## 3 Results and Discussion
Their number throughout the body is genetically determined and is essentially fixed at the birth of the animal. With the development and growth of the organism, only the width and length of the fibers increase, reaching their maximum size, which is typical of the breed, species, and even the individual at maturity. However, the achievement of maximum fiber size depends on the nutritional status of the animal. As the animal ages, the number of muscle fibers decreases, which is compensated, to some extent, by an increase in their thickness. More detailed information about the slaughter value of the tested animals is provided by the analysis of the ratio of meat to fat and bone. The data in Table 3 show that in the carcasses of fools, 1 kg of fat has an average of \(-15.92\) kg of meat, and 1 kg of bone has an average of 2.50 kg of meat. The first index is very important in this analysis, as it confirmed the higher (\(p\leq 0.05\)) dietary value of focal carcasses in comparison with those of adult horses. In the carcasses of adult horses, unfavorable results regarding the ratio of meat to fat and bone were observed, as these ratios were respectively 8.15 and 3.00 for carcasses of adult horses and 7.55 and 2.76 for carcasses of older horses. As the weight of the animal progressively increased, changes in the meat-to-bone ratio were also observed. For example, a 10 kg increase in the weight of a cattle carcass increased the meat-to-bone ratio by 0.031 [44]. The decisive factor in the chemical composition of horsemeat was the age of the animal [7; 33]. National studies conducted by [PERSON] and [PERSON] [38] and [PERSON] and [PERSON] [39] indicated that foal meat is characterized by a high content of protein (ranging from 21.16% to 22.44%) and water (ranging from 73.05% to 75.51%) and a low amount of fat (ranging from 0.86% to 2.0%). In other studies, the following numerical values were presented to characterize the basic chemical composition of the longest dorsal muscle: dry matter content ranging from 25.47% to 27.52%, water content ranging from 72.48% to 74.53%, protein content ranging from 19.94% to 22.50%, and fat content ranging from 1.56% to 4.65% [57]. On the other hand, [PERSON] [60] states that foal meat is characterized by a protein content ranging from 12.8% to 21.4% and a fat content ranging from 3.7% to 6.2%. According to many authors, as horses age, their meat contains decreasing amounts of water, with increasing amounts of fat and minerals [5; 29; 37; 61; 62]. [PERSON] et al. [37] reported that the water content in horsemeat is 74.1%, protein content is 21.5%, and fat content is 2.6%. The results of the chemical composition analysis of the meat of fools, as well as young and old horses, are presented in Table 4. The meat of young animals generally contains less protein and fat and more water compared with the meat from older animals. This fact was confirmed by the study presented in this paper. Statistically significant differences were observed depending on the age of the horses, specifically in relation to water, protein, and fat contents. It should be noted that the highest (\(p\leq 0.05\)) water content in the meat was found in fools (76.38%) and young horses (72.99%) compared with the meat of old horses (70.94%). The highest (\(p\leq 0.05\)) protein content was found in the groups of adult horses compared with group I. The amount of fat in the meat increased statistically significantly with the age of the horses. However, no statistically significant differences were found between age and ash content. The level of this component ranged from 1.01% (group II) to 1.19% (group III). The obtained distribution of numerical values confirmed the generally occurring regularity that with the age of horses (especially after 2-3 years), muscle tissue grows more intensively, and only later does fat tissue grow, which causes a simultaneous decrease in the amount of water in the meat in favor of the protein and fat content of this raw material.