Given a natural and healthy life, cows can live for 20 years or more. High-yielding dairy cows will last for only a quarter of that time. They are often culled after three lactations or less because they are chronically lame or infertile.
Lameness, mastitis, and infertility
Milk is heavy and a dairy cow may be carrying several extra pounds of milk in her udders. This can force her hind legs into an unnatural position, making it difficult to walk, and can result in lameness. It can also make standing and lying down difficult and uncomfortable.
Mastitis is a painful udder infection that is prevalent among dairy cows. 16.5 percent of deaths of dairy cows in the US are attributed to mastitis, which is more commonly reported than any other health problem in the dairy industry. Housing cows indoors for long periods can increase the prevalence of mastitis.
Infertility among high-yielding dairy cows is a major problem affecting 13 per cent of US dairy cows, commonly leading to cows being removed from the herd. It has been linked to stress, poor body condition, and the demands of high milk production.
Cows kept indoors have less opportunity to act naturally and exercise. Poor ventilation and high humidity increase the risk and spread of infection. These factors are likely to have an adverse effect on their health and welfare.
Hard concrete flooring can cause foot damage and is especially painful for lame cows. Zero-grazing systems, in which cows are housed year-round, have been linked to increased lameness among dairy cows.
In many old-fashioned systems, cows are kept in tie-stalls and stanchion barns which are even more confining. Here cows are tied up for all or part of the day when they are housed.
Sadly, the majority of US dairy cows are kept without access to pasture all year. Furthermore, around 20% of US dairy cows are housed in tie-stall systems.
Diet and hormones
The diet of high-yielding cows often has relatively little fibrous content and is inappropriate for their type of digestive system. This leads to acidity in the part of the stomach known as the “rumen,” and can cause acidosis and painful lameness from laminitis (hoof tissue inflammation).
In the US, many dairy cows are given growth hormones to increase their milk yield. This can increase welfare problems including lameness and mastitis. This practice is illegal throughout the EU.
Surplus dairy calves
In commercial dairy farming, nearly all calves are taken away from their mother shortly after birth. This causes severe distress to both the cow and her calf, and has long-term effects on the calf’s physical and social development.
High-yielding cows produce calves who are generally not suited to beef production, and some of them are transported to auction houses where they are sold as veal calves. Calves are vulnerable at this age and are not ready to cope with the stress of long-distance transport.
In the UK, as a result of extensive cooperation between Compassion in World Farming, the RSPCA, and the dairy industry (through the Calf Stakeholder Forum), more male dairy calves are now reared humanely for beef and the number of calves being shot at birth has greatly decreased. There is more work to do—approximately 100,000 calves are still shot every year.
Slaughtering dairy cows
When dairy cows can no longer produce a desirable quantity of milk, they may be transported long distances for slaughter.
There are more humane alternatives that take into account the welfare of the cow.