A technology for pilot production of feed products via microbiological conversion of plant raw materials (mixed substrate of pine sawdust and vegetative part of Jerusalem artichoke) by Plerotus ostreatus PO-4.1 and Pleurotus djamor PD-3.2 strains is developed. The technology includes hydrodynamic activation of substrate at the seed stock production stage. The overall technology includes three key stages: submerged fermentation of pure cultures of production strains; submerged-solid phase fermentation of hydrodynamicly activated plant raw materials for seed stock production; solid-state fermentation of mechanically ground plant substrate for feed products production. A successful approbation of submerged-solid state fermentation of production strains on media containing 3% of hydrodynamicly activated raw materials allowed for obtaining seed stock with 14.5 g/l yield of submerged mycelium biomass fully adopted for this type of substrate. Further use of this seed stock biomass at the solid state fermentation stage makes the overall process duration three times shorter compared to existing technologies for direct wood waste bioconversion. The pilot plant results show valuable practicability of plant raw material hydrodynamic activation with the purpose of enhancing its bioaccessibility with consequent increase in degree of microbiological conversion. The product of bioconversion contains 14–16% of protein, biofiber, vitamins and minerals and could be considered for successful use as feed by agricultural enterprises.