Genetic inbreeding depression load for conformation defects and dressage traits in the Pura Raza Española horse

Results highlight the importance of modeling individual-specific IDL in PRE genetic evaluations. IDL explained a substantial proportion of phenotypic variance and showed trait-specific patterns. Incorporating IDL into selection strategies enables more informed breeding decisions, allowing the retention of valuable genetic lines while minimizing deleterious inbreeding effects, thereby supporting more sustainable and resilient genetic improvement.