Genetic Structure Analysis of the Pura Raza Español Horse Population through Partial Inbreeding Coefficient Estimation.
Authors: Perdomo-González Davinia I, Sánchez-Guerrero María J, Molina Antonio, Valera Mercedes
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary Understanding the genetic architecture of the Pura Raza Español (PRE) breed is essential for maintaining population health whilst preserving breed characteristics, yet little has been known about how inbreeding patterns have shifted across the breed's recent history. Perdomo-González and colleagues analysed genealogical records from over 328,000 PRE horses to track inbreeding coefficients, relatedness measures, and crucially, partial inbreeding coefficients (Fij) that reveal each animal's inherited inbreeding burden from specific common ancestors. The average inbreeding coefficient fell measurably from 8.45% to 7.51% over two decades, with analysis of 10,244 ancestral contributors showing that whilst the total number of influential ancestors has increased, the genetic contribution from any single ancestor has proportionally decreased—each modern horse now inherits inbreeding from approximately 170 common ancestors rather than relying on a narrow genetic base. The researchers attribute this encouraging genetic diversification to larger population numbers, judicious use of artificial insemination, and breeders' growing ability to select for performance and conformation traits rather than pedigree reputation alone, suggesting that data-informed breeding decisions can genuinely reduce inbreeding depression in sport horse populations. For practitioners advising on breeding programmes, this work demonstrates that systematic genetic monitoring is already yielding tangible benefits in the PRE population and underscores the value of pedigree analysis in identifying which ancestral lines deserve priority in breeding decisions.
Read the full abstract on PubMed
Practical Takeaways
- •Modern breeding selection based on functionality, conformation, and breeding values rather than pedigree reputation is effectively reducing inbreeding in PRE populations
- •Breeders now have access to detailed genetic information (partial inbreeding coefficients) to make more informed mating decisions and minimize inbreeding depression
- •Increased census size and limited artificial insemination use have naturally distributed genetic contributions across more ancestors, reducing genetic bottlenecks in the breed
Key Findings
- •Average inbreeding coefficient (F) in PRE population decreased from 8.45% to 7.51% over 20 years
- •10,244 common ancestors contributed to partial inbreeding coefficients across 328,706 animals with 58,772,533 total records
- •Each descendant animal receives genetic contribution from an average of 170 common ancestors
- •Contributions from influential ancestors have changed over generations, with increased number of ancestors but decreased individual proportional contribution