Abstract: Agricultural systems must increase productivity while conserving the natural resource base and optimizing ecosystem services to meet the converging challenges posed by a growing human population, increasing costs of production inputs, and widespread environmental degradation. Thus, sustainability concerns justify the needs for readjustment of pasture strategies and redefining the role of forages in livestock production. The function of forages in pasture-based livestock systems needs to be broaden beyond their agronomic and animal nutrition benefits. Specifically, the potential of bioactive compounds found in forb species in reducing greenhouse gas (GHG) emissions, boosting animal immune system, increasing the biochemical richness of animal products and ecosystem benefits should be considered in designing pasture systems. It is key to take full advantage of the benefits provided by the biochemicals present in diverse arrays of forages, as they can contribute to the enhancement of feed efficiency and animal health at relatively low costs to the producer. The use of phytochemically diverse pastures that include legumes and forbs with high nutritive quality together with the presence of beneficial plant secondary compounds can improve the antioxidant capacity and the immune function of livestock and reduce animal CH4 emissions and nitrate (NO3) leaching from soils. The main tenet of the invited talk will be to provide information on recent research findings on the effects of temperate forb species with high bioactive compounds on animal production, health and GHG emissions. Furthermore, how these forages can be successfully incorporated in pasture systems and animal feeding programs in temperate agro-ecologies will be discussed.