We investigated the quality indices of the biomass from Avena sativa and Hordeum vulgare species which were grown in the experimental plot of the “Alexandru Ciubotaru” National Botanical Garden (Institute), Chisinau, Republic of Moldova. The results revealed that the dry matter of whole plants of the studied species contained 9.5-11.9% CP, 6.5-7.5% ash, 34.9- 35.6% CF, 36.7-37.4% ADF, 62.7-62.8% NDF, 2.9-4.6 % ADL, 16.3-16.7% TSS, with forage value 598-603 g/kg DDM, RFV= 89, 11.84-11.92 MJ/kg DE, 9.72-9.79 MJ/kg ME and 5.37-5.81 MJ/kg NEl. The nutrient content and energy value of the prepared hays were: 9.0-10.5% CP, 6.9-7.4% ash, 38.1- 43.5% CF, 40.4-45.6% ADF, 66.0-73.6% NDF, 4.5-5.0 % ADL, 5.1-111% TSS, 534-574 g/kg DDM, 10.69-11.40 MJ/kg DE, 8.76-9.36 MJ/kg ME, 4.79-5.39 MJ/kg NEl. The ensiled forage contained 10.2-12.9% CP, 7.8-11.4% ash, 33.8-39.3% CF, 34.7-41.3% ADF, 57.1.0-69.9% NDF, 1.8-4.0 % ADL, 2.6-12.9% TSS, 32.9-37.3% Cel, 22.4-28.6 % HC, 567-619 g/kg DDM, RFV= 76-100, 11.28-12.21MJ/kg DE, 9.26-10.06 MJ/kg ME and 5.29-6.10MJ/kg NEl. The biochemical methane potential of the studied substrates from Avena sativa reaches 329-355 l/kg VS, but Hordeum vulgare substrates – 361-379 l/kg VS. The collected straw from the studied species contained 6.2-4.5% CP, 5.9-8.2% ash, 5.6-6.8 % ADL, 44.3-48.2% Cel, 23.2-30.1 % HC with biochemical methane potential 282-308 l/kg VS and theoretical ethanol potential 541-574 L/t.