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The effects of stocking rate on the welfare of laying hens in non-cage systems - AW0223

This project represents a collaborative venture between the University of Bristol, ADAS Gleadthorpe and Dean`s Farms. It bulids on previous and current research on the welfare of laying hens in alternative systems (AW0124 and AW1028). Our work shows that the number of birds per house in alternative systems in the UK is typically between 5,000 and 8,000 birds, although the houses are generally subdivided to reduce `flock` size to between 2,500 and 4,000 birds. This information provides the baseline for our proposal. Stocking density can be manipulated by increasing flock size (holding area contstant) or decreasing available area (holding flock size constant), and these manipulations can have markedly different effects on bird behaviour.

The effects of stocking density on bird welfare will be examined by observations of bird behaviour, location, ease of access to facilities, corticosterone concentrations, physical condition, health and production.

In paralell with the main experiment we will examine effects of stocking density and `furniture` provision on bird welfare using access to our existing database (AW0124). Building on the epidemiological knowledge gained so far we will conduct a prospective study of farms employing different stocking densities, looking for differences in the time of onset of damaging pecking. Experiments will be conducted at Bristol to validate the relationship between faecal and blood corticosterone, and to investigate the navigational abilities of laying hens.
01: To examine the effects of stocking density and management practice on bird welfare using a broad range of physical, physiological and behavioural observations, and employing a replicated experimental design in a commercial setting.
02: To conduct a prospective study of UK farms already enrolled in our database (AW0214) to examine differences in the time of onset of feather pecking in flocks stocked at different densities, and in general measures of welfare in relation to `furniture` provision.
03: To undertake investigations of the relationship between blood and faecal corticosterone concentration in laying hens, and to apply these results to take non-invasive measures of corticosterone concentrations for birds in the experimental trials.
04: To undetakke investigation of the navigational abilities of chickens in relation to housing at different stocking densities, and the provision of `furniture`.
Project Documents
• Final Report : The effects of stocking rate on the welfare of laying hens in non-cage systems.   (335k)
Time-Scale and Cost
From: 2000

To: 2004

Cost: £624,493
Contractor / Funded Organisations
University - Bristol
Animal Welfare              
Plants and Animals              
Fields of Study
Animal Welfare