Foraging behavior of Highland cattle in silvopastoral systems in the Alps.

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. Supplementary Information: The online version contains supplementary material available at 10.1007/s10457-023-00926-z.

Nitrogen translocation by Highland cattle grazing in Alnus viridis-encroached pastures.

During the last decades, Alnus viridis has expanded over former montane pastures and meadows, due to land use and abandonment. This nitrogen-fixing woody species has triggered negative agro-environmental impacts, such as nitrogen (N) leaching, soil acidification and a reduced biodiversity. The aim of this study was to estimate the N translocation from A. viridis-encroached areas to adjacent open pastures by Highland cattle. In 2019 and 2020, Highland cattle herds equipped with GPS collars were placed in four A. viridis-encroached paddocks across Italy and Switzerland. The N content was measured in A. viridis leaves, herbaceous vegetation, and cattle dung pats, which were collected throughout the grazing season. Using GPS locations and collar activity sensors, livestock activity phases were discriminated. The N ingested by cattle was estimated through the N content of herbaceous vegetation and A. viridis leaves of vegetation patches visited by cattle during 24 h before dung sampling (N24H). The N content of herbaceous vegetation significantly increased with increasing A. viridis cover. The average N content in dung pats (31.2 ± 3.4 g.kg-1 DM) was higher than average values from literature on grazing cattle. Moreover, it was positively related to the N24H. Most of this N (29.5 ± 10.3 kg ha-1 yr-1) was translocated towards resting areas, which generally occurred on flat open pastures. Our results highlight the potential of Highland cattle to effectively translocate part of the ingested N from A. viridis-encroached towards targeted open areas, thus bringing new perspective for forage yield and quality improvement in the long-term. Supplementary Information: The online version contains supplementary material available at 10.1007/s10705-023-10282-0.