Conserving forage implies stabilizing the living material naturally composing it. Different conservation methods can be used offering a wide range of techniques for obtaining forage with a dry matter content ranging between 20 and 85%: direct-cut silage, semi-wilted and wilted silage, fielddried hay and barn-dried hay using ventilation... The processes at stake and the consequences of these different conservation techniques on key nutritional parameters are listed and described below. In order to minimize loss and preserve high nutritional values, successful haymaking should involve fast drying and preserving leaves, whereas successful silage production should involve pre-wilting or using effective preservatives. The nutritional value of haylage, which is easy to produce, is enough for animals with moderate nutritional requirements. Options have to be explored in order to better take into consideration the question of conservation when implementing multispecies grassland