Morpho-Functional Traits in Pura Raza Menorquina Horses: Genetic Parameters and Relationship with Coat Color Variables.
Authors: Perdomo-González Davinia I, García de Paredes Rocío de Las Aguas, Valera Mercedes, Bartolomé Ester, Gómez María Dolores
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary The Pura Raza Menorquina studbook restricts breeding to black-coated horses with minimal white markings, yet little was known about how coat colour traits genetically relate to the morpho-functional characteristics that breeders actually select for. Researchers evaluated 46 linear traits across 333 horses (≥4 years old) using standardised scoring by multiple appraisers, then applied Bayesian animal models to estimate heritabilities and genetic correlations within a pedigree of 757 animals. Coat colour quality showed moderate heritability (0.36) with particularly strong genetic correlation to upper neck line conformation (0.816), whilst percentage of white marks (heritability 0.23) demonstrated substantial negative genetic correlations with most functional traits—particularly hoof form (0.638)—suggesting these traits have somewhat independent genetic architectures. For practitioners and breeders, this means selecting against white markings may inadvertently improve functional traits, though the genetic independence of coat quality and markings indicates these characteristics warrant separate selection strategies to avoid unintended consequences. The findings support maintaining coat colour as a distinct breeding criterion rather than assuming it naturally aligns with morpho-functional improvement.
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Practical Takeaways
- •Coat color traits (quality of black and white marks) have moderate heritability and can be selected for in breeding programs, but they are genetically linked to morphofunctional traits—selecting against white marks may inadvertently improve functional conformation
- •The negative genetic correlations between white marks and functional traits suggest that the breed's selection against white marks aligns with improving performance traits, making phenotypic selection relatively efficient
- •Breeders should be aware that selecting for quality of black coat alone may differ genetically from selecting against white marks, requiring clarity on which trait is the actual breeding priority
Key Findings
- •Heritabilities of 46 linear morpho-functional traits ranged from 0.09 to 0.58, with coat color quality at 0.36 and white marks at 0.23
- •Quality of black coat color showed highest genetic correlation with upper neck line (0.816), suggesting pleiotropic effects
- •White marks showed highest genetic correlation with form of the hoof (0.638) and negative correlations with most functional traits
- •Genetic differentiation was observed between animals with better breeding values for coat color quality versus white marks, suggesting different genetic backgrounds