Which cow for pasture-based production systems?: Problematics and experimental design

Switzerland is a country of grasslands. The effective use of this resource is essential for the Swiss dairy industry. To ensure this, efficient milk production systems and cows suited to these systems are necessary. The existence of interactions between genotype and environment when comparing contrasting conditions of production raises the question of the suitability of our Swiss breeds, mainly influenced by North American genetics selected in confined environments with total mixed rations, to low-input, seasonal-calving systems. New Zealand, where this type of system dominated for decades, has selected cows that are fertile and efficient for the production of milk solids. The objective of this trial was to compare the global performances of the three main Swiss breeds (Red and White, Brown and Holstein-Friesian) with those of New Zealand Holstein-Friesian on pasture-based, end-of-winter seasonal calving farms.