Effects of Selection on Breed Contribution in the Caballo de Deporte Español.
Authors: Bartolomé Ester, Valera Mercedes, Fernández Jesús, Rodríguez-Ramilo Silvia Teresa
Journal: Animals : an open access journal from MDPI
Summary
Spain's Caballo de Deporte Español (CDE) programme has implemented selective breeding for sport performance over 15 years, yet whether these efforts have been strategically sound remains unclear. Researchers analysed the complete pedigrees of 19,045 registered animals and their performance records in show jumping, dressage and eventing, using genetic parameters including inbreeding coefficients, generation intervals and estimated breeding values (EBVs) tracked from 2004 onwards. The breed showed modest but measurable genetic gain—offspring EBVs exceeded those of their parents—though inbreeding coefficients (0.32%) revealed some degree of uncontrolled consanguineous mating and an effective population size of only 204, which raises medium-term sustainability concerns. With a generation interval of nearly 11 years and incomplete coordination amongst breeders, the CDE programme demonstrates the classic trade-off facing sport horse studbooks: genetic progress in jumping ability has been achieved, but at the risk of eroding the genetic diversity required to maintain long-term health and performance. Farriers, vets and coaches working with CDE bloodlines should recognise that whilst selection objectives are being met, breeding decisions require tighter coordination and strategic outcrossing to preserve population resilience without sacrificing the gains made over the past 15 years.
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Practical Takeaways
- •Selection for Show Jumping performance in CDE has been effective with measurable genetic gains, but breeders should coordinate efforts to maintain genetic diversity and avoid excessive inbreeding
- •The effective population size of 204 is relatively modest; breeders need strategic management practices to prevent future loss of genetic variation that could limit breeding options
- •Continue monitoring breeding values across disciplines (Dressage, Eventing) alongside Show Jumping to ensure balanced selection and avoid unintended negative consequences in other sport disciplines
Key Findings
- •Over 15 years of selection, Show Jumping EBVs in CDE offspring were generally higher than parental EBVs, indicating positive genetic response to selection
- •Inbreeding coefficient (F = 0.32%) was higher than expected under random mating, reflecting deliberate selective breeding practices
- •Effective population size of 204 with mean inbreeding coefficient of 0.32% and average relatedness of 0.09% indicates moderate genetic diversity constraints
- •Generation interval of 10.87 years and equivalent complete generations of 1.95 suggest relatively slow generational turnover in the breed