Beak trimming in poultry

SummaryBeak trimming in poultry is used extensively to control or prevent feather pecking or cannibalism. While the U.K. Codes of Recommendation for the Welfare of Livestock state that beak trimming should only be carried out as a last resort, it is still routinely performed in some breeds of birds.There is considerable variability in the amount of beak lost because of human error at trimming and the variability in the tissue damage produced by the cautery. While beak trimming is still often performed at the hatchery a number of reports recommend that it should be delayed until the birds are 7–8 weeks of age.The removal of part of the beak results in a number of anatomical physiological and behavioural alterations. The beak heals quickly after damage and shows some regrowth but the new tissue is mainly scar tissue and removal of part of the beak results in a permanent loss of sensory input from the beak. In addition to this loss of sensory input, extensive neuromas were formed adjacent to this scar tissue and these gave rise to abnormal spontaneous neural activity in the trigeminal nerve. The beak of the chicken has nociceptors present which would be stimulated by beak trimming and these nociceptors present near the beak stump showed abnormal patterns of activity.The removal of part of the beak resulted in an extensive shortening of the beak which created feeding difficulties with reduced food intake and body weight. There were also present changes in the behaviour of the birds.These anatomical physiological and behavioural consequences of beak trimming raise serious welfare questions concerning this practice.