Up to 42 kg per Square Metre: Inside Modern Broiler Sheds
2023 · Reporting by EFSA and University of Bristol researchers
Summary
Most chickens raised for meat are fast-growing breeds kept in large indoor sheds. The EU sets a baseline limit of 33 kg of live weight per square metre, which member states may raise to 39 or 42 kg/m² when extra conditions are met. In 2023 the European Food Safety Authority (EFSA) recommended a maximum of 11 kg/m² for fast-growing broilers to prevent serious welfare problems.
Part 1
What the limits mean in practice
Stocking density is measured as the total live weight of birds per square metre of usable floor, not as a head count. Under Council Directive 2007/43/EC the baseline maximum is 33 kg/m². Member states may allow up to 39 kg/m² where farms meet additional requirements on matters such as ventilation, temperature and record-keeping, and a further 3 kg/m² — 42 kg/m² in total — where flocks also meet criteria such as consistently low mortality.
At 42 kg/m², birds averaging 2.2 kg would stand about 19 to a square metre. Because density is measured by weight, it rises as the birds grow, so the shed is most crowded in the final days before the birds are collected for slaughter.
Part 2
Why density matters
EFSA's 2023 scientific opinion on the welfare of broilers on farm identifies restricted movement, leg and walking problems, and skin and footpad damage among the most important welfare problems for these birds. The causes interact: crowding, fast growth, wet litter and management all play a part, so density alone does not explain every case.
To prevent important welfare consequences, EFSA recommended a maximum of 11 kg/m² for fast-growing broilers. That is a scientific recommendation to EU lawmakers; it is not current law.
Part 3
Lameness on the shed floor
A large UK survey led by researchers at the University of Bristol, published in PLOS ONE in 2008, assessed about 51,000 birds in 176 flocks at a mean age of 40 days. It found that 27.6% walked poorly and 3.3% were almost unable to walk.
Those figures describe the flocks studied at the time rather than a current worldwide rate, but they show how common walking problems can be in fast-growing birds approaching slaughter age.
Part 4
What food companies have signed up to
The Better Chicken Commitment, a voluntary standard backed by animal-welfare groups and adopted by some food companies, caps stocking density at 30 kg/m². It also sets requirements on breed, enrichment, lighting and the slaughter method.
Because these commitments are voluntary, the legal limits above remain the floor for any farm that has not signed up.
Questions
Questions people ask
How many chickens are kept per square metre?
What did EFSA recommend for broiler chickens?
What is the Better Chicken Commitment?
Sources
Where this reporting comes from
Figures on this page come from the official reports, laws and peer-reviewed studies listed here. Campaign groups are cited only for what their own investigations recorded.
Facts reviewed: