Phenotypic characterization through identification of gait and coat color phenotype of the Mountain Pleasure Horse

BACKGROUND: Phenotypic characterization of traits like gait and coat color is useful for minor breed identification and conservation. The Mountain Pleasure Horse (MPH) is a minor American breed as it is listed as threatened by the Livestock Conservancy. OBJECTIVES: The study objective was to utilize phenotypic characterization for identifying gait and coat color phenotype of the MPH. METHODS: Gait was characterized utilizing frame-by-frame analysis to identify spatiotemporal variables of purebred horses (n = 6) performing the flat walk and saddle rack. Coat color was characterized using coat color assignments of purebred horses within the MPH Association database. Coat color was assessed in two stages: 1) living registered horses (n = 1,410) and 2) changes over time (1960-1980, n = 98; 1990-2010, n = 708). RESULTS: Gait phenotype for both gaits included a 4-beat stepping rhythm alternating between bipedal and tripedal support. The saddle rack had a faster velocity achieved by increasing stride length and decreasing stride and stance durations (P < 0.05). Coat color phenotype of living MPHs included 11 coat color assignments. The most frequent assignment was chestnut (31.4%) followed by chocolate (16.9%) and palomino (16.4%). The most frequent assignments between the years of 1960 and 1980 were chestnut (26.5%) and palomino (26.5%), while in the years of 1990 through 2010, it was chestnut (30.2%) and chocolate (20.9%). CONCLUSION: These traits inform selective breeding as populations grow; however, observed coat color shifts must be considered to ensure responsible, genetically informed conservation and long-term population sustainability goals and management decisions.