Feather pecking in laying hens is partly driven by nutritional deficiencies, particularly protein and specific amino acids; addressing diet can reduce this major welfare problem.
Feather pecking has multiple causes, and nutritional insufficiency is one of the most actionable. A hen whose diet is deficient in specific amino acids including methionine and tryptophan shows increased feather pecking behaviour that reflects a physiological need as well as a social and environmental problem. Addressing nutrition is therefore a welfare intervention that can reduce harm without requiring housing changes. The synergy between nutritional adequacy, appropriate stocking density, and enrichment provision means that addressing all three simultaneously achieves better outcomes than any single intervention alone.