During the period from 2005 to 2020, the trotting horse breeding industry in Ukraine suffered significant losses, and the number of breeding horses of the Oryol breed and the Ukrainian trotting breed group being approved decreased by 60–80%, respectively [3]. Today farms engaged in the breeding of pedigree horses are unprofitable, as a result of which the gene pool is impoverished and the herd is reduced. Under such conditions, it is quite difficult to carry out selection in the direction of genetic diversity. In this way, in order to plan effective samplings and selections of animals, it is necessary to carry out a comprehensive assessment of not only the breeding herd, but also the young animals that undergo testing [5]. For this purpose, an expert evaluation of trotting horses and thoroughbred riding breeds is held annually at hippodromes. Research purpose was to analyse the current condition of breeding young trotting horses that are tested at hippodromes, according to exterior and performance indicators. Research material and methods. The research was carried out in the production conditions of the branch “Odesa Hippodrome” and Communal enterprise “Kyiv Hippodrome”. The horses of trotting breeds aged 2–4 years, which were tested at these hippodromes and belonged to the following branches of State Enterprise “Horse Breeding of Ukraine” were selected for the experiments: Dibriv stud farm № 62, Zaporizhzhia stud farm № 86, Loziv stud farm № 124 and Lymariv stud farm № 61 (n = 93). To characterize the growth and development of the experimental animals, the following measurements were taken: height at the withers, chest girth, and wrist girth. The measurements were carried out using a measuring stick and a measuring tape according to the method by A. Krasnikov (1959). When evaluating trotters based on the obtained measurements, the Instruction on the grading of breeding horses was used. The working capacity of the studied herd of horses was assessed by the best agility at a distance of 1600 meters. Based on these data, the average rate of agility of horses in terms of breeds and horse owners was derived, and a statistical analysis was carried out in Excel using classic biometric methods by N. Plokhinskyi. Research results. To assess the exterior indicators of the trotter herd, the expert commission conducted a brood of trotters of all sex-age groups and breeds (n = 72). Subsequently, the results of breeding horses at the Dibriv stud farm, which were tested at Communal enterprise “Kyiv Hippodrome” (n = 21), were added to the obtained indicators. According to the breeding results at Odesa Hippodrome, the highest average score for exterior – 5.52 was given to the horses of the Dibriv stud farm. The average rating of this farm horses, which are tested at both hippodromes, was 5.11 points on the grading scale. According to working capacity indicators, the Dibriv stud farm leads among all farms – 7.9 points. Horses of the Zaporizhzhia stud farm received an average score of 5.26 for exterior, and 6.2 for working qualities; from Loziv – respectively, 4.64 and 7.1. The horses of the Lymariv stud farm according to the measurements did not meet the minimum requirements of the Instruction on the grading of breeding horses, and had the lowest average score for performance – 4.7. When studying the horses’ working qualities, it was found that the Dibriv stud farm representatives have the best agility indicators. The average score for working capacity by farm according to the Instruction on the grading of breeding horses is: Dibriv stud farm – 7.9; Zaporizhzhia – 6.2; Loziv – 7.1; Lymariv – 4.7. The herd of trotting stallions of all farms is mostly inferior to mares in terms of both appearance and performance. Consequently, according to the results of the realized actions, the mares received the 1st degree certificate.