Pigs in a factory farm, Germany Credit: Christian Adam/ullstein bild via Getty


November 16, 2020   5 mins

It puts itself about, doesn’t it, Sars-Cov-2? As well as spreading among humans, the virus crosses species. In all likelihood the virus transited to Homo sapiens sapiens from bats via pangolin sold in a Wuhan “wet market”. Last week 17 million farmed mink were culled in Denmark, after the weasel-like creatures were found to be infected with Sars-CoV-2, caught from workers; a mutant form of the virus  then “spilled back” from mink to humans. Five other countries have also reported coronavirus outbreaks at mink farms.

Does it matter? Certainly for the mink, most probably for you and me. Danish scientists are expressing concern about one mink-related strain of the virus which is believed to be less sensitive to protective antibodies, raising concerns about the effectiveness of any Covid vaccine. 

But the Danish mink episode is just one more proof that factory farms are ticking time-bombs of zoonotic disease — those which leap from animals to humans — and petri-dishes of bacterial infections. 

Humans are meant to be wise — indeed, so wise that we called ourselves sapiens twice — but you do wonder. We elevate ourselves over animals, consider them as Other, when biologically the species barrier between us is thin. Even non-existent. Take the common-or-garden pink pig, for instance: the pig so physiologically resembles humans that it has been used in medical  research for over 30 years as a translational model. That is, if it works in a pig it is likely to work in humans.

Our Western arrogance towards animalia is Rene Descartes’ fault, of course. As soon as the Enlightenment philosopher declared that  animals were automata, and only  humans conscious and deserving compassion, the creatures of the Earth were done for. 

If animals are “flesh robots”, ethically they can be as badly treated as you like. Add the generalised disconnect from nature concommitant with the Industrial Revolution, and the table appetites of late capitalism (more meat, please!) you end up with the factory farming of Peppa, Ermintrude and the Little Red Hen, plus the remainder of  Old Macdonald’s old-style farmyard. All of them reduced to “units” or “produce” rather than sentient beings. 

The welfare arguments against factory farming from PETA and vegans are familiar, and need no rehearsing. When, though, will humans finally learn that factory farming will kill them? 

By definition, a factory farm entails intensive rearing, with the livestock in close proximity, beak to beak, snout to snout. The old rule of farming — the one I was taught by my grandfather — is that “a sheep’s worst enemy is another sheep”. Put another way, any disease or sickness with animals close-packed “whips through the lot like wildfire”, in his words.

The overcrowding of animals in factory farms not only enables easy transmission of disease; according to the European Food Safety Agency, the stress from the overcrowding (often on bare concrete or metal slats), the inability to display normal behaviour compromises the animals’ immune system… which increases their susceptibility to disease. A vicious circle of malady. 

The circle of malady can become a spiral of death. Factory animals tend to be genetically similar to each other — clones, effectively — selected for traits such as big breasts or big rumps. Thus, a virus introduced into the herd or flock can run through it without meeting any resistance in the form of genetic variants to prevent its spread. 

It is different in the wild, or on farms which practise low-stocking densities. Viruses dislike killing their host, since if the host dies their demise follows. Out in the jungle or on organically-run Welsh hills, say, pathogens do not regularly encounter hosts, so the pathogen has to keep its virulence low — otherwise it runs out of hospitable bodies. But in a shed  with 250,000 laying hens the pathogen has a positive embarrassment of hosts, and can go through them like, well, wild fire.

This is why factory farms pose a bigger risk for zoonotic outbreaks than either the natural world or farms using low stocking rates. 

In 2018 a group of scientists analysed 39 “conversion events”, or antigenic shifts, whereby a pathogenic avian flu strain became more dangerous, exactly the sort of incidents that could cause a pandemic among humans: all but two were reported in intensive commercial poultry production systems. 

The world has already had portents of  how apocalyptic farm-reared zoonoses can be. We are not dealing with hypotheticals here. Between 1997 and 2006, the H5N1 virus — or avian flu — which was transmitted from poultry to humans, achieved a 59% mortality rate among people affected. For comparison, Covid-19’s mortality rate is in the neighborhood of 1%. 

Intensive poultry operations are the Manhattan Projects of viral development, and China is replete with them. Starting in the 1990s, as part of its economic transformation, China ramped up its food production systems to industrial scale. There are currently 5.27 billion chickens in China, most of them being farmed intensively.

Almost as nightmarish as avian H5N1 was the H1N1 swine flu which emerged from multiple viral gene “reassortment events” in farmed pigs in North America in 2009, before jumping to humans. The Swine Flu pandemic went global, killing  between 151,700 and 575,400, before being suppressed at great cost. 

In June this year a new strain of swine flu, similar to the one that caused the 2009 episode, was identified in China. Named G4 EA H1N1, it possesses “all the essential hallmarks of a candidate pandemic virus”, according to the authors of  one scientific paper. 

None of these near-misses have stopped the continual industrialisation of farming in the world’s most populous country. The latest pig farms in China are multistoried, with 1,270 pigs per floor, and over 90% of the meat on China’s plate comes from factory farms. 

And so China lurches from pandemic to pandemic: H7N9 avian flu; Covid-19; H1NI. African Swine Fever…

It is not just the mutant viruses manufactured in factory farms that are the stuff of bad dreams. The other pandemic risk associated with factory farms is from highly drug-resistant bacterial pathogens. Industrial farms are heavily reliant on antibiotics, both as prophylactics and as therapeutics. Overuse of these antibiotics causes bacteria to evolve, with those that mutate to survive the antibiotic becoming more dominant. 

Worldwide it is estimated that 73% of all antibiotics are used in farm animals. (In the UK the figure is about 30%.) According to leading authorities such as the European Medicines Agency and the WHO,  the overuse of antibiotics in farming contributes to higher levels of antibiotic resistance in some human infections.

This is more serious than most people understand, and already, every 15 minutes, one person in the US dies because of an infection that antibiotics can no longer beat. The post-antibiotic era is already here, and it will get worse. Small wonder then, that the Food and Agriculture Organisation of the United Nations says that “Livestock health is the weakest link in our global health chain.” 

The United Kingdom is a part of  that chain, if a slightly complacent one. DEFRA trumpeted recently: “We have some of the highest animal welfare standards in the world, as well as world-leading scientific capability on animal health, and we are continuing to explore ways to enhance our position as a global leader.”

DEFRA’s timing was unfortunate. So far this month three cases of  bird flu (the H5N8 and H5N2 strains) have been detected on poultry farms in England, leading to mass cullings. Cleary Britain has no special immunity against outbreaks of factory-farmed diseases. 

What is to be done? The world’s desire for animal flesh is unlikely to disappear soon. Presently, one billion pigs, three billion ducks and 69 billion chickens (the three most commonly killed terrestrial animals in the world) are slaughtered annually to meet the demand for meat.  

So we are not going to give up meat as a species, but as a matter of growing urgency we need to de-intensify and deindustrialise the livestock industry. It is not just humans who need to socially distance; we need to give the animals some space, and outdoors. The consequences if we don’t act soon could be truly catastrophic. 


John Lewis-Stempel is a farmer and writer on nature and history. His most recent books are The Sheep’s Tale and Nightwalking.

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