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Mega Dairies - Mega Problems

01 Feb 2016 09:00
What is a Mega Dairy?

There is no precise definition of a mega-dairy. A farm of 1000 cows grazed on a suitable acreage, milked once a day and over-wintered in sheds is not a mega-dairy. In contrast, the same number of cows held in sheds 24/7 all year, feed on a diet to increase milk yield and milked three times a day… that’s a Mega Dairy. It could be just 500 cows and it would still be a Mega Dairy but the ecomomics make this unlikely to happen. In reality a Mega Dairy tends to be 1000+ cows. The Chinese have recently built one that holds 100,000 cows … reportedly to serve the russian market. The Problems with Mega Dairies – an overview

Large intensive dairy operations where 1000’s of cows are kept in large sheds and fed high protein diets to increase milk yield are increasingly common. The approach used to management these units is often referred to as ‘zero-grazing’. This simply means the cows spend their lives in these sheds and are never allowed out to graze in a field and are fed a diet designed to optimise milk yields which is why there are also called CAFOs (Confined Animal Feeding Operations).

The zero-grazing approach to dairy farming has some inescapable and serious problems that fall broadly into three categories: Economic, Environmental and Animal Welfare. These are just some of the issues:


  • The race to reduce costs through factory farms has resulted in a spiral of over supply leading to a collapse in milk prices.
  • The low milk prices are driving smaller traditional dairy farms out of business but whose exit has little effect on the over supply.


  • The slurry from so many cows is very difficult to deal with and leads to an enormous amount of environmental damage.
  • There is increasing concern about the impact on health to people who live near to where the slurry is stored or spread.

Animal Welfare

  • The cows live in an unnaturally confined space that leads to all sorts of stress for these social herd animals. There is room to move about but it is limited.
  • They are part of a 24 hour operation and so are not afforded a natural diurnal rhythm of existence which again can lead to stress and to depression.
  • The cows are fed on a very unnatural diet that leads to problems that need to be managed with drugs.
  • Reduced life expectancy of the cows

The problems began some time ago. Back in 2009 the Animal Welfare Council published a report in which it states:

“The profitability of dairying has been in steady decline for the past decade. In 1997, the average gross margin on dairy farms was £933 per cow; this had fallen to £696 per cow in 2007. The reasons for the decline in profitability are complex but include sterling’s exchange rate, the milk quota system, the price paid by milk buyers and processors and the greater exposure to commodity markets.”

This short paragraph says it all. More recently the dairy industry has taken another hit due to the loss of access to significant markets in both Russian and China. (see refs 1 and 2)

The assumption is that to address the decline in profitablity we need to employ the economies of scale of a large dairy. Supporters of this type of farming claim this is the only way to make diary farming viable and then go on to argue that the cows have a better and more comfortable life than they would under a more natural regime. There may be some truth in the need for some economies of scale or the use of modern techniques for managing a dairy but this should never be at the expense of Animal Welfare or the Environment.

What is happening now is a spiral towards larger and larger indoor (zero-grazing) herds that is exacerbating the over-supply problem. The crash in milk prices is putting small traditional farmers out of business, with all the attendant human suffering and loss. Herds that have been built up over generations and are much loved are destroyed. This vicious circle needs to be broken and the trend reversed. We should know by now that markets are not self-correcting and often need to be closely regulated. But the only change on the horizon is the setting up of a ‘futures’ market to address some of the volatility in prices.


Unlike the Animal Welfare issues, the environmental issues are solvable but cost money.

The excreta from 1000+ cows has to go somewhere. Initially it is stored in large lagoons (like the one we are objecting to) along with diary parlour washings and other waste. The washings can contain various chemicals for disinfecting the parlour. The resulting slurry is a toxic brew, the detailed chemistry of which is not well understood. At its most basic, an open slurry lagoon will give off four main gases: methane, ammonia, carbon dioxide and nitrous oxide. These gases can cause considerable environmental damage both locally and globally. Methane is a global warming gas that is ten times more potent than carbon dioxide. However, these problems can be mitigated by putting a cover on the lagoon. This can reduce the gas emmission by up to 90%. But a large lagoon, typically 80m x 80m, is very expensive to cover. A floating cover for a lagoon this big could set you back £200,000. So many lagoons are not covered.

What should happen next is that the slurry is fed to an anaerobic biodigestor which addresses many of the environmental issues. They digestor provides energy that can be used on the farm or fed back into the grid, and the resulting digestate is far more benign. The problem is that a biodigestor, that can consume the output of a 1000 cows, is very expensive. The capital costs would be well in excess of £500,000. So on most farms the slurry from the lagoon is spread on fields at regular intervals, usually 2 or 4 times a year. This is when the real damage takes place.

Fields that used to be pasture would have supported a range of ground nesting birds, wild-flowers, insects and would have enjoyed a balanced and healthy ecosystem. But once the spreading begins these same fields become alien territory for most wildlife. The fields are repeatedly covered or injected with slurry which can kill microbial life in the soil and greatly reduces the insect population. Over time there can be a build of various elements, like copper from the parlour washings. Run-off can pollute local water-courses, and the regular traversing by large machines destroy the small remaining chance for ground nesting birds.

Injection into the soil (as oppose to spraying) is meant to prevent odour, the release of damaging ammonia and methane and stop run-off. But in reality the pipes to the injectors often leak and produce an aerosol that can travel a great distance causing damage to hedge rows, lichens, etc. Also, injection will only prevent run-off in ideal conditions. Often the ground is already wet or rain falls soon after. There are regulations that determine when and how much slurry is spread. But these are weak and while they help to curtail excesses they do not address the real long term issues. It is not a pretty story. Pathogens from Slurry

Slurry from dairy cattle can contain a range of pathogens like E.Coli-0157:H7, Salmonella, Cryptosporidium, etc. In a traditional muck heap, the composting effect will raise the temperature sufficiently so that after a week most of the pathogens will have been removed. In a slurry lagoon this does not happen. So, when the slurry is spread on the land there is increasing evidence of so called ‘pathways’ whereby they can travel a great distance and infect wild-life and enter the food chain. Anaerobic digestors have a very similar effect as muck heap as the process generates heat and destroys the pathogens.

Animal Welfare

The Five Freedoms was a concept developed some 30 years ago and is still used as a yardstick of Animal Wefare today. They state that an animal has the right to Freedom from:

  • Hunger and thirst (by providing fresh water and a nutritious diet)
  • Discomfort (by providing good shelter and a comfortable resting area)
  • Pain, injury and disease (by prevention and effective diagnosis and treatment)
  • Fear and distress (by ensuring conditions and treatment which avoid mental suffering)
  • Express normal behaviour (by giving them sufficient space, proper facilities and company of the animal’s own kind)

Mega Dairies can fail all five of these tests.

Hunger and Thirst

The main issue here is the diet. Zero-grazing operations feed the cows “concentrates” to increase production. For instance, the feed can include soya-bean, grains and fish-meal. None of these foods are what a herbivorous ruminant would naturally choose to eat. These unnatural foods can cause acid conditions in the gut which causes great discomfort for the cow and can, over time, lead to chronic conditions which can then manifest themselves as problems like lameness. (see below)

In 2009, the European Food Safety Agency published an important report called “Scientific Opinion on the Welfare of Dairy Cows” in which it states:

“If dairy cows are not kept on pasture for parts of the year, ie they are permanently on a zero-grazing system, there is an increased risk of lameness, hoof problems, teat tramp, mastitis, metritis, dystocia, ketosis, retained placenta and some bacterial infections”.

Pain, injury and disease

The unnatural diet, the lack of exercise, the stress of being held in sheds 24/7 all contribute to the many health problems. These cows are being pushed to their physiological and psychological limits which predispose them to infections and chronic conditions that then need to be managed. Lameness is a huge problem in zero-grazing units and if it is not treated quickly the pain can be severe and enduring. The other big problem is mastitis which is an inflamation of the udder and teats. It is a very painful condition for the cow and is very common.

Then after about 6 years the cow is killed. That is after what is about a quarter of her natural life span. By then the regime will have taken its toll and she will be worn-out and her productivity will have fallen below a threshold of profitability.

Discomfort + Fear and distress + Express normal behaviour

The Mootel seems to have been first mooted by Mr Peter Willes during the Nocton episode in 2009/10 along with another catch phrase “Cows don’t belong in fields”. The Mootel argument suggests that, given the choice, a cow will chose to be in one of Mr Willes’ sheds where she is fed, her bed changed regularly, is out of the rain and where there is a vet on hand to look after her health.

The problem with this argument is that the cows do not have any choice! It is simply a gross assumption that makes good “copy”, but is not backed up with any evidence. In fact there is a lot of evidence to the contrary.

Traditional (ie non-intensive) farmers will over-winter their cows indoors and feed them on the forage they will have harvested and stored during the summer. Then, in the early spring, the cows are let out into the fields and they will run and kick their hind legs and demonstrated that they are very happy to be ‘Free at last! Free at last! Thank God Almighty, we are free at last!’ (apologies to Martin Luther King)… as in these videos:

And yet more videos of the spring release: happy cows 1, happy cows 2, happy cows 3, happy cows 4,

Recent (2016) reports by both the Farm Animal Welfare Council and European Food Safety Authority have highlighted the continued welfare issues relating to dairy cattle, especially those housed in large sheds.

Cows do belong in fields… because that is where they are happiest. An open field with no possibility of shelter is not a comfortable place when the wind and rain is driving. So yes, fields should have shelter and most don’t. But a cow is not a stupid animal and would seek the shelter of the Mootel if it could in those circumstances… but when the rain stopped they would check-out and return to the field!

Conversely, look at the cows that are held under the zero-grazing regime. They are well looked after as one would expect as it is the operations interest to keep the cows healthy. However, their diet is unnatural and to keep the cows healthy requires constant monitoring and frequent intervention. The get very little exercise, live an entirely unnatural existance and in the end have a reduce life expectancy. But perhaps the most important aspect of their health that is overlooked is their mental well being.

Cows are intelligent sentient beings like most higher mammals. For instance, Dr Krista McLennan’s research has shown how cows make long lasting frienships. This video shows a cow upset by losing her friend https://www.youtube.com/watch?v=j1h8iHpL6jM

The Moral Argument

Factory farms and Mega Dairies in particular raise some fundamental moral questions about how we as consumers should take responsibility for what we eat.

The moral framework of a society is not static but evolves with new knowledge. The knowledge we have today about the origins of thought and consciousness must inform the moral judgements we make about how we treat animals and how we expect them to be treated on farms.

For instance, the study of artificial neural networks and the more general discipline of artificial life demonstrates that even an entity with very few neurons can display very complex behaviours. A famous example is Prof Widrow’s truck-backer-upper which was a network of 100 artificial neurons that was trained to control backing up a truck with a trailer to a loading platform. Anybody who has tried backing a trailer knows how tricky this is. This was done with just 100 neurons.

Just stop and think for a moment about the complex behaviour of a fly. How does it do that? The point is that even the most basic life-form can display very complex behaviour. This can be demonstrated with very simple artificial-life programs. These illustrate how complex systems display so called emergent properties. So where you have complexity then discernable properties will emerge, you will not just get a jumble of unrelated characteristics. This is the basis of consciousness. It is not rooted in any particular aspect of the brain, it is a consequence of both its organisation and its complexity.

A cow is a billion times more complex than an AI experiment. They do feel emotion, loss, fear, pleasure. There is a great deal in the literature to support this view (Prof Marc Bekoff, Prof Marian Dawkins, etc, etc). They have different perceptions, needs and priorities to you and me but they have a will and a desire to live … like you and me.

I had a dog, a boxer… he was a sensitive creature. He was some times happy and playful, some times unhappy or depressed. He was driven by perceptions and priorities which I often did not understand but he was without any doubt a sentient being.

Human society is constantly demonstrating how bad individuals are at understanding or accepting different perspectives to their own. This within our own species. It is therefore not surprising that we seem in general to be unable to see those outside our species with anything but a utilitarian view. But as a society we have become increasingly aware that while many animals experience the world through a very different prism of senses to our own they are nontheless sentient and emotional beings.

The arguments about the practical benefits of intensive dairy farming are mostly logically flawed or couched in terms of an emotional claim to an understanding of animal welfare that only the annointed can possess. I was brought up on a chicken farm and have lived most of my life in the country. I did some unspeakable things to chickens back then. It was the norm. I have learnt how wrong it was as part of the same journey that society as a whole has taken. Mega Farms are therefore anachronistic. It should now be self-evident that to hold 1000 cows in a shed for years on end and feed them a diet that nature did not design them for is no longer acceptable. It is immoral.

The mega dairy in China of 100,000 cows is something the world should be truly ashamed of… and angry about!

  1. China – restrictions and dairy

  2. Report on the Welfare of EU Dairy Cows – EuroGroup4Animals and Compassion In World Farming

  3. McLennan, K. M., 2012. Farmyard Friends. The Biologist. 59(4), 18-22

  4. McLennan, K. M., Littlemore, J., McCormick, W., 2012. The Effects of Short-Term Separation on Physiological parameters of Dairy cattle: Heart rate versus Cortisol.
    In: Proceedings of the Regional Meeting of the International Society of Applied Ethology, UK/Eire

  5. McLennan, K. M., Stewart, C., and Meredith, J., 2010. Social Bonds in Dairy Cattle – Preliminary Observations.
    In: Proceedings of the Regional Meeting of the International Society of Applied Ethology, UK/Eire p10

  6. McLennan, K. M., 2008. Social Bonds in Dairy Cattle: Effects of dynamic group systems on welfare and productivity.
    In: Proceedings of the Third Student Animal Welfare Conference, Writtle College.

  7. The Five Freedoms

  8. The Nocton Dairy Controversy

  9. The Truck Backer-Upper: An Example of Self Learning in Neural Networks

  10. Report on the welfare of EU dairy cows – CIWF and EG4A

  11. Prof Marc Bekoff – Do Cows Moo ‘Get Me The Hell Out of Here’ on Factory Farms?

  12. Prof Marion Dawkins – The Science of Animal Suffering – University of Oxford

  13. The Official Information Portal for Anaerobic Digestion

  14. Anaerobic digestion: opportunity or threat for dairy? – AHDB

  15. Plummeting milk price prompts ‘stealth’ rise of 2,000-cow ‘mega-dairies’ in UK – Independent

  16. Intensive farming link to bovine TB – Exeter University