A recent study published in the journal Environmental Science and Technology concludes that beef produced in feedlots has a smaller carbon footprint than meat raised exclusively on pastures. The study was commissioned by Meat and Livestock Australia, a marketing and research company for the red meat industry. Carbon accounting is becoming industry’s latest green washing tool. They fail to realize that while reducing an overall carbon footprint is important it is not the end all be all solution to a better food supply.
The study examined three operations: a beef producer, a sheepmeat (weird term isn’t it?) producer, and an organic beef producer. Results showed that the carbon footprint of feedlot production was 9.9kg of carbon dioxide equivalent (CO2e) per kilo of “hot standard carcass weight”(HSCW), while that of grass-finished beef was 12kg CO2e per kg/HSCW.
That term grass-finished beef is key here. Feedlot beef is finished on grain-usually corn. Finishing is the practice of fattening cattle for a few months before slaughter. Study co-author Matthias Schulz said grain-finishing “produces meat more efficiently, effectively offsetting the greenhouse impact of the additional transport and feed production needed.” However the real problem with grain-finishing isn’t the carbon footprint, but rather the health issues created by feeding cows grain in the first place, and how those problems become our problems.
A quick biology lesson: Cows are ruminants. This means they have a separate compartment in their stomach to hold the grasses they eat while bacteria converts the cellulose in the grass into protein and fats. Cows are meant to forage for grass, but since fattening them on corn is cheaper and quicker that is the route feedlots take. Switching a cow from grass to grain can have devastating effects. Michael Pollan wrote in the New York Times about what happens when we move cows from pastures to feedlots
Perhaps the most serious thing that can go wrong with a ruminant on corn is feedlot bloat. The rumen is always producing copious amounts of gas, which is normally expelled by belching during rumination. But when the diet contains too much starch and too little roughage, rumination all but stops, and a layer of foamy slime that can trap gas forms in the rumen. The rumen inflates like a balloon, pressing against the animal’s lungs. Unless action is promptly taken to relieve the pressure (usually by forcing a hose down the animal’s esophagus), the cow suffocates. A corn diet can also give a cow acidosis. Unlike that in our own highly acidic stomachs, the normal pH of a rumen is neutral. Corn makes it unnaturally acidic, however, causing a kind of bovine heartburn, which in some cases can kill the animal but usually just makes it sick. Acidotic animals go off their feed, pant and salivate excessively, paw at their bellies and eat dirt. The condition can lead to diarrhea, ulcers, bloat, liver disease and a general weakening of the immune system that leaves the animal vulnerable to everything from pneumonia to feedlot polio. Cows rarely live on feedlot diets for more than six months, which might be about as much as their digestive systems can tolerate.
These feedlot conditions means that cows are constantly given antibiotics, which leads to “superbugs.” Another side effect of grass-finishing is the acidity of a cow’s stomach now more closely resembles our own. This means that E.coli that once couldn’t survive a cow’s stomach can, which of course means our own stomach can’t kill it either.
The fact that beef companies are examining their carbon-footprint is a great thing, but the carbon footprint of a feedlot is only one of myriad concerns. I fear that by relying on one measure and promoting it’s virtues they hope to blind us to the other problems feedlots continue to cause.
Pollan’s arguments that you post here are extremely weak. Do cattle bloat in the feedlot, yes. Do cattle bloat on pasture, yes. In fact, I would suggest that more cattle die from bloat in a pasture than in a feedyard. I dont think there is any hard data to prove this, but I think I have a few more years of experience on the subject than Pollan and my experience tells me he is off base for this arguement. The one thing that I do know is that grain alone does not cause bloat.
Can a corn diet give cattle acidosis, yes. Do very many cattle suffer from acidosis in the feedyard, not very many. This is so because cattle feeders know that if you load a steers digestive system with starch, its not a good thing. They use very specific diet and ration management techniques that all but eliminate acidosis.
“These feedlot conditions means that cows are constantly given antibiotics, which leads to “superbugs.” Another side effect of grass-finishing is the acidity of a cow’s stomach now more closely resembles our own. This means that E.coli that once couldn’t survive a cow’s stomach can, which of course means our own stomach can’t kill it either.”
This statement is flawed as well. Any animal use of antibiotics has never been show to produce “superbugs”. E. coli can survive a cows “stomach” on grass or grain – its not a rumen or stomach pH thing. The STEC E. coli strains that make us sick have some mechanism that allows them to live in cattle (and other ruminants) digestive system. The cattle’s immune system does not recognize them as an issue, nor do the bacteria seem to negatively effect the host animal. We dont understand the whole relationship, but it is not diet related or antibiotic related.
So in closing, yes cattle (and other ruminants) have a unique capability to convert cellulose into protein and energy. However, this dose not exclude them being perfectly capable to utilize a starch based diet for growth as well. I just hope that most people realize that most of the time, people like Pollan have a specific agenda. They use partial truths to make their point. True journalism is to report all the facts and sides to an argument and let the readers decide how they feel on the subject. For some reason journalism now just tells people how to feel without the unbiased reporting.
Thanks for your comments. This is exactly what a site like FFF was built for.
I’ve spent some time reading over the scientific literature. After doing so I think Pollan got things mostly right. Diet and gastric shock survival of E. coli is a controversial topic, but most of the research has concluded that forage-fed animals have lower counts of E. coli. The exact reason aren’t clear yet, but as the research continues I think the ratio of forage cattle diet will increase.
Effect of preslaughter feeding system on weight loss, gut bacteria, and the physico-chemical properties of digesta in cattle | Zealand Journal of Agricultural Research, 43: 3, 351 — 361
This sentence, “These feedlot conditions means that cows are constantly given antibiotics, which leads to “superbugs” is my own, and it’s poorly written. In the interest of conciseness I subverted clarity. The idea behind the sentence is it’s not just the use of antibiotics in animals that have led to antibiotic-resistant bacteria, but the use of those same antibiotics in animals and humans. Nasty bugs that our drugs used to kill are now multi-drug resistant.
I didnt say Pollan was all wrong, he just tells the part of the story that supports his claims and fails to mention the other parts that do not. So in essense he is partially wrong!
The Calloway article (Current Issues in Molecular Biology, 2009) is an excellent review conducted by excelent scientists (ones I know personally).
“The proposal of such a dietary switch to reduce E. coli
O157:H7 shedding provoked a great deal of scientific
controversy (Diez-Gonzalez et al., 1998, Hancock et al.,
2000) and led to several studies that have subsequently
evaluated the effect of radical dietary shifts on E. coli
populations in cattle, however these studies have also
produced conflicting results (Table 1). When cattle were fed
a high-concentrate diet and switched to a diet containing
50% corn silage and 50% alfalfa hay, generic E. coli counts
decreased (Jordan and McEwen, 1998). Cattle fed an 80%
barley ration (which as shown previously tends to increase
EHEC shedding) were fasted for 48 h and then subsequently
switched to 100% alfalfa silage did not exhibit any change in
E. coli O157:H7 shedding (Buchko et al., 2000b). However,
when these same forage-fed animals were again fasted
for 48 h and re-fed 100% alfalfa silage, the prevalence of
E. coli O157:H7 shedding increased significantly (Buchko
et al., 2000b). In a study using experimentally infected
cattle, Researchers found that cattle fed hay shed E. coli
O157:H7 significantly longer than did grain-fed cattle (42
d vs. 4 d), but E. coli O157:H7 populations shed were
similar between dietary regimes and the diet shift did not
affect the acid resistance of E. coli O157:H7 (Hovde et al.,
1999). When cattle were abruptly switched from a finishing
diet that contained wet corn gluten feed to alfalfa hay for
5 d, colonic pH increased almost 1 pH unit, total E. coli
populations decreased approximately 10-fold (Scott et al.,
2000). These authors concluded “increased colonic pH was
not associated with reduced populations of acid resistant E.
coli” but “feeding hay for a short duration can reduce acidresistant
E. coli populations” (Scott et al., 2000).”
This paragraph pretty much lends itself to the fact that we have never been able to consistantly show that forage based diets reduce STEC E. coli. Research in this area will continue,but to go out and tell the public that “we know that grainfed cattle are teaming with E.coli and forage fed are not” is iresponsible. It would be like NASA saying, well this rocket only works everyonce in a while but we are confident it is ready for human space travel.
Now keep in mind that these are studies that changed the diet of the animal rather abrubply and significantly, and as with anybody this does cause “stress” in the digestive system. Stress rarely leads to consistant results, so who know what the real answer is.
I have not read the Clinical Infectous Diseases article entirely, did find the first page online but thats all. Whlie I would love to read it and give you my thoughts, I just do not have the time right now. I am not a vet, nor a solid understanding of what antibiotics are approved for all other livestock species. I do know cattle though and can only speak to the antibiotic use in cattle.
Im borrowing the next stuff from here http://www.explorebeef.org/CMDocs/ExploreBeef/FactSheet_AntibioticUseInCattleProduction.pdf. I know some will say that this has no merit becuase the beef industry funded it, and I say bull. Just becuase it was funded by a particular angency does not mean the science is not good and the results are not valid.
Multiple studies have reviewed whether antibiotic use in cattle production causes an increased risk to consumers by developing antibiotic-resistant foodborne or other pathogens, and none have found a connection
(Journal of Food Protection, July 2004; Journal of Antimicrobial Chemotherapy, 2003).
• The National Antimicrobial Resistance Monitoring System (NARMS) was established in 1996 as a collaborative effort among FDA’s Center for Veterinary Medicine, U.S. Department of Agriculture and the Centers for Disease Control
and Prevention. This program provides an early-warning system for detecting any change in pathogen resistance patterns. http://www.fda.gov/cvm/narms_pg.html
•Guidance 152 is an FDA recommended process implemented in 2003 that adds an additional safety measure to prevent antimicrobial resistance that may result from the use of antimicrobial drugs in animals.
http://www.fda.gov/cvm/Guidance/fguide152.pdf
• The beef industry takes seriously the potential of antimicrobial resistance. As a result, the industry has funded more than 13 comprehensive research projects to enhance the understanding of the basic science of resistance development, as well as collect information on the effects of beef production practices on resistance development in foodborne pathogens.
http://www.beefresearch.org
I think that we have more anitibiotic resistance problems due to abuse on the human side.
Again, those are my thoughts. Like you said, it is nice to have a place to discuss these issues and not feel like you are having to defend your sisters honor.
I think that we have more anitibiotic resistance problems due to abuse on the human side.
Try this for th NARMS site:
http://www.fda.gov/AnimalVeterinary/SafetyHealth/AntimicrobialResistance/NationalAntimicrobialResistanceMonitoringSystem/ucm059089.htm