By Seth Millstein for Sentient.
Broadcast version by Nadia Ramlagan for West Virginia News Service reporting for the Sentient-Public News Service Collaboration
Every year, humans around the world eat 360 million metric tons of meat. That’s a lot of animals — or more precisely, a lot of dead animals. At any given point, there are 23 billion animals in factory farms, and countless more being farmed or caught in the sea. As a result, the number of animals killed for food every day is almost too large of a number to comprehend.
Animal Agriculture, by the Numbers
Before getting into the death toll, it’s worth remembering that animals suffer immensely in factory farms, and on the way to slaughterhouses, and in slaughterhouses. Around 99 percent of livestock are raised in factory farms, and factory farms prioritize efficiency and profitability over animal welfare. There are few laws protecting livestock from abuse and mistreatment on farms, and violators of those laws are rarely prosecuted.
The result is a significant amount of pain and misery for farmed animals, and that suffering is an important thing to keep in mind as we dive into the numbers behind these animals’ deaths.
How Many Animals Are Killed for Food Every Day?
Quantifying animal slaughter is relatively straightforward — except when it comes to fish and other aquatic life. There are two reasons for this.
First, the United Nations Food and Agriculture Organization (FAO), which tracks global livestock statistics, measures fish production in weight, not number of animals. Second, the FAO’s numbers only include farmed fish, not those caught in the wild.
To overcome the first challenge, researchers attempt to convert the total pounds of fish caught into the total number of fish themselves. Obviously, this is an inexact science that requires quite a bit of guesswork, and as such, estimates of fish slaughter tend to vary significantly, and are generally expressed in relatively wide ranges.
As for the second challenge, researchers Alison Mood and Phil Brooke have attempted to quantify the number of wild fish caught every year, first by pulling data from multiple sources and then by converting the total weight of wild fish to an estimated number of animals.
The following numbers are based on 2022 data from the FAO, except for the fish tallies: for farmed fish, the low end of the range draws on research by the Sentience Institute, while the high end is based on an analysis by Mood and Brooke. For wild-caught fish, the low end and high ends of the estimate are both based on a range provided by Mood and Brooke.
With that being said, here are the best estimates of how many animals are killed every day on a per-species basis.
- Chickens: 206 million/day
- Farmed Fish: Between 211 million and 339 million
- Wild Fish: Between 3 billion and 6 billion
- Ducks: 9 million
- Pigs: 4 million
- Geese: 2 million
- Sheep: 1.7 million
- Rabbits: 1.5 million
- Turkeys: 1.4 million
- Goats: 1.4 million
- Cows: 846,000
- Pigeons & other birds: 134,000
- Buffalo: 77,000
- Horses: 13,000
- Other animals: 13,000
In total, this means that every 24 hours, between 3.4 and 6.5 billion animals are killed for food. That comes to a lower-end estimate of 1.2 trillion animals killed every year. That’s a positively staggering number. For contrast, anthropologists estimate that the
total number of human beings who’ve ever existed is just 117 billion.
A couple of things stand out about this data.
For one, if we exclude fish, the overwhelming majority of animals slaughtered for food are chickens. This isn’t a surprise, given that
poultry consumption has skyrocketed over the last 60 years: between 1961 and 2022, the average person went from eating 2.86 kg of chicken every year to 16.96 kg — an increase of almost 600 percent.
The consumption of other meats didn’t rise nearly as much over that period. There was a modest increase in per-capita pork consumption, from 7.97 kg to 13.89 kg; for every other meat, consumption has remained relatively stagnant over the last 60 years.
Also notable is the relatively high death tolls of animals that many Americans might not think of as meat sources for humans. Slaughtering horses for meat is illegal in the U.S., but that doesn’t stop people around the world from killing 13,000 of them every day. Rabbit meat isn’t a common dish in America, but it’s
wildly popular in China and the European Union.
Animals Slaughtered Who Are Never Eaten
One thing that’s particularly frustrating about all of this, from both an efficiency standpoint and an animal welfare standpoint, is that a sizable share of the animals killed for food are never even eaten.
A 2023 study published in Sustainable Production and Consumption found that
24 percent of livestock animals die prematurely at some point in the supply chain: they either die on the farm before they’re slaughtered, die in transit on their way to the slaughterhouse, die at a slaughterhouse but aren’t processed for food, or are thrown away by grocers, restaurants and consumers.
This wasted food adds up to about
18 billion animals a year. The meat from these animals never reaches the lips of any human, making their deaths — which, it should be stressed, are often excruciatingly painful and bloody — essentially pointless. What’s more, this tally doesn’t even include seafood; if it did, the amount of wasted meat would be many orders of magnitude higher.
In the U.S., around a quarter of animals in this category die on the farm from disease, injury or other causes. Another seven percent die in transit, and 13 percent are thrown away by grocers after being processed into meat.
Some of these “wasted deaths” are part and parcel of factory farm operations. Every year, around
six billion male chicks are intentionally killed, or “culled,” on factory farms due to the fact that they can’t lay eggs. In the seafood industry, billions of aquatic animals are caught by accident every year —
a phenomenon called bycatch — and are either killed or injured as a result.
It’s worth noting that these numbers vary significantly from country to country. The global average for wasted meat is around 2.4 animals per person per year, but in the U.S., it’s 7.1 animals per person — almost three times higher. On the other end of the spectrum is India, where only 0.4 animals per person are wasted every year.
The Hidden Death Tolls of the Environmental Destruction of the Meat Industry
The above death tolls only count animals who are farmed or caught with the goal of being eaten by humans. But the meat industry claims many other animal lives in more indirect ways.
For instance, cattle farming is the
number one driver of deforestation around the world, and deforestation inadvertently kills a whole lot of animals that were never intended to be food in the first place. In the Amazon alone,
2,300 animals are at risk of extinction due to deforestation, as the clearing of trees wipes out their natural habitats and deprives them of the resources they need to survive.
Another example is water pollution. The manure from livestock farms often leaks into nearby waterways, and this can have a ripple effect that results in many more animal deaths: Manure contains phosphorus and nitrogen, both of which promote the growth of algae; this eventually
leads to harmful algal blooms, which deplete the oxygen in the water and clog the gills of fish, killing them.
All of this is a long way of saying that killing one animal for food often results in many other animals dying.
The Bottom Line
The astonishing number of animals killed for food every day, both directly and indirectly, is a sobering reminder of the impact our appetite for meat has on the world around us. From the animals slaughtered on farms to the creatures killed by agriculture-driven deforestation and farm pollution, the death toll that a meat-based diet demands is much higher and more far-reaching than many people realize.
Seth Millstein wrote this article for Sentient.
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By Dawn Attride for Sentient.
Broadcast version by Alex Gonzalez for Arizona News Connection reporting for the Sentient-Public News Service Collaboration
Antimicrobial resistance is one of the largest health threats to humanity, according to the World Health Organization. It's been over 40 years since the discovery of a new antibiotic class; an ominous gap in modern medicine given the rise of superbugs and antibiotic-resistant bacteria. The spread and severity of antibiotic resistance is exacerbated by antibiotic overuse and lax prescribing standards, but also by animal agriculture. Depending on the country, roughly 70 percent of all antibiotics produced are used in agriculture to prevent disease, or enhance animal growth. This overuse not only fosters the spread of antibiotic-resistant bacteria in animals, but in humans who consume that meat.
At a critical meeting last month, the United Nations made a global pledge to reduce deaths from antibiotic resistance, which includes clamping down on antibiotic use in animal farming. Sentient's recent investigation in collaboration with The Bureau of Investigative Journalism found that Cargill routinely uses critically important antibiotics in livestock, despite rules from the FDA and warnings from the WHO.
It's clear that farmers need to reduce their dependence on antibiotics. But a complete ban would be a naive solution, says Jennifer Ronholm, Canada's research chair in agricultural microbiology and professor at McGill University. Ronholm argues a ban could result in food shortages and an uptick in livestock diseases. That's why her lab aims to uncover whether they can design and optimize animal microbiomes to lessen the need for antibiotic use in agriculture.
How Farming Practices Lead to Antibiotic Resistance
A lot of the pathogens we're seeing with high drug resistance originate from animals. Since the 1940s, roughly 50 percent of zoonotic diseases have been traced back to agriculture. "They're circulating in agriculture environments, picking up the [antibiotic resistance] genes and then circulating back to humans. So, figuring out a way to cut that zoonotic transfer feels like a really effective way to deal with the problem," Ronholm tells Sentient.
To prevent the emergence of zoonotic diseases, a 2022 paper called for reducing meat consumption to alleviate animal confinement on farms, and also to avoid clearing more land for agriculture. The paper's author, Matthew Hayek, described animal agriculture as a "trap of rising infectious diseases," and urged that escaping this trap means "limiting meat consumption."
Poor conditions on farms - such as cramped facilities and poor ventilation - can exacerbate the spread of antibiotic resistance. Recent estimates found 1.7 billion animals in the U.S. live on factory farms, up nearly 50 percent since 20 years ago, in response to growing demand for animal products. Further, factory farms produce twice as much sewage as the country's population. These confined conditions can create physical and mental stress for the animals, which may lead to weakened immune systems, making them more susceptible to infection. This, in tandem with the farm's high amounts of waste, creates an optimal environment for disease spread.
A study looking at the effects of various pig farming conditions found lower levels of antibiotic resistance in organic and alternative farms than in conventional farms. The authors suggest the lower levels were from tighter regulation of antibiotic use, straw bedding and open ventilation.
Optimizing Animal Microbiomes to Prevent Disease
The premise of Ronholm's research ties into a key microbial concept of competitive exclusion, or simply, that particular healthy gut bacteria will outcompete harmful bacteria. By maintaining a balanced microbiome, this competition can prevent infection and disease from taking place.
At a recent presentation for World Antimicrobial Resistance Congress Week, Ronholm explained how her lab isolates these bacteria that competitively exclude infectious bacteria from healthy animals. The goal is then to create a tailored probiotic solution that optimizes animal's microbiome to lessen reliance on antibiotics for treatment.
Ronholm is particularly interested in mastitis infection, which is the most common disease in dairy cattle. Cows can get mastitis when bacteria infect their udder from the process of milking, dirty milking equipment or from their environment. Mastitis infection causes udder pain, swelling, and may leave the cow disorientated and feeble. The probiotic, when developed, could be applied to the cow's udder daily after milking. This probiotic could then strengthen their udder microbiome to fend off infection.
In a 2022 study, her team looked at Staphylococcus aureus, a bacteria known for causing mastitis, and identified microbial differences in the cows who were susceptible to infection or not. The results showed three bacteria, most notably Aerococcus urinaeequi, as being protective against infection. In a further study published last month, the researchers also looked at mastitis caused by Escherichia coli infection and found that A. urinaeequi again prevented microbial colonization. Both papers were funded, in part, by a Canadian initiative called The Mastitis Network that aims to prevent mastitis and reduce antibiotic use on farms.
Erika Ganda, an assistant professor of food animal microbiomes at Penn State University, attended Ronholm's presentation and says the prospects of her research are "fantastic." Ganda's lab researches animal microbiomes to tackle antimicrobial resistance, while also bolstering health and food production.
For example, although antibiotics for growth promotion in livestock and poultry were banned in 2017 by the Food and Drug Administration, probiotics can act as a growth promotion alternative. Disease prevention and growth promotion aren't mutually exclusive, Ganda says. "It costs energy to fight disease, so if that energy doesn't go into the immune system but goes instead into making milk or putting on muscle mass, that is a way of growth promotion." In Ganda's 2024 paper, probiotic supplementation improved growth in broiler chickens compared to other natural sources like essential oils. However, it's important to note that various fast growth methods in chickens come with animal welfare concerns.
From Research Lab to Farm Use
While Ronholm's team has yet to put one of these synthetic microbiomes in an animal, they are hopeful to get to this stage soon. "We have one product that we tried in a pre-clinical trial this year that worked well. I think in less than 10 years these types of products will be on the market," Ronholm says, but notes that her lab is purely focused on the research, not the business end of things.
An important next step is to understand the exact mechanisms of these gut bacterial battles that prevent infection."It's possible that they won't be as effective as antibiotics and people will not want to switch. But I don't foresee large limitations, efficacy issues or scaling factors," Ronholm says.
Research suggests that probiotics, among other gut-enhancing products, may also ward off avian flu - a serious disease that affects both animals and humans. Probiotics appear to clear harmful microbes and repair inflammatory damage in later stages of the infection. However, an exact probiotic cocktail to protect against avian flu in all of its infectious stages requires further work, the researchers concluded.
Managing this issue of antibiotic resistance on farms, at its core, boils down to proper management practices and vaccination strategies on farms, Ganda says. "The cleaner [and] the healthier animals are, the less antibiotics we're going to need, the less antimicrobial resistance you're going to find," she says. For now, researchers like Ronholm and Ganda endeavor to create tailored and effective solutions that can be added into farm systems easily to protect animals from infection and mitigate the larger issue of antibiotic resistance. Other researchers are looking into viruses that kill harmful bacteria in animals and selective breeding to produce animals that are more resistant to infection.
However, the onus is ultimately on the industry to address their role in this growing global public health challenge, which is predicted to kill 10 million people annually by 2050. Whether new strategies such as targeted probiotics are incorporated on a large scale into farming practices is also up to the agricultural industry. Antibiotic resistance is becoming increasingly widespread in both humans and animals, and the cramped and unsanitary conditions on factory farms are clearly a systemic root of the problem.
Dawn Attride wrote this article for Sentient.
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