Genetic analysis of a temperament test as a tool to select against everyday life fearfulness in Rough Collie1

Abstract

Fear-related problems are common among Rough Collies in Sweden. Annually, on average, >200 Rough Collies are subjected to the dog mentality assessment (DMA), a temperament test during which 33 behavioral reactions are rated. Previous research has shown that a dog's DMA result can be condensed into 5 underlying personality traits. The aim of the study was to evaluate if it is possible to use the DMA for selection for temperament in Swedish Rough Collies, in particular to decrease everyday life fearfulness. We also wanted to compare 2 methods to compute the personality traits: summated scales (SS) and factor scores (FS). The DMA data for 2,953 Rough Collies were used to estimate genetic parameters for the 5 personality traits (both SS and FS), using a linear animal model including fixed effects of sex, year and month of test, and random effects of litter, judge, test occasion, genetic effect of the individual, and residual. Age at test was included as linear and quadratic regressions. The DMA personality trait heritability estimates ranged from 0.13 to 0.25. The SS showed greater or equal heritability estimates compared with the FS. To validate the DMA, data on everyday life behavior of 1,738 Rough Collies were collected using an extended version of the Canine Behavioral Assessment and Research Questionnaire. Each dog's questionnaire result was condensed into 18 underlying behavioral subscales. Genetic parameters for the subscales were estimated using a linear animal model, including a fixed effect of sex and random genetic effect of the individual and residual. Age when the questionnaire was completed was included as linear and quadratic regressions. Heritability estimates for the questionnaire subscales were 0.06 to 0.36. There were high and significant genetic correlations between DMA personality traits and questionnaire subscales. For instance, the DMA personality trait Curiosity/Fearlessness correlated strongly genetically to the questionnaire subscale Non-social fear (-0.70), DMA Sociability to Stranger-directed interest (0.87) and Stranger-directed fear (-0.80), DMA Playfulness to Human-directed play interest (0.63), and DMA Chase-proneness to Chasing (0.73). We could not detect any obvious difference in validity between DMA SS and FS. We conclude that the DMA is an effective tool for selection of breeding animals with the goal to decrease everyday life fearfulness among Swedish Rough Collies. The DMA can also be used for breeding for other traits. The SS method seems to perform at least as good the FS method.

Genetic Characterization of Dog Personality Traits

“…Our estimate for the latter falls within the range of previous reports based on standardized tests, with heritabilities of “reaction to gunfire” ranging between 0.23 and 0.56 (Ruefenacht et al 2002; van der Waaij et al 2008). The heritability estimate for Non-social fear (SetB) was similar to NoiseFear for this dataset and somewhat lower than found previously for Rough Collies ( h 2 = 0.36, SE 0.06) (Arvelius et al 2014a). Thus, it appears that genetic variation for this trait exists in various breeds, including gun dogs.…”

“…While C-BARQ has been used in a large number of studies on dog behavior, the genetic analysis of the traits derived from the questionnaire is still in its infancy, with only a handful of heritability estimates published to date ( e.g. , Liinamo et al 2007; Arvelius et al 2014a). The results presented in this study show that there is a consistency in detection of the genetic variance and detectable genomic associations for traits derived from C-BARQ, but also that quantification of the genetic component of C-BARQ-based traits is sensitive to how these behavioral factors are extracted from the questionnaire responses.…”

“…The distinct behavioral predispositions of individual dog breeds clearly indicate a strong genetic component to dog personality, which is further strengthened by estimates of substantial within-breed genetic variance found for a variety of dog behavioral traits across studies ( e.g. , Wilsson and Sundgren 1997; Saetre et al 2006; Meyer et al 2012; Arvelius et al 2014a; Persson et al 2015). …”

“…The reliability and validity of C-BARQ demonstrated by the developers of the method and others ( e.g. , Hsu and Serpell 2003; Svartberg 2005; Duffy and Serpell 2012) as well as the relationship between C-BARQ responses and standardized test scores (Arvelius et al 2014a) support its use as a tool in behavioral research (Wiener and Haskell 2016). Subsequently, it has been applied in studies of dog behavior by various groups ( e.g.…”

“…In most studies ( e.g. , Arvelius et al 2014a; Asp et al 2015), the grouping of questions and number of resulting traits are largely based on the definitions derived by the developers of the questionnaire (Hsu and Serpell 2003; Duffy and Serpell 2012), who used factor analysis to define 11 (and later, 14) behavioral traits. In a previous study of Labrador Retrievers, we used multivariate statistical techniques to define 12 personality traits from C-BARQ data (Lofgren et al 2014), some of which overlapped the previous grouping while others were novel.…”