DETERMINATION OF HERITABILITY OF RIDING HORSES IN VARIOUS DISCIPLINES OF EQUESTRIAN SPORT
Authors: Rudak A. N. 
Published: December 2019

Raising the competitiveness of horses of reared breeds, as well as reaching the European level is impossible without accelerated improvement of their breeding traits based on the modern breeding methods. Joint performances in various disciplines of equestrian sports of horses of Belarusian breeds with the best horses of foreign countries showed that the domestic livestock is significantly inferior in terms of performance. In this regard, there is an urgent need for a thorough assessment and development of fundamentally new methods of horse breeding according to performance based on the use of achievements of population genetics in the horse riding industry of the republic.
The aim of the research was to determine the genetic parameters (repeatability and heritability) of performance traits and assessment of the exterior of riding horses in various equestrian disciplines.
The research was carried out at the leading farm for breeding horses of Trakehner, Hannover and other riding breeds – Institution “Republican Center for Olympic Training of Equestrian Sports and Horse Breeding” of the Minsk district in the Minsk region.
The summary protocols of the results of its factory tests were the materials for assessing the motor, jumping, and athletic traits of young riding horses.
The coefficient of heritability of traits was calculated by the method of constructing one-way dispersion complexes, with gradations of phenotypic traits of the progeny of the used producing stallions. Heritability coefficients were as follows: assessment of the exterior – 0.109, performance – 0.365***, measurements (height at the withers) – 0.175**. Thus, as a result of calculations, a relatively low heritability of the studied traits of riding horses was determined, especially according to the results of evaluating the exterior and measurements, which was due to the relatively small number of horses in groups, biological characteristics of the experimental material and the effect of external factors.
The coefficients of rank correlation of the evaluation indicators of riding horses are determined, participating in competitions in various disciplines of equestrian sports and having passed factory tests at the age of 2 years. It was determined that coefficient of rank correlation of performance was the highest in schooling competitions (rs = 0,484**). This indicates that a moderate direct positive relationship reliably exists between the test results of riding horses at young age and their performance in sports. The lowest correlation coefficient was in triathlon (rs = 0,164).
It was determined that a significant effect on athletic performance is made not only by many genetic factors that determine the required inclinations of an animal, but also by the quality of the horse's preparation during the training process, its character and temperament, etc. In this regard, the correlation between the results of factory tests of young animals in terms of performance and their future sports career was studied. It was determined that the horses that received the highest score at young age according to the results of their factory tests were also the most successful in sport, were prize-winners of international competitions in triathlon. Most of the horses that performed in sports were horses with an assessment of athletic performance at young age of 8.0 scores – 37.4%, only 29.7% were horses with rating of 9.0 scores at factory tests, 55.5% were horses with rating of 5.0 to 7.0 scores.
The results of the studies prove that the coefficients of heritability and repeatability of the assessment of performance indicators of riding horses remain quite low. Correlation is positive, but not strong enough, which reduces the efficiency of selection of horses at young age to use them in sports in the future. Thus, it is necessary to follow the way of both increasing the number of horses tested at young age, and their rigorous selection at all stages of the breeding process.