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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By Grace Hussain for Sentient.
Broadcast version by Terri Dee for Indiana News Service reporting for the Sentient-Public News Service Collaboration

Egg producer Kipster recently announced it had failed to meet what was an ambitious goal - ending the practice of male chick culling in its U.S. supply chain, a practice responsible for culling six billion male chicks globally each year. The Dutch-based company had hoped to implement a technology called in-ovo sexing to eliminate this practice by fall of last year. But it hit a few roadblocks.

"We've been really trying hard to work with the technology provider and hatchery to get it to the United States," Sandra Vijn, who manages Kipster's U.S. operations, tells Sentient.

And there were other promising signs. Earlier this month, Walmart updated its animal welfare policies to prioritize "gendering innovation" within their egg supply chain, for instance. But the process is taking longer than expected.

Male chicks have long been considered a by-product by the egg industry because they don't lay eggs and they don't grow fast or large enough to compete with meat chickens. It's standard practice within the industry to kill them right after they hatch; approximately six billion male chicks are killed each year globally.

In-ovo technology eliminates the need to cull live, male chicks by determining whether the embryo developing inside the egg is male or female before they hatch. The male eggs are then discarded before they can finish developing. There are other alternative technologies being investigated by researchers too, like using genetic engineering to breed hens that only lay female eggs.

Still, the company is moving forward. Respeggt, a technology company that works with Kipster on the in-ovo technology, announced that their in-ovo sexing technology would be installed in the Nebraska hatchery that Kipster sources from this month. Vijn now expects to get sexed eggs from the hatchery sometime this summer. From there, it will take about 20 weeks for the hens to mature enough to start laying eggs, which the company expects to hit the market by late 2025.

Kipster Sees In-Ovo Sexing As a Temporary Solution

In-ovo sexing was not Kipster's first choice for the American market. The company wanted to take the production system that they use in the Netherlands - where male chicks are raised to be sold for meat - and replicate it in the U.S., says Vijn.

But that plan hit a snag. "We couldn't get a processor to work at the scale and price that we could afford," says Vijn. Instead of being sold for meat, the four flocks of adult roosters they had raised at their U.S. facility ended up being slaughtered, and their carcasses were donated to food banks.

For Vijn, raising male chicks for meat is preferable, as it cuts down on both waste and animal suffering. "We think that everything within our farm is a good source of food for people," she says. "With every rooster that can be eaten, there's less need to bring additional broiler chicks to life."

Ultimately, says Vijn, "we were looking at in-ovo as a temporary solution."

Satisfying the American Consumer

In the Netherlands, where Kipster was founded, consumers are willing to pay a premium for meat from chickens who had basic welfare accommodations - such as access to the outdoors - during their lives.

Since last year, all fresh chicken meat sold in Dutch grocery stores comes from slower-growth breeds of broiler chicken. Like their Dutch counterparts, consumers in the United States are also willing to pay extra for animal products - including up to 38 percent more for eggs according to a 2018 survey - that they believe were produced under higher welfare conditions.

A key difference between the two countries is that in the Netherlands, consumers buy and eat the rooster meat from layer chicken breeds, says Vijn. In Europe, Kipster also sells their spent hens - those who are no longer considered productive egg layers - for human consumption.

Consumers in the U.S. aren't so open to the idea, however. In the United States, the hens are sold for pet food.

In the U.S., Kipster raises Dekalb white chickens, a breed specifically bred to lay eggs, up to 500 in 100 weeks. Dekalb white chickens start laying eggs at around 18 weeks of age, weighing in at a little over 1300 grams.

Research has found that the high number of eggs they lay weakens their bones, making laying hens highly susceptible to bone fractures. Dekalb white chickens are especially vulnerable to these breaks.

Ultimately, the delay in bringing the technology to the United States came down to an issue of scale. Respeggt and Hendrix needed to know that there would be enough of a market for the sexed eggs. "The equipment we have is made to produce large numbers of female eggs, and acceptance from retail, and farmers took some time," Respeggt's representative told Sentient.

Sentient reached out directly to Neal Martin, General Manager of Hendrix ISA-U.S., a subsidiary of Hendrix Genetics, for comment and did not receive a reply.

For Kipster, adopting in-ovo technology remains a viable, albeit second-best option. "It really fits in our philosophy that we should be eating less eggs, less meat, less animal proteins," Vijn says, "but already use whatever is in the system so that we don't have to bring a life on earth just for the purpose of eating them."


Grace Hussain wrote this article for Sentient.


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Indiana's Natural Resources Commission will decide this week whether to allow bobcat trapping, giving Hoosiers one last chance to weigh in.

The meeting will be held Tuesday at 10 a.m. at Fort Harrison State Park in Indianapolis and will determine whether the state moves forward with a plan to permit bobcat trapping in 40 southern Indiana counties next fall.

Samantha Chapman, Indiana state director of the group Humane World for Animals, stressed Hoosier voices are critical at the meeting.

"We really want folks to show up and voice their opposition to this proposal," Chapman emphasized. "Indiana's bobcats are still recovering, and we need more data on what the actual numbers and populations are for bobcats in Indiana."

Opponents said the plan is premature. The Department of Natural Resources has released only a siting map, not a full study, raising concerns the species remains vulnerable. Humane World Animals urged residents to demand a zero quota, arguing the proposal prioritizes trappers over conservation.

The plan allows trappers to capture up to 250 bobcats, with each trapper limited to one and required to obtain a special license. Chapman warned trappers will kill bobcats at a time when Indiana must prevent past population declines rather than risk undoing decades of recovery.

"While the commission can legally set a quota of zero, it is instead proposed allowing 250 bobcats to be barbarically trapped, bludgeoned, strangled, stomped or shot," Chapman contended. "This is why we need Hoosiers to speak up at the Natural Resources Commission meeting."

Conservationists stressed live bobcats generate more economic benefits through tourism than trapping ever could. They urged Hoosiers to turn out in force Tuesday and speak before the commission makes its final decision.


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By Gabriella Sotelo for Sentient.
Broadcast version by Suzanne Potter for California News Service reporting for the Sentient-Public News Service Collaboration

As egg prices continue to skyrocket across the United States, some consumers are looking for alternative ways to secure affordable eggs, including turning to their backyard. Last month, U.S. Secretary of Agriculture, Brooke Rollins, penned a commentary outlining her plan to help "lower egg prices." Among her proposals - such as vaccinating chickens and reassessing California's Proposition 12, which tightened animal welfare laws - there was also a nod to raising backyard chickens.

In her commentary, Rollins writes that part of the plan is "to make it easier for families to raise backyard chickens." There was no expansion on this point, however, outside of a sentence in the USDA release of the plan promising to "minimize burdens on individual farmers and consumers who harvest homegrown eggs." A spate of articles also suggests the notion is picking up steam. Yet even though the idea may seem like a potential solution to rising egg prices, research suggests that keeping chickens for eggs may just bring the risks of avian flu to your backyard. In short, because your backyard is not protected from wild birds.

"The more birds that you have, especially when they kind of overlap with waterfowl habitat, for example, the increased risk you're going to have [of bird flu]," Maurice Pitesky, associate professor and expert in poultry disease modeling at the UC Davis School of Veterinary Medicine, tells Sentient.

The increased risk applies to industrial egg operations. Nearly 99 percent of farm animals in the U.S. are raised on factory farms - operations where animals are crowded together, often in unsanitary conditions. These settings are breeding grounds for diseases like bird flu, as the density and poor care make it easy for viruses to spread quickly. But it's not just factory farms that are at risk. In the past year, bird flu outbreaks have made headlines across the United States, and backyard chickens have not been immune to its reach.

Backyard Flocks Impacted

Over the last 30 days, 51 backyard flocks across the U.S. have confirmed cases of avian influenza, compared to 59 cases in commercial operations, as of March 3. While the number of affected backyard flocks is slightly lower overall, it's important to remember that the risk to smaller, home-raised flocks remains significant, primarily because the disease is often spread through wild birds - including their droppings and saliva - who can easily get to a backyard flock.

Wyoming recently reported its first human case of bird flu, which is believed to have been contracted from exposure to a backyard flock. The first severe case of avian flu in the U.S. occurred in December 2024 in Louisiana, where it was determined that the person had been exposed to sick and dead birds from a backyard flock. This person also became the first person in the U.S to die from the virus.

"This case underscores that, in addition to affected commercial poultry and dairy operations, wild birds and backyard flocks also can be a source of exposure," the Center for Disease Control has stated about this case.

Bird flu can spread to people through various routes in a backyard farm, according to the CDC, including direct contact with infected birds, their droppings and contaminated equipment.

The Spread: Wild Birds and Backyard Flocks

It's tempting to assume that backyard chickens are safer from bird flu than large commercial farms due to their smaller flock size and less crowded living conditions. But this assumption overlooks the critical role of wild birds in spreading the virus.

The virus is frequently carried by wild birds, many of which are migrating across the country. For backyard chicken keepers, this poses a serious risk, as wild birds can easily come into contact with their flocks, potentially bringing the virus with them.

Benjamin Anderson, an assistant professor in the Department of Environmental and Global Health at the University of Florida, told Sentient in an email that wild birds, particularly ducks and geese, are the main carriers that can introduce the flu into backyard flocks. Outbreaks are also more concentrated along migratory bird flyways, Anderson noted, with four major routes across the U.S.

A 2021 study on avian flu transmission pathways found that flocks near or in contact with waterfowl and migratory birds are at a higher risk of infection. Although the study primarily focuses on commercial farms, its insights are also relevant to backyard operations - in essence, the researchers found that the virus can spread more widely when chickens aren't properly isolated from these outside threats. Infected birds can release the virus through their saliva and feces - in other words, exposure doesn't require direct contact with a backyard chicken.

Though backyard chickens are often not as crowded together as chickens raised commercially, birds raised in backyards are vulnerable to bird flu thanks to the lack of strict biosecurity regulations. Unlike commercial farms, which are at least required to follow certain guidelines to prevent outbreaks (such as regular testing and isolating infected animals), there is no oversight or enforcement for smaller, home-raised flocks.

With backyard bird flocks, says Pitesky, "their biosecurity on average is not ideal." There are a number of reasons why that can be the case, including a lack of "adequate fencing." It can even be as simple as the hobbyist may be pressed for time. "People have lives," says Pitesky. To keep backyard chickens safe, Pitesky says, "it takes some time and energy and money."

Backyard chicken keepers may not be aware of the measures they should take to minimize risk of exposure. A 2024 survey study in the UK of 1,550 poultry keepers found that not all backyard poultry owners were following biosecurity measures mandated by the government. The researchers found that some poultry keepers were unaware of what was required of them or faced barriers such as expenses, fewer carers for the birds and other welfare concerns.

The CDC has issued guidelines for backyard chicken owners to follow, such as restricting human access to their chickens, keeping them in enclosed spaces and minimizing exposure to wild birds. But if backyard chicken keepers do not implement these protocols effectively, the birds are left exposed to the virus.

Should You Raise Backyard Chickens During a Bird Flu Outbreak?

Anecdotally at least, Anderson has found that more people are interested in having backyard chickens these days, especially with high egg prices. And though both Anderson and Pitesky see the appeal of having backyard flocks, they also point to the risk associated with keeping them.

It's crucial to understand that keeping backyard chickens during an outbreak requires significant research, preparation and strict adherence to CDC guidelines. The CDC recommends wearing personal protective equipment (PPE) when handling sick or dead birds, cleaning and disinfecting contaminated areas and avoiding stirring up dust or bird waste that may spread the virus. In an email to Sentient, Anderson writes "people should take necessary steps to learn how to raise poultry safely and according to local and state rules."

However, this guidance quickly becomes complicated - some infected birds (especially those that are infected with a low pathogenic strain of bird flu) may not show symptoms. This strain can then mutate into the highly pathogenic version. As a result, flock owners may not realize they need PPE or take proper measures when dealing with asymptomatic birds. They may end up spreading the virus unwittingly.

The Bottom Line

Though the current risk of contracting bird flu remains low for most of the public, the middle of a bird flu outbreak may not be the best time to start keeping backyard chickens. It may sound appealing to be able to source "free" eggs from your backyard, but the reality is that keeping backyard chickens safe from bird flu requires time and money. And ultimately, raising chickens in a backyard doesn't eliminate the risk of spreading the virus, and could even exacerbate the problem if you don't take the proper precautions recommended by the CDC.

As for Secretary Rollins' plan to make raising backyard chickens easier for homeowners, the details remain unclear. Sentient reached out to the USDA for more information on how her plan addresses these concerns, but has yet to receive a response.


Gabriella Sotelo wrote this article for Sentient.


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