Selective breeding for rapid growth in farmed Atlantic salmon has produced welfare burdens parallel to those seen in broiler chickens, with metabolic and cardiovascular consequences.
Farmed salmon genetics have followed a trajectory similar to broiler chickens: intense selection for growth rate has produced animals with welfare burdens built into their biology. Heart abnormalities — particularly hearts that cannot keep pace with the oxygen demands of rapid growth — affect a significant proportion of rapidly-growing farmed salmon, causing reduced welfare through impaired physiological function and potentially sudden cardiac death. Cataracts at rates far exceeding wild salmon populations indicate nutritional or genetic stress during development. The parallel with broiler chickens suggests that the pattern of trading welfare for production efficiency through genetics repeats across farmed species wherever selection pressure is applied without welfare constraints. Breed welfare standards that include health trait requirements alongside growth performance are the systemic solution, similar to the growing movement for slower-growing broiler breeds.