Chemical composition of forage crops (35% hungarian vetch, 35% forage peas, 10% oats, 10% triticale, 10% wheat) of different harvest times and fertilizer applications at different doses, relative feed value (RFV), relative feed quality (RFQ , energy contents (ME, NEL), in vitro digestibility parameters (TNDFD, TOMD, TDN, DMI), in vitro gas production, methane (CH 4 ) production, fractionation factor (PF), microbial protein (MP) and microbial protein synthesis efficiency Ankom Daisy in vitro fermentation system and in vitro gas production technique were used in the research carried out to determine their effects on (MPSE) and true degree of digestion (TDD). Harvesting at different times significantly affected (P<0.05) the CP