Unraveling feed and nutrient use efficiencies in grassland-based dairy farms

Grassland-based dairy farms are important for the provisioning of milk and ecosystem services. However, key factors interactions that influence feed use efficiency grassland-based in practice not well known understood, as a consequence no well-targeted recommendations can be provided. This paper addresses question ‘what main determine variations calculated N P efficiencies on subjected to agri-environmental regulations’. Monitoring modeling data from ~12000 The Netherlands over 4 year period (2017–2020), collected through KringloopWijzer model, were analyzed 2020 statistically detail. Farms greatly differed production intensity (range < 10 >25 Mg per ha yr) amount purchased feed. 5 95 percentile values frequency distribution annual mean at herd level 0.9 1.3 kg dry matter, respectively. Feed was related yield number young stock cow, share concentrates silage maize ration, net energy content grass. At level, increased with 21 28%, those 32 40%. Contrary expectations, surpluses farm remained more or less constant production, but amounts manure export strongly production. sensitive accounting externalization utilization. modeled ammonia methane emissions produced relatively low high efficiency. In conclusion, indicator profitability environmental performance farms. Differences between these indicators large, differences limited explanatory variables. Our study provides lessons improving