What effects does toe pecking have on laying hens' fearfulness, stress levels, susceptibility to infection, and mobility?

Increased fearfulness, increased stress levels, increased susceptibility to infection and diseases, and impaired mobility are some of the impacts that toe pecking can have on laying hen welfare.

Beak to Toes: Impact, Causes, and Prevention of Toe Pecking in Laying Hens

Damaging behaviors in poultry include feather pecking, vent pecking, and toe pecking. While feather and vent pecking are well-known welfare problems in poultry that have received significant attention from researchers and farmers, toe pecking remains relatively unknown. Therefore, this article aims to shed light on toe pecking.

Toe pecking (TP) occurs when a laying hen pecks at her toes or the toes of conspecifics, often resulting in toe wounds. Therefore, TP predisposes birds to toe injury and damage. Pain and distress have been associated with injury and wounds; consequently, TP can compromise the welfare of laying hens. In severe cases, toe pecking can affect up to 75% of a flock and cause as high as 10% mortality in TP-affected flocks, resulting in significant financial losses to growers.

Development of toe pecking

The onset of damaging behaviors in poultry has been associated with health concerns. Toe pecking typically emerges in groups of birds at 20 to 30 weeks of age, peaking between 30 and 50 weeks.

This pattern corresponds to transition periods to the layer barn following a rearing period in pullet barn and peak egg-laying, suggesting that TP development is associated with significant production stressors in a laying hen's life.

Impacts of toe pecking on laying hen welfare

Increased fearfulness

Laying hens experiencing toe wounds resulting from toe pecks may be more fearful of higher areas in their housing environment, such as the top tiers of a cage-free aviary system. Research has demonstrated that toe pecking victims take less time to descend from elevated platforms. This could stem from the discomfort and pain associated with toe injuries, causing hens to be cautious of walking activities that require extensive balance and coordination.

Increased stress levels

Toe-pecked hens have enlarged stress-responsive organs, particularly the adrenal glands. An increase in the size of these organs leads to an increase in stress hormone production. This indicates heightened stress levels in toe-pecked hens, which is an attempt by their system to cope with stressful situations.

Increased susceptibility to infection and diseases

Toe-pecked hens have elevated stress levels, which compromises their immune system and makes them more susceptible to diseases. On the other hand, open wounds provide potential entry points for pathogens, and these wounds could be easily infected. The combination of stress and open wounds can predispose hens to infectious diseases.

Impaired mobility

Toe damage is associated with reduced mobility and inability to walk properly. Impaired mobility is a significant concern for hens raised in non-cage housing systems because important resources, such as food and water, are usually located in areas that require the hens to navigate complex three-dimensional (3D) spatial configurations. Therefore, the inability of TP victims to adequately navigate their environment and utilize these resources could severely impair their welfare.

Beak to Toes: Impact, Causes, and Prevention of Toe Pecking in Laying Hens - Image 2

Summary

Toe pecking is an emerging welfare problem in laying hens housed in modern housing systems. Toe pecking may result in severe tissue damage and even death, leading to significant economic losses. In addition, birds receiving toe pecks may have elevated levels of fear and stress. Genetics, diet, lighting, toe wounds, health status, stress, and socialization have been proposed as factors associated with TP in layer flocks. A holistic approach that includes genetic, environmental, and management interventions is most likely to successfully prevent and alleviate TP in layer flocks, but more research will be valuable in providing solutions to this damaging behavior.

This article was originally published on Poultry Extension Collaborative (PEC) and it is reproduced here with permission from the authors.