Since late 2004, a spring-calving dairy cow herd has been managed to farm 80 hectares of permanent pastures with an extended grazing period (March to November) and winter feeding based on hay and very few concentrates. Using a systems experiment, the main objective consists in designing and evaluating an environmentally friendly system. Results from the first tow years of running have been analysed. Despite a rather good working of the forage system, reproductive performance of cows was dramatically impaired. Some ways of improvement were planned regarding the position of the calving season in the year. Spring grazing management, and especially fodder supply for the cows during this period, were also reconsidered. Some compromises between grassland production, biodiversity and some other envrironmental issues stil remain to be designed.