
Chicken welfare is influenced more by housing conditions than by
stocking density
Marian Stamp Dawkins, Christl A. Donnelly and Tracey A. Jones
Department of Zoology, University of Oxford, South Parks Road, Oxford
OX1 3PS, UK; Correspondence to: Marian Dawkins Email: marian.dawkins@zoo.ox.ac.uk
Abstract
Intensive broiler (meat) chicken production now exceeds 800 million
birds each year in the United Kingdom and 2 billion birds worldwide,
but it attracts accusations of poor welfare.
The European Union is currently adopting standards for broilers aimed
at a chief welfare concern—namely, overcrowding—by limiting
maximum 'stocking density' (bird weight per unit area). It is not clear,
however, whether this will genuinely improve bird welfare because evidence
is contradictory.
Here we report on broiler welfare in relation to the European Union
proposals through a large-scale study (2.7 million birds) with the unprecedented
cooperation of ten major broiler producers in an experimental manipulation
of stocking density under a range of commercial conditions.
Producer companies stocked birds to five different final densities,
but otherwise followed company practice, which we recorded in addition
to temperature, humidity, litter and air quality.
We assessed welfare through mortality, physiology, behaviour and health,
with an emphasis on leg health and walking ability.
Our results show that differences among producers in the environment
that they provide for chickens have more impact on welfare than has
stocking density itself.
Source
Nature 427, 342-344 (22 January 2004)
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Posted November 2007