Beak trimming egg-laying strains of chickens

Abstract

Bird behaviour, production, physiological measurements of stress, and pain as indicated by neural transmission in, and anatomy of the trimmed beak have been used as criteria to determine if beak trimming compromises bird well being. In addition, the welfare of those hens that are pecked by beak-intact hens has been evaluated. The welfare of a flock is assessed by mortality, incidence of cannibalism, feathering, and flock behaviour such as fearfulness or nervousness. Disadvantages of beak trimming include short-term and perhaps long-term pain, and short-term stress following beak trimming. Because feeding behaviour must adapt to a new beak form, a bird's ability to consume feed is impaired following beak trimming. Welfare advantages include reduced pecking, feather pulling, and cannibalism; better feather condition; less fearfulness and nervousness; less chronic stress; and decreased mortality. It appears that the welfare disadvantages are applicable to individual birds whose beaks are trimmed, while the welfare advantages are more applicable to the interactive flock. Behavioural evidence suggests that primary breeders of egg laying strains can select for more docile birds and minimize the need to beak trim. Therefore, using genetic stocks that require little or no beak trimming is the most desirable approach. However, under certain management systems (e.g., exposure to high intensity natural lighting) and with some genetic stocks, beak trimming is needed to prevent feather pecking and cannibalism. When employed, beak trimming should be conducted at 10 days of age or younger by trained personnel.