Livestock production contributes significantly to ammonia and greenhouse gas (GHG) emissions. The EIP-AGRI Focus Group on reducing livestock emissions looked for cost effective measures to reduce both methane (CH4 ) and ammonia (NH3 ). The 20 experts in the group described the current and new mitigation measures, explored their cost-effectiveness, identified success and fail-factors for implementation of emission-reducing measures and found areas where research, development and the exchange of knowledge is required.