The article outlines the regulatory requirements for assessing the quality of green fodder and the actual nutritional value of green mass at farms of the Vologda region. More than 100 green mass samples were investigated for the period 2016 - 2018. The results of the analysis showed a decrease in feed: dry matter from 24.46 to 22.92 g / kg, digestible protein by 1.36 g / kg and crude fiber from 21.22 to 20.74 g / kg, as well as an increase in nutritional value by indicators: raw protein from 16.14 to 16.27%, exchange energy from 11.19 to 11.26 MJ, sugar from 9.04 to 13.87% and carotene from 175.43 to 176.35 mg / kg. Analysis of the quality of the grass mass shows a great dependence of nutritional value on the prevailing climatic conditions in different years. Cereals and legumes in the Vologda region show a fairly high nutritional value of green mass under favorable climatic conditions, compliance with the technology of harvesting bulk feed, taking into account regulatory requirements for quality assessment. This affects the final assessment of the harvested feed. Research in this area should be deepened and carried out using highly productive agrophytocenosis of promising forage crops. Since green mass underlies the laying of high-quality silage, knowledge of its chemical composition and nutritional value is of paramount importance.