Alnus viridis encroachment threatens ecosystem service provision in Central European mountain grasslands. Robust livestock is a potential management strategy, but its medium- and long-term effects remain unquantified. We studied the impact of Highland cattle in two encroached summer pastures in the Italian and Swiss Alps: Vogna and Bovonne, respectively. Vegetation cover dynamics over the last decades were reconstructed using aerial and satellite imagery. Cattle movements were monitored with GPS, and botanical surveys were conducted in 2019 and 2024. After cattle introduction, shrubland cover decreased at both sites. GPS data revealed preferential use of pastures, with progressive grazing within A. viridis stands. Species richness increased from 30.6 to 32.9 at Vogna and from 25.5 to 32.2 at Bovonne, where forage quality, measured as pastoral value, also improved. These results highlight Highland cattle as an effective agrorestoration tool to mitigate shrub encroachment and restore grassland biodiversity.