Muscle myopathies in broiler chickens — including wooden breast, white striping, and spaghetti meat — are welfare and production quality problems arising from extreme growth rates and modern genetic selection.
Broiler myopathies represent a welfare crisis produced by extreme genetic selection for rapid growth. The affected muscles show pathological changes consistent with painful conditions in other species — inflammation, fibrosis, and cell death. While definitive evidence that myopathic birds experience pain is difficult to establish, the precautionary principle demands action given the scale of impact. Birds with severe wooden breast spend more time resting, show gait abnormalities, and have elevated physiological stress markers. The industry's response has been slow because myopathic birds reach market weight and are profitable despite the welfare cost. Transition to slower-growing breeds meaningfully addresses the problem but increases production costs — a cost that welfare-focused consumers, retailers, and food service companies are increasingly willing to absorb.