VegSocUK Information Sheet THE VEGETARIAN SOCIETY ___________________________________ BROILER CHICKENS Broiler chickens are reared for meat rather than for eggs. The broiler industry began in the late 1950's when strains were selectively bred for meat production. In 1992 over 600 million broiler chickens were slaughtered in the UK. BROILER CHICKEN PRODUCTION Broiler chickens are housed in large, windowless sheds in massive flocks of between 20 000 and 50 000 birds. Some flocks are even larger and over 100 000 birds is not uncommon. Feeding, watering, temperature and ventilation are all automatic. Birds are not caged and the concrete floored sheds are covered with a layer of litter, usually wood shavings though shredded paper or chopped straw may also be used. Broiler chickens are slaughtered after just six or seven weeks (a chicken's natural lifespan is around seven years). Some chickens are slaughtered after four weeks. These are marketed as pouissons or spring chickens. A few are kept beyond the seven weeks to be sold as the larger roasting chickens. Broiler farmers usually rear five or six batches of chickens a year. Two or three weeks are needed between batches to allow the sheds to be cleared of litter and fumigated. The litter is not changed or cleaned during the chickens time in the sheds and so becomes increasingly wet and greasy and covered in the bird's faeces. It is estimated that 80% of the litter by weight consists of faeces by the time of slaughter. This capping of litter with a greasy layer is exacerbated by a diet which includes the recycled blood, offal and feathers of dead birds. Artificial lighting within the broiler sheds is carefully controlled. Initially, lighting is bright to accustom the chicks to the location of food and water and encourage maximum eating and rapid growth. This lighting is then dimmed to a level of 2-5 lux in order to discourage aggression and fighting between chickens. The deep gloom in the sheds is continual except for half-hour each day when the lighting is turned off completely so that the birds may become used to total darkness. This means that in the event of a power cut or failure, panic and mass suffocation is less likely to ensue. Birds are closely packed and have little space to move around in. The recommended stocking density is expressed as 34kg of bird weight per m2. This means each bird has an area of 0.05m2, similar in size of this A4 sheet of paper. As the birds grow, conditions deteriorate and the sheds become increasingly crowded until the shed floor becomes a solid mass of chickens competing to reach food and water. WELFARE AND DISEASE Selective breeding for rapid weight gain and the use of growth promoting antibiotics in feed means many broilers are unable to support their own weight. Twenty years ago broiler chickens took about 84 days to rear. Today, broilers reach the same weight in only 42 days. An Agriculture & Food Research Council study found that up to 80% of broilers suffer from broken bones or other skeletal defects whilst the Farm Animal Welfare Council (FAWC) Working Group on the Welfare of Broiler Chickens witnessed "leg problems of varying degrees of severity" on almost every farm visited. Birds severely crippled and deformed die of starvation and thirst, unable to reach food or water. Other birds may only be able to move by using their wings to balance. The FAWC descr ibes these birds as "obviously distressed". The unnatural growth rate of broilers together with the lack of space to move or exercise encourages the birds to rest on the wet, dirty, ammonia-ridden litter. This leads to painful breast blisters and hock burns. Hock burns can often be seen on chickens sold in supermarkets (the hocks are the upper joints of legs). Foot and breast lesions and ulcerations are also frequent. The intensive nature and poor living conditions of broiler sheds means the birds are prone to numerous diseases. Strong ammonia fumes can lead to keratocon-junctivitis, a painful eye condition leading to blindness. Heart attacks (also called acute death syndrome), chronic respiratory disease, fatty liver and kidney syndrome and a wide range of bacterial and viral infections can lead to high mortality amongst flocks. Heat stress in sheds can also lead to considerable deaths. Many broilers die during periods of hot weather due to inadequate ventilation. Mortality in broiler chickens is estimated at around 6% or some 36 million birds each year. One of a stockperson's main jobs is the removal of dead birds. The FAWC estimate that each stockperson looks after an average of 80 000 birds and that the inspection of individual birds is impossible. In the overcrowded gloom of the broiler sheds dead and dying birds can easily go unnoticed. The decomposing corpses of dead chickens are often seen in broiler shed litter spread as fertiliser on agricultural land. The unhealthy, intensive nature of broiler farms means bacteria can spread easily through flocks. Salmonella and campylobacter are widespread in broiler farms and frequent causes of food poisoning in humans. TRANSPORT AND SLAUGHTER The catching and transport of birds prior to slaughter can cause considerable pain and distress. Gangs of bird catchers move through the broiler sheds, each catcher holding several birds upside down by their legs and cramming them into crates which are then loaded onto lorries. Dislocated hips, broken wings and legs, and bruising are common occurrences. Transport to slaughter can be a considerable distance and the birds may be exposed to extremes of weather. Cold, heat stress, suffocation and shock all take their toll. It has been said that six million birds die on route to slaughter each year. On reaching the slaughterhouse, the chickens are removed from their crates and hung upside down shackled by their feet to a moving line. Their heads and neck are dragged through an electrically charged water bath designed to stun the birds, rendering them unconscious. The moving line then takes the birds to an automatic neck cutter. Birds are then bled for a minimum of 1 1/2 minutes before entering a scalding tank. Scalding makes plucking easier. Inadequate stunning and neck-cutting means many chickens are still alive when entering the scalding tank. One study found nearly 25% of birds still not dead on entering the scalding tank. Stunning may be inadequate if the current used is too low. The EC recommend a current of 120mA (milliamperes) in order to induce cardiac arrest and so kill the bird. Very few broiler slaughterhouses use a stunning current this high, claiming high currents cause carcass damage. It is also claimed that stunning is preferable to killing as it allows the bird's beating heart to expell as much blood from the body as possible after neck-cutting. Neither of these claims are substantiated by scientific evidence. Neck-cutting is also inefficient. A Compassion In World Farming study on the Welfare at Slaughter of Broiler Chickens concluded that the overwhelming majority of broilers do not have their necks cut efficiently. Adequate neck cutting involving severing both the carotid arteries (the major blood supplies to the brain) is opposed by the poultry industry on the basis that it would cause problems for the automatic evisceration (disembowelment) of birds. BREEDING STOCK Broilers are hatched from eggs laid by breeding stock. These are usually housed on deep litter and are slaughtered at 64 weeks when their peak egg production is past. Breeding stock are deprived of food rations to prevent obesity. ___________________________________ // This article is copyright to the Vegetarian Society (UK), but may be freely copied for non-commercial use provided it is kept intact, not altered and these lines are included. For futher information contact: The Vegetarian Society, Parkdale, Dunham Road, Altrincham, Cheshire WA14 4QG, England. Tel: (England) 061 928 0793 email: vegsoc@vegsoc.demon.co.uk // [The text of this file was obtained from the Vegetarian Society (UK) in March 1995.]