The experience with cultivation of Festulolium braunii (Felopa variety) in mixtures with red clover (Tenia variety), and alfalfa (Tula variety), was founded in April 2007 on an experimental object of Grassland Department and Green Areas Creation UP-H in Siedlce. The first experimental factor were 3-grass-legumes mixtures having the following composition: M1 – Festulolium braunii 50%, Trifolium pretense L. 50%, M2 – Festulolium braunii 50%, Medicago sativa ssp. media 50%, M3 – Festulolium braunii 50%, Trifolium pratense L. 25%, Medicago sativa ssp. media 25%. Combinations with soil’s medium amendment was marked as UG, and without soil’s medium amendment – BUG. In addition, nitrogen fertilization in the annual dose of 60 kg N∙ha-1, potassium 120 kg K2O∙ha-1 and phosphorus in the amount of 80 kg P2O5∙ha-1 were applied on all plots. Detailed study included the chemical composition of plant, which was determined at the Institute of Technology and Life Sciences in Falenty. The obtained results were used to calculate the following measures of the energy of and protein value feed: NEL – net energy of lactation, JPM∙kg-1D.M. – feed unit for milk production, JPŻ∙kg-1 D.M. – feed unit for livestock production, nBO – useful protein, BNŻ – rumen nitrogen balance. Furthermore, using the multivariate comparative of taxonomic analysis method the synthetic comparative measure of forage quality Q was evaluated. The use of soil’s medium amendment, regardless of the types of mixture, cuts and years of research, resulted in higher values of all measures. However, the analysis of synthetic measure of feed quality showed that in terms feed quality the best was the three component Festulolium braunii mixture with Trifolium pratense L. and Medicago sativa ssp. media.