Rejection of grass around dung pats; influence of smell, taste or both?

Dung pats reduce the surface of grass growth and cows reject grass around these pats, which decreases forage area and lowers the utilization of the pasture. The question is whether the rejection is due to smell, taste or both. In four grassland plots four treatments (six dung pats per treatment) were assigned with artificial dung pats; (1) untreated (control), (2) smell absent, taste present, (3) smell present, taste absent, (4) smell absent, taste absent. Three weeks after introduction of the dung pats, 10 cows were introduced in a plot during daytime on four consecutive days (new plot each day). Grass length and grazed surface around the dung pats was measured before and after grazing. The results show that smell, and the combination of smell and taste has a negative effect on the intake of grass. These results are of interest for dung pat management on grassland.