Through the signing of the Covenant on Enteric Emissions for Cattle by the Flemish Government and by various partners from the agri-food chain, the commitment was made to achieve a reduction of 0.44 MT CO2-eq in enteric emissions in the period 2021-2030. Ration adjustments are one of the three climate-mitigating pillars, whereby in conventional agriculture the focus is on the incorporation of specific feed stuffs (e.g. rapeseed meal in combination with beer marc, extruded linseed) or feed additives (e.g. nitrate, 3-NOP). Some of these solutions cannot be used in organic farming because of the limited availability of a bio-variety, while other solutions meet with fundamental, legal or agricultural objections. Consequently, in this project, alternative solutions are sought within a biological context.

Within this project, various grassland herbs and woody plants (trees or shrubs) or specific parts thereof are put forward as alternative roughage components. The choice for the test components is made on the basis of literature regarding specific bioactive substances in these crops with potential methane suppressing activity at rumen level and on the basis of their applicability within the Flemish biological ruminant sectors. The investigated strategies should therefore fit within the holistic systems approach that is specific to organic farming. With this project proposal, we aim to screen a large range of alternative roughages in vitro, in which the methane suppressive effect is studied in relation to their share in the ration (dose response), to the seasonal influences and to their preservation. In addition, these in vitro simulations in the laboratory will provide insight into the active components and the mechanisms responsible for the methane suppression and additional (positive) side effects (eg potential for improved nitrogen efficiency, parasite suppression, application of minerals and trace elements) will be mapped. These experimental results are fed back to the field in every phase of the project, which facilitates the feasibility for integration within the biological ruminant sector and the preparation of a follow-up trajectory for in vivo validation.