Use of individual race results in the estimation of genetic parameters of trotting performance for Finnhorse and Standardbred trotters

Authors

• T. THUNEBERG-SELONEN
• J. PÖSÖ
• E. MÄNTYSAARI

DOI: https://doi.org/10.23986/afsci.5635

Abstract

The heritability and repeatability for trotting performance traits were estimated from individual race results. Data comprised of records from 1991 to 1995 for 4808 Finnhorses and from 1993 to 1995 for 5869 Standardbred trotters. The statistical model included the additive genetic effect of an animal and two permanent environmental effects, and the fixed effects of sex, age, starting method*starting lane combination, driver and race. The first permanent environmental effect described repeatability over a horses career while the second one characterized repeatability within a racing year. Variance components for three trotting performance traits were estimated by the animal model and the method of restricted maximum likelihood (REML). Heritability and repeatability estimates were moderately high for time at finish (h 2 =0.230.28 and r=0.500.57), moderate for ranking within a race (h 2 =0.12 and r=0.25) and low for earnings (h 2 =0.050.09 and r=0.150.18). Time at finish seemed to be the most usable measure of trotting performance because of its wide information substance. However, time at finish does not take into account records of disqualified horses or of those which did not finish, but use of earnings, either from individual race results or preferably from annual records, is one possible way to consider records of such horses.;