Is factory farming's neck on the chopping block?
Image credit: Dreamstime
Since the Covid-19 crisis began, there have been calls for factory farming to be banned or at least regulated.
Humans have farmed animals since 11,000 BCE, but today, two out of every three of the 70 billion farm animals killed for food each year are farmed industrially in factory farms.
There are benefits to this. Companies make a lot of money from economies of scale and consumers have a never-ending supply of cheap meals and snacks. Imagine McDonald’s without its burgers, a German Christmas Market with no sausages, and a supermarket anywhere without its chicken nuggets and ‘chow meins’. Now imagine the world without Covid-19.
Criticism of factory farming has grown since the pandemic began, and not just because it’s cruel to keep thousands of animals in tiny confined spaces, without space to move or fresh air to breathe, pumped full of antibiotics to keep them alive.
Professor Lars Angenent, an environmental scientist at the University of Tubingen, also points out unhygienic conditions for workers in slaughterhouses, the amount of fossil fuels, phosphorus and water used during the meat production process and the climate-damaging emissions it produces. “We are in a complex crisis with current food production,” he says. “The meat is cheap, but at the cost of many other things that are not sustainable.”
More recently, attention has turned to the role of intensive farming practices in the evolution, transmission and spread of infectious diseases.
In April, Virginijus Sinkevicius, EU commissioner for the environment, stated that there is strong evidence that the way meat is produced, and not just in China, played a role in the Covid-19 pandemic.
At the beginning of May, researchers from the Universities of Sheffield and Bath warned that intensive farming involving overuse of antibiotics, high numbers of animals and low genetic diversity increases the likelihood of pathogens becoming a major public health risk.
One of the researchers, Evangelos Mourkas, a biologist from the University of Bath, explains that the conditions in large-scale factory farms, with animals packed closely together, increase the likelihood of pathogens spreading through herds and flocks. “It’s no different from standing next to someone with Covid-19 for hours on end,” he says. “If they’ve got it, you’ll get it too.”
There’s a long history of animal pathogens passing into human populations as a result of the ways in which we farm animals for food. Smallpox, salmonella, influenza, even bubonic plague, first passed over to humans living in close proximity to farm animals many thousands of years ago, either directly from the animals or indirectly by encouraging rodents and other scavengers to visit their settlements.
Virologist John Oxford has suggested that the 1918-20 Spanish flu pandemic, during which 17-50 million people died, began on a British Army farm on the Western Front. He contends that early symptoms of the disease were actually found as far back as 1916, in the British camp in Etaples, the site of the army hospital complex and where the army also kept livestock and poultry farms to feed the troops. Oxford argues that the virus spent the next couple of years mutating into the more virulent form that devastated the world. Others claim that the disease originated on a pig farm in Kansas, close to a US Army training camp, and it was brought to the Western Front by soldiers from this camp. It was dubbed Spanish flu, apparently because Spain’s King Alfonso XIII caught it.
Over the last 30 years, there has been a major escalation of intensive animal farming practices. The world’s poultry population increased by 76 per cent in developing countries and 23 per cent in developed countries according to the World Health Organization. The United Nations Food and Agriculture Organization reports that in developing countries, per capita consumption of meat grew by about 50 per cent from the early 1970s to the early 1990s.
At the same time, we’ve seen the emergence of new infectious diseases that have subsequently passed over to humans. Swine flu has broken out several times over the last ten years, the most destructive episode being the 2009-10 pandemic, which killed around 284,000 people. Avian flu outbreaks have become more common since the late 1990s.
“The pathogens which threaten public health are what we call high-risk, generalists,” says Mourkas. “These pathogens have the ability to affect multiple host species, switch from one host species to another, with each switch causing a change in the pathogen’s DNA, making it harder to locate the pathogen and disable it.”
Supporters of factory farming, however, insist that megafarms and intensive farms are cheaper to run, take up less space, enable animals to be kept securely away from predators and potential carriers of disease. Conditions are tightly controlled and if disease develops the livestock can be treated quickly. Gary Ford, from the National Farmers Union, says: “Animal husbandry and stockmanship are the greatest factors that determine animal health and welfare, not farm size or system of production.”
At the end of April, John Tyson of Tyson Foods, one of the biggest US meat producers, declared that the American food supply was breaking down, complaining that it and other big companies were being forced to close meat processing plants because their workers were becoming infected with Covid-19.
Tyson added that millions of livestock would have to be slaughtered and disposed of on farms, as there was nowhere for farmers to sell the animals, with slaughterhouses and restaurants closed. “The food supply chain is breaking,” he wrote in a full-page ad in major newspapers, warning of potential meat shortages. “There will be a limited supply of our products available in grocery stores until we are able to reopen our facilities that are currently closed.”
Mourkas explains that through the intensive farming of certain species, modern humans have interfered with evolution and, as a result, made it easier for certain pathogens to spread. “There are 200 billion wild birds on the planet and the chicken used to be just one of those many wild birds – a jungle fowl, which for millions of years evolved at its own speed,” he says. “What we have done, is take one of those species, domesticated it, and made one out of six or seven birds on Earth a chicken. From an evolutionary perspective this is insane. It’s the same story with cows. The biomass of cows, globally, is more than that of all wild mammals combined.”
Mourkas adds that when one or two animals are so prevalent, the pathogens inside them also become prevalent. “We have created a new niche for infectious pathogens,” he says. “Imagine 1.5 billion cows, each cow producing 30 kilos of manure each day, they are shedding viruses into the environment in huge amounts.”
Mourkas also explains how this can help pathogens pass to humans. “Influenza was originally a virus in ducks. The normal route was that one duck has the virus, sheds it in water, another duck comes and takes the virus,” he says. “Suddenly the virus finds itself in a chicken, can’t spread through water anymore, so it becomes airborne.”
“Because of Covid-19, a government might say OK, what we’re doing now is not so good. The need for a change is obvious to a lot of people, but Covid-19 is not the only problem.”
It’s not just the sheer numbers of factory-farmed chickens and the tightly packed conditions that facilitate the spread of pathogens, it’s also the birds’ genetics.
This March, an RSPCA report outlined that three breeds account for the majority of chicken meat produced globally, each of which has been genetically selected to grow to slaughter weight as quickly as possible, on the minimum amount of feed.
The report showed how the global supply of chickens is dominated by three firms Cobb, Aviagen and Hubbard, now a subsidiary of Aviagen. In the UK, Aviagen produces 70-80 per cent of meat chickens, Cobb 20-30 per cent, Hubbard less than 5 per cent.
Researcher Dr Laura Dixon, an animal and veterinary scientist from Scotland’s Rural College, assessed the production and welfare characteristics of the conventional breeds and compared this with a slower growing breed. Dr Dixon discovered that chickens which were more efficient at converting feed into body weight had significantly poorer health than the slower-growing breed.
Since the late 1950s, genetics companies have approximately halved the amount of time it takes for a meat chicken to achieve the same slaughter weight – at the rate of about one day shorter per year.
The problem with all this, from a public health perspective, is that when one animal gets sick, the pathogen can more easily spread to all the original chicken’s genetic clones. With a genetically diverse flock the pathogen would have to adjust to the different DNA within the flock members, which would at least slow down the speed of transmission.
Matt Wadiak, CEO of Cook’s Venture, a regenerative agriculture start-up based in San Francisco and Arkansas, explains that genetic selection for growth speed can also deprive other parts of the chicken’s body of energy and oxygen, and put pressure on the bird’s organs, especially the heart and lungs. Because of this, antibiotics are relied upon to keep weak and sickly animals alive long enough to reach slaughter weight, or to lay eggs, if that is their purpose. Unfortunately, the pathogens inside them have, with regular exposure to antibiotics, frequently become resistant, making pathogens that do cross over into human populations harder to treat.
“Our biggest fear is that a new mutation leads to a deadly and highly transmissible pathogen resistant to antibiotics,” says Andrew DeCoriolis from US non-profit Farm Forward. “If things stay as they are it seems only a matter of time until this happens.”
There are slower-growing breeds of chicken, and the RSPCA found that these breeds had better health and immunity to pathogens. According to Wadiak, it’s also possible to breed chickens with strong immune systems, through genetic selection.
“Through genome testing you can identify certain characteristics that you’d like to develop through natural breeding,” says Wadiak. “You can eliminate undesirable traits, create breed resistance to disease and less reliance on conventional feed crops.”
He adds: “There’s an incredible amount of science and data involved to enable us to understand whether animals are going to do well or not. We use natural selection practices based on data and good science to make better decisions to build healthier animals with better immune systems.”
He continues: “A lot of tracking, traceability goes into that – tracking the paternal stock through many generations of ancestry, working out where that leads to and where we’re trying to get to.”
A number of recent reports support the idea that chickens can be genetically selected for strong immune systems. In 2018, researchers at the US Department of Agriculture discovered that roosters with naturally high levels of cytokines and chemokines in their blood could ward off dangerous pathogens. The same year, a study out of Wageningen University and Research found that chickens bred for natural antibodies have a higher immune response, particularly against bacterial diseases.
Last year, experts at the Imperial College London and the Pirbright Institute, a bioscience research centre, identified variations in the genes of chicken antiviral proteins called IFITMs, which could affect the chicken’s ability to fight viral infections.
IFITMs are proteins found in many animals, including humans, that are activated by the immune system and stop viruses from entering and replicating in host cells. Changes in the genes of IFITM proteins can alter their activity and location, which has an effect on their ability to restrict viral infections.
“Now that we have identified these genetic differences, we can start to understand how they affect the birds’ responses to viral infections,” says Dr Mark Fife, head of the genetics and genomics group at Pirbright. “If particular variations are found to provide extra protection, they could be selected by commercial breeding programmes to help make chickens more resistant to economically important diseases.”
There’s an obvious question, here. If it’s possible to breed chickens with strong immune systems, which might be resistant to infectious pathogens, why isn’t it compulsory to breed them so? Sadly, the answer is also all too obvious. “Slower-growing breeds don’t convert food as efficiently, so it costs more to grow them,” Wadiak says.
Any changes to the current meat production system would require some serious political will. The global meat sector was valued by Research and Markets at $945.7bn in 2018, and was forecast to increase to $1,142.9bn by 2023. That’s a lot of money and therefore a lot of political clout.
In recent months, both the UK and US government have taken measures to support intensive farming, although towards the end of April, Members of the European Parliament voted to cut funding for farms that exceed a certain stock density. The parliament’s environment committee also voted to block national subsidies for large facilities which don’t respect basic animal welfare. Now, animals must be able to lie down, stand up, extend their limbs and move around.
In the USA, Senators Cory Booker and Elizabeth Warren are co-sponsoring a bill that, if passed, would see factory farms phased out by 2040 and replaced with pasture-based livestock, specialty crops and organic commodity production.
For the food producers, DeCoriolis says the answer is to replace huge intensive farms with smaller flocks of genetically diverse animals that have healthy immune systems. Wadiak thinks stronger data sets to support livestock husbandry based on the cultivated selection of animals, with, in the future, some machine learning, could be “a really useful genetic tool to understand the biological properties of animals to aid selection”.
Another of the cohort of researchers who worked with Mourkas, Sam Sheppard from the Milner Centre for Evolution at the University of Bath, wants more responsible farming methods to reduce the risk of outbreaks of problematic pathogens in the future.
Angenent believes that the agricultural model we have is simply not working. “Because of Covid-19, a government might say ‘OK, what we’re doing now is not so good’. The need for a change is obvious to a lot of people but Covid-19 is not the only problem.”
Mourkas thinks that as the meat-producing industry makes so much profit every year it could easily spend some of its money on research to try and tackle these problems. “We need more research on biosecurity strategies and interventions for all of the pathogens,” he says.
The cost of the Covid-19 pandemic is a staggering 387,000 deaths so far (WHO figures, 5 June) and potentially $5.8-8.8tn according to the Asian Development Bank, in May. It’s time, now, for leaders around the world to decide.
Will it be public health requirements that drive their agricultural policies, both in the immediate future and the long term? Or the economic needs of factory-farming corporations?
“After all this, how seriously are we going to take the future pandemic risk?” DeCoriolis asks. “Are we willing to do what is necessary to protect ourselves from future events?”
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