Regarding CH4production relative to DM, the trend for a difference between treatments underlines a lower productionfor SF than for pure T and RC at the end of the fermentation. This result would then support previous findings indicating aneffect of SF in CH4reduction, even if this effect is inconsistent in literature. Theodoridou et al. (2011) and Niderkorn et al.(2012) highlighted the role of CT from fresh freeze-dried samples of SF to limit the in vitro CH4production, using polyethyleneglycol (PEG), a compound which can compete with protein to bind CT (Jones and Mangan, 1977).