Similar recent selection criteria associated with different behavioural effects in two dog breeds

Area of Science:

• Canine behavior genetics
• Animal breeding
• Quantitative genetics

Background:

• Recent decades have seen dog breed divergence into distinct morphological and behavioral types due to selective breeding.
• These breed splits offer valuable models for behavior genetics research, particularly when selection targets specific behavioral traits.

Purpose of the Study:

• To investigate behavioral differences between selection lines within Golden Retrievers and Labrador Retrievers.
• To compare the behavioral profiles of 'common' (pet/conformation) and 'field' (hunting) types within these breeds.
• To test the hypothesis that behavioral profiles of these types are similar across breeds.

Main Methods:

• Analysis of pedigree data and standardized behavioral test results from 902 Golden Retrievers and 1672 Labrador Retrievers.
• Utilized principal component analysis to identify six key behavioral components.
• Examined breed and type effects, including interactions, on behavioral components and estimated heritability.

Main Results:

• Breed and type significantly influenced all six behavioral components, with notable breed-type interactions.
• In Labradors, the common type exhibited higher curiosity than the field type; the opposite was observed in Golden Retrievers.
• Heritability estimates indicated substantial genetic influence on behavior, with differing heritabilities between types within breeds, suggesting varied selection pressures.

Conclusions:

• Despite shared genetic origins and similar selection goals, distinct behavioral differences exist between common and field types within Golden Retrievers and Labrador Retrievers.
• The observed breed-type interactions suggest that the underlying genetic architecture for behavior differs between these breeds.
• These findings underscore the complexity of behavior genetics in selectively bred dog populations.