonia nitrogen excretion, causing a decline in feed efficiency and acting as environmental pollutants. Antibiotics were used to reduce these losses in the rumen, but this approach was restricted in animal products. Some plants or their bioactive extracts/metabolites such as organo-sulphur compounds, saponins, essential oils, flavonoids, and tannins exhibited the potential to limit the methanogenesis by altering the rumen microflora. Plant extracts, including clove (Syzygium aromaticum) bud oil and clove extracts, were used as feed additives to manipulate rumen fermentation. Clove oil interacts with bacterial cells and inhibits the growth multiplication of methanogenic and deaminating bacteria. This results in a reduction in ammonia, nitrogen, methane, acetate concentration, and high propionate and butyrate concentrations. Eugenol is one of the bioactive constituents in clove that manipulate rumen fermentation by increasing propionate production, decrease acetate and methane production, and alter the proteolysis pattern, peptidolysis, and amino acid deamination in the rumen. The current review reports on using of clove phytochemicals and extracts in manipulating rumen fermentation to inhibit methanogenesis and energy loss as well as ammonia–nitrogen waste.

牲畜摄入的能量中有一部分对甲烷排放有重要贡献，浪费的能量以甲烷（2–15％）和氨（75–95％）的形式浪费。反刍动物中的微生物发酵会通过氨氮的排泄而导致甲烷生成和蛋白质能量的损失，从而导致饲料效率下降，并成为环境污染物。抗生素被用来减少瘤胃中的这些损失，但是这种方法在动物产品中受到限制。一些植物或其生物活性提取物/代谢物，例如有机硫化合物，皂角苷，香精油，类黄酮和单宁酸，可能通过改变瘤胃微生物区系而限制产甲烷作用。植物提取物，包括丁香（丁香）将芽油和丁香提取物用作饲料添加剂，以控制瘤胃发酵。丁香油与细菌细胞相互作用，并抑制产甲烷和脱氨细菌的生长繁殖。这导致氨，氮，甲烷，乙酸盐的浓度以及高丙酸根和丁酸根的浓度降低。丁香酚是丁香中的生物活性成分之一，可通过增加丙酸盐的产生，减少乙酸盐和甲烷的产生并改变瘤胃中的蛋白水解模式，肽水解作用和氨基酸脱氨作用来操纵瘤胃发酵。本篇综述报道了使用丁香植物化学物质和提取物来操纵瘤胃发酵，以抑制甲烷生成和能量损失以及氨氮浪费。