Man has bred chickens to be one of the most numerous birds on Earth and one of the most popular, cheapest and widespread human meats.
The domesticated chicken was bred from the red junglefowl (Gallus gallus) of south-east Asia. Jungle fowl live in forests in small flocks of up to 30 birds and tend to stay within a range of about 0.5 to 5 ha (about 1 to 12 acres). Flocks are variously composed of males and females, all males, or a cock and some hens. They tend not to fly far, often only up to a perch, over obstacles and to avoid danger. They recognise each other and like to be near birds they know. The modern chicken-producing industry has developed two types of chicken from the red jungle fowl: the broiler hen for fast meat production and the egg-layer.
Most chickens scratched about outdoors in small free-ranging flocks before World War II and people ate them only on special occasions. Then the invention of refrigeration emerged as a factor that changed poultry farming, especially in the US, and the mass raising of chickens began. Highly intensive industrial scale farming (factory farming), developed as the most efficient means of production, that is maximum production for the minimum cost. Now broiler production, in the US is managed by only about 50 poultry companies, of which the top ten account for over 60 percent of all US broiler production. Egg production similarly transformed itself.
Housing, Care, Growth, & Health
Broiler chicks hatch in massive automatically run hatcheries. Then they are transported to huge, long, windowless, purpose-built broiler sheds where they spend the rest of their lives. The chicks arrive at their shed motherless, all mixed together, and each must fend alone for herself.
Each broiler shed can contain 100,000 chicks. Chicks have room to move about, but when grown they stand in a solid mass with no space to move and conditions deteriorate quickly.
Feeding, watering, lighting, temperature and ventilation are automated in the sheds. Shed floors are spread with litter, such as wood shavings or chopped straw.
Overcrowding increases stress, spread of disease, and chickens begin dying. Some chickens die of starvation and thirst. Weakened they cannot reach food and water.
Providing welfare is impossible with so many hens. Sick birds if found are killed. But the dead and the dying easily go unnoticed, decompose and are trodden into the litter by the living birds.
No one cleans out the shed so hens live on litter made increasingly filthy by accumulating faeces and decomposing bodies. The end use of broiler shed litter is fertiliser scattered on farmland or compressed into pellets and sold as garden fertiliser.
Poor conditions induce illnesses. Among the health problems hens can suffer from are deformed skeletons, weak legs - making standing impossible, sores on their breast and legs ('hock burns' from long-term squatting in the ammonia of their faeces) and ulcerated feet.
Broilers in these conditions can pose a threat to human health. Bacteria that cause food poisoning in humans, such as Salmonella, are common in broiler chickens.
Broilers are made to grow fast to reduce the cost of their meat and to sell more of them by raising them more quickly. From a day old chick, modern hens reach around 2 kg in six weeks. In former times they took twice as long to reach market weight.
But fast growth injuries health. Heart and lungs suffer, unable to keep pace with rapid body growth to support disproportionately large bodies. Adult broilers can be crippled because the bones of their legs, growing less quickly, cannot support their body weight.
The condition of broilers' beset them with many disorders and diseases. Millions of broilers die every year before they reach six weeks of age.
At six/seven weeks of age the broilers are cleared out of their shed to the slaughterhouse (chickens can live several years naturally). Then farmhands clean out the shed for the next batch of chicks. Around six batches of chickens can be completed a year.
Tens of millions of breeders are needed each year to lay the vast numbers of broiler chicks; six million and 60 million hens every year respectively in just Britain and the United States alone. Breeding hens are not allowed to mother their chicks. Their eggs are delivered to hatcheries where they are incubated and hatched automatically.
Breeding hens are selectively bred to pass on a rapid growth rate to their offspring. Because breeders have this rapid growth rate themselves they need a lot of food to keep going. However, breeders would die from obesity if they ate as they would like, so food is largely withheld from them. Thus breeders live in a constant state of starvation.
Breeders are usually housed in massive sheds in conditions like their offspring and suffer similar diseases and injuries. They are slaughtered after a year when their egg production declines and are processed into low quality meat products such as pies and soups.
Transport & Slaughter
When the time comes, transport and slaughter is the same for all hens, whether broiler or breeder. Farm workers grab the hens by a leg (which can dislocate the hip) and cram them into cages that are then loaded by the thousands onto lorries. Broken bones, dislocations, bruises, pain and distress are common. The hens can travel considerable distances, are exposed to extremes of heat, cold, thirst and suffocation, and many do not survive the journey.
At highly automated slaughterhouses workers hang hens upside down on a moving chain that carries them to an electrified water dip. Their heads drag through the dip and the electricity stuns them. The moving chain then carries them in turn to an automatic neck-slashing blade, a tank with scalding hot water to loosen feathers and a plucking machine to remove them. Finally an automatic machine cuts their heads off and more machines slice their bodies open and remove their innards.
Hanging upside down is extra painful for hens with injuries from their housing or transport. Many birds may squirm in pain, raise their heads, miss stunning and go consciousness to neck-cutting. Or they may recover consciousness during the bleeding to death. Many birds may still be alive when plunged into the scalding water tank.
Heads, organs and feathers are thrown out or turned into meal to feed other animals. Bodies are refrigerated for the table.
People produce 70 billion chickens annually worldwide.
The table below gives an idea of the massive scale of the modern chicken industry. The data come in tonnes of ready to cook chicken (minus heads, feet and internal organs) but by dividing by the average ready to cook weight of, say, 2 kg, we can arrive at a measure of chicken numbers.
The Table shows that 28 billion broiler are produced worldwide annually. However, when you add the five billion egg-laying hens and the tens of millions of breeding chickens worldwide, you get about 35 billion. But, virtually all these are hens (broilers are females because males do not taste as good). Male and female chicks are hatched in equal numbers. So to include males we must double the figure to 70 billion chickens produced annually worldwide. What happens to male chicks? They are killed soon after hatching and go into pet food, low cost products and fertiliser).
Body Weight & Growth Rate
Not only have the numbers of chickens shot up in recent times, but the body weight of chickens and the rate at which chickens are made to grow have increased too. For example, the average live weight per broiler in the US nearly doubled in 50 years (1945 to 2001) from 1.3 kg (3 lbs) per chicken to 2.3 kg (5 lbs) per chicken; and the rate of chicken production increased 40 fold (in comparison cattle and pig production only doubled).
The scale of chicken killing is staggering. Billions of chickens are slaughtered annually - a death rate of over 2,000 chickens per second throughout the year, year after year. What other animal suffers such a death rate inflicted on his kind?
There are virtually no laws in any country specifically for chickens. The Farm Animal Welfare Council in Britain recommended simple basic care for farm animals in their Five Freedoms: