The aim was to examine if including a range of grassland species could help to balance the diet on organic dairy farms compared with traditional mixtures. Four different grass species and four legume species were grown and harvested in mixtures with one grass and one legume for two growing seasons. The species turned out to have very individual mineral, vitamin and fiber profiles and organic matter digestibility, not influenced by year. Among the legumes red clover (Trifolium pratense) and white clover (Trifolium repens) had the highest feeding value and red clover had further a high content of Co, Cu and Zn. Lucerne (Medicago sativa) had as red clover a high growth potential in mixture but had in general a low content of macro and micro minerals with exception of Se. Lotus (Lotus corniculatus) had a low competitive strength, and the effect of the whole herbage was therefore limited even that the content of the vitamins were high. Among the grasses perennial ryegrass (Lolium perenne) generally had the highest feeding value, and a higher content of the macro and micro minerals and of vitamins as well than the other grasses (hybrid ryegrass (Lolium hybridum), meadow fescue (Festuca pratensis) and timothy (Phleum pratense)). The only exception was meadow fescue, which had a higher content of alfa-tocopherol
