## 1 Introduction  
Modern livestock complexes for the maintenance of large cattle specialized in milk and beef production are enterprises with a high level of automation of technological processes. However, some of these processes cannot be executed with 100% efficiency without human intervention [1]. One such process is the feeding of animals, which involves a complex of preparatory measures for calculating and justifying the composition of feed components and the energy value of the mixed diet [2]. In general, when forming the feeding ration for animals, the farmer adheres to a strictly rational approach from the perspective of milk or beef productivity, as well as the preservation of animal health, ensuring productive longevity [3]. Achieving high levels of animal efficiency in terms of milk and beef production is determined by the feedstock of the animals, the balance of the diet, and the energy value of the feed [4]. The nutritional or energy value of feeds used for animal feeding is typically determined through preliminary analysis, where a key indicator is the dry matter content. This indicator determines the amount of nutrients that the animal will receive by consuming a specific component of the feed mixture [5]. The dry matter content in plant feeds for agricultural animals is measured using gravimetric, dielometric, and optical methods. The gravimetric method, most common in countries with low investment attractiveness in the agricultural sector, particularly in terms of technological provision, involves the sampling of the analyzed feed, weighing, and then recording the initial mass indicator of the taken feed portion. Subsequently, the feed portion undergoes drying by placing it in a dehydrator or a household drying chamber using special containers. It is processed until the mass of the processed feed portion ceases to decrease (indicating complete drying of the sample). By calculating the proportion, the percentage of lost moisture is determined, and conclusions are drawn about the level of dry matter/moisture of the investigated feed. This described method is most frequently used by farmers to determine dry matter indicators on the farm without laboratory services. However, it does not provide entirely accurate results due to the fact that complete drying of the feed to 100% is impossible when interacting with the surrounding environment. Part of the feed may adhere to the used utensils and absorb moisture from the surroundings. The significant disadvantages of this method include it being a fire hazard, as well as the labor-intensive sample preparation (up to 30 min per sample) [1; 6]. Among commercial devices, the dielcometric method has gained the widest prevalence, which is based on the correlation between the dielectric permittivity of a material and its moisture content. Instruments that operate based on the dielcometric method are designed as a rod, one end of which is placed into the tested sample, while the measuring part is located at the other end. The moisture assessment results can be obtained within 20 s. However, a significant drawback of the method is that the tested sample must be tightly compressed, which is why the method is most effective for determining the moisture content of wood, feed compacted in a trench, or gathered into briquettes using special presses. Otherwise, the device introduces a high level of error [1; 7]. Optical methods represent the most promising direction, with broad developmental potential compared to the methods mentioned above. Instruments based on optics are more costly in terms of development and manufacturing. However, the potential of the hardware aspect offers significantly wider possibilities in terms of the number of determinable parameters. For example, devices released to the market, such as Aurora NIR (Mayville, WI, USA) and Dinamica Generale (Poggio Rusco, Italy), enable not only the determination of dry matter content but also protein, ash, and fiber. The principle on which the operation of such devices is based is near-infrared spectroscopy [1; 8].