Modelling genetic evaluation for dressage in Pura Raza Español horses with focus on the rider effect.

The study evaluates the potential genetic predisposition of Pura Raza Español horses for dressage and the impact of riders as part of the evaluation process.

Research Purpose and Methodology

• The purpose of the research was to establish the most effective model for evaluating the genetic potential of Spanish Purebred, also known as Pura Raza Español horses, for dressage. More specifically, the research aimed to establish how to properly account for the impact of the rider in the genetic evaluation of these horses.
• The researchers took 8867 performance records collected between 2004 and 2011 from 1234 horses aged 4-6 years old for analysis. They used dressage test scores as their performance indicator. The data for evaluation also included the pedigree details of 8487 individuals.
• A BLUP (Best Linear Unbiased Prediction) animal model was used for evaluation, incorporating systematic effects such as horse’s age, gender, travel time, training level, stud of birth, and event. A Bayesian approach was used in the analysis of these systematic effects.

Comparative Analysis of Different Models

• Different models were compared with the inclusion of varying random effects such as the rider, match (i.e., rider-horse interaction), and permanent environmental effects. All models considered included animal and residual effects.
• The comparison between these models was made using a cross-validation approach. This method is used to estimate how accurately a predictive model will perform in practice.

Research Findings and Conclusion

• The research concluded that the best model for assessing the genetic effect on Pura Raza Español horses’ performance in dressage tests includes components of rider and horse interaction, along with permanent environmental effects.
• In terms of systematic effects, the inclusion of the event or the birth stud provided essential data for a good fit of the model.
• The implication of these findings may affect the way genetic predisposition for dressage in horses can be evaluated, taking into serious consideration factors such as rider-horse interaction and non-genetic environmental variables.