title: Genome-wide association mapping of heritable temperament variation in the Tennessee Walking Horse.
abstract: Temperament is a key criterion in the selection of horses for both leisure and competitive riding to ensure optimal performance and safety. The Tennessee Walking Horse (TWH) is described as a calm, docile breed and is often used as a trail, show and pleasure horse. However, among horse owners and caretakers, there are anecdotes supporting familial and disciplinal typical behaviors and personalities. To investigate the contribution of genetics to temperament, we collected a behavior questionnaire, brief training history and identifying information for 276 TWH, as well as blood or hair samples for DNA. Factor analysis was conducted on the 20-item questionnaire for the set of 216 horses that met inclusion thresholds. Factor analysis identified four temperament factors in TWH: 'anxious', 'tractable', 'agonistic' and 'gregarious'. These four factors account for 64% of the total trait variance. DNA from 113 TWHs were selected and genotyped using the Equine SNP70 bead chip for three separate genome-wide association studies (GWAs) using the factor 1-anxious, factor 2-tractable and factor 3-agonistic scores as the phenotype. Quantitative association analysis identified significant candidate loci for each factor that warrant further investigation.
authors.affiliation: Department of Animal Science, Cornell University, Ithaca, NY.
authors.forename: E A
authors.initials: EA
authors.lastname: Staiger
authors.affiliation: Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN.
authors.forename: J D
authors.initials: JD
authors.lastname: Albright
authors.affiliation: Department of Animal Science, University of Florida, Gainesville, FL, USA.
authors.forename: S A
authors.initials: SA
authors.lastname: Brooks
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D056426:Genetic Loci; D055106:Genome-Wide Association Study; D006736:Horses / Q000235:genetics*; D010641:Phenotype; D013694:Temperament
keywords: Agonistic; anxious; behavior; gait; gregarious; horse; polymorphism; principal component analysis; sociability; trainability