The purpose of this work was to evaluate the grazing effects of large herbivorous ungulates on the reducing of mowing yield in maintained grasslands. The fieldwork was performed in the area of Ljubljansko barje, Rakitna and Kočevje. The selected areas covered the entire population gradient of deer density. In the selected areas, we set up 189 plots in the start of April, 63 of which were enclosures. The plots were spread out so that the sample covered the entire interval of distances from the forest edge. After mowing and sampling were completed, we determined that the average rate of grazing in the studied areas amounted to from 2% in Ljubljansko barje to 11% in the Kočevje area. Contrary to the assumptions, the rate of grazing did not significantly decrease with increasing distance from the forest edge. Within individual areas, there was significant variability in the rate of grazing on the grasslands, which was attributed to differences in local deer densities and differences in the use of individual micro-locations.