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

Abstract

The most popular use of the Pura Raza Español horse in sport is for dressage competitions. Tests on young sport horses were first established in 2004 in Spain to collect data for the genetic evaluation of this breed's suitability for dressage. The aim of this study was to compare eight different models to find out the most appropriate way to include the rider in the genetic evaluation of dressage. A progressive removal of systematic effects from model was also analysed. A total of 8867 performance records collected between 2004 and 2011 from 1234 horses aged between 4 and 6 years old were used. The final score in the dressage test was used as the performance trait. The pedigree matrix contained 8487 individuals. A BLUP animal model was applied using a Bayesian approach with TM software. The horse's age, gender, travelling time, training level, stud of birth and event were included as systematic effects in all the models. Apart from the animal and residual effects that were present in all models, different models were compared combining random effects such as the rider, match (i.e. rider-horse interaction) and permanent environmental effects. A cross-validation approach was used to evaluate the models' prediction ability. The best model included the permanent environmental, rider and match random effects. As far as systematic effects are concerned, the event or the stud of birth was essential effects needed to fit the data.

Analysis of competition performance in dressage and show jumping of Dutch Warmblood horses

“…This is in line with earlier findings in the literature (e.g. Bartolom e et al 2013;S anchez Guerrero et al 2014) which conclude that ignoring a rider effect resulted in an overestimation of the genetic parameters. The structure of the data may complicate disentangling the effects of the horse and the rider.…”

“…; Sánchez Guerrero et al . ). However, many riders only ride a limited number of horses and many horses are ridden by only one rider in competition.…”

“…A well-balanced communication between rider and horse is important for a good performance of the horse (Peham et al 2004;Sch€ ollhorn et al 2006). For that reason, it is important to consider the rider effect in the genetic evaluations of horses (Bartolom e et al 2013;S anchez Guerrero et al 2014). However, many riders only ride a limited number of horses and many horses are ridden by only one rider in competition.…”

Morphological and genetic diversity of Pura Raza Español horse with regard to the coat colour

“…renowned lineages which are heavily used as breeders(Valera, Molina, Gutiérrez, Gómez, & Goyache, 2005). Thus, the number of stallions employed among breeders is limited considering their census, narrowing its genetic base (Sánchez-Guerrero,Cervantes, Valera, & Gutiérrez, 2014). In this sense, F IS values were also low and positive in most subpopulations, suggesting a slight excess of homozygosity and some kind of directional mating among them.Those differential traits were probably produced by the different primary selection objectives derived from the breeders′ aims as well as by restrictions derived from fluctuations of the breeding studbook policies.…”

Genetic structure and connectivity analysis in a large domestic livestock meta‐population: The case of the Pura Raza Español horses

“…Breeders of PRE horses have a clear and well-defined breeding policy, which includes conformation, gaits and functionality (Classical Dressage) as the main selection criteria (Sánchez, Cervantes, Valera, & Gutiérrez, 2014). Since the early 1960s, breeding animals have been steadily exported abroad to establish subpopulations able to provide PRE horses to the commercial equine industry worldwide.…”