Selective breeding of farmed salmon has dramatically increased growth rates, raising welfare questions about whether genetic selection has created health and behavioral compromises similar to those in broiler chickens.
Salmon genetics and welfare presents a trajectory warning — the same pattern of rapid growth selection that created welfare problems in broiler chickens is occurring in farmed salmon, with similar consequences emerging. Spinal deformities, cardiac problems, and increased disease susceptibility in fast-growing strains reflect the physiological costs of extreme selection for growth at the expense of other fitness traits. The difference from the broiler situation is that we have an opportunity to course-correct through genetic selection that explicitly includes welfare-relevant health traits alongside growth, before welfare problems become as endemic as they are in fast-growing chicken breeds.