Conclusions

Sustainable forage production in dairy farming systems of north-west Europe ensures economic benefit and social welfare. However, sustainability is ensured only if its eco-efficiency (e.g. GHG emissions, nutrient losses) matches or even outbalances the forage pro- duction in other regions of the world. The use of obligatory grassland as a forage resource for feeding dairy cows mitigates the global competition for arable land and is thus a key argument in favour of grass- land. However, the grass and forage science commu- nity faces the challenge of developing a well-grounded methodological basis for the assessment of sustainabil- ity and, furthermore, of providing comprehensive and reliable data to allow for comparisons among and within different production systems in all regions of the world. In this way, favourable dairy production systems and forage production regions in terms of sus- tainably intensifying dairy farming could be identified

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