Eco-ecient pasture based dairy farm systems: a comparison of New Zealand, €e Netherlands and Ireland

European and New Zealand dairy farmers pursue high productivity, while meeting the requirements of environmental legislation. Due to market constraints, New Zealand dairy farming has traditionally relied on low-input grazed perennial ryegrass (Lolium perenne L.) – white clover (Trifolium repens L.) pastures and on grazed forage crops in seasons with low pasture production. However, in the past three decades the use of synthetic nitrogen (N) increased, allowing higher stocking rates and more milk production per hectare, but increasing N surplus per hectare and therefore potential N loss to the environment. !e use of supplements has also increased, with an increasing number of farmers investing in infrastructure to feed cows o"-pasture during the winter. !is is seen to bene#t the animal as well as the environmentbecause supplements provide the opportunity to reduce surplus N intake, and collected urine and faeces can be applied e$ciently on pastures or crops. In Europe, indoor systems, use of supplements and e$cient manure application methods are common. !ere is interest in improving production and utilisation ofhome-grown pastures and crops to reduce costs and overall environmental footprint. !is is where the challenge for European and New Zealand dairy systems meet: there is a common need to examine how crops and forages can be used to improve N e$ciency in the soil-plant-dairy cow system. Combining best practices and recent advances in European and New Zealand research provides scope for cost- and nutrient-e$cient and highly productive dairy farm systems