Technical Abstract: Pastures containing multiple plant species have been shown to have greater plant productivity than pasture planted with a single plant species. However, it has not been determined whether this increase in plant productivity translates into increased animal productivity. Therefore, a study was designed to evaluate the effects of various forage mixtures on intake, grazing behavior, and productivity of lactating dairy cows. The results indicate that the forage mixture in pastures did not have a major impact on intake or productivity of grazing dairy cows. However, milk conjugated linoleic acid content was greater in cows consuming forage mixtures containing a greater number of plant species. Forage production and carrying capacity of the pastures were greater on the more complex mixtures. This fact sheet summarizes this research project at the USDA-ARS Pasture Systems and Watershed Management Research Unit in University Park, PA.