Roles of the beak in poultry. Effects of debeaking

Abstract

Debeaking is the cut of a part of the beak of domestic birds. The amount of beak tissue cut and the age at debeaking modulate the consequences of debeaking on poultry behaviour.

The beak is essential to the bird for feed particle prehension, exploration of the environment, preening and social defense. It is an efficient tool. Beak epiderm contains dermal pappillae which play an important role in precise tactile discrimination. Debeaking the chicken reduces the input of sensorial information and leads to the formation of neuroma (abnormal and painfull proliferation of nervous tissues at the cutting point). However if birds are debeaked earlier than ten day old, both neuroma formation and pain are reduced. Debeaking can induce pain but also a reduction of sensorial perception. Debeaking reduces food intake and the efficiency of prehension feed particles by the bird. This reduces growth in debeaked chickens. However a debeaking effect on laying performances is still controversial. The major long term effect of debeaking on bird’s behaviour is inaction.

Some floor raised birds (turkeys, layers...) require debeaking in practice to limit feather pecking and cannibalism. Choosing a housing system which excludes cages might limit the possibility to suppress mutilation of the beak, the chicken’s major contact with its environment.