For Animals, Grass Each Day Keeps Doctors Away

Two ranchers lock horns with another Atlantic writer and argue that animals that roam are healthier than others


Nicolette Hahn Niman

Last year, James McWilliams made the inflammatory argument in the New York Times that keeping livestock outdoors can be unsafe for animals and humans, a thesis he now reprises here . Raising animals on pasture is our particular expertise, so we jumped at The Atlantic 's invitation to respond. Regrettably for McWilliams, but fortunately for farm animals, farmers, and consumers, the overwhelming body of scientific evidence confirms what common sense already tells us: animals are happier and healthier when raised with sunshine, fresh air, and grass, and given the opportunity to exercise. Not surprisingly, animals raised on pasture also produce healthier and safer (not to mention tastier) food.

McWilliams asks, "To what extent are animals raised under free-range conditions prone to contracting diseases that can affect humans?" This is indeed an intriguing question. But his articles fail to address it fully, focusing primarily instead on just two narrow issues: Trichinosis in pigs and Salmonella in poultry, both of which, he implies, are more prevalent in outdoor systems.

We'll address Trichinosis and Salmonella momentarily. First, it's important to definitively dispel the suggestion that animals' health (and therefore food safety) is at risk when they spend time outside, a myth deliberated fostered by the animal confinement industry. In fact, the reverse is true: although free-range animals might occasionally be susceptible to a handful of diseases under rare circumstances, overall they have fewer diseases and fewer injuries, and their illnesses are less virulent than those of animals raised in confinement. We know this from both our years of practical experience raising livestock ourselves and working with hundreds of other farms, and from many years of research into the scientific literature. Here's some of what we've learned.

History of animal confinement industry closely tied with drug use

We start by examining history. Nicolette's book, Righteous Porkchop , traces the animal confinement industry's origins and rise. The shift from outdoor farming to buildings began in the 1920s, with chickens. When poultry farmers first started raising larger flocks in confinement, typical rates of death loss quadrupled, jumping from 5 to 20 percent. "With commercialization and greater intensification have come [new] disease problems ... The chances of disease spread are materially enhanced," two professors of poultry husbandry wrote in the 1930s.

Because crowded, enclosed groups of animals are ideal breeding grounds for diseases, high rates of morbidity and mortality remained the norm in confined poultry flocks until around 1950, when farmers began adding the antibiotic Ren-O-Sal to chickens' daily feed. This and other drugs became the enablers of total confinement production, essentially making it possible to raise animals in otherwise unlivable conditions.

Over the following decades, it became standard practice to add antibiotics (and other drugs) to the daily feed of pigs and cattle, as well as poultry. For example, an estimated 97 percent of hog finishing operations continually feed the animals antibiotics. Today, in response to Congress's efforts to regulate the practice, the livestock and poultry industry itself declares that these drugs are imperative for preventing illness and death for animals living in intensive confinement.

Serious public health threats stem from confinement industry methods

The meat industry's heavy reliance on a system that requires these pharmaceuticals has a tremendous public health cost. The Union of Concerned Scientists estimates that every year 70 percent of antibiotics used in the United States are added to the feed or water of animals living in industrial operations. Farmers and farm workers are at particular risk, but anyone can come in contact with antibiotic-resistant pathogens through the soil, air, or water coming off farming operations, as well as in meat and eggs bought at grocery stores.

Research by Johns Hopkins University School of Public Health and others has connected the livestock and poultry industry's drug overuse with the rise of antibiotic-resistant diseases , such as methicillin-resistant Staphylococcus aureus (MRSA), which the Infectious Disease Society of America estimates are killing some 63,000 people annually. A few decades ago, staph infections were readily curable with antibiotics, but no longer. In 2005, MRSA alone resulted in 18,000 deaths in this country, more than HIV-AIDS, and in a University of Iowa study researchers demonstrated that 49 percent of pigs and 45 percent of farmers at confinement operations in Illinois and Iowa tested positive for it. McWilliams and agribusiness critics of free-range pig operations should take note: when the researchers examined pigs and farmers at pasture-based pig farms they found no MRSA. None .

On top of antibiotic resistant infections, other dangers for workers and animals permeate confinement operations. Particularly hazardous is the air: Canadian research in 2004 showed that airborne pathogens in confinement buildings can be 1000 times more numerous than in outdoor air, and research by the University of Iowa's Dr. Kelly Donham shows that some 30 percent of confinement animal industry workers have chronic respiratory problems. And antibiotic-resistant diseases are just one of the many types of dangerous infections arising from confinement operations. Dr. Ellen Silbergeld, professor at Johns Hopkins School of Public Health, says of industrial animal operations, "For many years, there's been a great deal of concern about their potential contribution to the evolution and spread of newly emerging diseases."

Dairy cows, pigs, and laying hens much healthier on pasture

Scores of studies document dairy cows' chronic discomfort and health problems from a life on concrete. Bovines in the wild spend most of their waking hours in an ambulant state of grazing, walking an average of 2.5 miles a day, all the while taking 50 to 80 bites of forage per minute.

But life in confinement allows virtually no exercise and zero grazing. Standing on cement for hours of every day "is murder on cows' legs," animal welfare expert Marlene Halverson says. For every 100 U.S. dairy cows, for instance, there are 35 to 56 cases of lameness. Conversely, welfare and health markedly improve when animals exercise outdoors. A 2007 study in the Journal of Dairy Science found that pasture cured cow lameness, and a 2006 study in Preventative Veterinary Medicine found it curative of joint swelling and open sores.

Similarly, pigs in nature are curious and active, typically ranging several miles per day and rooting and grazing for most of their waking hours, but according to the non-profit organization Compassion in World Farming , "the shift away from traditional pig farming to large-scale intensive methods has resulted in significant concerns for the welfare of millions of pigs throughout the world." In confinement settings their movement is restricted to a few feet or, for breeding sows, no movement at all because they are caged in narrow metal crates.

Severely confined sows suffer from health problems including urinary tract infections; muscle weakness; inflamed joints; chronic painful skin lesions on their udders, backs, hips, and shoulders; and high rates of lameness, according several studies. Numerous university studies show widespread incidence of stereotypies (stress-related repetitive behaviors) among crated sows.

Chickens, too, fare better—in both welfare and health—when they have access to pasture. Caged hens have extremely weak and brittle bones due to their physical inactivity, leading to frequent bone fractures, according to a 2004 paper in the Poultry Science Symposium Series. To minimize the risk of bone fractures, the European Union Animal Health and Welfare Panel has recommended that "all systems for housing hens ... provide sufficient space for walking, wing flapping, and other activities," which is provided at free-range farms.



Trichinosis not a threat

In spite of this host of well documented health problems for both animals and people, McWilliams asserts that American consumers should worry about trichinosis in free-range pig farming, a disease caused by the parasitic worm Trichinella spiralis . Frankly, this is absurd. Here again history is helpful.

Decades ago, when many U.S. pigs literally lived in trash dumps, Americans were rightly concerned about trichinosis. As the 1953 Farmer Veterinarian's Handbook stated: "Pigs are infected by eating garbage" containing raw flesh contaminated with Trichinella worms. In 1950, 10 percent of U.S. hogs were fed garbage, making trichinosis a real threat. This practice has ceased, and, consequently, trichinosis has almost vanished. Center for Disease Control and Prevention records show that from 1997 to 2001 there were an average of just 12 U.S. cases per year— from all sources (including from eating wild animals, which is now the most common source).

As additional evidence—anecdotal but powerful—we also note that Bill oversaw the production of some 80 million pounds of pork from free roaming pigs in the 10 years he ran the natural meat company Niman Ranch. Not a single case of trichinosis ever surfaced.

Salmonella far more prevalent in caged hens

McWilliams also implies that Salmonella in laying hens is a greater problem with free-range farming than with caged hens. This is just wrong. McWilliams goes on to discuss other poultry diseases, implying that outdoor access leads to unsafe food, which is also untrue.

First off, one of his main sources for the claim is a report by the Humane Society of the United States (HSUS). But HSUS doesn't agree with him. In fact, Dr. Sara Shields, animal welfare expert and co-author of the very HSUS report he cites, told us that McWilliams was misusing the report, taking the statement out of context. "Curiously, Dr. McWilliams's excerpt stopped just before reaching a sentence that actually espoused the benefits of free-range production," she told us. The report's next sentence states: "... other disease risks are minimized by factors associated with the outdoor, free-range environment: Natural sunlight kills many pathogens and virus particles, and the lower stocking densities and access to fresh air typical of free-range flocks lower infection and transmission rates."

Moreover, other HSUS reports expand on the serious public health risks associated with confinement agriculture as compared to free-range production. According to Dr. Shields, "new research shows that the risk of Salmonella is much greater in conventional battery cage production—where hens cannot even flap their wings—compared to alternative systems that offer hens more room to move." A recent paper to which HSUS contributed describes a 2007 European Food Safety Authority report:

" EU-wide Salmonella survey was launched in which more than 30,000 samples were taken from more than 5,000 operations across two dozen countries. This represents the best available data set comparing Salmonella infection risk between different laying hen housing systems. Without exception, for every Salmonella serotype grouping reported and for every type of production system examined, there was significantly higher Salmonella risk in operations confining hens in cages."

The paper goes on to explain that compared to battery cage egg production, the odds of Salmonella enteritidis contamination were 98 percent lower in free-range systems; for Salmonella typhimurium —the most common U.S. source of Salmonella poisoning—the odds were 93 percent lower in organic and free-range systems; and for the other Salmonella serotypes found, the odds were 99 percent lower in free-range birds. Not surprisingly, the European Food Safety Authority report concluded that "Cage flock holdings are more likely to be contaminated with Salmonella ."

Numerous other studies have reached similar conclusions, according to Dr. Shields. "The scientific evidence is overwhelming," she told us, "that operations confining hens in cages are at the highest risk for Salmonella contamination."

More nutritious food

McWilliams never mentions nutrition, but for most consumers, it's an important consideration in their food choices. Serious research, summarized in the Union of Concerned Scientists's 2006 publication " Greener Pastures ," has shown that food from pasture-raised animals is more nutritious. "Greener Pastures" reported that grazing dairies produce food that is higher in both the beneficial fatty acids ALA and CLA, an effect that was particularly pronounced in cheese from pasture-raised animals.

Likewise, a 2003 Penn State study found a dramatic difference in the nutritional qualities of eggs from pasture-raised hens: "On average, we saw about twice as much vitamin E and 40 percent more vitamin A in the yolks of pasture-fed birds than in the caged birds," the lead researcher reported. "The longer the animals were on pasture, the more vitamins they produced."

Bottom line: pasture farming kicks the butt of confinement production

James McWilliams seems to delight in throwing wrenches at the sustainable food movement. But this time he's come up with nothing more than a red herring. Claiming that consumers need to especially worry about the safety of food from pasture-raised animals is patently ridiculous.

Of course, we encourage everyone to learn about where their food comes from and do their best to ensure that it comes from a safe source. But there's no reason to fret that a pasture-based farm is less safe than a conventional operation, and every reason to believe just the opposite.

All credible sources—scientific research, practical farming experience, and common sense—tell us that farm animals are healthiest when provided the opportunity to thrive in environments where they can breathe fresh air, graze, exercise, and soak up the sun. Our parents told us as children to "go outside and run around a while" because they knew that activity and fresh air would keep us in good health. And so it is with animals raised for food. The healthiest, safest, and most nutritious food comes from farms that follow that sage wisdom of our parents.