The article presents the experimental study on the influence of moisture content in hard wheat varieties, such as Yuka, Tanya, Batko, Yubileynaya 100, on the energy efficiency of grinding in a horizontal rotary crusher. The relationship between grain moisture, specific energy consumption and grinding quality was compared to data obtained from traditional grinding methods, specifically hammer and roller mills. The study revealed that grain moisture significantly affects energy consumption: at low moisture levels (<10%), grain hardness increases, leading to higher equipment wear and greater energy requirements, while high moisture content (> 16%) causes material adhesion and deterioration in grinding quality. The optimal moisture ranges for minimal energy consumption (2.3–3.6 kWh/t) was identified as 8–12%, which is twice as efficient as roller mills (6–8 kWh/t) and hammer crushers (8–10 kWh/t). In addition, high uniformity in particle size distribution (up to 96%) was achieved, with minimal non-standard fractions (≤ 5%). Moreover, special attention was given to the structural advantages of the horizontal rotary crusher, where grain disintegration occurs through shearing and chipping—the least energy-intensive mechanisms. The influence of rotor speed (950 rpm) and working clearance (0.4 mm) was examined on productivity (230–260 kg/h) and grinding quality. Adjusting grain moisture prior to grinding is a critical factor in reducing energy consumption in the feed industry. A moisture content of 12–14% is recommended to optimize energy efficiency, feed quality and equipment durability.