Optimized Grazing: for increased economic and ecological sustainability in Swedish milk production

Swedish milk production is mostly based on indoor management of dairy cows with a partial outdoor management period during summer. Giving dairy cows access to pasture improves animal health and welfare, and lowers feed costs. In addition, maintaining pastures increases biodiversity and carbon sequestration into soil, thereby increasing the ecological sustainability of the dairy farm. However, one main concern regarding grazing is that the transition of cows from indoor feeding to pasture in the spring may cause a drop in milk production which compromises the economical sustainability of the dairy farm.

The aim of this project is to identify the causes behind the drop in milk production and to find dietary strategies that could maintain milk yields after transition to pasture and thus promote grazing as a natural part of sustainable dairy farming in Sweden.

The project includes two grazing trials with dairy cows at the Röbäcksdalen dairy research barn in Umeå, SLU. The first grazing trial will be conducted in spring – summer 2024. In this trial, we will investigate how different adjustments to the indoor diet of dairy cows affects their milk production, milk composition, nitrogen utilization and efficiency, and metabolism after transition to pasture. The second grazing trial will be conducted in spring 2025. In this trial, we will use the information acquired from the first grazing trial to test and evaluate different adjustments to the indoor diet in order to maintain milk yields after transition to pasture.