Repeatability of free jumping parameters on tests of different duration

The aim of this study was to compare the effect of the horse on various performance tests calculated for free jumping parameters. Free jumping parameters were measured on the basis of video image analysis. Three groups of horses were compared: 141 stallions on the 11-month test (744 jumps), 50 stallions on the 8-month test (301 jumps) and 43 stallions on the 100-day test (221 jumps). Linear measurements of taking off and landing distances, height of limb lifting above the obstacle, height of elevation of “bascule points” and position of the head were measured. The statistical model was comparable for all tests including the random effect of the horse, fixed effects of the test, height of the obstacle and successive number of the jump. Repeatability on the 11-month test was high for taking off, landing and bascule parameters and reached values from 0.50 to 0.60. Repeatability of heights of limb lifting in the 11-month test was lower, but at the same value of about 0.3 for front and hind limbs. In the test of the same duration but for horses selected as the best ones-the repeatability of limb lifting was higher for front limbs and almost the same for hind limbs. Repeatability of the parameters that characterised the length of the jump and the bascule of the horse was higher in the test for the best horses and reached 0.82 for landing and 0.66-0.77 for bascule points. Repeatability of almost all jumping parameters reached highest values in the group of the best horses with longer training.