Dishing the Dirt

The Secret History of Meat

PART TWO: THE LIVES OF FARMED ANIMALS

All Farms are Factory Farms

In the UK today, less than 2% of our population are directly involved in agriculture. To the overwhelming majority of us, food production in the 21st Century is as alien and mysterious as space exploration – little wonder then, that the anachronistic fantasy of Farmer Giles chewing hay and sending Daisy off to market still lingers in our culture. To understand the meat on our plates, we need to dispense with these comforting illusions and examine modern farming as it really is.

As any farmer will tell you, farming is a business. Success in business is underpinned by a simple principle - maximising productivity and minimising cost. Producing animals for food is entirely about getting as much meat 0r other product out of them as possible while spending as little as possible in the process. Whether a farmed animal is confined to a battery cage or roaming a Scottish hillside, the same principle applies. A farmer’s priority is not to have healthy or happy animals but to have productive animals and the two do not amount to the same thing. If feed and labour costs can be reduced far enough by cramming 30,000 chickens into a single shed, then the increased stress on individual animals is worth it. If it is cheaper to let a few lambs die of cold than employ another shepherd, then that’s what a farmer will do. If pigs can be bred to produce litters of twelve in which one or two piglets may starve to death, that makes far more sense than a litter of eight in which all piglets survive. Husbandry techniques subject animals to physical and mental stress but if the outcome is more meat at less cost, that is a price the farmer is happy to pay. The ruthless logic of profit and loss dictates how animals live and when they die.

The greatest cost in raising animals intensively is their food and thus the Holy Grail of farming is to maximise “feed-conversion ratios” – in other words, to get the biggest output of meat, milk or eggs from the smallest input of feed. The more quickly animals gain weight, the sooner they will carry enough meat to be ready for slaughter and the sooner the farmer can stop spending money and start making it. By selectively breeding animals with the best feed-conversion, modern farming has created new strains of animals whose bodies could never survive or even arise in nature. Animals are “designed” to gain weight above all else, including their health. These distorted priorities have led, for instance, to the situation in which turkeys are so large they can no longer mate naturally.

Farmed animals are slaughtered as soon as they reach the point of maximum profitability. Once they carry sufficient meat, feeding them is a waste of money. That means that most are killed at the point of physical maturity – a point which now comes for many of them before they have even reached reproductive maturity: people don’t eat chickens, pigs and ducks – they eat chicks, piglets and ducklings. Years of selective breeding have thus produced animals which are never intended to survive into adulthood and the consequence is that they are prone to ill health and disease as described above. However, not all animals die young: animals sent for slaughter must be replaced so more must constantly be bred. The animals used as breeding stock, however, need to have all of the productive “qualities” of meat animals (because their offspring are killed for meat) but are kept alive far longer. The consequences include grossly-overweight sows – a fifth of whom go so lame they have to be killed – and chickens whose food has to be rationed to prevent them from growing so big they would die.

Today, all farms are factory farms. Some look more like factories than others but the same principles of efficiency and cost-cutting apply across the board and the impact on animal health is the same. Nevertheless, different kinds of farms carry different problems and risks and a brief look at farming techniques will help to explain the litany of disease, infection and welfare problems uncovered in the following section.

Intensive Farming

These are the classic factory farms. In the UK, 95% of chickens, 99% of  ducks, over 90% of meat pigs and the overwhelming majority of turkeys are reared intensively. Crowded together indoors, these animals eat, breathe and excrete in the same physical space every day. The inevitable result is dirty and unhealthy conditions, frequently compounded by poor hygiene standards as a result of paring labour costs to the bone. The overcrowded, insanitary conditions have the same effect as in human slums: infectious illnesses are transmitted rapidly through the populations. To keep these illnesses at bay, farmers routinely dose animals with drugs such as vaccines and antibiotics but death rates of 5-15% of all animals are still common on intensive units.

Feeding is usually automatic and standardised industrial feed is carefully formulated for maximum weight gain. Feed costs are the largest expense in intensive production so price is a critical factor in the farmers choice of feed. Factory-produced feeds may become contaminated with animal by-products, drugs and infections, either at source or on-farm. In all intensive units, sheer numbers of animals preclude the possibility of detecting individual animals’ health or welfare problems.

Extensive farming

‘Traditional’ farming may be more pleasing to the eye but animals in fields are also at risk from the way they are kept. Vulnerable to the vagaries of their environment they can and do fall prey to parasites, infection, weather and the condition of the land on which they are kept – partly because selective breeding for ‘productivity’ has weakened their ability to resist these natural hazards. In many cases, such as hill sheep, standards of supervision are necessarily poor because the animals are roaming over wide areas: diseases of neglect invariably result. Food may be labelled “free range” if animals have spent only a portion of their lives outside or have simply had access to an open-air range. Free range poultry are usually kept in flocks which still number in the thousands or tens of thousands and even cattle and sheep may also be confined indoors for considerable periods – such as during the winter or for fattening prior to slaughter. At these times, extensively-farmed animals are at the same risk of infectious illness as intensively-reared animals.

Organic Farming

Organic farming is basically designed to ensure that food products and the land used to produce them are as free as possible from artificial chemicals like drugs and chemical fertilisers. It is primarily concerned with the quality of food rather than the treatment of animals, although in practice organic standards usually set higher levels of welfare than are found in non-organic systems. This is mainly because where the use of drugs and chemicals is restricted, better care must be taken of individual animals in order to safeguard their health. In general, organic systems favour outdoor rearing, lower stocking densities and more “natural” husbandry techniques, such as longer periods before weaning.

This approach does not necessarily reduce levels of disease, however. These more expensive techniques are reflected in the price of organic food, a premium which allows organic farmers to accept greater losses of animals during rearing. The mortality rate of organic broiler chickens, for instance, is around double that of intensively reared chickens[153] – parasites and infectious disease being easily acquired from the environment and fewer drugs being used to control them. Similarly, scab, a skin infection in sheep (see below) appears to present a greater risk in organic sheep than non-organic because the use of conventional treatments is restricted.[40] The organic ideal of chemical-free farming may sometimes be obtained at the expense of animal health.

Markets and transport

As commodities, animals are traded and transported whenever the opportunity for profit exists and for some this may occur at several stages in their lives. Animals such as chickens are bred in specialist hatcheries before being sold on to producers for “growing” while livestock farmers of all kinds replenish their herds or “improve” their breeding stock by buying “replacements” in. Pigs may be traded several times, from breeders to growers to “finishing” units and all animals face transport to slaughter. Livestock markets see thousands of animals passing through them, with animals crowded into pens for inspection by potential buyers. Despite the recent experience of foot-and-mouth in the UK, basic standards of hygiene and welfare are frequently neglected [41] and the potential for cross-contamination at markets and on farms themselves is considerable. In transport lorries, stressed animals are packed together, sometimes in layers with the animals in the top tiers dropping excrement on those below.

The Lives of Chickens

877 million slaughtered in UK in 2003 [42]

Natural lifespan, 7 years: slaughtered at 6 weeks (meat chickens), 2-3 years (laying hens)

At any one time, over 100 million broiler (meat) chickens are being raised in the UK – over 95% of them on factory farms. Despite the fact that they live for only a fraction of their natural lifespans, the broiler industry still expects around one in every twenty chickens to die during the few weeks between hatching and slaughter – a figure equivalent to 100,000 dying every day.[152] Of course, only the sickest birds fail to survive so these figures indicate a huge underlying problem of disease and animal suffering. Examining the lives of broiler chickens, it isn’t hard to see why that is the case.

Feathered Frankensteins

Broiler chickens are highly selectively bred for maximal weight gain, especially to satisfy the demand for breast meat. They now reach slaughter weight almost twice as quickly as they did 40 years ago.[43] Because the breeding process has artificially prioritised muscle development, broilers’ bones, hearts and lungs have not been able to keep pace with their increased weight and the consequence is birds under enormous physiological stress from both skeletal and circulatory diseases. Broilers have seven times the mortality rate of laying hens, even though layers live for years rather than weeks.[43]

The level of leg problems in broilers has been bluntly described by Government advisory body the Farm Animal Welfare Council as “unacceptable”.[44] One survey found that over 90% of chickens had an abnormal gait (ie were lame to some extent),[45] and post-mortem studies show birds suffering from fractures and/or dislocations.[43] While some of these problems may have been caused at or just before slaughter (see below) even an industry survey in 2002 found instances as high as 28% of birds in a single flock detectably lame.[43] The specific causes of lameness vary and include tibial dyschondroplasia and femoral head necrosis, caused by infection. Tibial dyschondroplasia has been found in 50% or more of birds in European studies.[43] Research shows that given the choice lame birds show a preference for food medicated with pain killers, indicating that their disability is also a source of pain.[46]

The hearts and lungs of these birds must provide oxygen and blood to all the excess muscle and this puts them under severe strain. The result is circulatory diseases such as heart failure and ascites – a build up of fluid in the birds’ abdomens because their hearts are not strong enough to pump it round their huge bodies. The EU’s Scientific Committee Animal Welfare found evidence of ascites in chicks just 3 days old, a shocking indictment of the physical deformities created by selective breeding.[48] A major cause of death in broiler chickens is so-called “flip over”, more scientifically-known as Sudden Death Syndrome. The colloquial name is an accurate if callous description of the problem – birds collapse suddenly following a brief period of very obvious distress, falling on their backs and dying within seconds. Although they show no apparent signs of illness before death, SDS is caused by acute heart failure and bigger birds are more likely to die from this condition.[46]

In the Ghetto

Thanks to breeding for weight gain, broiler chickens are born with the health problems noted above but factory farming techniques place them at even greater risk of disease. Up to 30,000 birds may be housed in a single shed and usual practice in the UK is for them to remain on the same litter throughout their lives. Over that period, accumulated excreta turns the litter from loose and dry chippings into a moist, spongy mass. To maximise time spent feeding, birds are frequently given just one hour of darkness in every 24 – placing them under still greater strain. Insanitary conditions and overcrowding are a recipe for both infection and the physiological stress which decreases resistance to disease. Broilers are thus vulnerable to a range of infectious diseases.

Coccidiosis is a parasitic infection of the intestines and most chickens are infected with it by the time they are a few weeks old.[47] Coccidia are single-celled protozoa and their ‘eggs’ survive in chicken sheds despite cleaning. These eggs are ingested by new birds as they are introduced to the sheds and passed on in their droppings. The main symptom is bloody diarrhoea. Because intensive conditions provide perfect conditions for the spread of this disease, broilers are routinely dosed with medication to control it although the main drug used, nicarbazin, has been shown to cause hormonal problems and birth defects in animals studies.[49] Larger parasites such as roundworms can also affect chickens, especially free range and organic flocks which forage in the open.

Other infectious diseases include infectious bronchitis and infectious bursal disease. IBwill usually infect every bird in a flock once it takes hold but it can be hard to detect at first: signs of the disease range from decreased growth rate to the deaths of a quarter of all birds in an infected flock.[46] IBDtargets birds’ immune systems and can cause high mortality – it is “prevalent wherever poultry are kept”.[50]

Skin diseases are also common, some as a result of prolonged contact with moist, infected litter, causing ammonia burns and blisters. These are sometimes visible on processed chicken on sale in the form of black or brown marks on the legs, known as hock burns. Any break in the skin will quickly become infected by the faeces-soiled litter and further infection may spread through the bloodstream.

The End of the Road

After six to seven weeks of being “grown”, all the chickens in each shed are sent for slaughter on the same day. In a process known as “depopulation”, thousands of birds are caught and loaded in boxes for transportation by lorry to the abattoir. Rough handling during catching is thought to be responsible for a significant number of leg injuries detected at slaughter. Birds who have known nothing but the ventilated, temperature-controlled interior of a huge shed for their entire lives are then driven in open-sided lorries to the slaughterhouses. Crammed tightly into boxes, they may peck and claw at one another. The entire process is so stressful that around half-a-million chickens each year die in the short period between catching and slaughter.[43]

Chicken Farming and Human Illness

Salmonella are intestinal bacteria, found in all animals including humans. Salmonella cause up to half-a-million cases of food poisoning and over 100 deaths in the UK per year (see Part One). The bacteria may be introduced to chicken flocks from outside the sheds, transmitted from parent to offspring through eggs or simply linger in inadequately cleaned poultry sheds. The bacteria are excreted in the faeces of infected chickens and as chickens eat faeces, it spreads easily in broiler chicken flocks. It rarely causes illness in the birds themselves. Despite a huge campaign against it, it is still found in over 40 million butchered chicken carcases a year.[51]

Like salmonella, campylobacter are bacteria found in the gut of many animals, although most commonly in poultry [52] (see Part One). Infection of an entire flock will usually take just a few days although it is actually more common in free-range and organic birds because it is widespread in the environment.[52] Responsible for up to 5 million cases of food poisoning a year in the UK, campylobacter is found in half of all chicken on supermarket shelves.[51]Chicken is the largest single source of campylobacter poisoning.

Bird Flu

One of the most devastating illnesses that can affect chickens and other poultry is avian influenza or bird flu. Outbreaks of the disease occur regularly throughout the world and the outbreak that was first detected in January 2004 in the Far East has still not been brought under control at the time of writing (January 2005). Bird flu is a classic example of a “local” problem having global importance as affected countries such as Thailand and Vietnam have become increasingly significant exporters of poultry - the UK imported 12,000 tonnes of frozen chicken from Thailand in 2003.[53] Tesco, in particular, sourced much of its chicken in Thailand. Nor is the disease solely found in developing nations: in 2003 an outbreak as close as Holland led to the slaughter of 60% of its national flock.

In a scenario familiar from BSE, the devastating economic consequences of export bans as a result of bird flu make both producers and governments reluctant to admit to the problem. Many scientists believe that the current outbreak could have originated in China [54] but the Chinese aren’t letting on. What is sure is that the Thai authorities protested that their outbreak of bird flu was chicken cholera, possibly for as long as two months after the disease was first detected – presumably in an attempt to preserve their export markets.[55], [56]

Bird flu is a highly infectious viral disease, spread by direct contact with faeces from infected birds, contaminated feed, water, equipment and clothing, from eggs in hatcheries and wild birds acting as carriers of the virus. It causes a variety of symptoms in poultry, including respiratory distress and diarrhoea. Both the disease and the control methods used to contain it – mass slaughter of animals – carry enormous welfare implications for poultry but the risks associated with the disease are not confined to birds.

Like all viruses, the bird flu virus is constantly mutating and at least two strains at present can infect humans: the less virulent H9N2 and the more deadly H5N1. Although only 44 cases of H5N1 have been confirmed in the current outbreak at the time of writing, 32 of these cases have been fatal – a mortality rate of over 75 per cent.[57] Total numbers are low because at present the virus can only be caught directly from birds but the major concern for human health is that if the virus mutates further, it could become transmissible from human to human. Many scientists now believe that the flu epidemic of 1918 which killed 40-50 million people worldwide was a mutated bird flu virus [58] and similar mutations have led to two other epidemics. The World Health Organisation has warned that there is a real risk of such a mutation occurring and that current vaccines may not be effective against the new illness. Peter Cordingley, regional co-ordinator for the WHO in Manila expresses the risk in the bluntest terms: "We don't have any defence against the disease," he says. "If it latches on to a human influenza virus then it could cause serious international damage".[59]New reports from Thailand (September 2004) indicate the first instance of human-to-human transmission of bird flu. WHO have confirmed that a mother caught the disease from her daughter. Both died.[60]

Laying Hens

There are around 30 million laying hens in the UK, approximately 70 per cent of whom are still kept in battery cages.[61] Where broilers have a lifespan of six-to-seven weeks before slaughter, laying hens are expected to live for two to three years – before being slaughtered for low grade meat once their ‘productivity’ falls off. While layers are markedly smaller than broilers, and thus spared some of the consequences of inflated size, they have also been selectively reared for productivity - today producing hundreds of eggs a year where they used to produce just a few dozen. Layers are thus prone to many of the same infectious diseases and parasites as broilers as well as diseases specific to them. Ironically, layers suffer bone and leg problems too but for completely different reasons to those affecting broilers.

A major and distressing cause of death in layers is egg peritonitis – infection and inflammation in the abdominal cavity caused by eggs. There are a number of causes of this disease, including the virus which causes infectious bronchitis in broilers, and E. coli infection of the laying duct. If hens are unable to expel an egg it may cause infection leading to peritonitis, especially if the egg breaks internally, providing a rich medium for bacterial growth. Prolapses may also occur, where part of the laying duct protrudes from the hen. Hens naturally peck at anything unusual and the result is that pecking from other birds turns the prolapse into a bloody and infected wound.

As for lameness in layers, the problem here is not excessive size but a combination of two problems – lack of exercise and weakening of bones due to calcium loss. Caged birds, in particular, get so little exercise that they have no opportunity to build up leg strength. The shells of eggs are high in calcium and egg production leads to lowered calcium in the bones, increasing the risk of fractures and lameness. Brittle bones are more easily broken and one survey found that 14 per cent of caged birds were actually suffering from broken bones while a further 13 per cent had healed fractures.[62]

Among caged birds, welfare and disease problems of all kinds may be exacerbated by difficulty in inspecting birds – cages are stacked in tiers and the top and bottom layers may be both poorly lit and difficult for stock keepers to reach and see.

Salmonella and Eggs

The “salmonella scare” of 1988 was the fore-runner of many recent food crises. The then junior health minister, Edwina Currie, provoked outrage by stating that most egg production in the UK was affected by salmonella. Egg sales plummeted and the minister lost her job. Although figures never backed her claim about the level of contamination, the minister’s concerns were well grounded, based as they were on the advice coming to her that a new salmonella strain was linked directly to eggs.[63] The industry howled and her head rolled but 10 years later, a vaccination programme was undertaken which now sees 80 per cent of chickens vaccinated against one of the most common strains of salmonella (salmonella enteritidis). Sixteen years down the line, salmonella contamination of eggs is a third of the level it stood at when Mrs Currie made her comments, the most recent survey indicating a contamination rate of one box of eggs in every 290.[64]

While this improvement is certainly welcome, as 27 million eggs are eaten in the UK each day, this still nearly 100,000 infected eggs in total per day. Imported eggs may not reach even that standard – Spanish eggs infected with salmonella are thought to have led to over 6,000 cases of food poisoning in the last two years.[65]

Turkeys

21 million slaughtered in UK in 2003 [42]

Natural lifespan 10 years; slaughtered at 8-26 weeks

After chickens and farmed salmon, the animal subjected to factory farming in the greatest numbers is the turkey. Over 20 million are reared and killed each year, a third of those at Christmas. Turkeys have also been selectively bred for maximal weight gain and the result is an animal that has lost the ability to fly and suffers from a litany of diseases. Breeding stags are so large that they are incapable of mating naturally and require to be masturbated by a stock keeper to provide semen for artificial insemination. Pathologically obese, they suffer from clogged coronary vessels, heart failure, ascites and congested livers.

Needless to say, turkeys suffer from severe lameness. Most have degeneration of the hip joints leading to severe lesions. Dr Colin Whitehead of the Agricultural and Food Research Council states that 70 per cent of the heavier birds are “suffering pain rather than just discomfort”.[66] One consequence of severely reduced mobility is birds unable to walk to feeding and watering points. These so-called starve outs account for as many as a million deaths in turkey sheds each year

Turkeys are also as vulnerable to infectious disease and parasites as broiler chickens, suffering from both diseases which afflict all poultry and specific diseases of their own. These include Paramyxovirus 2 and Blackhead disease. Pasteurellosis, or fowl cholera is especially prevalent in turkeys, its effects ranging from mild infection to severe illness and death. The fungal lung infection aspergillosis is found in all poultry but turkeys seem especially vulnerable.

Ducks

20 million slaughtered in UK in 2003

Natural lifespans 10-15 years: slaughtered at 6-7 weeks

20 million ducks are reared and slaughtered for meat in the UK each year – over 95% of them in intensive conditions virtually indistinguishable from those in which chickens and turkeys are reared. These naturally aquatic animals are denied any water in which to swim and the law does not even oblige producers to provide water for them to preen themselves.

Many of the illnesses from which they suffer are familiar from other poultry: pasteurellosis, bird flu, infectious bursal disease, aspergillosis, starve-outs and salmonella and e. coli infections – all are greatly exacerbated by factory farming. Ducks are also susceptible to duck plague – a highly infectious disease caused by the herpes virus and duck virus hepatitis which can cause death within hours of onset. Ducks are prone to developing septicaemia (blood poisoning) as a result of infectious illnesses. An outbreak of septicaemia in 2003 on a farm belonging to one of the UK’s major duck producers, Kerry Foods, led to the RSPCA having to put down nearly 100 ducks – something which should have been done by the farm itself. In a subsequent prosecution, counsel for the RSPCA said “this is a case about lack of inspection”.[67] Mortality rates for ducks are about 5% - in other words a million birds a year.

Like all poultry, ducks are also prone to leg disorders as a result of selective breeding for greater size. Ducks now reach weights of 3.5 kg in just 49 days, compared to 40 years ago, when it took 63 days to reach the same weight.[68]

For more information on ducks, see Viva!’s report , Duck Out of Water.

Geese

Stop Press: At the time of writing, an outbreak of goose parvovirus has been diagnosed in the UK for the first time in 23 years. Causing weakness, anorexia, diarrhoea and nasal discharge, this highly infectious disease has so far killed over half of all animals infected. Geese may carry the disease while showing no symptoms and transmit it through faeces or eggs.[70]

The Lives of Pigs

9 million slaughtered in UK in 2003 [42]

Natural lifespan: up to 20 years; slaughtered at around 6 months old

The overwhelming majority of pig production in the UK is intensive. 75% of breeding sows are kept indoors for their entire lives and only 1% of all ‘finishing’ pigs – ie those being prepared for slaughter - are kept outside. At any one time, over 90% of Britain’s five million pigs will be confined indoors in factory farms.

Pigs are confined in buildings with concrete or slatted flooring for ease of cleaning. A grown pig, however, produces 10 times the faeces of a human being and efficient and complete cleaning of pens containing 10 or 20 pigs in sheds containing hundreds of pigs is simply impossible to achieve. Inevitably, pigs end up lying in their own excrement. Straw or other bedding is used in some systems but replacing it frequently is time consuming and expensive so it often becomes fouled.

Wild pigs – which are exactly the same species as all farmed pigs – normally have litters of around 6-7 piglets. However, this level of productivity is insufficient for the meat industry and selective breeding has led to sows who now routinely produce litters of double this size. More piglets means smaller and weaker piglets and more competition for their mothers’ milk. As a result, although more pigs are born, around one in 20 are born dead and one in ten fail to survive to weaning.[71] This means, on average, more than one piglet dying in every litter. Causes of death include starvation, chilling, infections and being lain on by the mother. “Overlying” is the most common cause of death but frequently masks underlying problems – weak and hungry piglets are most likely to be crushed. Farmers would obviously prefer all piglets to survive but so long as their losses are not greater than their competitors, they will not be concerned. Piglets which die before weaning consume no commercial feed and thus incur virtually no costs. Ten live pigs from a litter of 12 is still a more profitable proposition than all piglets surviving in a litter of seven.

In order to re-impregnate breeding sows as soon as possible, weaning takes place at either three or four weeks depending on the system used. Naturally weaning would be a gradual process, not completed until the piglet was two to three months old. Abrupt, early weaning puts piglets’ immature digestive systems under stress, resulting in scours, severe diarrhoea. According to one animal feed expert, pigs are weaned at the time of “peak vulnerability”[72] and another notes that “young pigs have considerable difficulty digesting their feed from weaning until two months of age”.[73] Scours are not confined to newly-weaned pigs, however. Swine dysentery, E. coli infections, rotavirussalmonella and porcine intestinal adenomatosis all cause scours in pigs – in many cases fatally: up to three-quarters of all pigs on a farm infected with swine dysentery may die.[74] Pig Farming magazine identified the contributing factors to scours and their list of culprits reads like a description of factory farming: poor hygiene, overcrowding, lack of or unclean bedding, overcrowding and dirty water or feed bins.[75]

The dirt and overcrowding of factory farms leads directly to another major category of pig illnesses: respiratory disease. This has been described by an Upjohn veterinary adviser as possibly the most important disease threat to pigs.[76] Lung lesions associated with pneumonia are found in as many as 50 per cent of pig carcasses at slaughter[74] while 80% of pig herds are affected by enzootic pneumonia, the most common type.[77] Pleuropneumonia causes anorexia, fever and laboured breathing in pigs and blood-stained froth may be seen at the mouth – mortality among infected pigs may be as high as 50 per cent.[74] Atrophic rhinitis is an infective illness causing sneezing followed by distortions of the nose and even bones of the face: 20-30 per cent of pigs at slaughter may show signs of the disease.[78]

Viral diseases have become increasingly common in recent years. In 1991 the UK was struck by the first of many new illnesses – porcine reproductive and respiratory syndrome which is now endemic in the UK and causes increased abortions and premature births in breeding pigs and respiratory disease in weaned pigs.

Two more new diseases thought to be viral in origin have emerged in the last few years: post-weaning multisytemic wasting syndrome (PMWS) and porcine dermatitis and nephropathy (PDNS). PMWS strikes down newly weaned piglets and may cause up to 20% of piglets to die. Signs of infection range from laboured breathing and jaundice to unexplained deaths in a herd. While a virus has been implicated in its spread, mortality from PMWS is associated with low standards of hygiene, high stocking densities and early weaning – in other words, again, the characteristic features of factory farming. PDNS mainly affects older pigs and causes kidney damage and haemorhaging under the skin. Because these diseases have a huge impact on productivity, farmers take them very seriously indeed.

Amongst many other illnesses, pigs are also widely affected by meningitis, which may be present in up to 50% of pigs.[79] This bacterial infection results in sudden death of pigs that seem in good condition. If the pig is seen alive, he may show signs of incordination, tremor, paralysis and spasms before dying within four hours of showing symptoms.Exudative dermatitis, also called “Greasy Pig Disease”. This very distressing illness causes piglets to develop excess secretions which can rapidly lead to infected lesions, skin loss and death. Up to 60 per cent of finishing pigs may suffer from stomach ulcers [80] and a recent abattoir survey found six out of 10 batches of pigs had roundworm infection.[81] A similar survey found that 24 per cent of finishing pigs had mange.[82]

Mutilations

Pigs are also subject to intentional damage. Because piglets have sharp teeth which can cause damage to other pigs, teeth are often ground down or clipped with pliers – often exposing the pulp. On animals under 7 days old no anaesthetic is required but not only is the process itself very painful, it causes continued severe pain to piglets until they lose their milk teeth around 50 days later.[83] Tails are also clipped to prevent other piglets from biting them – again, without anaesthetic on piglets under 7 days old. Around 40 per cent of all piglets are subjected to these mutilations.[84] Pigs with sufficient mental stimulation and adequate nutrition very rarely tail-bite but these painful mutilations are simpler and cheaper for farmers to perform than providing environmental enrichment on factory farms.

Mixing it up

Unlike chickens, which will remain in the same shed from days old to slaughter, pigs are frequently moved – sometimes within the farm, sometimes from one farm to another. They are taken from their mothers abruptly at weaning and mixed with other litters and are likely to be moved again a few weeks later for ‘growing’ and again later for ‘finishing’. Some farms specialize in just one part of the process. As animals which have evolved to live in stable family groups this mixing is extremely stressful for pigs and leads to fighting, injuries and lowered resistance to disease and infection. It also provides a perfect opportunity for the spread of disease.

Pig Farming and Human Illness

In 2000, the ministry of agriculture calculated that 23 per cent of the nation’s pigs are affected by Salmonella and that 5.3 per cent of carcasses checked were infected.[85] There is no evidence of any improvement in levels of contamination since that time. Further, live transport and markets transmit this disease. Up to 20 per cent of Salmonella-free pigs are infected during transport and at the abattoir from contaminated excreta.[86]

Pigs also carry campylobacter and E.coli while listeria is carried on 58 per cent of pigs’skin.[87]

For more information on pig farming in the UK, see Viva!’s Pig in Hell report.

The Lives of Cattle

2.25 million sent for slaughter in 2003 [42]

Natural lifespan, approximately 25 years; slaughtered at 5-10 years (dairy), 1-2.5 years (beef)

The image of cows grazing in the field remains an unchanging constant in the countryside. Behind the picture of tradition and tranquility, however, lies exploitation and the dedicated pursuit of productivity. Whether they are dairy cows, driven to secrete huge quantities of milk at a devastating cost to their health, or beef cattle, designed to simply eat, get big and die, cattle are devastated by ill health, pain and disease.

Against Nature

Traditional grazing may be the most visible aspect of cattle farming but it represents only a part of the life of a cow. Today, cattle are almost universally kept in housing in winter and there is an increasing trend towards what the industry euphemistically calls, “year-round housing” – in other words, intensive farming for cows. Cattle no longer subsist on grass and straw but are given commercial supplements designed to maximise feed-conversion while selective breeding has led to specialised – and unnatural – cows whose health suffers accordingly (see below).

When it does occur, grazing on pasture may provide animals with the fresh air, exercise and mental stimulation which are denied to indoor-reared animals but it also exposes them to a range of environmental hazards. Unlike wild animals, domesticated animals have no evolutionary pressure to develop resistance against such diseases and the farmer’s reliance on vaccines, antibiotics and other medications is all that stands between them and a deceptively hostile landscape. Wild animals also roam over wide areas in relatively small numbers: farmed animals, densely packed into fields, exist in a far from natural state and the consequence is increased vulnerability to disease.

The concentration of cattle in fields – just like chickens in broiler sheds – provides parasites of all kinds with a rich food supply, fostering colonisation of the land on which they graze. Liver fluke is a common infection of both cattle and sheep, siting itself in the liver and causing anaemia, poor condition, scours (diarrhoea) and – in the worst cases – death. The fluke is a microscopic parasite which survives in wet pasture, reproduces inside snails and is then passed to cattle as they eat contaminated grass. Cattle are also afflicted by ostertagia, stomach worms, and, like chickens, suffer from coccidiosis, causing bloody diarrhoea and even death in calves.

Scours are a fact of life for cattle and probably the commonest cause of death in calves.[88] Early weaning plays a significant part in the development of scours in dairy calves (see below) but a range of causes exist for cattle of all kinds. As well as the above parasites, scours are also caused by (among others) salmonella and E. coli infections and rotavirus. Rotavirus is a highly infectious viral illness which destroys the lining of the small intestine, preventing reabsorption of water causing severe diarrhoea. Another bacterial infection picked up from pasture is Johne’s Disease, which cannot be treated with antibiotics and causes severe weight loss in cattle. Widespread wherever dairying takes place, cases of Johne’s in the UK have more than doubled in the last 10 years.[12] In a reminder that not all problems are natural in origin, however, cattle are also afflicted by tyre wire disease, which is exactly what it says it is. Wires from the tyres used as weights for tarpaulins on many farms work loose as the tyres degrade and are eaten by cattle – usually mixed in with straw - causing severe pain and distress.

Parasites do not just affect the digestive system and the self-explanatory lung worm burrow through the intestinal wall after being eaten and migrate to the lungs where the larvae hatch and cause coughing, panting and death. The worms are large enough to be seen with the naked eye on autopsy. Like most farmed animals, cattle also suffer heavily from pneumonia, which affects 1.9 million cattle annually and kills 157,000 calves a year.[89] 3 calves in every hundred die of pneumonia [90] and vaccines exist for only half the known infections which cause it.[91] Cattle are also susceptible to tuberculosis: about 5% of herds were infected in 2003 but numbers are currently rising by 18% per annum.[12]

Again like pigs and chickens, cattle are also plagued by lameness. Around 30,000 cattle each year are affected so badly that they are culled [92] while one abattoir survey found that three-quarters had foot or leg changes at slaughter which could lead to lameness.[93] The RSPCA estimate that one million cattle each winter suffer from digital dermatitis – a very painful inflammation of the hooves [92] – and the Veterinary Times has described the level of digital lameness in cattle as at an “all time high”.[94] Over the last six years, according to research, lameness incidence has increased from 38 to 55 cases/100 cows”.[95] This is despite the fact that the Government advisory body, the Farm Animal Welfare Council, described lameness in dairy cattle as “at an unacceptably high level” back in 1997.[96] The list of causes of lameness is a very long one, cows being at risk from both infections caught from the soil and damage caused by hard flooring in cow sheds. For dairy cows, the unnatural gait caused by the size and weight of their udders (see below) contributes to laminitis, essentially inflammation of the hoof.

Daisy is Dying

Dairy cattle are among the most exploited, abused and stressed animals on the planet. Producer’s margins in the dairy industry are very low indeed so maximising milk productivity is utterly essential. Cows, like every other mammal, only lactate when they have offspring to nurse so a dairy cow’s life is a constant cycle of pregnancy and lactation – both extremely demanding physiological conditions. On top of this physiological stress comes a powerful psychological stress: the separation of mothers from calves. Most dairy calves are weaned within days and sometimes hours of birth. After being allowed to suckle her colostrum – the first milk produced by the mother after birth, which provides vital immunity to the calf – they are taken from their mothers as soon as possible in order to maximise the mount of milk available for human consumption. The consequence – just as with piglets – is scours for calves and additional stress for their mothers.

For the same reason, the dairy cow is also one of the most striking examples of selective breeding producing an animal afflicted with a body that could never survive in nature. A “productive” dairy cow will supply up to 12,000 litres of milk per year from massively distended udders – working out at between 25 and 40 litres of milk per day (allowing for periods when she is not lactating). This is approximately 10 times more than her calf could require and is a product of artificial selection and careful nutrition. Milk is a high protein, high energy substance and producing it in such quantities places a huge burden on the cow. The typical dairy cow is extremely thin, with pelvic and rib bones easily visible – indeed, those qualities are signs of a “good” specimen of a dairy cow. The energy lost in milk production is so great, however, that most Fresian/Holsteins manage only a little over three lactations before becoming exhausted and being culled as unproductive.[97] Because cows only lactate when they have offspring to feed, an infertile dairycow is a useless dairy cow: 125,000 are slaughtered simply for being infertile each year.[92]

Dairy cows suffer hugely from mastitis, infection of the udders - in fact, this disease kills more dairy cows than any other disease that afflicts them. Around one million cases arise each year and 90,000 cattle are culled for it.[92] Infection can be picked up from pasture, E. coli being a major cause when distended, low-hanging udders become contaminated by manure. Other infective agents include staphylococcus aureus and klebsiella. Mastitis causes pain, inflammation and pus-production, which can be visible in milk. Farmers monitor the amount of the cow’s immune and udder cells in milk in order to try to pick up mastitis before obvious symptoms appear: 200-250 million cells per litre is considered an acceptable figure in the UK.[98]

Beef on the Bone

While some cattle are ‘mixed’ breeds, used for both dairy and beef production, none are ideally suited to both. Around half of British beef comes from specialised beef cows, which have been bred to produce a significantly different kind of body to dairy cattle – one in which muscle weight gain is the priority. Some have been specifically bred for so-called double-muscling, overdevelopment of muscles caused by a genetic mutation. Belgian Blues are the most common double-muscled breed in the UK but while the mutation favours lean meat production, it comes at a considerable price to the animals. Easily fatigued and stressed, double-muscled cows are also so muscular around their hind-quarters that their birth canals cannot stretch enough to expel their large calves: nearly half require Caesarian section and over one in ten calves die at birth.[99]

Double-muscling is a result of a very specific mutation but in general, breeding and feeding for weight gain leads to predictable problems: lameness (one study finding 98% of beef bulls studied had joint or bone problems) [99] and metabolic problems such as bloat (excess gas production, which can be fatal) and acidosis, a disturbance in the chemical balance of the body.

Cattle And Human Health

Cattle are a major source of E.coli infection and food poisoning. One severe case of E. coli 0157 infection recently was caused by a child simply being splashed with manure but consumption of meat is the more common route for this infection.  Both tuberculosis in cattle and brucellosis (an uncommon infection causing outbreaks of spontaneous abortions in a herd) can be contracted by human beings and, of course, BSE is the source of variant CJD in human beings (see Part One).

Infection in milk has been recently linked with Crohn’s Disease, a chronic inflammation of the lining of the gut, causing ulcers and severe diarrhoea, often leading to internal bleeding and other complications. Around 200,000 people in the UK suffer from Crohn’s. A bacterium carried by cattle (Mycobacterium avium paratuberculosis) has been found in the guts of all sufferers of the disease. Many doctors believe it is contracted through dairy products. At least 17 per cent of dairy herds carry the bug, with about 5 per cent of milk on sale testing positive for it.[100]

Lastly, lactose intolerance – in other words, inability to digest dairy products - is extremely common worldwide: it occurs in 75 per cent of human beings and although Caucasian people tend to have lower levels, it is still estimated that four to five million British people are affected.[101] Symptoms include bloating and diarrhoea.

Stop Press: October 2004. An Irish man in his twenties has just been diagnosed with vCJD. Doctors report that he has never received a blood transfusion - it is therefore likely that he contracted the disease directly through eating infected beef or beef products.[102]

The Lives of Sheep

15 million slaughtered in 2003 [42]

Natural lifespan, 10-12 years: slaughtered (lambs), 3-6 months

Of all food animals in the UK, sheep are the most likely to be reared out of doors and, in the case of hill sheep, may even lead semi-wild existences, roaming over large areas and interacting with their keepers comparatively rarely. That does not mean, however, that they are immune to the financial imperatives which put all farmed animals at risk of disease. Sheep are reared extensively because that is normally the most cost-efficient way of rearing them – not because it ensures their health or welfare. Sheep are originally animals from dry, mountainous areas and their feet are not suited to soft pasture like that found in many lowland sheep areas. They are also, just like cattle, stocked at very high densities in lowland areas – and, like cattle, increasingly housed indoors for extended periods. Little surprise then that high on the list of diseases afflicting sheep are those we have already encountered in other farmed animals – lameness, pneumonia and parasites.

According to Defra, the UK’s ministry of agriculture, 92% of sheep flocks in the UK “have a problem with lameness” and some 3 million individual sheep may become lame each year.[103] Two major causes of lameness in sheep are scald, a bacterial infection and footrot, a secondary infection on top of scald. Scald is caught from a bacteria found in sheep droppings and is thus easily acquired from intensively-used pasture or dirty bedding in housing. Footrot causes inflammation and even necrosis (death) of soft tissues under the hoof and produces a foul smelling discharge. A survey in Scotland found that 40% of farmers thought footrot a “medium” or “large” problem but only 6% of them vaccinated against it.[104] Sheep also suffer from digital dermatitis, similar to the condition suffered by cattle.

Pneumonia in sheep is frequently caused by pasteurella, an extremely widespread infection which also causes general illness and “loss of condition”. Farmers vaccinate against pneumonia but vaccines are not always effective. Because symptoms are not obvious in individual animals, pneumonia may often pass untreated by the farmer.

Parasites are a common problem for sheep, with familiar culprits like round worm, coccidiosis and liver fluke picked up from pasture. Up to 1,000 liver fluke may infest a single sheep’s liver. Because of their wooly coats, sheep are also at particular risk of skin infestations. The Leather Confederation estimates that 14% of sheepskins are damaged by lice or mites.[103] Sheep mites are the cause of the very common, scab. Scab is well named: an allergic reaction to the mites’ droppings leads to blistered lesions on the sheep’s skin which form scabs. As the mites spread over its skin, the inflammation and scabbing spreads causing intense irritation. In severe cases, infestation can cover the sheep from head to tail. While all herds may be afflicted by scab, hill sheep are most at risk. Farmers are obliged by law to treat scab as soon as they detect it but hill sheep may be irregularly inspected, allowing the infestation to take hold. Dipping can prevent it but is not practiced by all farmers: the National Sheep Association estimated that only 30% of farmers in Scotland dip their sheep.[103]

A particularly distressing problem unique to sheep is fly strike. Blowflies lay their eggs in the fleece, commonly in the inevitably faeces-soiled area around the rump. When the larvae hatch they feed on the sheep’s skin, causing open wounds that may then attract further infestation. Essentially, the sheep is being eaten alive by maggots. In the words of the University of Bristol Parasitology department:

“The maggots feed directly on the skin of the infested sheep, creating serious welfare and economic problems. The presence of feeding blowfly maggots causes considerable distress to the sheep and if untreated may lead to its death within a few days. Strike affects over a million sheep and 80 per cent of farms each year in the UK.”[106]

Flystrike is also an acknowledged problem in organic systems.[107]

The attractive and popular sight of lambs playing in the field also masks an ugly reality – disease and death in both ewes and lambs. It is widely accepted that at least 10 per cent and perhaps as many as 20 per cent of lambs die before weaning and sale and around one in twenty ewes may die during pregnancy or at lambing.[103] Ewes die for many reasons, including difficult births, malnutrition (especially if she is carrying more than one lamb, see below) and infections. Lambs – especially those born outside - die from difficult births, hypothermia, starvation and infectious illnesses like pneumonia. As with cattle, heavily muscled lambs and ewes may make the birth process more difficult while breeding of ewes for higher “productivity” – either more pregnancies per year or more lambs per pregnancy -  increases the risk. Abortion is a common problem in sheep, frequently caused by infections such as chlamydia, campylobacter, toxoplasmosis and salmonella.

Scrapie is still a problem in the UK, with official estimates putting the number of cases at around three per 1000, although some suggestions put the infection rate considerably higher.[103] Of particular concern is the possibility that scrapie may mask symptoms of BSE – as revealed in Part One, sheep can be infected with BSE in laboratory conditions and the possibility of sheep carrying the disease is very real.

Like other cloven-hoofed animals, sheep are, of course, at risk of foot-and-mouth (see below).

Sheep and Human Illness

Sheep meat is capable of transmitting all the common food-borne pathogens, including salmonella, campylobacter and e.coli. Like other meats, it may also be contaminated by clostridium perfingrens which sheep may pick up from infected soil. This species of clostridium is most famous as the cause of gas gangrene in infected wounds although it more commonly causes food poisoning, tens of thousands of cases estimated per year.

Whether sheep carry or transmit BSE/vCJD is still not known (see Part One). At present the Food Standards Agency is advising that there is no risk but further research is being carried out.  

Foot and Mouth Disease

Foot and mouth disease caused major epidemics in the UK in 1967 and 2001. The virus affects cloven-footed animals and  cattle, sheep, pigs, and goats are all susceptible to it. The common signs of the disease are vesicles (blisters) in the animal’s mouth or on the feet – hence its name – and vets report that tongues can become so inflamed that their outer coating may simply slough off entire.[93] Other symptoms include fever, lameness and being off feed. Cattle experience reduced milk yields, sore teats when milking, and frothy saliva around the lips. FMD is rarely fatal and it usually runs its course in two or three weeks after which the great majority of animals recover naturally.

The 2001 crisis, which ended up costing the UK £8 billion,[109] began early in February at Burnside pig farm in Northumberland. It was reported that the source of the outbreak may have been infected meat fed in swill to the pigs. The farmer, Robert Waugh, said that he collected school and restaurant waste to swill feed his pigs, and that he had not fed the pigs “anything that hadn’t already been served up on bairns’ plates”.[110] School dinners, however, contain burgers, sausages, mince and other cheap processed meat made from mechanically recovered meat (MRM) – a slurry obtained from pig and chicken bones. Farmers are supposed to check their animals daily by law but despite the fact that vets found the animals had been showing obvious signs of the illness, Mr Waugh did not report the cases of foot and mouth at his farm (he was later found guilty of nine animal health and cruelty charges [109]). When the outbreak was first identified in Essex, it was discovered that Mr Waugh’s infected animals had been sent there for slaughter. What only emerged years after the outbreak (and the semi-official inquiries into it) was that warning signs about Mr Waugh’s preparation of swill were missed by a Government vet who inspected his property not long before the disease emerged. The vet later guiltily admitted, “Had this inspection been more rigorous... then this awful 2001 FMD epidemic would never have come about”.[111]

The contagious nature of the virus meant that Mr Waugh’s ignorance was critical. Infected animals excrete the virus a few days before signs of the disease develop. Forced ventilation in factory farms, gives rise to large viral plumes which can travel by air for long distances and the virus is found in great quantity in the fluid from the blisters, and in saliva, milk and dung. It can be spread by infected animals and carcasses touching healthy animals, by transportation, markets, farms, carried on clothing and infected meat in feed.

By September 2001, over 10,000 farms had been affected and over 6 million animals slaughtered. The disposal of carcases on such a scale posed problems of its own. In some areas, residents were forced to live with the smell of smouldering animals for weeks, and the risk of inhaling the cancer-causing dioxins released. The Department of Environment confirmed that fires lit during the first six weeks of the crisis released 63 grams of dioxins into the atmosphere – 18 per cent of the UK's average annual emissions.[112] Also notorious was the UK-wide disinfectant programme – which was regularly flouted – and the use of landfills to bury animal bodies: in Watchtree, near Great Orton, 500,000 carcasses were disposed at a single site.[113]

Vaccines have been available for 50 years (although because there are 80 strains of foot and mouth they are only partially effective) but the EU has banned the vaccine because it implies the disease is endemic. Effectively, the industry gambles that the cost of an outbreak every 20 years or so will be less than that of losing foreign markets. Today, Defra says: “Slaughter remains the basic control policy because widespread disease throughout the country would cause significant welfare problems and be economically disastrous” due to the effects of the disease, namely:

Affected animals lose condition and secondary bacterial infections may prolong convalescence. The most serious effects of the disease however are seen in dairy cattle. Loss of milk yield will certainly be experienced. Chronic mastitis may develop and the value of a cow is permanently reduced.[114]

So, this slaughter-all tactic was for commercial reasons. After fully recovering from the disease the animal’s milk and meat production is affected and productivity is lost.

A report by a committee of the European Parliament slammed the handling of the crisis, accusing the government of breaking animal welfare laws, generating miles of unnecessary red tape, and damaging human and environmental health.[116]  The Royal Society’s Infectious Disease in Livestock report and the official Anderson Lessons to be Learned enquiry both highlighted ministers’ failure to prepare for the outbreak and advised that vaccination should form part of a future strategy for containing the disease – although they supported culling of diseased and contaminated animals. The Anderson enquiry stated this should be vaccination to live rather than vaccination to kill, and so burning animals on mass pyres should not be used as a strategy in future for disposing of slaughtered cattle.[117]

Still Learning Our Lesson

In the case of foot and mouth, the stable door was shut after the horse was long gone by banning swill – just as the feeding of cattle to cattle was banned after BSE. The fact remains, in 2001, a bloody-minded farmer unwilling to accept the consequences of his actions and a less-than-rigorous inspection by an official vet cost the lives of millions of animals and devastated the rural and national economy to the tune of billions of pounds. With international trade and tourism growing, the government admits another outbreak is quite possible. A Defra spokesman says: “A careless person throwing a sandwich over a fence to a pig - and we could see the start of another outbreak.”[118] Livestock agriculture’s killer combination of commercial self-interest and official neglect could strike again at any time.

Fish and Sea Food

NB  The number of fish and other ‘seafood’ animals killed and eaten for consumption in the UK is unknown: catches are measured by weight rather than numbers of animals. Age and size of individual animals within a species may vary considerably.

Fish is frequently perceived as the “healthy” meat – when it’s perceived as meat at all. Fish themselves are seen as the ultimate free-range and organic animal, swimming at liberty through the pristine waters of the ocean before being scooped up in nets and delivered fresh and shiny to the plate. Needless to say, this is another anachronistic illusion and far from guaranteeing their wholesomeness, the fact that fish are marine animals is the source of the threat they pose.

Fouling Nemo

There is no longer anything pristine about the ocean. Environmental contaminants from pesticides and fertilisers to animal slurry and industrial waste reach all our waterways and are ultimately discharged into the sea. As a proportion of seawater, contaminants are tiny but by eating fish, we manage to magnify the risks they pose to our health. Uniquely among the animals we eat, many fish are (naturally) carnivorous, many species consumed by us being at the top of the marine food chain. At every level of that chain, when fish eat other fish they also consume the environmental pollutants in their bodies. A big fish like a salmon or a tuna will act as a concentrated reservoir of all the pollutants acquired by all the fish it has eaten – and then it is eaten by us.

The kind of pollutants acquired by fish are some of the nastiest we have. Of most concern are metals such as mercury and the industrial chemicals, dioxins and PCBs. Mercury damages kidneys and the nervous system, can increase the risk of heart attack and poses a particular risk to unborn children. PCBs may damage the immune system, increase the risk of some cancers, and contribute to infertility and birth defects. These pollutants are known as Persistent Organic Pollutants or POPs because they are toxic and persist in natural systems. They are fat soluble and thus ‘bioaccumulate’ in food chains, stored in the fatty tissues of animals, including fish – and, of course, humans.

The facts are stark: all fish are contaminated by POPs. When MAFF (the UK ministry of agriculture at the time) tested 132 samples of marine fish in 1999, all contained dioxins and PCBs.[119] The World Health Organisation sets a recommended limit on consumption of contaminants like POPs, called the Tolerable Daily Intake or TDI. The Food Standards Agency (FSA) conducted further testing in 2002 and when its findings were analysed by the Consumer’s Association, they concluded that as much as a third of the UK population was exceeding the TDI for PCB contaminants.[120]

In the case of mercury, a Department of Health committee in 2002 stated that fish was the most important contributor to dietary exposure to mercury.[121] Levels are so high that the FSA sets limits on consumption: pregnant and breast-feeding women and children under 16 are advised to limit consumption of tuna and avoid some species altogether.[122] In fact, the FSA recommends that women and girls shouldn’t have more than two portions of oily fish a week “if you think you might have a baby one day” because of the risk of bio-accumulation within their bodies. However, the FSA also describe the process of recommending safe limits as a “balance” between the frequently-publicised health benefits of oily fish and the risks posed by contaminants. What they fail to mention is that all the health benefits derived from fish can be derived from plant sources, meaning there is no need to endanger one’s health by eating fish at all.[123]

Farming Nemo

Our appetite for fish is increasingly being satisfied by farmed fish, or aquaculture, as it is officially known. Aquaculture is the fastest growing sector of food production in the world, as all the economic advantages of intensification are magnified by declining and increasingly inaccessible populations of wild fish. Virtually all salmon sold in supermarkets in the UK is now farmed [124] while farmed trout is increasingly popular and the farming of cod – effectively wiped out in the wild – has just begun on a commercial basis. Predictably, however, the diseases and health problems associated with intensification have been no brake on the progress of this cash-driven juggernaut.

The problem of contamination is actually magnified in farmed fish. Farmed in coastal waters, inevitably the most contaminated parts of the marine environment, fish in aquaculture are also subject to the same pressures to maximise feed conversion as other farmed animals. That feed takes the form of concentrated, industrial feed, just like the kinds used in land-based farming – except that it is made from other fish, that have been caught at sea. The result is that farmed fish ingest concentrated pollutants as well. A study in 2002 found that farmed salmon show higher levels of PCBs, organophosphates and polybrominated diphenylethers (PBDEs, used as flame-retardants industrially) than wild salmon.[125] Research in August 2003 found Scottish farmed salmon had 16 times the level of dioxin-like PCBs than wild salmon.[126]

With up to 50,000 salmon crammed into a single sea cage, it isn’t hard to predict the kind of health problems which might arise. Effectively, of course, farmed fish swim in a permanent solution of their own excrement and this exacerbates all the other problems to which they are prone. Fin damage from the physical trauma of constant contact with other fish or sides of the pen is common – it may also be caused by cannibalism, just as with land animals such as chickens and pigs. Parasites afflict fish just as they do land animals, sea lice posing a huge problem to farmed salmon. These small crustaceans infest the skin and feed on blood and flesh and penned salmon are an ideal feeding ground for them (they drop off when wild salmon return to fresh water to spawn but farmed salmon, of course, never do that). Sea lice are treated by dousing the fish with toxins like organophosphates or medicating them in-feed. Diseases like furunculosis (which causes boil-like lesions on the skin), bacterial kidney disease and infectious salmon anaemia may sweep through overcrowded pens and are responsible for millions of death a year. Mortality of smolts (the immature salmon introduced to the cages) may be as high as 30 per cent before slaughter – an indication of severe health and welfare problems.[127]

Antibioticsare used both prophylactically and therapeutically in aquaculture in just the same way as land-based farming, and have been implicated in antibiotic resistance.[5]  Shrimp are also farmed on a huge scale, especially in the developing world. The human antibiotic chloramphenicol, for instance, has been used extensively in shrimp aquaculture. A particular problem in aquaculture is the impossibility of isolating the farmed animal population from wild sea animals, or the farm itself from the surrounding environment. Farmed animals regularly ‘escape’ into the wild, while wild animals may consume their feed or swim in contaminated water from sea cages.  The acquisition or transfer of antibiotic-resistance from farmed to wild fish or molluscs is inevitable.

In the Pink

The flesh of wild salmon has a distinctive pink colour, caused by natural dyes in the animals they feed on. The concentrated feed given to farmed salmon don’t contain these dyes and as a result, farmed salmon is naturally grey. To compensate for this deficiency, a dye is added to their feed. The most common dye used in Britain is canthaxanthin – which isalso used in poultry feed to add colour to both chicken flesh and the yolks of eggs. There is some evidence that damage to the human eye may be caused by high levels of canthaxanthin. The risk has recently been considered by the European Commission who expressed concern that people who eat high amounts of eggs, poultry and farmed fish may exceed recommended doses.[128] They recommended lowering the dose added to fish feed by about two-thirds, a move which has been resisted by the salmon industry who are concerned that the lower dose will fail to have the desired cosmetic effect.

Seafood and Human Health

Nemo’s Revenge

In addition to human-derived toxins, fish and other seafood may harbour a number of dangerous bacteria and parasites, such as vibrio paraharemolyticus and vibrio cholerae, which can cause classic and sometimes very serious food poisoning. Seafood is also responsible for a portion of salmonella and campylobacter poisoning. Almost all of seafood’s natural pathogens are easily destroyed by proper cooking but inadequate cooking or poor kitchen hygiene can allow them to survive and infect whoever eats them. As raw fish, sushi carries specific risks, including Diphyllobothrium latum, a fish tapeworm that can grow up to six feet long in the human intestine.

Fish and especially shellfish can also acquire natural toxins from plankton on which they feed. Some of these toxins are incredibly dangerous to humans, targeting the nervous system and causing paralysis, coma and even death. Contamination of mussels with diarrhetic shellfish poisoning was first detected in 1990 and has led to the closure of a number of cockle and mussel beds since while paralytic shellfish poisoning has led to the closure of scallop beds in Scotland. [129]

Hepatitis A, a viral infection of the liver, is found in raw or partially cooked shellfish which have been contaminated by sewage. The Norwalk virus found in raw oysters and mussels causes stomach cramps, dehydrating diarrhoea and fever. It is most common in children who have yet to build up immunity but may also affect hospital patients. There are thousands of cases each year, although – like all food poisoning – the exact number is unknown.[130]

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