European cattle farmers are facing increased demand for pasture-based and environmentally friendly products. Although feeding strategies to reduce Greenhouse Gas (GHG) emissions have been studied intensively, strategies for grazing systems are under-researched. The lack of easy-to-implement technologies for methane measurement with grazing cattle complicates the necessary large-scale studies. GrASTech will develop an animal-mounted sensor platform for methane measurement in grazing cattle and validate using established techniques (Respiration chambers, LaserGun and Greenfeed). Additionally, herd productivity, which has a major impact on GHG emission intensity (per kg product), will be improved using a wide range of precision livestock farming technologies. All strategies will be evaluated using life cycle assessment in order to find net positive effects. GrASTech will provide important advances towards achieving the challenging goals of the climate action plan.