The sowing period significantly affects organic matter accumulation in the green mass of the studied plant: peas, spring barley, and oats. Experiments were carried out in the agricultural artel (collective farm) "Zarya" of the Kemerovo region-Kuzbass in 2019-2020. The article presents the results of comparing different sowing dates obtained by cultivation of mixed crops and single crops of annual forage crops. Despite the insignificant differences in growing conditions, the experiment established a pattern that characterizes the reaction of the studied plants to the sowing period. The analysis of the nutritional value of haylage obtained from mixed crops has been carried out. The article presents the feed organoleptic assessment (color, odor), active acidity, biochemical assessment (mass fraction of dry matter; crude protein; crude fat; crude fiber; content of lactic, acetic, and butyric acids), calculated feed units, metabolic energy, and nitrogen-free extractive substances. As a result of the research, links between the sowing period and such quality indicators as the content of crude fat, protein, fiber, and ash were revealed.
