EN
The objective of this study was to estimate variance components of Polish Arab horses’ racing performance. The traits studied were the log of annual earnings and rank. Fixed effects of the year of race, herd, sex, the annual number of starts and random animal and permanent environment effects were evaluated on both earnings and rank at finish in Polish Arab horses. The obtained data included 2243 records on 4- and 5-year-old horses by 143 sires. Only races in which 4- and 5-year-olds competed were used. Heritability estimates of earnings and rank at finish were 0.22 and 0.25, respectively. Repeatability estimates of these traits were the same as heritability estimates. All the estimates of genetic and phenotypic correlations between the log of earnings and rank at finish were high and positive. Earnings and rank are good criteria for genetic improvement. Rank seems to be a better measure of racing performance.