Conformational Defects in the Limbs of Menorca Purebred Horses and Their Relationship to Functionality

Limb-conformation defects significantly influence equine performance and welfare, necessitating thorough investigation for effective management. This study examines the prevalence and genetic parameters of 14 limb-conformation defects in Menorca Purebred horses using data from 1120 records (509 animals with an average age of 101.87 ± 1.74 months) collected between 2015 and 2023. Defects were evaluated using a three-class scale by three appraisers, and a Bayesian approach via Gibbs sampling was employed to estimate genetic parameters including gender, birth period, stud selection criteria, evaluation age and appraiser as fixed effects. Splay-footed forelimb and closed hocks were the most prevalent defects (67.20% and 62.53%, respectively). Horses with any of the defects analyzed have been observed to obtain significantly lower scores for both walk and trot. Heritability estimates range from 0.12 (s.d.: 0.025) for closed hock to 0.30 (s.d.: 0.054) for base narrow, confirming the genetic influences on the expression of limb conformation defects. The divergent defect in hind limbs showed the highest genetic correlations with forelimb defects (camped under, -0.69; s.d: 0.32 and camped out, 0.70; s.d: 0.27). The significant genetic correlations between defects highlight the complexity of the relationships, which requires careful consideration.