Aug 19 2010
Runny Egg Logic
Remember when Salmonella was a tomato thing? A Jalapeño problem? A peanut panic? (A Peter Pandemic?) Well, this month it's eggs under the infectious-disease spotlight, and you'd almost think the Humane Society of the United States has completely forgotten about all the vegetarian foods that can carry the bug.
By now we’re all aware of the ongoing recall of about 330 million eggs following a spike in cases of salmonella poisoning. And since every bit of news about animal protein has a corresponding HSUS press release, the animal rights group has already issued a statement from its favorite “Dr. Doom” spokesman.
Michael Greger, HSUS’s vegan public health expert, is calling for egg farmers to go “cage-free” in order to reduce the salmonella risk. Here’s the central claim in HSUS’s press release (emphasis added):
Every scientific study published in recent years shows that confining hens in cages results in significantly increased Salmonella risk, including a 2010 study that found 7 times greater odds of Salmonella Enteriditis contamination in operations caging hens.
“Every scientific study” is a pretty definitive statement. Not “most”studies, or “many,” but “every” study.
Is it true? Heck no. HSUS is ignoring lots of science. Maybe on purpose.
For starters, the 2010 study from the Veterinary Record journal—the only study that HSUS actually cites—doesn’t agree with the group’s unqualified conclusion. The study’s authors write that while there might be a (truly) tiny bit less bacteria present in “cage free” flocks, that's mainly because the flocks are smaller. And there’s actually no way to tell whether that translates into any health risk to people.
More on that study in a moment. But first, let’s look at some other recent research that blows a hole in that "every scientific study" nonsense, and argues against blaming chicken cages for making people sick.
- A 2009 Swedish study found that bacteria levels among hens kept in "floor housing systems" (i.e., "cage-free") were more than three times greater than those found where hens were kept in cages. This is because "bacteria concentration increase[s] with increasing dust concentration," and cage-free hens are exposed to a lot more dust.
- A 2008 study published in Japan’s Journal of Poultry Science compared traditional caged hens with those in larger “enriched” cages and cage-free “aviary” systems. It concluded: “No significant differences could be found in prevalence of Salmonella between laying hens reared in conventional and enriched cages and aviary.”
- A 2008 report published in World’s Poultry Science Journal declared: “Contamination of eggshells with aerobic bacteria is generally higher for nest eggs from non-cage systems compared to nest eggs from furnished cages or eggs from conventional cages.”
- A 2005 study published in the U.S. journal Poultry Science compared salmonella levels in “aviary” (cage-free) and “battery cage” housing systems with various methods of handling manure. It found: “The system with the lowest chance of infection was the cage system with wet manure.”
- A 2004 study conducted by the British government found “no statistically significant difference … between the prevalence of Salmonella contamination in samples from different egg production types.” This study sampled nearly 5,000 dozen eggs from England, Scotland, Wales, and Northern Ireland.
And there are more where these came from. But let’s return to this year’s Veterinary Record study, the one HSUS cites in its press release.
The authors use something called Population Attributable Fractions (PAFs) to measure how much human disease we can trace back to a specific risk factor on the farm. (Risk factors might include how many hens are in a flock, whether or not the animals’ feed is grown on the same farm, and how many field mice are milling about.) Here’s what they say about those PAFs (emphasis added):
PAFs assume a causal link between risk factors and disease. While causality is assumed between these factors and Salmonella in order to interpret the PAFs, it is impossible to verify a causal role through cross-sectional studies such as the present study, and caution is needed when interpreting the PAFs.
In other words, there’s no direct connection between hen cages and sick people.
Here’s how the authors conclude the study. Note how cages aren’t mentioned at all (emphasis added):
Combinations such as improved cleaning and disinfection, vaccination, the use of foot dips and brushes, and improved rodent control could have significant effects on reducing Salmonella levels on farms in Great Britain, and the findings of the present study support previous work emphasising the importance of maintaining good farm biosecurity, hygiene practices and pest control in reducing levels of Salmonella on layer farms.
Earlier in this same study, the authors calculate that if farmers simply conducted better rodent control, vaccinated their flocks, and harvested a whole flock before growing a new one, we might see “a 97 percent reduction” of salmonella in egg-laying hens.
None of this seems to matter to HSUS. The group recently published a “white paper” with its typical, apocalyptic claims about caged chickens. The group even has a scary infographic. And the visuals are based on a single study from Europe, conducted between 2004 and 2005.
And guess what? Yet again, the study itself doesn’t support the spin that HSUS is giving it.
Here’s what the European Food Safety Authority writes (emphasis added):
Cage production was found to be associated with a higher risk of positivity than for the other investigated laying hens production types. However, compared to the other production types, cage production was characterised by larger flock sizes. Organic flocks were on average of the smallest size, whereas the barn and the free-range standard flocks were of low to medium size. Consequently cage production as well as a larger flock size were associated with a higher risk of positivity. But it was not possible to determine which of these two factors was a true risk factor for positivity.
Translation: The more chickens you have, no matter where you keep them, the more likely it is that they’ll pass bacteria around. (Heck, the same is true for pre-school children.)
Why couldn’t HSUS and Michael Greger just have written that? At least it would have the virtue of being true. And while they're at it, some perspective is in order—or at least two common-sense reminders. (You may remember these from our discussion of the U.S. Constitution's "Commerce Clause" as it applies to California's "Proposition 2" egg law.)
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USDA scientists have found that only about 1 in every 20,000 eggs might be contaminated with Salmonella. At current consumption rates, the average American might encounter one of those eggs every 84 years.
- Even if an egg is contaminated with Salmonella, the only way it can translate into a human illness is if the egg isn’t refrigerated or cooked properly.
Feel scrambled yet? Us too.
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Posted on 08/19/2010 at 01:00 PM by the HumaneWatch Team
The Best of HumaneWatch • Animal Agriculture • Eggs • (20) CommentsComments
Leigh, that’s an emotional argument that you’re making. This post just showed you a half-dozen studies indicating that you’re wrong, but you’re still convinced you’re right. Why is that? You might have personal reasons to object to chicken cages, but salmonella infection shouldn’t be one of them. Get with the program.
I don’t eat eggs very often, but when I do I don’t want an egg with a bright orange-red yolk from free range chickens. They taste too strong.
Featherhead,
So if a study is scientific then it’s truth…I assume you buy into global warming. Absolutely volumes of studies validating human induced global warming. Scientific studies change and are debatable on every level and articles that I cannot post are accessible on Google Scholar. Nothing in science is concrete. I appreciate your nasty disrespect for my interjecting that maybe, just maybe we should respect creation and the off chance that in doing so we generate a superior product.
“All test studies that I can find do indeed confirm that Cage free chickens do indeed decrease chances of dangerous levels of salmonella due to the stress the animal is under.”
Leigh,
I also think it would be better for chickens to be raised in more open environments, a solid argument about Salmonella risks would be very helpful. I am very interested in seeing these test studies, could you please link to them.
I copied this from the online Yahoo article about the egg contamination.
So how can consumers tell if an egg contains salmonella? There is no way for grocery shoppers to tell if an egg has been contaminated, according to Rob Gravani, a professor of food science at the Cornell University. In fact, Salmonella affect chicken of every quality, and there is no valid scientific evidence that shows that poultry products labeled “Kosher,” “free-range,” “organic,” or “natural” have more or less of the bacteria, according to FSIS.
So where does the HSUS get their “facts”? Off the back of a cracker jack box would be my guess.
Leigh—There’s an old saying in academia (I’m an ag extension professor) that goes like this: “For every Ph.D, there’s an equal and opposite Ph.D.”
On the surface, you’re right. Studies change and evolve. And knee-jerk scientific consensuses can be dead wrong, just like emotional responses from individuals can be dead wrong.
This thread started with your knee-jerk reaction to the salmonella scare. It’s you who didn’t seem willing to imagine that your preconceptions might be wrong.
Bottom line is that for every study you show me that says cage-free hens are less susceptible to salmonella, I can show you one where they weren’t. In the face of such a stalemate, are we supposed to uproot a billion-dollar section of agriculture? No, I don’t think so. Even though it might feed your emotional need to be right.
Emotional or not - the public is starting to demand change. I wonder if Ag doesn’t need to learn a little lesson from the newspaper, music and movie industries and start preparing itself for that change rather than shoving it’s fingers in its ears yelling “lalalalalala, no no no no, I can’t hear you.”
Those producers who are willing to meet the needs/whims/desires of their customers are those who will succeed - so really, the argument of whether the customer is making reasoned, logical decisions is moot.
Personally, I’m on Dr. Grandin’s side - we have a responsibility to our animals - and that’s at the VERY LEAST. I am a reasoned and logical consumer, I have two degrees in agronomy, some of my best friends are animal producers and I am demanding change.
Featherhead - so appropriately name - Salmonella or no, cruelty in the name of dollars is wrong, even if it is “standard industry practice”, You are what you eat.
This seems to be a biosecurity problem. Could rodents and two legged RATS be responsible for the contamination or even sabotage? The timing of this out-break and the cage-free eggs issue seems a little coincidental. Maybe HOMELAND SECURITY should check this out. Just wondering.
@Theresa and @W Bruce—Who gets to decide what constitutes cruelty? There are many “standard industry practices” that I’m just fine with, and so are most consumers—because most consumers vote with their wallets. If you want to buy the $5 dozen of eggs, be my guest. But let me have the $1.89 dozen, thank you very much. As long as both options are available, and the retail prices reflect the farmers’ actual cost to produce them, why argue? (Can’t we just agree to disagree?)
Let’s backtrack a moment. HSUS ADMITS TO SENDING UNDERCOVER PEOPLE TO BOTH OF THESE FARMS. It is obvious, with false pretense, the undercovers were there to do no good.. Willful sloppy work and hygiene practices (no boot dips or brushes, dirty uniforms, and the tracking-in of off premise bacteria) would put this type of operation out of business in short time.
I’ll bet there were signs posted, “No Visitors Allowed” and signs instructing employees as to standard procedures. All to prevent such happenings. After the undercovers left, the problems developed.
Other firms have taken undercovers and their source sponsors to court and won. The undercovers lied and applied for their jobs under false pretense. That should be easy to prove. The “good name” of these farms is at stake. They should take proper action.
Farmers don’t “produce” a million or so eggs a day. I get my eggs from a farmer family- they sometimes run out of eggs. Yes, salmonilla is everywhere. I’ll take my local 3.50 dozen unstressed eggs & let others have their cheep recall bombs.
I like the interesting turn this discussion has taken. Theresa raised the issue of consumerism saying “Those producers who are willing to meet the needs/whims/desires of their customers are those who will succeed.”
I am in favor of consumerism because it is about choice. I am opposed to the HSUS because it is anti-choice and pro-criminalization. The HSUS uses legislation and litigation to destroy choice in the name of their greater good. If they trusted the consumer to do the right thing, they would just educate to influence choices rather than legislate and litigate to eliminate them.
I think modern factory farming processes have big problems, but I don’t think the animals are being badly treated.
They are, however, being badly fed.
We’re used to the bland-tasting meat and animal products produced from these operations, but it comes as no surprise to learn that they’re extremely unhealthy for us to eat.
The level of Omega 6 in feed lot cattle as opposed to grass-fed is jaw-dropping. Eggs suffer from the same problem.
The quality of animal feeds really needs to be thought out better to improve human health. Chickens, like all livestock, should be given varied, ample fresh foods, not fed on a diet of nothing but grain and processed remnants. A bit of periodic access to natural sunlight would be in order as well.
The salmonella threat is really secondary to the larger issue…poor nutrition for these animals works out to poor nutrition for us. It’s fairly obvious that bad bugs like salmonella will thrive in animals with depressed immune systems, and animals that have gut bacteria that are out of balance (fed on improper diets).
Cages have nothing to do with it.
We currently have an internal “salmonella” strain which as Donna points out, may be due to poor nutrition and/or other stress factors. This is dangerous because the chickens are transmitting the bacteria directly into the eggs.
But one must remember, that “free-range” eggs, by their very nature, are externally exposed to other strains of salmonella, as they lay in waste for more extended period of time, due to the fact they are laid in a stationary nest.
So, neither process guarantees “safe” eggs.
In a caged system the waste drops though the bottom of the cage onto a conveyor and is hauled away from the chickens. The same applies to their freshly laid eggs…they drop onto a conveyor and are carried away as soon as they are laid. Cleanliness of the egg and environment itself is more sanitary, but more crowded. Free-range is less crowded, but less sanitary. Eggs will most likely only be collected a few times, if that many, per day…mostly likely laying in waste. (Chickens are horrendously dirty creatures…) In addition, the term “pecking order” comes from chickens. They are not social beings. Depending on breed or variety, size and age, they have varying temperaments, and large older hens, will peck smaller, younger hens, of the same variety…or bigger birds will simply pick on smaller birds. So, caging allows similar sized, similar aged birds to be put together to lessen that particular stress.
There is NO “one-size-fits-all” solution. Each and every method has it’s own unique risks and benefits. Weighing the humane treatment of the animals in our food supply, while supplying a safe, yet affordable food product, is not an easy task. Nor is it one that will ever be completely safe, nor perhaps, completely humane. The challenge is in adequately balancing the two for the benefit of both with the least risk.
“All test studies that I can find do indeed confirm that Cage free chickens do indeed decrease chances of dangerous levels of salmonella due to the stress the animal is under.”
Which leads me to believe that the results of scientific study are important to Leigh.
Then when studies were cited:
“So if a study is scientific then it’s truth…I assume you buy into global warming. Absolutely volumes of studies validating human induced global warming. Scientific studies change and are debatable on every level and articles that I cannot post are accessible on Google Scholar.”
So…studies are only factual and relevant if they support Leigh’s beliefs.
I think one thing that is being ignored with this story is that proper handling and cooking of the eggs will greatly reduce the incidence of becoming sick even if you eat an infected egg. If cooked properly you are going to kill the bacteria in the cooking process. I was raised on a commercial family hog farm. Growing up we raised a lot of food we ate and proper food preparation and cooking procedures was drummed into our heads from the time I was little. The reason being is a majority of food borne illness comes from improper handling of raw foods during prep and/or improper cooking.
As far as claims that the Ag Industry is burying their heads and doesn’t ant to change is wrong. We aren’t opposed to change, we are opposed to being forced into making changes based only on emotions. This is how we make our living. Food production is how we put roof over our heads, food on the table and clothes on our backs for ourselves and our families. So before we make changes we have to consider many different factors. Plus we want our options to have scientific research that we can evaluate. All of which takes time. The Ag industry like any other industries is constantly evolving and changing. We are being charged to feed more people, with less resources, and keep prices low. Not an easy task.
I live fairly near buildings owned by these companies, and my cousin lives half a mile from a ten-building site owned by them. My cousin keeps livestock, and was told by the company that she can’t let her animals drink from their usual water source, a stream through her pasture, because it will be contaminated! This is the stream kids wade barefoot in during summer and slide on the ice on in winter. This is the stream that waters the animals that are their livelihood.
There is something wrong when companies can do this. I also live on a working farm, and I know that this company is just trying to make money to survive, as are all of us in the often unappreciated profession of farming, where we have to buy at retail and sell at wholesale while simply trying to feed our families and our world.
This situation shows how already complicated and difficult farming is; we do NOT need HSUS stirring up more trouble for us!
So where does the HSUS get their “facts”? Off the back of a cracker jack box would be my guess.
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All test studies that I can find do indeed confirm that Cage free chickens do indeed decrease chances of dangerous levels of salmonella due to the stress the animal is under. Temple Grandin spends time discussing when fear begins and it is when the animal is unable to do it’s business in what it perceives as safe. (i.e. In a dark nest box instead of in the open like a wire cage). However, cage free does not mean out scratching around in the pasture which indeed does make the best eggs according to many chefs. These eggs are products of hens consuming chlorophyll which produces an egg where the yokes are darker in color and hold their form. I have huge concerns about industrial agriculture and that is coming from someone who grows their own food including lamb, roaster birds, turkeys, beef and a percentage of the vegetables we consume each year. Therefore I am not an animal rights activist yet feel a huge obligation to be a good steward and that means respecting the animal and it’s needs. The cage birds egg system is wrong from start to finish.