Selective breeding programs for farmed fish have prioritized growth rate and feed conversion over welfare traits, creating fish with reduced stress tolerance and higher disease susceptibility.
As with broiler chickens and commercial turkeys, extreme selection for production traits in farmed fish creates animals biologically predisposed to welfare problems. Skeletal deformities, immune deficiency, and reduced coping capacity are inheritable consequences of narrow production-focused breeding. Incorporating welfare traits into breeding program objectives is technically feasible but requires industry commitment.