Effects of different oils and plant extracts on in vitro ruminal methane production

Abstract

Effects of oils and plant extracts on CH4 production from a barley grain (47%) – barley silage diet [53%; dry matter (DM) basis] were investigated. Exp. 1 used ruminal fluid alone (control), canola oil (CO), sunflower oil (SO), cod liver oil (CLO), or a (70:30) mixture of CO and CLO (MIX) at 2.5 or 5% of DM. CH4/g DMD increased (p < 0.05) for CO5, SO2.5, CLO5, and MIX5. In Exp. 2, MIX5, hop extract at 7.5 (H7.5) and 15.0 (H15.0) and steroidal saponin extract at 2.4 (S2.4) and 4.8 (S4.8)% DM with and without MIX5 were examined. H7.5–MIX and S2.4–MIX increased CH4/g DMD (p < 0.05). Addition of oil resulted in a decline in DMD in both experiments. None of the additives reduced CH4/g DMD. Further studies to determine if more than one mitigation additive has detrimental or synergistic impacts on CH4 produced per unit DMD are required.