Genetic Indicators of Performance Resilience in Barrel Racing Quarter Horses

Resilience, defined as the capacity to maintain consistent performance under variable conditions, has emerged as a relevant breeding objective in livestock systems, yet remains largely unexplored in equine populations. The objectives of this study were to (1) derive indicators of resilience from longitudinal barrel racing time (BRT) records in Brazilian Quarter Horses, (2) estimate genetic parameters for these indicators, and (3) quantify their genetic relationships with BRT and accumulated career earnings (ACE). The dataset comprised BRT records from barrel racing events held between 2010 and 2024, involving 10 665 horses. Resilience indicators were derived from short-term deviations around an expected performance trajectory after removing systematic effects and persistent horse- and rider-specific performance levels. Three indicators were evaluated: median absolute deviation (MAD), logarithm of the variance of deviations (LNVAR), and proportion of positive deviations (PPOS). Posterior mean heritability estimates for the resilience indicators were low (0.06 to 0.09), but still indicated exploitable additive genetic variation. Genetic correlations revealed a near-complete overlap between MAD and LNVAR (0.987), while PPOS captured partially distinct genetic information. All resilience indicators showed favorable genetic associations with ACE (mean -0.59) and positive associations with BRT (mean 0.44), indicating that genetically more resilient horses tended to perform faster and achieve higher economic returns. Therefore, resilience indicators derived from longitudinal performance records captured genetically meaningful variation related to performance consistency and economic success. These indicators complemented traditional performance traits and provided a scalable framework for incorporating resilience and long-term regularity into genetic evaluations of sport horses.