Discriminant Canonical Analysis of the Contribution of Spanish and Arabian Purebred Horses to the Genetic Diversity and Population Structure of Hispano-Arabian Horses.
Authors: Marín Navas Carmen, Delgado Bermejo Juan Vicente, McLean Amy Katherine, León Jurado José Manuel, Torres Antonio Rodriguez de la Borbolla Y Ruiberriz de, Navas González Francisco Javier
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary Researchers analysed over 207,000 pedigree records spanning 135 years to examine genetic diversity and population structure across Arabian, Spanish Purebred, and Hispano-Arabian horses, employing canonical discriminant analysis to quantify how each parent breed contributes to the hybrid population's genetic makeup. The Hispano-Arabian breed displays closer genetic affinity to the Arabian than the Spanish Purebred line, with current inbreeding coefficients of 2.89% compared to 8.44% and 8.50% in the purebred populations respectively—a difference reflecting the hybrid's broader genetic base. Genetic diversity loss is modest across all three breeds (4–7%), but the study identified increasing inbreeding trends that could be mitigated through selective use of founders with high genetic contribution indices and by extending generation intervals. For practitioners involved in breeding programmes, these findings suggest that prioritising individuals with optimal genetic contributions whilst maintaining longer intervals between generations offers a practical strategy to preserve diversity and limit accumulation of deleterious recessive traits. The research underscores the value of detailed pedigree analysis in managing population health, particularly for breeds where strategic outcrossing decisions could sustain genetic potential across generations.
Read the full abstract on PubMed
Practical Takeaways
- •Breeders should prioritize selecting animals with high Genetic Contribution Index (GCI) to balance founder contributions and maintain genetic diversity across generations
- •Consider extending generation intervals in breeding programs, particularly for Arabian and Spanish Purebred horses which show higher inbreeding coefficients (8.4-8.5%) compared to Hispano-Arabian (2.89%)
- •Monitor pedigree completeness and use population genetic tools to track inbreeding trends and make data-informed breeding decisions to prevent accumulation of deleterious alleles
Key Findings
- •Hispano-Arabian horses show high population structure and are genetically more closely related to Arabian Purebred (6%) than Spanish Purebred horses
- •Inbreeding levels differ significantly across breeds: Arabian Purebred 8.44%, Spanish Purebred 8.50%, and Hispano-Arabian 2.89%
- •Current genetic diversity loss estimated at 6% for Arabian Purebred, 7% for Spanish Purebred, and 4% for Hispano-Arabian horses
- •Increasing generation interval length could effectively reduce inbreeding accumulation in all three studied horse breeds