The work objective is to study an advanced way of enhancing the nutritive value of the mixed feed by co-extrusion of the grain mixtures with chopped green legumes that differ in high content of vitamins and protein. The task of this investigation is an experimental determination of rational parameters and operating modes of the equipment for the extrusion process. Standard techniques are used to study the extrusion process when the properties of raw materials and modes of the extruder EC-75 (75kg/hr) change: extrudable mixture humidity, weight percentage of the chopped green mass in the mixture, and the extruder screw frequency of rotation at different feed rate of the mixture. The residual content of β-carotene as a quite valuable but impermanent component of the received product is used as a key marker of the process. The restrictive conditions are organoleptical properties of the product, humidity after cooling, and occurrence of the undistorted grain material. Energy efficiency of the process is evaluated by the criteria of the specific energy consumption. The study results of the extrusion process are as follows. Its optimal characteristics are determined: mixture supply is 60 kg / hr, mixture temperature at the matrix outlet is 120-125°C, content of the chopped green mass in the mixture is 14-15%, screw rate speed is 220-240 rpm with the specific energy consumption of 90-95 kW hr/t.