Companion animals

Successful selection against fearfulness in Swedish Rough Collie dogs - direct and indirect selection response

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Abstract

The objective of this study was to evaluate the efficiency of selection against fearfulness in the Swedish rough collie breed. In 2009, contact was taken from the Collie breed club because they were concerned that a large proportion of Rough Collie dogs expressed a high level of fearfulness in everyday situations. Since 2000, 30% to 50% of the Rough Collies registered in the Swedish Kennel Club each year take the Dog Mentality Assessment (DMA), during which 33 behavioral reactions are rated. At that time, a dog's DMA result was condensed into 5 underlying traits: Sociability, Playfulness, Curiosity/Fearlessness, Chase-proneness, and Aggressiveness. After initial statistical analyses, estimated breeding values (EBVs) were first published in 2012. The breed club's focus in discussions with breeders was to achieve EBVs for Curiosity/Fearlessness above the average, but EBVs were also published for the other traits, except Aggressiveness. Also, an EBV for Gunshot Avoidance was published. These EBVs were updated roughly twice yearly from then on. In connection with the development of EBVs for personality traits for other working dog breeds, DMA-data on Collies (Rough n=5223, Smooth n=1048) were collected in September 2025. Genetic parameters and EBVs were estimated for 7 traits, with Distance Play in addition to the previous traits. The mixed linear animal model contained fixed effects of sex, age at test, and year, and random effects of evaluator and additive genetic effect. EBVs were standardized (mean 100, genetic SD 15). Mean EBVs were plotted against birth year to display the genetic trend. Because for several traits there was a visible change in the trend for the Rough Collie from 2016 and onwards, a linear regression of EBV on birth year was estimated for two periods, 2000-2015 and 2016-2025. Heritability estimates for Sociability, Playfulness, and Curiosity/Fearlessness ranged from 0.26 to 0.32; for Distance Play, Chase-proneness, and Aggressiveness heritability was around 0.2, and for Gunshot Avoidance 0.13. Genetic correlations were strong among Sociability, Playfulness, and Distance Play (0.5-0.7), and Playfulness (0.5), Distance Play (0.4), and Gunshot Avoidance (‑0.8) were strongly correlated with Curiosity/Fearlessness. The increase in EBVs for the Rough Collie for Curiosity/Fearlessness went from 0.31 index units per year in the early period to 0.81 in the later period. For Sociability, Playfulness, Distance Play, and Chase-proneness the early trends were low or slightly negative (-0.1 to 0.05) but increased to 0.37, 0.51, 0.88, and 0.56, respectively, in the later period. For Gunshot Avoidance the slope changed from -0.37 to -0.45. Regression coefficients higher than |0.05| were significant (p< 0.05). Our conclusion is that the EBVs for Curiosity/Fearlessness have been used for selection, and this has decreased the fearfulness in Swedish Rough Collie dogs and had a correlated response in other traits.

Keywords: 2026

How to Cite:

Strandberg, E., Arvelius, P. & Nilsson, K., (2026) “Successful selection against fearfulness in Swedish Rough Collie dogs - direct and indirect selection response”, World Congress on Genetics Applied to Livestock Production Digital Archive 2026(1): 2289760. doi: https://doi.org/10.31274/wcgalp.24301

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