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Battery cages are wire cages for egg-laying hens. They are so small that the hens cannot flap their wings, so barren they have no nest for their eggs, and so restricting that the birds’ bones often become so brittle they can snap like dry twigs.
Cages may be stacked up to 9 tiers high, with as many as 90,000 birds caged in one windowless building.
In the EU, about 90% of the 271 million laying hens are currently kept in battery cages. The EU is the world’s second largest egg producer after China.
The European Union has agreed to ban battery cages by 2012.
About 99% of the 270 million hens in the USA are kept in battery cages.

The 1999 Ban – A Triumph for Animal Welfare Campaigners

On June 15th 1999, the EU Council of Agriculture Ministers agreed to ban the use of conventional battery cages from 2012. The new Laying Hens Directive (Council Directive 1999/74/EC) forbids the introduction of newly built battery cages from 2003, and from that date space allowance in existing conventional battery cages will be increased from 450 cm2 to 550 cm2. So called ‘Enriched’ cages, in which hens must have at least 750 cm2 per hen, a nest, litter and perches, will still be allowed.

The European Commission is due to submit a report to the Council on the various systems of egg production not later than January 1st 2005. The Commission will then bring out further proposals taking into account the conclusions of the report and the outcome of WTO negotiations.

In the battery system, hens are crammed into a cage so small that the hens cannot stretch their wings, let alone walk, or peck and scratch at the ground. Under these conditions, hens are prevented from performing most of their natural behaviours, such as dust bathing, perching, or laying their eggs in a nest. Up to 90,000 caged hens can be crammed into one windowless shed. The cages in Europe are stacked between 4 and 9 cages high. Japan is said to have the world’s highest battery cage unit, with cages stacked 18-tiers high.

The world laying hen population is currently estimated at 4,700 million. The USA has 270 million laying hens, and is the third largest egg producer, behind China (800 million) and the EU (271 million). An estimated 70-80% of the world’s laying hens are kept in cages, mostly in so-called ‘developed’ countries.

Intensive cage systems were first developed in the USA and Europe. Deep concern over factory farming’s role in successive food safety scares, environmental degradation, rural decline, and animal cruelty, has led to the European Union taking serious steps toward de-intensifying its agriculture. One such measure was the 1999 agreement by Europe’s ruling Council to ban the battery cage for laying hens – the system that epitomises factory farming - within 12 years.

Evidence of Suffering

There is clear scientific evidence that hens suffer in battery cages. Common sense also tells us that to keep a healthy hen in a barren wire cage, with less space than an ordinary sheet of typing paper, is bound to cause suffering. Such conditions prevent the hens performing their natural behaviours, and cause their bodies to degenerate through lack of exercise.

Brittle Bones & Injured Feet

Battery hens suffer Caged Layer Osteoporosis (CLO), or brittle bones. Research has shown that 35% of premature deaths in cages are due to CLO, a slow death from paralysis and starvation at the back of the cage. A 1993 report in Poultry Advisor described it thus:

“After a long period of egg production, caged layers have difficulty standing and their body is held in a vertical position. They may lose control of their legs and lie on their sides, indicative of a type of paralysis. Usually there is no loss of egg production, shell quality or interior egg quality. Some of the bones may be fractured, some will break when the bird is handled… The birds appear healthy but they die due to starvation later on if left in their cages in the recumbent position. The bones appear to be osteopetrotic [diseased] and so brittle that the ribs give way causing the heart to be punctured.”1

Confined to the cage, the hen is unable to forage by scratching and pecking at the ground. Under natural conditions, a large proportion of a hen’s day would be spent looking for food. Denied this simple activity, the hen’s claws can grow long or twisted, and be torn off. They can even grow around the wire mesh of the sloping cage floor. The slope itself puts painful pressure on the hen’s toes, causing damage to the bird’s feet.

European Scientists Acknowledge Cruelty

In 1996, the European Union’s committee of scientific and veterinary experts published a report acknowledging the behavioural needs of hens, and the welfare problems caused by caging. After reviewing the evidence, the Scientific Veterinary Committee report found that:

“Hens have a strong preference for laying their eggs in a nest and are highly motivated to perform nesting behaviour”.

“Hens have a strong preference for a littered floor for pecking, scratching and dust-bathing”.

“Hens have a preference to perch, especially at night”.

All of these behaviours are denied to caged hens. The report concluded that:

“Battery cage systems provide a barren environment for the birds… It is clear that because of its small size and its barrenness, the battery cage as used at present has inherent severe disadvantages for the welfare of hens”.

Even now, and despite overwhelming evidence to the contrary, proponents of battery egg production persist in the claim that hens in battery cages are virtually a distinct species, with different needs from hens on range – a case of “what they’ve never known they don’t miss, and have, most conveniently, forgotten”.

Further Expert Views on Suffering in Battery Cages

“The worst torture to which a battery hen is exposed is the inability to retire somewhere for the laying act. For the person who knows something about animals it is truly heart-rending to watch how a chicken tries again and again to crawl beneath her fellow cagemates to search there in vain for cover.” Professor Konrad Lorenz, Nobel Prize Winner and animal behaviourist.

“Anyone who has studied the social life of birds carefully will know that theirs is a subtle and complex world, where food and water are only a small part of their behavioural needs. The brain of each bird is programmed with a complicated set of drives and responses that set it on the path to a life full of special territorial, nesting, roosting, grooming, parental, aggressive and sexual activities in addition to the simple feeding behaviour. All these are denied the battery hens.” Dr. Desmond Morris, zoologist, author and animal behaviourist.

“Junglefowl, which are the wild ancestors of our domesticated chickens, spend long hours scratching away at the covering of leaves that hides one of their favourite foods – the minute seeds of bamboo. An ancestral memory of this way of life seems to have carried down the generations into the cages of our modern intensive farms so that even highly domesticated breeds have the same drive to scratch away to get their food – if they have the opportunity. If hens that have been kept all their lives on wire floors with no sight or contact with anything that could be scratched or raked over are suddenly… given access to a floor of peat… they dust bathe, eat particles of peat and scratch with their feet. It is not just the extra comfort afforded by a soft floor that attracts them, but all the behaviour they can do there as well… Chickens in battery cages which have wire floors and no loose substrate for the birds to scratch and dust bathe in, can often be seen to go through all the motions of having a dust bath. They squat down, raise their feathers, and rub themselves against the floor and flick imaginary dust from their backs. They behave as though real dust were being moved through their feathers, but there is nothing really there. If such dust-deprived birds are eventually given access to something in which they can have a real dust bath, like wood shavings or peat, they go in for a complete orgy of dust bathing. They do it over and over again, apparently making up for lost time…” Dr Marion Stamp Dawkins, Research Lecturer, Department of Zoology, University of Oxford. Extract from “Through Our Eyes Only? – The Search for Animal Consciousness, W.H. Freeman, Spektrum 1993.

“(Secondly) the scientific results that have been accumulating over the last twelve years have supported the view that the battery hen suffers unnecessarily and that the causes are inherent in the battery cage system. The task during the years to come is therefore primarily to develop and test good alternative systems, rather than trying to prove or disprove drawbacks and benefits of battery cage systems.” Klaus Vestergaard, Dept. of Animal Science and Animal Health, Royal Veterinary and Agricultural University, Denmark, addressing a seminar on the laying hen, organised by the European Conference Group on the Protection of Farm Animals, March 1992.

“The Commission report referred to in recital 2, based on an opinion from the Scientific Veterinary Committee, concludes that the welfare conditions of hens kept in current battery cages and in other systems of rearing are inadequate and that certain of their needs cannot be met in such cages.” Official Journal of the European Communities, 3 8 1999.

“I conclude that the battery system as described to me is cruel in respect of the almost total restraint of the birds and the incidence of broken bones when they are taken for slaughter.” Mr Justice Bell, Summing up in the McDonald libel case, The High Court, London, July 1997.

The Legal Situation – Minimum Legal Standards for Battery Hens

The fact that the battery hen has had her own ‘welfare’ legislation is regarded as an irony by welfarists. The very term “welfare” in relation to a hen in a battery cage is a misnomer.

The legislation on laying hens is currently contained within The Welfare of Farmed Animals (England) Regulations 2000, which implement European Directive 88/166/EEC. This lays down minimum standards for the protection of laying hens. The 1999 Laying Hens Directive phasing out barren battery cages by 2012 will replace it. Although woefully inadequate, these minimum standards are significantly higher than the traditional space allowance of 348 cm2 per hen in the USA (a single sheet of typing paper covers 620 cm2).

Until the improvements in cage space per hen come into force in 2003, the following are legal requirements for battery hens:

The cage area, measured on a horizontal plane, for each laying hen shall be not less than:

1000 cm2 where one hen is kept in the cage (this never happens in commercial units – Ed.)
750 cm2 where two hens are kept in the cage (see above – Ed.)
550 cm2 where three hens are kept in the cage, and
450 cm2 where four or more hens are kept in the cage.

NB: Most UK commercial units keep five hens to each battery cage.

The conditions under which battery hens must be kept continues with detailed strictures, including the height of the cage, for 65% of its area, being not less than 35 cm; the floor of the cages shall be constructed so as to support adequately each of the forward facing claws of each foot; and the slope of the floor shall not exceed 14% or 8 degrees, when made of rectangular wire mesh, and 21.3% or 12 degrees for other types of floor.

The above requirements represent a truly cruel, minimal degree of environmental enrichment for a bird programmed with all the instincts, the “ancestral memory”, of the junglefowl. It is to the credit of EU Ministers that the system is the subject of a forthcoming ban.

General Legal Requirements

Under current legislation, battery cages in Europe must be designed, constructed and maintained to prevent injury or unnecessary suffering “to the extent possible in the existing state of technology”.

Cages shall be of a type which avoids injury when hens are put in and taken out; and have no sharp edges or protrusions likely to cause injury or trap the birds.

Cages must be equipped and maintained to prevent escape.

Except in the case of therapeutic or prophylactic treatment, all laying hens shall have access to “adequate, nutritious and hygienic” feed each day to maintain them in good health and satisfy nutritional needs.

Adequate fresh drinking water must be available at all times.

Air quality within the unit must not be harmful to the hens.

Hens must have an “appropriate” resting period each day when the light intensity is reduced to allow proper rest.

Hens shall be cared for by “a sufficient number of personnel with adequate knowledge and experience of laying hens and of the production system used”.

Inspection of Battery Hens

The 1978 Welfare of Livestock Intensive Units (revoked, and now included in the 2000 Regulations) did at least prohibit the worst neglect. Until then “feeding up on Fridays”, whereby farmers would give the hens extra feed before having a weekend off, was openly recommended in the UK’s leading industry magazine, Poultry World. In her groundbreaking book, Animal Machines (1964), Ruth Harrison quoted from Farming Express (1961). Describing one particular farm, the journalist had written:

“So now the 30,000 layers, 8,000 growers and 3,500 head of breeding stock… are left from mid-day Saturday until Monday morning without attention. And every member of the staff works a five or five and a half day week.”

The Welfare of Farmed Animals (2000) Regulations state (in Schedule 2, paras 6-8) that the laying hen shall be cared for by “personnel with adequate knowledge and experience of the production system used”, and “the flock or group of hens shall be thoroughly inspected at least once a day and a source of light (whether fixed or portable) shall be available which is strong enough for each bird to be seen clearly”. In addition, units where cages are stacked higher than three tiers are operating illegally unless “suitable devices or measures make it possible to inspect thoroughly all tiers without difficulty”. In other words, climbing onto part of a lower tier, or not looking properly at all, is not acceptable.

Proper Inspection – An Unrealistic Goal

In the early 1980s, Chickens’ Lib (now know as the Farm Animal Welfare Network) drew attention to the impossibility of inspecting hens in battery cages. To summarise the main points in its statement:

The battery system is inherently illegal under UK (and now EU) law, since the hens cannot be inspected, as the law requires.

In a unit containing 40,000 hens* stacked in four tiers, 10,000 of the birds will be in cages at the lowest level. Battery hens are generally given 17 hours of light, to mimic summer time. However, lighting is low, and more so in bottom tiers, which are often in the shadow of higher ones. The stockperson must crouch down to see into crowded, dimly lit cages. Sick or bullied birds are hard to detect. Tumours are common amongst high-producing hens2 and these may not be noticed until birds are taken from their cages for slaughter. “Catchers” work at high-speed, and are not qualified to detect diseased birds. Another common disease condition among battery hens is brittle bones3. This leads to fractures, which though painful may not be readily noticed by the stockperson.

* Many units hold larger numbers of birds; with more than 90,000 hens in one building not unknown in the UK.

There are 3,600 seconds in an hour. Allowing one second per bird, it would take one person approximately three hours to glance at each bird in the bottom tier alone of a 40,000-bird unit. The scenario of a stockperson crawling along (daily) at floor level, inspecting the well-being of thousands of birds, is far-fetched.

Birds in top cages are also harder to inspect. Legislation requires stock-people to use “suitable devices or measures” to see into cages higher than three levels (a trolley may be used). Setting up such devices takes time, and again, the 10,000 birds at this level will receive a bare second’s attention.

Working from the calculation of one second per bird, one stock-person would take more than eleven hours (excluding lunch/tea breaks, weekends, etc.) to achieve these minimal inspections. Many unscheduled things occur during the course of a day (trapped birds, dead birds to remove, broken cages, etc.) resulting in delays.

Clearly, inspection (as required by EU law) of a 40,000-bird unit cannot be achieved by one person alone. If divided between two stock-people, they would engage in no other tasks beyond that of inspecting the birds (FAWN’s calculation spread over a 7 day working week, severely detracting from the economic advantages of the cage system).

The abolition of the battery cage throughout the EU will rectify a situation where hens are kept in a way which cannot, per se, fulfil the requirements of legislation.

The Treatment of Sick Caged Hens

Paragraph 9(2) in Schedule 2 (Additional Conditions Under Which Laying Hens in Battery Cages Must be Kept) states that any hens showing poor health or behavioural changes are treated. Suggestions are: “treatment, isolation, culling or correction of environmental factors; and any other form of remedial action which might be necessary.” As pointed out above, the design and conditions in a battery unit often mean that hens are left until death draws attention to their plight (removing ‘deads’ is recognised as a stockperson’s daily task).

An alarm system must be installed “which will operate even if the principal electricity supply to it has failed”.

When units are emptied of hens, thorough cleaning and disinfecting must take place, and surfaces and equipment kept “satisfactorily” clean.

Electrical Current to Immobilise Hens Outlawed

Under the legislation, no person shall apply an electrical current to laying hens for the purposes of immobilisation.


Bhat, G.A., 1993. Cage layer fatigue – an important problem in cage layer operations. Poultry Advisor, 26: 61-62.

Anjum, A.D. et al, (1989). Oviduct Magnum Tumours in the Domestic Fowl and Their Association With Laying. Veterinary Record, Volume 125, Number 2, 42-43.

Gregory, N.G. & Wilkins, L.J. (1989). “Broken Bones in Domestic Fowl: Handling and Processing Damage in End-of-Lay Battery Hens”. British Poultry Science, 30, pp 555-562


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