The analysis of the efficiency of the particle sizes of the feed components used in feed rations resulted in proof of the significance of the feed particle size not only while feeding animals with loose dry or wet mixtures but also with feed granules. The study showed that to increase the efficiency of hammer crushers it is relevant to substantiate the parameters of the hammer rotor and the method the raw materials are supplied into the crusher’s working chamber. The experiment involved a stand, which enabled determining the strength of stems while being broken. A sieve classifier was applied to measure the average particle size of the ground products. The rotor speed was monitored electronically and duplicated by a manual tachometer. The average diameter of clover samples was 1.64 mm and correspondingly 3.3 mm of lupine; the length of the samples was 50 and 100 mm. The breaking force on a clover stalk with 13.2% of moisture was 97 N max and 4.4 N min, and correspondingly in the case of a lupine stalk – 22.7 N max and 1.5 N min with 12.3% of moisture. In our case, grinding clover and lupine hay with the minimal energy density Qs, 60 m·s-1 was considered to be the efficient speed of the hammers υм, and the grinding modulus М was within 1.0-1.3 mm. With the different values of the hammer speed and the crusher grinding chamber width of 180 mm, the results of the experimental studies showed that regardless of a supply method and a type of processed raw materials, the output of the ground products was distributed quite unevenly across the width of the working chamber. However, it was found that the peripheral feeding method was significantly more effective than a central one, since the quicker the work was done, the more efficient it became. While at speed υм = 30 m·s-1, the unevenness of the product output under the central supply method was greater than that of the peripheral one only in 8-14%, at speed υм = 75-80 m·s-1 this difference reached 20-32%.