Hens & Eggs
The Laying Hen
Today's modern laying hen or domestic fowl is descended from the Red Junglefowl (Gallus gallus) of Asia. This wild ancestor inhabits tropical and subtropical forest edges and during its distinct breeding season lays 5-6 eggs in a clutch before incubating for 18-20 days (del Hoyo et al, 1994). Compare this with modern breeds of domestic hen, which lay over 300 eggs in a year.
Domestication started over 8,000 years ago. Modern selective breeding techniques have resulted in distinct strains for egg laying and meat production. The emphasis has been on 'efficiency' - maximum output for minimum food intake (Appleby et al, 1992). This breed specialisation has gone so far that birds of the laying strain do not make good meat birds. This causes ethical and potential welfare problems, since male birds of the laying strain neither lay eggs nor produce meat efficiently so are killed when a day old.
Despite centuries of domestication, laying hens retain the natural behaviours shown by their wild ancestors. This 'ancestral memory' of the birds' natural way of life has been carried down the generations so that hens retain the need to carry out behaviours such as building a nest, perching, pecking and scratching at the ground, dust-bathing, etc (Dawkins, 1993). For the majority of the world's egg-laying hens, the farming system renders it impossible to perform most of these natural behaviours.
The Egg Industry
The world laying hen population is currently estimated at 4,700 million. The 15 countries of the European Union (EU) house 271 million laying hens, second only to the 800 million birds in China. Other major egg-producing regions include the USA (270 million birds), Japan (152 million), India (123 million) and Mexico (103 million) (IEC, 2001).
Worldwide, some 70-80% of laying hens are housed in battery cages. The proportion of caged hens in the EU is about 90%. This is likely to change rapidly following the coming into force of the 1999 Laying Hens Directive, which prohibits barren battery cages by 2012. So-called "enriched" cages will continue to be legal. There are 29.2 million hens in the UK egg-laying flock. About 78% are currently in cages, with the rest in alternative non-cage systems: 16% kept free range; and 6% in perchery/barn systems (Williams, 2000).
There are 26,500 flocks of egg-laying hens in the UK producing 8,800 million eggs per year, the majority for UK consumption. Over 75% of hens are kept in flocks of 20,000 birds or more (BEIS, 2001).
Consumers
In the UK, the average consumer eats 170 eggs per year. Of these, 140 are eaten as eggs bought in shell, whilst 30 will be consumed in processed form such as in cakes and ready-made meals. The UK laying flock produces 8,800 million eggs per year. The majority (60.5%) are sold through retailers, whilst catering outlets account for 21%, and food manufacturers using egg as an ingredient take 18.5% of the total (BEIS, 2001).
From 2004, European Union legislation will make it compulsory for eggs to be labelled according to method of production. The following terms will apply:
- Battery eggs will be labelled "Eggs from caged hens";
- Barn eggs will be labelled "Barn" eggs;
- Free-range eggs will be labelled "Free Range" eggs.
Farming systems for eggs
Battery Cages
In the battery system, hens are crammed into a cage so small that they 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 and 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.
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. These 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.
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 Scientific Veterinary Committee Report
In 1996 the European Union's committee of scientific and veterinary experts published a reportacknowledging 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".
In 1999 the European Union 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 per bird. To put these space allowances into context, an A4 sheet of typing paper covers 620 cm2. So-called 'enriched' cages will not be banned under this new legislation.
"Enriched" Cages
The European Union has agreed to ban barren battery cages from 2012. However "enriched" cages will still be allowed. "Enriched" cages must provide at least 750 cm2 per hen, of which 600 cm2 is "useable area", the rest being shared space for items such as a nest box. "Enriched" cages must be 45 cm high over most of the cage. This compares with 450 cm2 of cage space per hen in battery cages and a height of 40 cm. "Enriched" cages must also have a nest, "litter such that pecking and scratching are possible", 15 cm of perch space per hen, and a claw-shortening device.
It is claimed that "enriched" cages will be better for the hens' welfare than battery cages. However scientific and practical evidence shows that, in welfare terms, a cage is still a cage, "enriched" or not, and that birds will continue to suffer. The space and facilities provided in "enriched" cages are so inadequate that they deprive the birds of the ability to fulfil natural behaviours, leading to abnormal behaviours, frustration, suffering and body degeneration (Lymbery, in press).
Barn Systems
"Barn" eggs are produced from hens kept in loose flocks confined within a shed. Birds in this system are not caged and can roam throughout their house but are not let outside. They are provided with perches, platforms, and nestboxes and litter areas. Some barn units keep their hens in large flock sizes of up to 16,000 birds in conditions that can resemble a crowded football terrace.
Free Range Systems
"Free Range" often conjures up idyllic images of hens scratching in the farmyard. The reality is often very different. They are often kept in "Barn"-type houses in flocks of up to 16,000 in large sheds. They are often debeaked. The birds must have access to the outdoor range area, which can be stocked at a maximum of 2,500 birds per hectare of land available to the hens. However, in large-scale free range units, often less than 50% of the birds regularly go outside. As with all commercial laying hens, after usually a year of egg production they are slaughtered.
Debeaking
Many hens are debeaked. A red-hot blade sears off a chunk of the birds' sensitive beak. This suffering is caused in order to stop birds pecking at each other or cannibalising, common problems on commercial egg farms - whether caged or free range.
Debeaking, often referred to as 'beak trimming', is a serious mutilation which is carried out on a large proportion of laying hens in all production systems. It has been suggested that debeaking is no more painful than for humans cutting their nails. This is a false analogy, since scientific evidence shows that hens not only feel pain at the time of the operation but can also suffer a lasting, chronic pain.
Debeaking is carried out to stop the hens pecking out one another's feathers, an abnormal behaviour that can lead to cannibalism. It is widely acknowledged that these behaviours are borne out of frustration of natural behaviours, leading to stress in industrial-scale poultry farms. Debeaking adds insult to injury by punishing the birds themselves for the bad husbandry systems they are kept in.
Brittle Bones & Malignant Tumours
The average hen lays about 300 eggs a year. Some reach 330 eggs a year. That's nearly one a day. This compares with the laying of 5-6 eggs per brood during the breeding season of the hens' wild ancestors. The modern drive toward ever-greater egg production puts strain on the birds' physiological system. Is it any wonder that hens all too often suffer osteoporosis and malignant tumours?
Bone weakness in laying hens is a major cause of concern. Although it can mainly be attributed to the battery hen's almost total lack of exercise (Broom, 1992), the great demand for calcium for the formation of egg shells depletes natural stores of calcium in the hen's body, often leading to severe osteopenia (RSPCA, 1989).
Another welfare problem associated with pushing hens to lay more eggs is the development of malignant tumours of the oviduct. In one investigation, a significant proportion of malignant tumours of the oviduct were identified in 20,000 'spent' layers selected from ten different farms. The researchers concluded, "... the increase in the prevalence of the (magnum) tumour coincides with continued selection of fowl for high egg production" (Anjum, 1989).
Slaughter of Spent Hens
Most egg-laying hens in the UK are sent for slaughter after a year of egg production. This can be a traumatic experience for hens as they are caught and bundled into crates before being transported by lorry to the slaughterhouse. One study found that at the time of catching and crating, levels of the stress hormone corticosterone in battery hens were 10 times higher than normal. Once caught, the hens are held by their legs and carried upside down out of the shed and packed into crates for transport, often breaking their bones in the process (Turner & Lymbery, 1999).
On average 29% of battery hens arriving at the slaughterhouse are reported to have at least one freshly-broken bone. Removing the birds from the crates and hanging them upside down on the shackle to await slaughter increases the proportion of hens with broken bones to 45% (Gregory and Wilkins, 1989; Gregory, 1994). "Spent" hens can be worth as little as two pence per bird. After slaughter their carcasses will be used in chicken soups, pastes, pies, pet food, etc.
Slaughter of Cock Chicks
For every hen hatched for egg laying there is a cock chick that is killed almost immediately after struggling from the egg. Modern selective breeding techniques have resulted in distinct strains of chicken for egg laying and meat production. This breed specialisation has gone so far that birds of the laying strain do not make good meat birds. As male birds of the laying strain do not lay eggs and will not produce meat efficiently, they are killed when a day old.
Official advice is to kill the chicks before they are 72 hours old using carbon dioxide (CO2) gas. Where small numbers of chicks are involved, neck dislocation or decapitation is also advised. (MAFF, 1987). Another often-used method is a mechanical 'homogeniser', which minces the chicks alive. About 30 million cock chicks a year are killed a year in Britain alone.
Eggs, Food & The Environment
Food vs. Feed
Hens laying eggs don't produce food, they waste it! It takes 3 kilos of grain as chicken feed to produce one kilo of eggs. This is because the conversion of crops by farm animals into food for humans is grossly inefficient. And it is not only food, such as grain, which could be fed directly to humans, that is wasted. Each battery egg takes about 180 litres of water to produce. Compare this with the human use of water in developing countries. In India, for example, the poorest people use an average of only 10 litres of water each per day (O'Brien, 1998).
Environmental Impact
Ammonia gas escaping into the atmosphere is a serious pollutant linked to acid rain. Studies of farm animal housing have shown that egg farms have one of the highest farm emission rates of ammonia gas. Laying-hen houses in the UK and other European countries have also been found to have levels of ammonia and inhalable dust close to or over the regulated limits for continuous exposure for animals or for 8-hour occupational exposure for stockpersons (Turner, 1999). The intensive farming of eggs depends on a plentiful supply of affordable feed, which is usually grown intensively using chemical fertilisers and pesticides. Intensive farming practices have been linked to severe declines in farmland wildlife such as birds.
Human Health
Salmonella
Eggs are an important source of salmonella food poisoning. Eggs were responsible for 10% of Infectious Intestinal Disease (IID), or food poisoning, outbreaks in England and Wales in the period 1992-1999 (FSA, 2000). Nearly 17,000 cases of salmonella infection in humans were confirmed in 1999. This represents a 53% fall in cases since the peak of 36,400 in 1997 (ACMSF, 2001). In 1988 the then Health Minister, Edwina Currie, caused controversy by claiming that most egg production in the UK was infected with salmonella. Reports of salmonella infection have only just fallen back below pre-Edwina Currie levels. Advice from the Government's Food Standards Agency (FSA) is that "eating raw eggs may pose a health risk. Vulnerable groups such as the elderly, the sick, babies and pregnant women should only consume eggs that have been cooked until the white and yolks are solid" (FSA, 2001).
Cholesterol
Eggs are a rich source of cholesterol, which is linked to heart disease. A single egg contains most of a person's recommended maximum daily cholesterol intake.
PHILIP LYMBERY
11th June 2002