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, SO_2.5, CLO₅, and MIX₅. In Exp. 2, MIX₅, hop extract at 7.5 (H_7.5) and 15.0 (H_15.0) and steroidal saponin extract at 2.4 (S_2.4) and 4.8 (S_4.8)% DM with and without MIX₅ were examined. H_7.5–MIX and S_2.4–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.

Keywords:

• Oil
• plant extracts
• methane
• rumen

Acknowledgements

This work was supported by the Agriculture and Agri-Food Canada, Norwegian Research Council, Norwegian Dairy Co-operative, Agricultural Purchasing and Marketing Corporation, Meat and Egg Co-operative and Norwegian Meat and Poultry Research Centre. The authors also acknowledge the technical assistance of Darryl Vedres and Zhong Xu.