Project Opti-Milk: Performence of the milk production based on grazed grassland

On a typical site in the Swiss plains the productivity of a dairy production system with maximum proportion of grazing was studied over three years (April2001 to March 2004) The experimental herd consisted of 14 Simmental/red Holstein and two Jersey cows with an average life weight of 592 kg cow-1. After an average calving date in mid February grazing started at the end of March and lasted until mid November. The experimental land consisted fully of grassland, of which 63% was sown grass legume ley (sown in 2000) and 37% was permanent grassland (with 33% Agrostis stolonifera). The over all stocking rate was 2.5 cows ha-1 during the first two years and 2.0 cows ha-1 in the extremely dry year 2003. On a dry matter basis, the yearly average ration consisted of 62-70% grazing, 35% grass silage plus hay and 5% or 405 kg dry matter concentrate. The milk yield per hectare forage surface achieved clearly surpassed experience values from conventional valley dairy farms. On average over the three years 14’291 kg ECM ha-1 were produced. Thus, the full grazing system with seasonal calving in spring proved to be highly productive under Swiss valley conditions.