About

Feed management decisions are critical for ruminant production systems and also strongly affect agricultural greenhouse
gas (GHG) emissions. Although ruminant management and production conditions differ between countries, a transnational approach is critical for extending knowledge of ruminant dietary effects on greenhouse gas (GHG) emissions and sustainable production, and improving GHG accounting methodologies.

CEDERS aims to align national agricultural GHG inventory and mitigation research across an international consortium of 9 countries (8 partner countries plus New Zealand). Its main goal is to delineate dietary effects on various on-farm GHG sources and their trade-offs, at the farm and national scales.

The objectives of CEDERS are to:

• Develop, expand and refine databases to evaluate dietary mitigation strategies on digestion, excretion, manure composition, and related GHG emissions.
• Fill, by experimentation, high-priority knowledge gaps on dietary effects on ruminant and manure emissions.
• Evaluate, using monitored farm cases in a modelling platform, the consequences of dietary mitigation measures on total farm GHG emissions.
• Improve farm accounting and national inventory methodologies to capture effects of dietary mitigation measures for on-farm GHG emissions.
• Disseminate the implications of these findings to end-users of GHG accounting.

Results

By expanding on a database originating from FACCE-JPI Global Network Relationships the effect of dietary mitigation strategies on the emissions of enteric methane emission and from excreta/manure was evaluated.

Further, an integral evaluation of the main greenhouse gas emissions (livestock, manure, soil/crop) by use of a modelling platform of sophisticated process-oriented models for a wide range of well-monitored farm cases. 

Furthermore, the model for enteric methane (the Dutch Tier 3) is compared with current inventory methodology in a selection of partner countries.

Simultaneous experimental testing (at lab, cow and farm scale) to evaluate trade-offs and synergies between these two emissions sources (factors studied dietary nitrogen, starch and lipid content, grass/maize exchange) indicates strong trade-offs between enteric and excreta/manure emissions are possible, but these depend on the basal diet and dietary measures taken. Instead of generic adoption of the mitigating effect on enteric methane, careful diet formulation is needed to prevent such trade-offs and achieve a maximum synergistic of reduced nitrogen emission. These CEDERS results are reflected against current approaches in inventory, accounting/C footprinting and IPCC guidelines. The aim is to consolidate this in 2020/2021 into recommendations for the stakeholders involved in these approaches.