Genetic parameters for harmony and gaits in Hispano-Arabe horses estimated by Bayesian methods and Restricted Maximum Likelihood

Genetic parameters for harmony and gaits (walk, trot and canter) were estimated in the Hispano-Arabe horse breed. The data set included 12,957 records of 901 animals, collected from 2000 to 2014, and was analysed by Bayesian procedures (Gibbs Sampling) and Restricted Maximum Likelihood. The multivariate animal model with repeated records included management group, sex, combination of year and event of evaluation, season of evaluation as fixed effect, plus age at classification and proportion of Arabian genes as linear covariates and additive genetic, permanent environmental and judge as random effects. Bayesian heritability/repeatability estimates for harmony, walk, trot and canter were 0.18/0.35, 0.10/0.18, 0.13/0.27 and 0.13/0.20, respectively, with standard errors from 0.02 to 0.05. Estimates of additive genetic correlations among harmony and gaits traits ranged from 0.45 to 0.83, and were stronger between harmony and trot or canter than between walk and trot. Analyses by Restricted Maximum Likelihood yielded similar results, and correlations between breeding values estimated by both procedures ranged from 0.80 to 0.94.