Could Free-Range Farming Lead to More Animal-Borne Pandemics?

Farmers across the United States are adopting free-range farming methods, which allow their livestock to roam freely on open pastures, as opposed to traditional factory farming practices that keep the animals contained in cramped spaces. While some consumers view free-range methods as more humane and healthier, a new study warns that allowing animals to roam outside could actually increase the risk of animal-borne pandemics spreading from farm to farm and infecting wild populations of birds and mammals.

the free range What does that mean?
The label free range is widely used in Australia, where up to nine million hens are farmed in conditions that fall well short of industry standards. Even on free range farms, eggs may be laid by hens kept indoors in cramped cages with little space or light. According to government figures from 2016, more than 75 percent of chickens are grown in large factory farms. This means that even free range eggs do not meet consumer expectations about animal welfare and food safety. The term free range also has no legal definition in Australia. There are no minimum requirements for outdoor access, stocking density or living conditions, meaning it can be applied to products ranging from industrial farming systems to small backyard operations with a handful of birds.

Study shows free-range poultry are more likely to spread salmonella
According to a new study published in Frontiers in Veterinary Science, free-range poultry are more likely than their confined counterparts to carry dangerous salmonella. The findings could shed light on why an alarming number of foodborne illnesses in humans stem from poultry products—and have implications for public health worldwide. As recently as 2016, 22 million Americans were sickened by food poisoning, said one of the study’s authors, Renata Ivanek of Vienna University of Technology. Salmonella is one of many pathogens that can cause severe illness and death in some cases. Therefore, it is important to understand how it spreads and evolves during outbreaks so we can better control them with vaccination programs or other preventative measures.

What can you do?
The answer, according to a new study published today in The Lancet Infectious Diseases, is as simple as keeping farm animals indoors. Researchers from The Pirbright Institute and University of Cambridge have found that an increase in free-range farming may lead to an increase in animal-borne diseases. This method of raising chickens, pigs and other livestock on open farms has been growing steadily since World War II, but there has not been much research into its effects on disease spread—until now. We’ve seen a huge rise in global free-range farming over recent decades, with billions more animals kept outdoors than before. Our study indicates that this trend could be contributing to increased numbers of zoonotic infections being transmitted between wild and farmed species, said senior author Alan Jackson (pictured above), Professor of Comparative Epidemiology at The Pirbright Institute. Our results suggest we should be cautious about expanding free-range farming without better risk assessments taking place first.

Why this matters
Hundreds of people in dozens of countries were infected with a new strain of bird flu from live poultry markets during 2013, and almost 600 million birds were culled by authorities in an attempt to stop its propagate. The fact that all these infections started from contact with live chickens or ducks, rather than meat from supermarkets or restaurants, was surprising. Most avian influenza viruses (known as bird flu) are thought to originate on commercial poultry farms. However, there is some evidence that wild waterfowl can carry strains of H5N1 virus—the type which caused an outbreak in Hong Kong in 1997—and pass it onto domestic poultry. If so, free-range farming could actually be increasing our risk of contracting animal-borne pandemics.

Relevance today
As global demand for animal products grows, so does international trade of livestock and poultry. But with it comes an increased risk of pathogens jumping from farm animals to humans. One possible way of minimizing that risk is by limiting how close animals are kept to people, which is what proponents call free-range farming. However, a new study published in mBio shows that such methods may not be as safe as previously thought. Researchers found that when chickens were raised in low-density settings—which mimic free range conditions—the birds had a higher prevalence of Salmonella than chickens raised in high-density settings. This finding suggests that free-range farming practices may lead to more human infections if adopted globally. If you’re interested in learning more about why free-range farming could lead to more animal-borne pandemics, read on!

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