Suffering in Silence
Most people see dairy cows grazing in the field and think that they have an easy, peaceful life, and die naturally at a ripe old age. In reality, the dairy cow is the hardest worked of all farmed animals, nurturing a growing calf inside her while simultaneously producing 24-40 litres of milk a day. No other farmed animal carries this dual load of pregnancy and lactation.
Professor John Webster has likened the workload of the high-yielding dairy cow to that of:
“…a jogger who goes running for six to eight hours every day” and believes that “the only humans who work harder than the dairy cow are cyclists in the Tour de France.”
Professor John Webster (37)
This enormous physical burden takes its toll on the cow’s body and after only two to four lactations she is culled, either due to infertility, mastitis, severe lameness or because her milk yield has dropped (8, 31). A healthy beef cow, in comparison, can produce 10 or more calves before reaching physical exhaustion.
“As far as the welfare issue is concerned, the problems with beef cattle are nothing compared to the problems in the dairy industry. So anyone who avoids beef and elects to eat cheese due to welfare concerns is missing the point.”
Professor John Webster (8, 78)
In nature, cows are prey animals and as such evolved not to be very vocal because any noise can attract potential predators. The misconception that dairy cows do not suffer often stems from the fact that they do not display the signs of distress that we expect to see, such as bellowing, immobility or loss of appetite (8). Thus, even if they are suffering, they don’t show it apart from a few physical reactions such as different posture or urinating. It’s been shown that even in the most stressful place – abattoir – only about ten per cent of them vocalise; however they emit fear pheromones in their urine that signal danger to the other animals (42).
The high-yielding Holstein cow is a large animal who simply cannot consume enough food at pasture to sustain her enormous milk output as well as her other bodily functions, leaving her in a constant state of ‘metabolic hunger’ (7, 8). At pasture, her food intake is limited by the rate at which she can consume and digest grass. As grass is high in fibre, it fills up the rumen (stomach) quickly, causing the cow to feel ‘full up’ while at the same time still feeling hungry for nutrients (7, 8). Standing and eating for hours on end is also very tiring work and cows, who would naturally spend 12-14 hours a day lying down, face conflicting motivation to eat or rest (8, 51). Rye grass pastures, which are very high in nitrogen, can lead to increased urea in the cow’s blood, making her feel sick and impairing her appetite (8).
The dairy cow’s feelings can be summarised as “simultaneously hungry, tired, full up and feeling sick”. Professor John Webster (8)
Due to their inability to meet the metabolic demands of lactation, it is normal for cows to ‘milk off their backs’ in early lactation (draw on body reserves), resulting in a ‘coat rack’ appearance with the bones of the hips and spine protruding (8, 37). Dairy farmers consider this to be a normal metabolic situation in high-yielding dairy cows and have come to accept ‘bony’ dairy cows as typical, when in fact they are malnourished (79).
Ketosis and Fatty Liver Syndrome
The abnormal demands on the cow’s energy reserves often leads to ketosis and fatty liver syndrome (8). Ketosis occurs when the cow’s body fat begins to break down in an effort to bridge the ‘energy gap’ during early lactation (80). Body fat is transported to the liver where it’s broken down to metabolites which are then utilised by the body tissues (80). Excess mobilisation of fat can lead to a toxic level of ketones (by-products of fat breakdown) accumulating in the blood, milk and urine, causing a loss of appetite and drop in milk yield (80). Affected cows may also exhibit nervous signs, which include excessive salivation, licking of walls or gates, poor co-ordination and aggression (80).
There is a limit to the amount of fat the liver can break down and process and when this limit is reached, the surplus fat accumulates in the liver (79). This ‘fatty liver syndrome’ reduces the normal function of the liver and, because it is a vital organ, many normal body functions are upset. Milk production, mastitis and fertility are all adversely affected by fatty liver (79).
Milk Fever (Hypocalcaemia)
Milk fever is one of the most common metabolic disorders in dairy cattle, usually occurring just before, during or immediately after calving (81). It is caused by low blood calcium resulting from the high calcium demands of pregnancy and lactation. When the cow’s blood calcium becomes too low to support normal nerve and muscle function, she collapses and is unable to stand until her blood calcium becomes normal again (82). Death can be rapid, with milk fever being the most common cause of sudden death in dairy cows (81). According to the National Animal Disease Information Service (NADIS), it can also cause calving problems and subsequent calf deaths (82).
Grass Staggers (Hypomagnesaemia)
Grass staggers (or grass tetany) occurs when the cow’s intake of magnesium is lower than her output (83). It occurs most commonly in lactating cows at pasture as grass can be very low in magnesium, especially rye grass, while the output of magnesium in milk is high (83). Clinical signs can appear very rapidly as cows do not store magnesium and must rely on a daily intake. Initially, animals become nervous and excitable, and then begin to stagger and fall over (83). This can quickly progress to convulsions, coma and ultimately death. The short duration of clinical signs means that the mortality rate is high, as many animals are found dead before anyone notices they are ill (83).
High Protein Concentrates
While the obvious solution to the problem of hunger and mineral deficiency in ‘high yield’ dairy cows would be to stop breeding animals with such a high milk output, dairy farmers are increasingly feeding their cows on high protein feed concentrates instead (8). These concentrates, which are usually made from GM soya and maize, are higher in calories than grass and thus provide more energy (8). However, they are also high in amino acids which further accelerate milk production (8). The result of this is increased milk production in the short term but loss of body condition, infertility and greater susceptibility to illness later on simply because it’s not natural for the cow’s body to work that way (8). The high starch and protein content of feed concentrates also cause digestive problems which lead to a reduction in appetite, bloating and lameness induced by laminitis (7, 8, 40).
Lameness is a major reason for culling of dairy cows, according to the latest figures, accounting for about 10 per cent of culls (5). Experts on animal welfare agree that it causes considerable pain and distress to the cow and impacts on all aspects of her life (5).
The average number of lame cows in a herd is 17 per cent – although at some farms this number is as high as 49 per cent (5). The Farm Animal Welfare Council stated in their recent report: “There is no evidence that the incidence of lameness has improved over the past decade.” (5)
Lameness is extremely painful, often compared to the pain humans would feel if walking directly on the lunula (quick) of their nails (41). But because many lame cows continue to milk satisfactorily, they are forced to struggle on despite their severe pain (8).
Approximately 80 per cent of cases of lameness are due to foot problems and the remainder to leg damage (84). Sole ulcers, white line disease, digital dermatitis and laminitis are the most common foot problems and are caused by a number of complex factors (8, 40, 84). The majority of leg lameness is due to physical damage from badly designed cubicles and to injury at calving (84).
Seventy-five per cent of sole ulcers and white line disease (cracks in the outer rim of the sole which allow dirt and bacteria to enter, causing abscesses) occur in the outer claw of the hind feet (8). This is directly linked to the presence of the huge udder which pushes the cow’s hind legs apart and forces her to adopt an abnormal gait, putting extra pressure on the outer claws (37). Poor hoof quality, caused by nutritional deficiencies, can also predispose the sole to ulcers (39).
Both sole ulcers and white line disease cause chronic pain which gets worse with time (8). They are further aggravated by the long distances many cows must walk between pasture and milking parlour twice a day, and also by winter cubicle housing where many cows are forced to stand on concrete for extended periods of time (discussed further below) (8).
“Most farmers only elect to treat the most severe cases, for example where there has been complete penetration of the sole, inducing deep pain from standing on concrete and scalding pain through exposure of sensitive underlying tissue to acid slurry.”
Professor John Webster (8)
Incidence of digital dermatitis, a painful bacterial infection of the foot, has increased in recent years due to a combination of factors (8) and is now a major cause of lameness (5). Many indoor cubicles were installed when the predominant dairy breed was the British Friesian, which commonly weighed around 550kg, but the increased popularity of the Holstein means that many cows now weigh in excess of 700kg and the cubicles are too small for them (41, 84). As a consequence, cows are often forced to stand with their hind feet in the slurry passage behind the cubicle (84). Slurry is highly acidic and softens the cow’s feet, allowing bacteria to penetrate (84). In addition, most dairy farmers have switched from hay to silage as winter cattle feed (8). Whereas hay is composed of dry grass and other herbaceous plants, silage is wet, fermented grass which causes wet manure, contributing to hygiene problems when cows are housed indoors (8).
Roads, tracks and gateways which have rough, uneven surfaces can cause puncture wounds in the foot which are susceptible to infection (84). When allowed to walk at their own speed, cows are able to place their feet carefully to avoid obstacles or rough objects. When forced to hurry, they bunch together and cannot choose where to step and are more likely to sustain damage from sharp stones (84). In many dairy units the ageing concrete floors have become broken or cracked, causing abrasions and punctures of the sole which are also easily infected (39). Although digital dermatitis can be treated with antibiotics, once it’s established in a herd it is very difficult to eradicate (8).
Laminitis is the acute or chronic inflammation of the soft tissue (laminae) between the bone and the outer horny wall of the foot which “results in great pain to the animal” (85).
To understand the pain of laminitis Professor Webster suggests “… imagine crushing all your fingernails in the door then standing on your fingertips.” (8)
The soft tissue of the foot is well endowed with nerves and blood vessels which carry oxygen and nutrients to support hoof growth, and is therefore very sensitive to toxins in the blood (39). Feed concentrates which are high in protein and starch cause toxins to be produced in the rumen which are absorbed into the blood stream and irritate the soft foot tissue, causing inflammation and damaging blood vessels, especially in the feet (39, 41). According to Defra, there’s a significant link between high protein diets and lameness (39, 41). Wet silage, which is high in acid and ammonia, can also lead to toxins in the blood which cause laminitis (39).
Laminitis can also occur when cows are being moved too much or forced to walk longer distances, especially on hard surfaces. This can lead to them being over-exercised and it has been associated with the acute onset of laminitis (41). When a foot is affected by laminitis the blood flow is restricted, affecting hoof growth and resulting in softer soles which are more prone to disease, such as ulcers and white line disease, as well as punctures, leading to digital dermatitis (39).
Cubicle Housing and Lameness
The inadequately sized cubicles in which most dairy cows spend six months of the year contribute to the high incidence of lameness in several ways. The problem of cows having to stand with their hind legs in the slurry passage has been outlined above. The small size of the cubicles also makes it difficult for modern cows to lie down comfortably, reducing the amount of time that they spend lying down and increasing the pressure on their legs and feet (5, 8).
Some cows avoid the cubicles altogether and instead lie in the aisles or slurry passages where they become very dirty and increase their risk of hock abrasions, lameness and mastitis (discussed further below) (40). Some cows may be forced to spend long periods standing or lying down in the passages because there are not enough cubicles for all of the cows in the herd (8). Due to the social hierarchy of the herd, subordinate cows may also be reluctant to lie in cubicles next to dominant cows, opting to stand or lie in the passages instead (5, 8). To overcome this problem, the FAWC recommends that indoor housing units contain five per cent more cubicles than the number of cows (5).
Many cubicle units have concrete bases because they are easier to clean, but they are also hard and uncomfortable and may lead to swelling of the knees and hocks as well as pressure sores (41, 85). Under The Welfare of Livestock Regulations 1994, dairy farmers must provide indoor cows ‘access at all times to a well-drained and bedded lying area’ (41). In practice, however, the bedding provided is often little more than a thin layer of sawdust or straw which does not provide adequate cushioning to keep the cow comfortable or prevent contact sores (5). The use of mats or cow mattresses in cubicles helps provide cushioning but must still be covered in bedding such as sand, straw or shavings to prevent contact sores and keep the mat dry (41, 77).
Mastitis is a painful bacterial infection of the udder which affects around 30 per cent of British dairy cows at any one time, with one million cases of clinical mastitis occurring in the UK every year (5, 8, 40, 57). Between 40 and 65 cows out of 100 suffer from clinical mastitis every year with around a quarter of these being repeat cases (57). While clinical mastitis produces obvious symptoms such as swollen, hard udders and discoloured or clotted milk, mastitis can also occur in a subclinical form with no visible changes to the udder or milk, making the number of these cases impossible to calculate (5, 37).
Mastitis is the most common disease in dairy cows and is a major reason for premature culling. In 2011, 17 per cent of cows were culled because of mastitis (57). And the disease is far from declining – as experts on farm animal health warn: “The prevalence of subclinical mastitis is greater now than in 1997.” (5)
Mastitis pathogens (microscopic organisms causing the infection), of which there are over 200, belong to one of two categories: contagious or environmental (77). Streptococcus uberis and Escherichia coli (E.coli) are by far the most common causes of mastitis and are both environmental pathogens, thriving in dirty, wet bedding and poorly ventilated buildings (40, 77). Both contagious and environmental pathogens can be transmitted from cow to cow via the milking machine (77). The failure in combating environmental mastitis is largely due to the increase in herd size and the very high milk yield of the modern dairy cow (77).
Larger herds make it difficult to properly monitor each cow and her milk, allowing infected animals to enter the milking chamber and pass the infection on via the milking machine (77). Larger herds also produce more manure which accumulates in housing units, creating an environment in which bacteria thrive (77). High-yielding dairy cows who are only milked twice a day may leak milk on to the cubicle bedding when their udder becomes full, producing a bacterial haven of faeces, bedding and milk (77). The abnormal accumulation of milk in the udder also strains the udder tissues and predisposes high-yielding cows to mastitis (7, 37). The combined weight of blood, udder tissue and stored milk can result in a total udder weight of 50-75kg (77). In beef cows, who have normal sized (small compared to dairy cows) udders, the incidence of mastitis is a fraction of that in dairy herds (37).
Poorly designed and maintained milking machines are also recognised as major contributors to udder infection (39, 77, 86). Despite the major role they play on a dairy farm, milk machine maintenance is often neglected (77). This can lead to physical damage of the teats, which are richly endowed with nerves and therefore highly sensitive, and allow infection to penetrate the udder (77). Faulty machines can also actively transport bacteria into the udder (39, 77).
Housing can also lead to teat damage – large cows in narrow cubicles may push their legs through into the adjacent cubicle and accidentally crush their neighbour’s teats (77). Disruption to an established herd, either by the addition of new members or splitting it into smaller groups, can result in fighting which may also cause teat injuries (77). Severe teat injuries, such as total teat amputation, are surprisingly common in dairy herds (77).
Summer mastitis, an acute illness of dry (ie not lactating) dairy cows, is common in temperate countries such as Britain. It occurs in 35-60 per cent of UK herds annually, affecting over 20,000 animals (40, 77). The main means of transmission is the sheep head fly (Hydrotoea irritans) which feeds on cattle blood (77). Damaged teats predispose cows to infection (40). Summer mastitis causes extensive, painful damage to the udder which becomes swollen, hot and hard and produces a thick, foul smelling secretion. Severely affected cows become lame from the pain, with extreme cases leading to abortion and death (5, 77).
Mastitis is usually treated with antibiotics applied directly into the teats but the problem with this is that antibiotic resistant bacteria evolve very quickly.
When a cow is suffering from mastitis, her body produces large numbers of white blood cells which migrate to the udder to fight the infection (87). Many of these cells together with dead cells from the inner lining of the udder then pass out in her milk, and the greater the infection the higher the number of these ‘somatic’ cells in the milk (87). Dairy processors use somatic cell count to determine what price they pay farmers for their milk, imposing financial penalties for milk with high somatic cell counts (77, 87).
Latest figures show there is wide variation in somatic cell count with an average of between 100,000 and 250,000 cells/ml (5). These numbers have risen by 30 per cent since 1998 so it’s evident this is a serious issue and the situation has worsened over the past decade (5).
Under EU regulations, milk with a somatic cell count as high as 400 million per litre may still be sold for human consumption (77, 87). Some farmers feed milk which exceeds this threshold to the calves (77).
Antibiotics are routinely used to treat mastitis and may be injected up the teat canal or administered orally (77). Intramammary (in the teat canal) injections, if performed carelessly, can cause teat canal damage which is extremely painful and increases susceptibility to infection. To reduce the amount of drug residue which enters the food chain, all antibiotics have a specified post-treatment milk withholding period stated on the product (77). Due to public health concerns, the EU imposes limits on the maximum permissible level of antibiotics in milk, which is currently set at 0.0067 mg/litre (88). Dairy processors use random sampling to test milk for residues, penalising those farmers whose milk fails to meet these restrictions (77).
To help reduce the amount of mastitis in dairy herds, most farmers practice 100 per cent dry cow therapy – as recommended by Defra (77, 86). This involves injecting a long-acting antibiotic into all four teats of all cows, whether infected or not, as soon as they enter their dry period (77, 86). Cows that suffer from repeated cases of mastitis or have persistently high somatic cell counts are routinely killed (86).
The arduous life that dairy cows endure causes such rapid physical degradation that an alarmingly high number of young animals are killed due to infertility (8, 40, 89). A killing rate of 25 per cent is normal for most dairy herds and poor fertility is the single biggest factor (31, 40, 90).
Although infertility in itself is not a welfare problem, it is an indicator of poor welfare resulting from physical exhaustion (8, 40, 89). Even the Milk Development Council acknowledged that “the drive towards increased milk yield has resulted, in part, to decreased fertility” (91).
To help combat the problem of infertility, the use of fertility drugs is now widespread on dairy farms in Britain (92, 93). Cows are given hormones to help increase conception rates, but also as a herd management tool to ensure that groups of calves are conceived and born around the same time (91, 92).
There is an obvious trend – fertility of dairy cattle is reducing as milk yields increase (89, 90). Stress could be one important cause and it’s been shown that (89):
- Fertility is lower after caesarian operations and when the clinical conditions of lameness, milk fever or mastitis worsen.
- Changes in social hierarchy or groupings increase the number of inseminations required per pregnancy and so does transport.
- Embryos collected from heat-stressed donor cows are less viable.
- Human-animal interactions negatively influence stress in cows which can lead to lower fertility.
Stray electrical current
Stray electricity occurs when electricity is unable to make its way to the main earthing system and a natural path for it to travel back to earth in a milking parlour is the steelwork. Water, used in large volumes in the parlour and elsewhere (for washing surfaces but also drinking water for the cows), makes the problem even worse.
Electricity is used on farms to control the movement of cows, eg electronic gates in the milking parlour, electrified bars in front of self-feed silage or electrified cow trainers to make cows step backwards out of cubicles when they urinate or defecate (42).
Research shows cows are sensitive to just 0.5V (much more sensitive than people) and stray voltage results in cows receiving a tingle or a mild shock that disturbs their normal behaviour. And when a cow is nervous she won’t let go of her milk so it stays in the udder until the next milking (94). By the time the milk is released, it has been in the udder for several hours and apart from causing significant discomfort to the cow, it can lead to or aggravate mastitis.
During a recent random testing of UK farms, none of the 23 tested was completely clear of stray voltage (94). The most common problem is electricity from an electric fence running through steel barriers in the milking parlour. If stray electricity is present in a water through, cows won’t drink naturally, avoiding immersing their muzzle, but lap at the water instead (42).
Surplus dairy cows, calves and all beef/dairy calves (that can’t be used for replenishing the herd), are routinely sold at livestock markets. And when a farmer decides to sell his or her dairy farm, the herd of milking cows will be sold off, usually at a market.
Even if the farmer decides to go to the nearest market for dairy cattle, it can mean travelling across several counties (95). However, farmers do not necessarily take their animals to the nearest livestock market; they take them where dairy cows are most in demand to get a better price which means many hours of travelling and stress for the animals.
On top of these long journeys, many cows sent to market must also endure the uncomfortable pressure of overly full udders.
It is common practice to send dairy cows to market or to agricultural shows with overstocked udders and freshly calved cows especially are in high demand (40, 96). This means that the cow is not milked on the morning of the sale or show so that her udder looks full, making the cow “more attractive to prospective buyers or judges” (40).
Despite this being against welfare advice and farmers are being warned against this practice, cows continue to be sent to markets with overstocked udders (97).
The Welfare of Animals at Markets Order 1990 prohibits an animal being exposed for sale in a market if she is likely to give birth while she is there, as well as The Welfare of Animals (Transport) Order 1997 which states that animals likely to give birth must not be transported (97). Despite these laws, and the well-established fact that the stress of transport and the market itself may induce labour or abortion, the FAWC highlight the continuing problem of pregnant animals being brought to market in their report (97).