Nutritional mitigation and grassland climate adaptation strategies in relation to enteric methane emissions from dairy cattle on grass silage based-rations: effectiveness and trade-offs

It is well known that the production of anthropogenic greenhouse gases (GHG) is the main driver for climate change and the contribution of enteric methane (CH4) emission derived from cattle is undeniable. Nutritional strategies can be implemented to reduce these emissions, while climate change itself also affects the cattle sector due to negative effects on feed production. As such, farmers need to work on two fronts in their management: implementation of both mitigation and adaptation strategies. This is particularly challenging in grass-based rations, as several CH4 mitigation strategies seem less effective in cows fed grass-based rations, while enhanced enteric CH4 emissions may be associated with grassland-products from climate adaptation strategies. In this project, the influence of nutritional GHG mitigation strategies or grassland adaptation strategies on the enteric CH4 emissions in dairy cattle fed grass-based rations will be investigated. In the first work package, the introduction of extruded linseed or rapeseed meal in grass silage-based rations will be investigated to reveal the mitigating mode of action. In the second work package, the potential trade-offs between mitigation and the implementation of drought tolerant grass species or grassland herbs will be investigated. These results will lead to the implementation of these strategies at farm level in order to reach the Flemish and European reduction goals in Climate Action plans.