Foraging behavior of Highland cattle in silvopastoral systems in the Alps

Abstract

Trees and shrubs expanded in the last decades in European mountains due to land abandonment and the decrease in grazing pressure, and are expected to further spread also due to climate change. As a consequence of low forage quality and topographic constraints, the management of mountain environments dominated by woody vegetation with livestock is often challenging. Silvopastoral systems based on cattle hardy breeds able to forage on woody plants, such as Highland cattle, could be a suitable option for the management and restoration of such environments. In this study, we used direct observations to explore the foraging behavior of Highland cattle in four study areas across the western Alps. In particular, we assessed: (1) cattle diet composition, (2) the selection for more than 30 tree and shrub species, and (3) the relationships between species consumption and their abundance in the environment. Highland cattle fed on a mixture of both woody and herbaceous species, including between 15 and 46% of woody plants in the diet. Some trees (e.g., Celtis australis, Fraxinus spp., and Populus tremula) and shrubs (e.g., Frangula alnus, Rhamnus spp., and Rubus idaeus) were positively selected by cattle, thus they could be an important forage supplement to their diet. Moreover, the results highlighted that relative species consumption generally increased with increasing species abundance in the environment, suggesting that this cattle breed could be suitable to control shrub expansion in highly encroached areas. The outcomes of this study can support the development of targeted silvopastoral systems in the Alps.