Welfare issues for egg laying hens
It is estimated that over 60% of the world’s eggs are produced in industrial systems, mostly using barren battery cages.
Hens in barren battery cage
The barren battery cage was banned in the EU on 01 January 2012. These cages typically held 4 to 5 hens but in other countries around the world they are still legal and some may house as many as 6 to 8 birds. The space allowance per bird in the barren battery cage holding 4 to 5 hens is less than an A4 sheet of paper, and the height is only just enough to allow the hen to stand upright. In countries where there may be 8 birds, such as the US, the space allowance per hen is sometimes only half as much.
The cages usually have a sloping wire mesh floor and are kept in rows stacked in several tiers. Each unit typically holds tens of thousands of hens this way and the largest sheds can contain well over a hundred thousand birds. They are typically kept in closed sheds that are artificially lit and ventilated.
Caged hens may never experience natural light or fresh air and do not leave their cages until they are taken for slaughter.
Hens in colony cage system
Although the barren battery cage was banned in the EU on 01 January 2012, the use of ‘enriched’ cages remains legal. The original enriched cages housed 10 hens, but most recent systems are colony cages housing 60-80 hens.
Colony cages are slightly less crowded (space per hen around 20% larger than an A4 piece of paper) and the hens have a small area to move around in. Nest boxes, litter, perch space and ‘claw shortening devices’ must be provided.
Enriched cages provide some improvement but they are still restrictive, the hens cannot fly up to a high perch to be safe from feather pecking, the litter area is often very limited and effective dust-bathing isn’t possible.
Joint statement against modified or 'enriched' cages by the major animal protection organisations in the United States and European Union.
Modern commercial hens have been bred to produce very high numbers of eggs. This depletes the hen’s store of calcium and can result in high levels of osteoporosis (brittle bones) and fractures. Restricted movement can also contribute to osteoporosis.
Several tiers of crowded cages make inspection difficult and in large cage units injured birds may be left to die unnoticed.
Hens often lose a large proportion of their feathers due to damage from the sides of the cage and pecking from other hens. To prevent feather pecking, chicks often have part of their beaks cut off, without anaesthetic. Beak-trimming with a blade became illegal in the UK in 2011 but infra-red trimming is still permitted.
Even though it is often claimed that confined animals are better protected from infection, recent UK surveys have found that the prevalence of Salmonella infection was more than 3 times higher on battery cage farms than on free-range farms.
There are alternative methods of egg production that do not require the hen to endure the suffering of cages.