Semi-natural, marginal pastures offer a plethora of ecosystem services but they are often underused in modern agriculture. We analysed if robust cattle valorise these services more efficiently than highly productive cattle. We assessed anatomy, feeding and movement behaviour of Highland cattle (HC) as a model for robust cattle and compared it to the medium-productive Original Brown and highproductive Angus×Holstein in a controlled experiment in the Swiss Alps. Additionally, we investigated the vegetation of 25 pastures of HC with adjacent pastures of highly productive cattle. HC differed significantly from productive breeds: (1) HC were significantly lighter, but had large claws and covered less distance. Consequently, trampling pressure was lower and trampling-adapted plant species were rarer on HC pastures. Since these plants outcompete more-susceptible species, biodiversity was higher on HC pastures. (2) HC grazed least selectively and foraged unattractive plants, whereas high-productive cattle preferred nutrient-rich, easily digestible forage. Thereby, HC reduce problematic plants. (3) HC used the pasture most evenly and exploited different resources. (4) The productive breeds lost weight on the marginal pastures, whereas HC gained weight, indicating a more efficient roughage conversion. Robust cattle make efficient use of marginal grassland, thereby valorising these pastures and promoting biodiversity.