Selective breeding of Atlantic salmon for growth and disease resistance has welfare implications. Understanding how genetics influences salmon health and behaviour matters for aquaculture welfare.
Genetic selection in farmed Atlantic salmon has focused historically on growth rate and feed efficiency, with welfare traits incorporated more recently. Rapid growth is associated with cardiac and skeletal problems in some genetic lines, raising welfare concerns that parallel those in broiler chicken breeding. Modern breeding programs are increasingly incorporating disease resistance, skeletal health, and cardiovascular function alongside production traits. Research into heritable variation in stress coping styles — proactive versus reactive types — is opening possibilities for selecting salmon that cope better with aquaculture conditions. Genetic improvement for welfare requires clear welfare trait definitions, validated phenotyping methods, and commitment from breeding companies to weight welfare traits in selection indexes.