Selective breeding has increased farmed salmon growth rate dramatically, but fast-growing strains show higher rates of skeletal deformity, heart problems, and other welfare-compromising conditions.
Farmed salmon genetic welfare parallels the broiler chicken problem: selective breeding for rapid growth has created animals whose biology is poorly suited to supporting their body size and growth rate. Skeletal deformities in fast-growing salmon cause chronic pain and movement impairment throughout the production cycle. Heart disease is endemic in fast-growing strains. The welfare solution mirrors the broiler solution: transitioning to slower-growing, healthier strains that sacrifice some growth efficiency for dramatically better individual welfare outcomes. Consumer demand for welfare-certified salmon and regulatory requirements for health monitoring can drive this transition.