EFFICIENCY OF SELECTION MODELS ACCORDING TO GENEALOGICAL GROUPS IN OBTAINING BREEDING MARES IN THE ORLOV’S TROTTER OF THE UKRAINIAN POPULATION

Abstract

The object of research was the Ukrainian massif of breeding mares of the Orlov’s Trotter, registered on January 1, 2022 (n=194). The 75.1% (145 mares) of all breeding mares were tested on hippodromes. It was determined that there were low-level negative correlations between mares' agility indicators and body measurements. However, positive relations were established analyzing the correlations between the record agility and the measurements of the mares of different studs. It was determined that mares tested at the Kyiv Hippodrome with a high probability (p>0.95-0.99) prevailed in terms of agility of herdmates tested at the Odessa Hippodrome, both in terms of record agility and agility revealed in all age periods. There were found 299 Orlov’s Trotters of the 2.10 min agility class and more lively, of which 25 horses entered the 2.05 min and faster, 2 horses - to class 2.00 min and faster during the selection period from 2001 to 2021. It was determined that mares of the Orlov’s Trotters of the Ukrainian population of the agility class of 2.05 min were not found to be faster, the fastest mare in the modern reproductive composition is Antalya 2.05,7, gray, 2014 (Aphorism - Artistka) of the Dibrivsky stud. Of all tested mares, only 13.8% have a high class of agility 2.10 min faster. The predominant number of mare’s agility class’s 2.10.1-2.15.0 min (31.1%) 2.15.1-2.20 min (24.1%). Based on the analysis of pedigrees, it was determined that the domestic population of the Orlov’s Trotter is structured according to 8 genealogical lines and 32 maternal families. The most developed region in terms of both stallions and mares is Barchuk-Zapad line (40.6 and 31.4%, respectively). The largest number of tested mares comes from the breeding line Barchuk-Zadap and Pion lines. The highest record agility for the distance of 1600 m belongs to mares Voin (136.6±1.75 s), Barchuk (136.8±1.25 s), Ispolnitielny (137.3±4.19 s), Boltik (137.6 ±5.11 s) and Pilot (137.7±2.44 s) lines. The most precocious (the fastest in a 2-year-old mare) are Ispolnitielnyi (145.7±3.78 s), Barchuk (147.3±1.27 s), Barchuk-Zapad (147.8±1.45 s) lines. The 53 genealogical combinations were recorded in the studied array of mares. The most numerous interlineal combinations were Pion × Pion (13 mares), Barchuk × Zapad (taking into account that the Zapad branch originates from the Barchuk line) (9 mares), as well as crosses Zapad × Pion (10 mares) and Zapad × Ispolnitielny (9 mares). In terms of record agility, there prevailed mares obtained from crosses Voin × Pion (134.1±3.07 s), Ispolnitielnyi × Zapad (134.6±3.89 s), Pilot × Pion (134.8±4.76 s). Thus, these combinations are the most effective in selecting parental pairs to obtain the fastest mares for the reproductive population.