Genetic parameter estimation of sport performance traits in Iranian jumping horses using REML

Genetic evaluation of sport horses using various methods is commonly carried out in many countries, except for Iran. Accurate estimation of genetic parameters for functional traits in horses has always been a subject of interest among livestock breeders. The aim of this study was to investigate the genetic parameters of athletic performance traits in Iranian jumping horses. Traits include race completion time (RCT), rank at the end of the competition (REC), and number of errors in the competition (NEC). The study were conducted based on Equestrian Federation of Iran (FEI) athletic performance records of 1498 horses (10–23 years old). The genetic parameters were estimated by using Restricted Maximum Likelihood (REML) procedures and airemf90 software. The statistical model included fixed effects of birth year, sex, age, breed, height of obstacles, date/city, level of difficulty of the event and random effects of rider, permanent environment and an additive genetic effect. Heritability of RCT, REC and NEC traits were estimated 0.03, 0.11 and 0.09 and their repeatability were 0.16, 0.25 and 0.13, respectively. Genetic and phenotypic trends of RCT, REC and NEC traits were estimated -0.002, 0.0091, 0.0003 and -0.7057, 0.2575, -0.0807, respectively. According to this result, the performance traits are highly affected by environmental factors, especially the effect of the rider, but among the studied traits, selection based on rank traits can lead to more genetic progress. It can be concluded that we can apply these parameters to improve the genetic potential of show jumping performance records and design the appropriate breeding strategies for horse jumping population in Iran.