Thinning — the partial removal of birds from broiler flocks to reduce density — is a widespread practice with significant welfare implications for both removed and remaining birds.
Thinning is an inherent welfare compromise of high-density broiler production. The catching and loading process causes acute stress, injury, and sometimes death from cardiac arrest in fast-growing heavy birds. The welfare case against thinning is strong, and systems that avoid it through end-of-line lower density production achieve better welfare outcomes. Consumer and regulatory pressure for reduced stocking densities would remove the commercial rationale for thinning.