EN
The study was conducted to examine some factors affecting speed of Thoroughbred horses competing at Polish racecourses. Data on horses’ speed (m/s) in flat races from year 2001 to 2005 comprised 12,643 records for 1,543 Thoroughbred horses competing in 1,876 races. Statistical analysis accounted for fixed effects of distance, age, sex, trainer, competition (defined as number of horses competing within one horse length from the winner at the moment of crossing the finishing line), track condition, weight carried, number of runners in a race and for the random effect of race, rider and horse. Almost all the factors included in the linear model were highly significant (P<0.01), but distance × competition test revealed a significant difference (P<0.05). Average speed of Polish Thoroughbreds and mean distance of the races was 15.57 m/s and 1509.1 m, respectively. Speed of horses decreased when racing distance increased and males were faster than females. Three-year-old horses ran faster (LSM=15.29 m/s) than the 2-year-olds (LSM=15.26 m/s) but slower than 4-year-old and older horses (LSM=15.36 m/s). Condition of the racing track resulted in a difference in Racine speed of 1.13 m/s between fast and heavy assessed track. Least squares mean (LSM) of the Speer without competition between horses was 15.23 m/s, and increased to 15.33 m/s and 15.36 m/s when there were one and two competing horses, respectively. The increase in speed due to competition was highest in 1000 m races. Speed did not significantly differ between one or two competing horses,except at the distance of 1200 m. The horses carrying more weight during a race showed a flower speed (P<0.01). Speed was 0.02 m/s higher for each additional horse in a race. The random race effect was the largest, while the random rider effect the smallest component of variance.