Conséquences énergétiques, économiques et environnementales de l’adaptation au changement climatique de systèmes fourragers bovins lait du Grand Ouest

On the economic, energetic and environmental consequences when adaptating dairy forage systems to climate change in West of France

This article explores the consequences of adaptation to climate change of six dairy cattle systems in West of France. Using participatory approach with six groups of dairy farmers in Brittany and the Pays de la Loire region, adaptation pathways of diverse systems have been co-designed with the serious game Forage Rummy®. Impacts of future climate on forages were simulated using climate data from the DRIAS platform and using STICS model. Choices upon forages, ley compositions and herd management were made to ensure the balance between year-round forage production and animal feeding requirements with the support of a computerized model. This model allowed the comparisons between initial systems and adapted co-designed systems. The six resulting systems all have reduced livestock density and diversified their forage production to overcome two consecutive years with median yields of 50% of the driest years over 2041-2060. Diversification implies most of the time higher fuel consumption which was estimated the Mécaflash® tool. Cost of the feeding systems adapted to climate change are often higher than initial systems based on past climate. Milk carbon footprints, estimated through CAP’2ER Level1, decrease due to technical optimization of feed plan and herd management. Although strategies to adapt dairy farming systems to climate change may lead to higher costs of production with maintained production level, results suggest that there might be a synergy between adaptation and mitigation in the studied context.