I live in Australia, so most of the research I have done on farming practises is specific to Australia.
Dairy milk is produced by female cows who have given birth to a calf. As with any mammal, the mother cow’s breast milk is produced for the calf, rather than for a completely unrelated species (i.e. humans). To synchronise milking and ensure efficiency on farms, cows are artificially inseminated to keep them pregnant. Some babies are induced prematurely, and all babies are removed from the mother after birth so that the milk can be harvest for human use, even on organic farms. This is traumatic for both mother and child. Dairy cows live approximately 1/5 of the time they would live if they were allowed to live naturally, due to the high demand on their bodies from milking. Once they collapse from exhaustion, they are killed.
Selectively bred and genetically modified for high yield, modern dairy cows have a grossly expanded capacity for milk production, producing about 35-50 litres of milk per day—about ten times more milk than her calf would need. This places enormous strain on cows, reducing their natural life expectancy from 20 years to 7 years at the most. Many are sent to slaughter even younger than this, because they have collapsed and can no longer produce milk.
The great weight of their udders often causes painful stretching or tearing of ligaments and painful foot problems, such as laminitis. They are also susceptible to painful infections of the teat and udder (mastitis), with the vacuum milking process known to increase the possibility of infection. Being machine milked, the front teats may be subjected to vacuum pulsing for up to two minutes after this part of the udder has been emptied, and while the hind teats are still yielding. This is believed to be painful for the cow, and may also weaken tissue. Mastitis is treated with antibiotics, injected into the udder immediately after the last milking of a lactation and remains there in concentrations high enough to kill mastitis bacteria for between 20 and 70 days.
In Australia, most recent industry figures indicate that around 400,000 unwanted dairy calves, not wanted for herd replacement or rearing for pink veal, are slaughtered each year as ‘waste-products’ of the dairy industry — usually at around 5 – 6 days old. They aren’t valued because they don’t grow at the same rate as beef calves and their meat quality is considered sub-standard by the beef industry. Farmers are allowed to withhold milk from five day old calves for up to 30 hours before they are slaughtered, in order to make transport to the abattoir efficient. Calves normally suckle about 5 times a day.
Dairy cows are also dehorned or disbudded, and some have their tails removed. Disbudding is done to young females by applying heat cauterization to the horn buds, or by using a knife or scoop tool to remove all the horn growth tissues in the horn bud. While pain relief regimes have been developed, it is done without analgesia or sedation. If not disbudded in youth, older dairy cattle may be ‘dehorned’. Researchers have shown that dehorning adult cattle has ‘severe adverse effects on welfare’, but it does look as though the industry is discouraging this practise after pressure from welfare groups.
Docking, or tail removal (done using surgical amputation or tight elastic rings) is done because dairy farmers don’t like to be swished in the face with a dirty tail whilst in the milking shed, and because some of them feel that that dirty tails contribute to higher bacterial contamination and higher levels of mastitis. New shed designs and research have made both reasons redundant and industry bodies generally discourage it, yet the practice still continues in some areas of Australia. Without a tail the cows are irritated by flies that they are unable to dislodge.
Australia is doing fairly well when it comes to the use of hormones in dairy cattle. Seasonal calving is being practised less, partly due to increasing use of supplements and grains. This has resulted in a reduction in the old method of using hormones to synchronise oestrus (or heat) in cattle, which enabled farmers to know when cows would be fertile so they could plan insemination and match calving with peak pasture growth. In the interests of maintaining access to some export markets, the Australian dairy industry has instigated a policy to voluntarily ban the use of the hormone oestradiol benzoate for this purpose. They do have ‘alternative mechanisms’ which may be utilized in consultation with their veterinarians, but the industry is vague as to what these ‘alternate mechanisms’ are. Australian dairy farmers are allowed to use oxytocin, though, to stimulate milk-let down when cows are anxious or uncomfortable and to aid more complete removal of milk in inflamed udders. Growth hormones, including bovine somatotropin (BST) in dairy cattle, are banned in Australia.