Something in the Air

What is ammonia?

Ammonia (NH3) is a toxic gas created by the disintegration of organic materials by bacteria. It’s water soluble, and therefore may be absorbed into wet dust particles and wet bedding on farm floors as well as into salivary bodily secretions, such as eye, nose and mouth fluids, and the protective mucous layer surrounding the body of fishes.

What are ammonia’s effects?

Ammonia causes three main injuries to the skin of birds exploited for their flesh: leg soars, hock burns, and pressure wounds. These injuries are caused by prolonged contact of the skin with the ammonia-saturated bedding on farms. This prolonged contact occurs when "broilers" (birds exploited in the meat industry) lie motionless. Why does this happen?

• Overcrowding. Farmers crowd chickens to their maximum survival capacity, and sometimes even beyond: 10-20 birds to a square meter in open sheds, and about 28 birds in climate-controlled sheds. The area allowed to each chicken is therefore smaller than a 20 by 20 centimeter floor tile. As they increase in size, they can hardly move in the midst of such overcrowding - to the degree that even to reach the water and feeding troughs they must step on each other.

• Genetic distortion. The birds exploited today in the meat industry have undergone intense artificial selection over the last few decades, resulting in drastic physiological changes: they grow at a vast speed (they gain 60 times their original body weight in just over seven weeks) and the proportions between their body parts are distorted. Artificial selection has increased breast size at the expense of the rest of the body parts, to the point that the body's center of gravity tilts the body forward and obstructs walking. Chicks' legs are not fit to carry this rapid increase in body weight, and about one-third of them suffer intense pain with every step they take. The rest of the birds suffer skeletal and limping problems. About one half suffer a distortion in the heel bone, an ailment that was once rare.

• Lack of stimulation. Fowls in nature, or even in an open yard, are stimulated by their surroundings, which encourages them to move and work their bodies. Factory farmed chickens have no option to forage for their own food, to acquaint themselves to a diverse, changing environment, or to take care of their young. In the last stages of their rearing, when the overcrowding causes an increase in aggressiveness and intragroup conflicts, they are deprived of even the few visual stimulations the shed offers, since farmers have found that blacking out the shed decreases the damages caused by such aggressiveness.

Living in a sewer

The vast overcrowding of animals in factories causes pollution in the air that they breathe. The situation is particularly severe in poultry farms and artificial fishponds, where the overcrowding is at its greatest. The air in chicken sheds contains large quantities of dust, microorganisms, and gases - including ammonia. The ammonia is emitted from the shed's bedding, into which the excrement and water spilled from the troughs and cooling systems are absorbed. The bedding is not cleaned until after the birds are sent to slaughter. The birds, therefore, breathe the fumes of their own excrement. In winter they receive very little ventilation, since the farmers prefer to prevent air movement in order to save on heating expenses. In summer, the supplied ventilation is not enough because the birds pant to cool off their bodies (as they do not have sweat glands) and the particles of ammonia-saturated dust easily penetrate the respiratory system.

Sensitive birds

While the farmers are warned thoroughly about the effects of ammonia on humans, indicative even after a few minutes of exposure, the birds are left imprisoned in the polluted air without protection for months and even years. On top of that, they are also more vulnerable than mammals (including humans, of course) to the damages of ammonia. Their lunges operate at an increased rate and the surface area of their respiratory system is larger than similarly-sized mammals, therefore they absorb more ammonia compared to humans in similar conditions. Prolonged exposure to ammonia causes substantial changes to the basic structure of the lunges and trachea. One of the damages is the destruction of the cilia lining - the tiny hair-like bodies lining the tracks of the respiratory system from the nasal cavity to the lungs. The purpose of these hairs is to prevent the penetration of particles and various pathogens into the respiratory system, and their deterioration exposes the bird to many diseases and breathing problems.

Ammoniac diseases

Exposure to ammonia at or above a certain concentration (25 millionths of air volume), considered dangerous to humans staying in a poultry facility too long, causes avian respiratory system diseases, oversensitivity to viruses and decreased growth rate. But even ammonia concentrations at a fifth of that strength - which do not affect human beings - are found to damage avian cilia lining and make them more vulnerable to breathing disorders. And indeed, many of the chickens exploited in the meat industry suffer from prolonged distressed breathing and "ammonia poisoning.”

Toxic to humans as well

Farmer's health and safety inspections performed by researchers from Melbourne University found that 70% of farmers reported eye burning, about 30% reported permanent coughing and about 15% reported asthma and chronicle bronchitis. Consequently, the researchers warned the farmers to spend as little as time possible in poultry sheds and to wear a respirator while inside. Maytal Nuriel from Anonymous, who visited a poultry breeding farm in Kfar Yehushua, elaborates:


Recommendations from different countries on limiting ammonia exposure also take into consideration environmental protection, mainly due to the severe damages caused by waste from dairies, poultry farms and aquaculture facilities, which contaminates underground drinking water with ammonia and other carcinogenic compounds. Other recommendations are intended to prevent damaging the quality or safety of the chicken flesh, which may be contaminated by high ammonia concentrations.

Pressure wounds

The farmers do not lose money due to the chickens’ lack of movement. On the contrary, crippled birds burn less calories and thus save on food expenses. It is only the chickens who suffer: when they lie in ammonia-soaked bedding their skin develops soars and burns. When crouching, the gigantic heavy breast is pressed to the ground and 60% of the body weight weighs on the breastbone. As a result, pressure wounds form: the pressure on the skin creates pockets filled with viscous liquid under the breastbone skin. These pockets are parallel to pressure wounds of sick or disabled people who are confined to their bed for long periods of time. But in the chicken sheds these wounds are immersed in an ammoniac bedding, which makes them chronic.

Hock burns

When the chickens are displayed in stores for the consumer wrapped in plastic there remains little, if any, evidence of the suffering and injuries that the chickens have endured throughout their rearing. One exception is hock burns, which are sometimes identifiable on chickens sold in freezers. The burns leave a dark, sometimes turbid purplish mark on the birds’ knee joint, or somewhat below it. The burns are created by prolonged ammonia exposure, causing great pain to the birds.

The burns hit the stores

United Kingdom animal welfare organization Compassion in World Farming started researching the prevalence of hock burns on birds sold in grocery stores in the 1990s. These statistics were used to appeal to store managers to market birds that are kept in less harsh conditions. In a national survey published by the organization in 1996, hock burns were reported to be found on the skin of 34.9% of the birds examined. A 2005 report, based on a questionnaire sent to supermarkets, indicates hock burns are found on 10% to less than 5% of birds. Surveys conducted in Denmark and Sweden and published in 2003 found hock burns on 21.6% to 48.5% of birds. It is noteworthy that the rearing conditions of birds exploited for meat on organic farms in Israel (such as in Kfar Yehushua) do not contribute much to the welfare of the birds: the chickens hardly make use of the open space allowed to them because they suffer from serious bodily distortions (more than any other animal exploited in agriculture) as a result of artificial selection. The first step in bettering the welfare conditions of poultry in the meat industry is using old "genetic lines,” from a time when the birds were not yet so severely distorted.

Slow blinding

The exposure of the birds' eyes to ammonia may cause inflammation of the cornea and conjunctiva. People who stay inside a poultry shed for even a few minutes suffer eye burning and tearing. And the chicks - staying in the shed for weeks - are even more sensitive. In the cold months of the year the inflammation develops to the point of blindness. The inflammation causes severe pain, and the birds tend to scratch their eyes with their wings, while sounding shrieks of pain. But the suffering from this disease does not come down to only the pain caused by it. The birds, as their sight grows increasingly weaker, suffer also from thirst and hunger as their ability to find the water and food deteriorates. Some studies suggest that ammonia combined with saliva gives the food a bitter and repugnant taste, which puts them off it, causing them to eat less. Impaired vision may also more generally affect their ability to familiarize themselves and cope with the environment. Along with that, the birds' hostility increases, and as a result the birds suffer from fatigue in an atmosphere of continuous expressions of aggressiveness, and from the violent attacks themselves.