Effects of Plantain ( L.) Metabolites Aucubin, Acteoside, and Catalpol on Methane Emissions .

Plantain (PL) contains plant secondary metabolites (PSM), such as acteoside, aucubin, and catalpol, known for their bioactive properties. While acteoside and aucubin have been linked to reducing nitrogen losses in grazed pastures, their effects on enteric methane (CH) emissions remain unexplored. Three batch culture experiments were conducted to assess the effects of PSM on rumen fermentation, using PL pastures with varying PSM concentrations, purified PSM compounds, and/or their combinations added to ryegrass (, RG), which does not contain these PSM.