Beak shape variation And pecking damage

Amajor challenge in the laying hen industry is controlling or preventing outbreaks of severe feather pecking, which can lead to cannibalism and mortality.

To minimise the severity of severe feather pecking and cannibalism in laying hen flocks, infrared beak treatment is commonly performed at the hatchery just after the birds are hatched. Despite scientific evidence that infrared beak treatment is more welfare-friendly than older methods, the demand to ban all forms of beak treatment is increasing. Although beak treatment is currently the most effective method, there are other management practices that can help reduce the severity of severe feather pecking behaviour.

Recently, researchers and poultry breeding companies have focused on genetic selection against this behaviour – selecting birds that exhibit low levels of feather pecking. However, measuring the behaviour of individual hens within a large flock can be difficult. Instead, birds can be genetically selected for traits related to severe feather pecking that are easier to measure, such as feather cover, liveability and beak shape.

A collaboration between SRUC, the Roslin Institute (Edinburgh University) and Lohmann Breeders is investigating the potential of using the naturally occurring beak shapes that exist within laying hen flocks as a way to limit pecking damage in hens. Beak shape is heritable, which means that genetic selection for hens with naturally blunter (shorter) beaks may help reduce feather pecking and mortality, as it is thought these birds may be less capable of causing damage.

Using x-ray technology (which allows for the analysis of both the external beak shape and the underlying bones), the shape of the premaxillary (within the top beak) and the dentary (within the bottom beak) bones was analysed in two different genetic lines of non-beaktreated White Leghorn laying hens. The analysis showed that Line B hens had premaxillary bones with a more pronounced downwards curvature and dentary bones that were wider and longer compared to Line A hens.

The size of the premaxillary and dentary bones also differed significantly between the two lines, suggesting that the size of the bone may influence its shape.

This work is important as it helps lay the foundation for using the natural beak shape as a tool to reduce feather pecking damage and cannibalism in laying hen flocks.

BLUNTING THE BLOWS: SRUC, Edinburgh University and Lohmann Breeders collaborated to produce a study on the potential to use naturally occurring beak shapes to inform genetic selection to reduce feather pecking damage.