Integrating Performance Records and Genetic Evaluations in Spanish Horse Populations Competing in Olympic Disciplines.

Overview

• This study analyzes performance and genetic data from Spanish horses competing in Olympic equestrian disciplines to assess their genetic quality and progress.
• It integrates performance records with pedigree information using a unified genetic evaluation model to compare breeds and guide breeding programs.

Study Purpose and Context

• The research focuses on the main populations of Spanish horses involved in three Olympic equestrian disciplines: Dressage, Show Jumping, and Eventing.
• It aims to evaluate genetic merit—measured through Estimated Breeding Values (EBVs) and a Genetic Global Index (GGI)—to improve the effectiveness of official breeding programs.
• The study covers nearly two decades of competitive records and genetic data to assess trends and breed differences.

Data Used

• Performance records spanned from 2004 to 2023, involving:
  • Dressage: 101,093 participations
  • Show Jumping: 319,000 participations
  • Eventing: 17,535 participations
• Pedigree data included:
  • Dressage: 35,589 horses
  • Show Jumping: 33,935 horses
  • Eventing: 12,102 horses

Methodology

• Performance and pedigree data were analyzed using BLUP (Best Linear Unbiased Prediction) animal models, providing standardized EBVs with a mean of 100 ± 20.
• A Genetic Global Index (GGI) was calculated as a composite measure of genetic merit.
• A single unified genetic evaluation model was applied to all studbooks and breeds, allowing direct comparisons of genetic quality across breeds.

Key Findings

• Dressage:
  • Three breeds analyzed: Caballo de Deporte Español (CDE), Pura Raza Española (PRE), and Spanish Anglo-Árabe (AA).
  • Mean EBVs were similar among breeds both in the full population and in the top 10% of performers.
  • Positive genetic trends (improvement over birth years) were observed in CDE and PRE.
  • No significant genetic trend observed in AA.
• Show Jumping:
  • CDE exhibited the highest mean EBVs, reaching up to 109.27 with accuracies up to 0.72.
  • A clear positive genetic trend was detected in CDE, indicating ongoing improvement.
• Eventing:
  • CDE and AA showed similar EBVs.
  • PRE displayed consistently lower EBVs but showed a comparatively more favorable genetic trend over time.
• Selection Intensity and Breeding Decisions:
  • PRE breeders consistently used animals with GGI above 100, showing stronger genetic selection pressure.
  • CDE and AA demonstrated discrepancies between genetic merit and reproductive use, suggesting less optimal use of genetic information.

Implications and Recommendations

• The unified Spanish genetic evaluation system is effective in generating reliable comparative data across breeds.
• It has enabled measurable genetic progress, particularly in CDE and PRE populations.
• Breeders could improve the selection response by better integrating genetic data into reproductive decisions.
• Improving decision-making and the use of genetic information within breeding programs can maximize genetic gains.

Conclusion

• This extensive integration of performance and genetic evaluations supports optimized breeding strategies in Spanish Olympic equestrian disciplines.
• The approach facilitates direct breed comparison, guides selection intensity, and highlights areas for enhanced breeder education and program management.