Organics

[MissAmy]

I did a search for this topic but didn't find it. If I'm repeating something, please feel free to move or delete this post.

I was talking today with a friend who is contemplating going all organic in her diet when it comes to fruits and vegetables. We were discussing the merits, or lack thereof, of making such a switch.

So, I thought I would ask the opinions of the eGullet universe. Do you think it is worth it to buy all organic produce? Is it really that much more healthy in the long run or just a current fad that will fade away? Do you try to incorporate organics when you can, or do you just not care?

Please tell me, I'd love to hear what you all think.

[russ parsons]

have your friend order a copy of "agrarian dreams" by julie guthman. i think that a lot of the time when people talk about "organic" what they're really thinking about is small, family-owned farms that take care with their fruits and vegetables. this is true of some organic growers, but it is also true of some conventional growers (and there is a big gray area between organic farming and wanton use of chemicals). for what it's worth, in 10 years of testing fruits and vegetables, the epa has found chemical residues that exceed the regulated standard in less than 1% fo samples.

[annanstee]

There are other issues though- other than the chemicals one ingests from non organic fruits and vegetables.

I do prefer them, and probably 50-60% of the food I buy is organic- most of the fruits and vegetables- yoghurt, eggs, and butter, meat and chicken when I can.

Why?

You are right- part of the reason is that alot of the organic stuff is raised by smaller producers who seem to care more about what they are doing.

They also often produce a more interesting variety, not the same old species all of the time.

The real issues for me are health, sustainability, and GMO's. I just don't feel comfortable having Monsanto own the patent on my food.

[Patrick S]

I value freshness, taste and other "sensory" qualities of food, and my limited experience with organic produce has not convinced me that it is superior in these respects. I do not worry at all about the nanograms of synthetic pesticide residues on normal produce, don't see them as a significant health risk, and therefore will not pay the much higher price for produce that doesn't contain them.

[shrek]

We have organic vegetables delivered every week, and while we do eat other non-organic fruits and vegetables I have to say that the organic food is better. I think the main reason for that is that with the organic, locally grown produce we are eating food that is in season, and some measure of care is taken in growing it.

I like the fact that I know the guy who is growing my vegetables, and I love the variety and different types of vegetables that I receive each week. That they are also organic is a bonus, but not the only reason I buy them. Throughout the winter we have been feasting on white and orange sweet potatoes, purple fingerlings, golden and candycane beets, red, yellow and white carrots, and scrumptious microgreens. They taste fantastic and they look appetizing.

[bavila]

We have organic vegetables delivered every week.

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This gets to the point of is it good because it's organic or is it good because it's local and therefore fresher? I lean toward the local/fresher argument.

The only taste difference I've noticed in a grocery store purchased certified organic item and conventional is in dairy products. Local beats non-local for taste everytime for any product.

You should consider WHY you care about something being "organic" or not.

There's a Consumer Reports piece from the last year or so about whether you're getting your money's worth when buying organic. They measured pesticide residues on various organic and conventional produce. The organic benefit from that perspective was negligible on broccoli and asparagus (I think), but better for apples and peaches.

[annanstee]

We have organic vegetables delivered every week.

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This gets to the point of is it good because it's organic or is it good because it's local and therefore fresher? I lean toward the local/fresher argument.

The only taste difference I've noticed in a grocery store purchased certified organic item and conventional is in dairy products. Local beats non-local for taste everytime for any product.

You should consider WHY you care about something being "organic" or not.

There's a Consumer Reports piece from the last year or so about whether you're getting your money's worth when buying organic. They measured pesticide residues on various organic and conventional produce. The organic benefit from that perspective was negligible on broccoli and asparagus (I think), but better for apples and peaches.

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I guess I am lucky, because in my area organic produce and dairy are not very expensive compared to the standard- meat is, however.

As far as meat goes, there is absolutely no comparison between a battery chicken and a free range bird. If that bird is organic, so much the better.

It is true that the taste is likely better because the produce is in season and because it has often travelled a much shorter distance. One result of the latter is that producers can let the fruit actually ripen on the tree.

The point to me is that the organic producer is more interested in the "sensory" qualities than a standard producer more interested in "travels well".

And whither GMO's? There is simply not enough evidence out there to tell me whether it is safe to graft - say blowfly- genes onto corn.

Edited for punctuation

Edited April 4, 2006 by annanstee (log)

[ludja]

. . .

There's a Consumer Reports piece from the last year or so about whether you're getting your money's worth when buying organic.  They measured pesticide residues on various organic and conventional produce.  The organic benefit from that perspective was negligible on broccoli and asparagus (I think), but better for apples and peaches.

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I've seen similar articles that rate the relative amounts of pesticides on different types of fruit and vegetable produce. Some produce is easier to clean as well or is eaten without the skin. I thought I had saved an article with a good list but can't seem to find it now.

[russ parsons]

part of the reason is that alot of the organic stuff is raised by smaller producers who seem to care more about what they are doing. They also often produce a more interesting variety, not the same old species all of the time. The real issues for me are health, sustainability, and GMO's.  I just don't feel comfortable having Monsanto own the patent on my food.

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hmmm, don't mean to be argumentative, but this is kind of a perfect example of what i was talking about. your intentions are certainly in the right place. and i'm all for supporting small farmers, but that doesn't mean organic. earthbound farms runs about 45,000 acres of lettuce. interesting varieties? that's a small farmer attribute, not an organic one. gmos? about the only food crop in the us with a significant gmo percentage is soybeans (watch out tofu eaters!). the gmo corn you hear so much about is field corn, not sweet corn.

[annanstee]

part of the reason is that alot of the organic stuff is raised by smaller producers who seem to care more about what they are doing. They also often produce a more interesting variety, not the same old species all of the time. The real issues for me are health, sustainability, and GMO's.  I just don't feel comfortable having Monsanto own the patent on my food.

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hmmm, don't mean to be argumentative, but this is kind of a perfect example of what i was talking about. your intentions are certainly in the right place. and i'm all for supporting small farmers, but that doesn't mean organic. earthbound farms runs about 45,000 acres of lettuce. interesting varieties? that's a small farmer attribute, not an organic one. gmos? about the only food crop in the us with a significant gmo percentage is soybeans (watch out tofu eaters!). the gmo corn you hear so much about is field corn, not sweet corn.

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Don't forget about Rapeseed (Canola).

And you are right- there are two real arguments here.

Lets just say that I prefer local, sustainable, seasonal, organic food for ethical, environmental, and health reasons.

I will buy local and organic first,

local, small producer, sustainable second

non local organic 3rd,

standard agro-factory stuff last.

Edited April 4, 2006 by annanstee (log)

[Patrick S]

And whither GMO's?  There is simply not enough evidence out there to tell me whether it is safe to graft - say blowfly- genes onto corn.

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Well, no one to my knowledge has yet created a transgenic corn cultivar with blowfly genes, so that evidence couldn't possibly exist. For those transgenic cultivars that do actually exist -- like Bt corn-- there is an enormous amount of literature.

[russ parsons]

well, maybe i am being argumentative. but this is something i feel strongly about. i have covered agriculture for 20 years and i know a bit about it. "organic" has become a shorthand phrase for a lot of very good practices that don't necessarily include organic. furthermore, it is reductive, breaking a very complex mix into organic (good) and nonorganic (filthy chemical users). this is just not real world. there are some farmers who overuse chemicals, but there are a lot more who use them responsibly. there is a significant gray area between pure and impure. there are many conventional farmers who use many of the techniques we might think of as organic--cover crops, beneficial insects, etc. but they do spray when they need to.

look, we've got a much more serious problem in this country with the overprescription of antibiotics and the resulting immune super-bugs, but that doesn't mean we're all going to become christian scientists over it.

[NYC Mike]

I value freshness, taste and other "sensory" qualities of food, and my limited experience with organic produce has not convinced me that it is superior in these respects. I do not worry at all about the nanograms of synthetic pesticide residues on normal produce, don't see them as a significant health risk, and therefore will not pay the much higher price for produce that doesn't contain them.

I'm with Patrick on this one. In Manhattan where I live it would at least double my currect family of 5 grocery budget to buy organic. Not only is it not worth it (IMO) its not prudent or fiscally responsible.

-Mike

[Patrick S]

Regarding the hypothesis that organic produce is superior in terms of sensory qualities and/or overall subjective preference, the existing literature is at best inconsistent, and doesn't permit many generalizations. Bourn and Prescott (2002) review the available studies in the journal Critical Reviews in Food Science and Nutrition. There are a couple of types of studies that have been done. One type of study is a discrimination study, in which subjects are given organic and nonorganic samples of produce and asked to differentiate which is which. Another type os study has subjects rate the samples on a variety of dimensions -- flavor, juiciness, color, etc. A third type simply ask subjects "Which do you like better?" A crucial component of all these studies is that they are blind -- the subjects don't know in advance which is which, and so can not be influenced by unconscious biases or expectations. The bottom line(s) in their review are that the research is limited, but what exists is inconsistent and doesn't support the view that organic produces is superior in any general in terms of sensory qualities or subjective liking.

One interesting thing they discuss is studies showing that if you tell someone that something is organic, they actually rate their subjective preference for the organic more highly.

Given a general failure to report consistent ability to discriminate the sensory properties of organic and conventional produce, it is not very surprising that studies of preference also fail to show a consistent pattern of results. Why then does there seem to be a conviction, presumably primarily among regular consumers, that organic produce is better tasting? Two of the sensory studies reviewed may give insight into this. It has been demonstrated that labeling associated with a food can create expectations regarding its sensory properties, and ultimately its acceptability.177,178 Both Schutz and Lorenz170 and Johansson et al.176 examined the impact of information about growing method on consumer preferences for organic and conventional vegetables. In both studies, this information influenced acceptability, in that relative to these same foods unlabeled, products labeled as organic generally showed increases in measures of preference. Thus, both studies suggest that consumers have expectations regarding the superior taste of organic produce. It may be that this derives either from a rationalization of the higher cost of organic produce or a belief that chemical fertilizers are more likely to impart unacceptable sensory qualities. Important also in the effects of labels on food acceptability is the fact that consumers can bring their actual perceptions and preferences into line with such expectations.177 Hence, such beliefs may be reinforced by repeated consumption of organic produce.

Bourn and Prescott, 2002. A Comparison of the Nutritional Value, Sensory Qualities, and Food Safety of Organically and Conventionally Produced Foods. Critical Reviews in Food Science and Nutrition, 42(1):1–34.

Edited April 4, 2006 by Patrick S (log)

[bavila]

"organic" has become a shorthand phrase for a lot of very good practices that don't necessarily include organic. furthermore, it is reductive, breaking a very complex mix into organic (good) and nonorganic (filthy chemical users). this is just not real world. there are some farmers who overuse chemicals, but there are a lot more who use them responsibly. there is a significant gray area between pure and impure.

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Amen.

Some things are really difficult to grow without any pesticides. Like the aforementioned peaches and apples.

I also am not so worried about the GMO thing. Plants do really whacky things on their own genetically, and we've messed with genotypes through selective pollination for millenia. Maybe it can cause harm, and maybe it can't. Just because it came from a lab doesn't mean it's bad.

[TPO]

the gmo corn you hear so much about is field corn, not sweet corn.

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From what I have read, field corn is what corn syrup is made of. So all of our sodas and such made with high fructose corn syrup are made with gmo corn. I would love to be wrong, though.

When it comes to shopping, I try to buy local fruit and vegetables both for flavor and environmental impact (in other words, they haven't been shipped across the country in a semi). If I can't get local produce, I'll choose between regular and organic based on price and quality. For meat I prefer free-range but sometimes I get frugal and buy regular meat. Eggs and milk are always organic in my house though, that's one thing I won't go without.

[annanstee]

And whither GMO's?  There is simply not enough evidence out there to tell me whether it is safe to graft - say blowfly- genes onto corn.

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Well, no one to my knowledge has yet created a transgenic corn cultivar with blowfly genes, so that evidence couldn't possibly exist. For those transgenic cultivars that do actually exist -- like Bt corn-- there is an enormous amount of literature.

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You're right- and that was meant to be kind of a joke.

To me there is a distinction between transgenesis between widely variant species and cross breeding.

look, we've got a much more serious problem in this country with the overprescription of antibiotics and the resulting immune super-bugs, but that doesn't mean we're all going to become christian scientists over it.

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But aren't antibiotic resistant crops implicated in the problem of Superbugs?

Edited April 4, 2006 by annanstee (log)

[Zucchini Mama]

This site has information on organic/ local/ fair trade issues: daily granola

Organic food is better for the consumer, the soil, the ground water, air, and the health of wild and domestic animals. However, you must figure in the fossil fuels used to transport organic foods from a long distance into the equation. Organic standards have their own set of controversial issues, which will differ in the U.S. and Canada.

I eat as much local organic food as possible, because I believe in protecting the planet for future generations, and because I believe that organic food is more nutritional and flavorful, therefore can be better value for the money. The issue of the human treatment of animals is an issue I won't get into here, but it factors in as well.

David Suzuki is a brilliant Canadian scientist who has many intelligent things to say against GM food. I will dig out some references. Aside from the science, I don't want these huge corportations patenting the food chain to make themselves rich, while they deplete our environment and endanger our food security.

Talk to the twenty-something generation: many of whom are very aware of these issues. Thank God.

[Zucchini Mama]

Here is the first in a series of articles on GM Foods from the David Suzuki Foundation web site.

[Shalmanese]

the gmo corn you hear so much about is field corn, not sweet corn.

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From what I have read, field corn is what corn syrup is made of. So all of our sodas and such made with high fructose corn syrup are made with gmo corn. I would love to be wrong, though.

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So? Corn syrup is so highly refined that it's chemically equivilant no matter where it comes from. There is no concievable way for your body to distinguish GM and non GM corn syrup.

[srhcb]

I buy high quality.

Reasonable price is a consideration.

If it's organic, that's a bonus.

SB (is what he eats)

[tejon]

Lets just say that I prefer local, sustainable, seasonal, organic food for ethical, environmental, and health reasons.

I will buy local and organic first,

local, small producer, sustainable second

non local organic 3rd,

standard agro-factory stuff last.

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I'll put myself here as well. Hoping to add my own garden to the top of this list in the very near future, too.

[TPO]

the gmo corn you hear so much about is field corn, not sweet corn.

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From what I have read, field corn is what corn syrup is made of. So all of our sodas and such made with high fructose corn syrup are made with gmo corn. I would love to be wrong, though.

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So? Corn syrup is so highly refined that it's chemically equivilant no matter where it comes from. There is no concievable way for your body to distinguish GM and non GM corn syrup.

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Is this why the FDA does not require safety testing on GM foods? Or is it just corn syrup that is chemically equivalent?

I'm not sure why I care so much as I don't drink much soda. I guess the differences between how the US perceives GM foods and how other nations perceive them kind of fascinates me.

Hoping to add my own garden to the top of this list in the very near future, too.

I should have added this to my list as well. Right now I grow a few vegetables but I would really like to have a bigger garden. I also would like to purchase more local, organic foods from the farmers market during the summer and can/freeze them for winter use.

[Patrick S]

look, we've got a much more serious problem in this country with the overprescription of antibiotics and the resulting immune super-bugs, but that doesn't mean we're all going to become christian scientists over it.

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But aren't antibiotic resistant crops implicated in the problem of Superbugs?

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If you are asking if the use of antibiotic resistance markers in transgenic crops has created or measurably worsened the problem of antibiotic-resistant bacteria, there appears to be a concensus among experts in microbiology and plant biotechnology that the answer is 'no'. The following is something I wrote in 2003 when I was reading a lot about this issue, and reflects the data available at that time. I'm not a scientist, but what I read convinced me that this was another non-issue.

The short version is this -- despite repeated attempts to demonstrate it, there is no evidence that the resistance markers even can be transferred from transgenic plants to bacteria, which of course would have to occur for an ab-resistant bacterium to be created. Second, even if such a transfer were to occur, it would not have any measurable impact, because the very same ab-resistance same markers are already abundant in soil and human gut bacteria.

With GM crops, the biggest concern is that the resistance marker gene (ntpII and blaTEM1 being the two most widely used) will be released during digestion and then incorporated into soil or gut bacteria. Firstly, the probability of such markers being transferred from GM plant to a bacteria is considered vanisinghly small. Despite many attempts, no such successful transfer has been observed in the lab, even using experimental designs that can detect these events at extremely low rates, except under very special experimental conditions where large portions of the transferred gene are *already present* in the target bacteria (Jelenic, 2003). There is also a scientific concensus that such transfer, even if they did occur, would not have any significant impact on the efficacy of antibiotics  (e.g. Conner et al, 2003; Cook, 2000; FAO/WHO, 2000; Flavell et al, 1992; Gay, 2001; Jelenic, 2003; Royal Society, 1998; Salyers, 1999; SCAN, 1996; SOT, 2003).

Three scientific committes queried by the European Commision as to the risk of transfer of the blaTEM1 gene, an ampicillin resistance gene that codes for the protein beta lactamase, concluded that "(a) the possibility of transfer of a functional bla-gene construct from genetically modified  maize into bacteria is virtually zero, and (b) that if the virtually impossible event occurred, it would have no clinical significance" (SCAN, 1996). The 2000 joint FAO/WHO report on the safety aspects of GM plants concluded that for "antibiotic resistance genes currently in use in genetically modified plants, the available data suggest that the consequences of horizontal gene transfer will be unlikely to pose a significant threat to the current therapeutic use of the respective drugs" (p. 12).

The reason that transfer of such markers would not pose a significant risk even if it did occur is that these markers are already abundant in both human gut bacteria and in soil bacteria that enter humans from dietary sources. For instance, the human gut flora is estimated to contain on average ~1 trillion neomycin or kanamycin-resistant bacteria (Flavell et al, 1992). Resistance genes in these bacteria are present on mobile elements like plasmids and transposons that can be easily tranferred between bacteria. Whatever additional risk posed by resistance markers in GM is utterly miniscule compared to the abundant background of soil and gut bacteria that already contain the resistance marker. Discussing the risks of using nptII (neomycin phosphotransferase II gene), which is the most common antibiotic resistance marker in GM crops, Jelenic (2003, p. 187) explains that:

. . . the contribution of plant derived kanamycin resistance gene is expected to be extremely small since genes for resistance to kanamycin already occur quite commonly in the animal gut microflora [e.g. the flora of the human gut naturally contains about 10^12 kanamycin resistant bacteria (11)]. It has been calculated that consumption of GM tomato containing nptII gene would lead to a maximum projected increase in the number of kanamycin resistant bacteria in the human gut of 2.6 · 10–13 % [i.e. 0.00000000000026%] (14). Furthermore, antibiotic resistance genes occurring naturally in gastrointestinal flora are often associated with highly mobile genetic elements like conjugative plasmids and transposons (e.g. nptII gene was originally isolated as a component of transposon Tn5 from the gastrointestinal bacterium E. coli) that are readily mobilizable between taxa and represent the most common method of acquiring antibiotic resistance determinants among bacteria. Thus, the practical impact of the transfer of kanamycin resistance gene from GM plants to gastrointestinal bacteria would be negligible.

Abigail Salyers, president of the American Microbiological Association and an expert on antibiotic resistance, comes to a similar conclusion with regards to the blaTEM1gene, another marker gene used in some GM crops. After noting the extremely low probability that a transfer to bacteria would occur and the already widespread occurence of this marker in bacteria, Salyers writes:

"Compared to the high existing background of ampicillin resistance, the virtually nonexistent chance of an additional increment of ampicillin resistance due to movement of bla from corn to bacteria could be compared to adding a drop of water to an ocean. Another point is worth considering here. The wide variation in levels of ampicillin resistance between different areas may be due in part to differences in exposure to ampicillin. That is, the critical feature is the selection pressure. Accordingly, it seems most rational to direct attention toward the overuse of antibiotics, both on the farm and in human medicine, rather than worrying about an unproven and probably infinitesimal risk that new copies of the bla gene would enter bacteria."

As Salyers points out, uncooked fruits and vegetables contain soil bacteria, of which a significant proportion already carry antibiotic resistance genes, are much more lilely to pose a risk. Transfer of resistance markers from these bacteria to human gut bacteria is "many orders of magnitude" more likely than transfer of resistance markers to human gut bacteria from GM food.

Jelenic, 2003. Controversy Associated With the Common Component of Most Transgenic Plants – Kanamycin Resistance Marker Gene. Food Technol. Biotechnol. 41, 183–190.

Conner et al, 2003. The release of genetically modified crops into the environment: Part II. Overview of ecological risk assessment. The Plant Journal 33, 19–46.

Cook, 2000. Science-Based Risk Assessment for the Approval and Use of Plants in Agricultural and Other Environments. Agricultural Biotechnology and the Poor Report, Consultative Group on International Agricultural Research. http://www.cgiar.org/biotech/rep0100/Cook.pdf

FAO/WHO, 2000. Safety aspects of genetically modified foods of plant origin. Report of a Joint FAO/WHO Expert Consultation on Foods Derived from Biotechnology. WHO, Switzerland. http://www.who.int/foodsafety/publications...ec_june2000/en/

Gay, 2001. The biosafety of antibiotic resistance markers in plant transformation and the dissemination of genes through horizontal gene flow. In Safety of Genetically Engineered Crops (Custers, R., ed.). Zwijnaarde, Belgium: Flander Interuniversity Institute for Biotechnology, pp. 135–159.

Flavell, 1992. Selectable marker genes: Safe for plants? Biotechnology (N.Y.) 10, 141–144.

Royal Society, 1998. Genetically Modified Plants for Food Use. Policy Document 2/98. The Royal Society, London.

Salyers, 1999. Genetically engineered foods: safety issues associated with antibiotic resistance genes. University of Illinois and APUA (Alliance for the Prudent Use of Antibiotics) Reservoirs of Antibiotic Resistance Network. http://www.roar.antibiotic.org, www.healthsci.tufts.edu/apua/salyersreport.htm

[Patrick S]

While we're on the subject of organics, there have been a couple of recent papers comparing organic dairy production to conventional dairy production that have produced somewhat surprising results. The first one compared the incidence of mastitis in cows raised on organic farms versus those on conventional farms, and actually found the incidence to be higher on the organic farms. Presumably this might be partly explained by the use of prophylactic antibiotics in conventional farms? The following was presented at the 12th Int. Conf. on Production Diseases in Farm Animals, East Lansing, USA, on July 19-22, 2004.

Problemstellung und Zielsetzung

Subclinical mastitis is one of the most costly diseases in dairy production and is more frequent in farms with organic production (OP) than in farms with integrated production (IP). Previous studies have shown that the prevalance of subclinical mastitis of cows in Swiss OP farms is relatively high (Busato, Trachsel, Schällibaum, Blum. 2000. Prevent. Vet. Med. 44, 205-220). Epidemiological studies comparing chronic mastitis in OP and IP farms are lacking.

Material und Methoden

We have investigated 970 cows in 60 randomly selected OP farms and 60 comparable IP farms in the canton of Berne to test the hypothesis that the prevalence, risk factors and patterns of udder pathogens in OP and IP cows are different. California Mastitis Tests (CMT) were performed at around 31 d p.p. in 483 OP and 487 IP cows and at around 102 d p.p. in 419 OP and 421 IP cows. Cows with CMT ≥1+ in one quarter but without clinical signs of mastitis were considered to have subclinical mastitis. Of quarters with CMT ≥2+ a milk sample was taken for bacteriological follow-up. Somatic cell counts (SCC) were available from breeder organisations.

Ergebnisse und Bedeutung

Cow-level prevalences of subclinical mastitis for visits 2 and 3 (31 and 102 d p.p.) were 39 and 40% in OP farms and 34 and 35% in IP farms, resp. Quarter-level prevalences of mastitis were 15 and 18% in OP farms and 12 and 15% in IP farms, resp. The median SCC (in 103 cells/mL milk) at 31 and 102 d p.p. were 42 and 45 in OP cows and 28 and 36 in IP cows. Prevalences of Staphylococcus aureus and other staphylococci were higher in IP than OP farms, whereas prevalences of Streptococci other than Streptococcus agalactiae and Corynebacterium bovis were higher in OP than in IP farms. Breed, teat or udder injuries, no antibiotic dry cow therapy, and SCC before drying off were identified as significant risk factors for the development of subclinical mastitis. In conclusion, there was a higher number of subclinical mastitis in the first 100 d of lactation in OP than IP farms. Some of the found risk factors were strongly related to the two different farming systems. However, the farm type was less important than cow and management factors, albeit the farm type is confounded with differences in management factors. The separate analysis of risk factors for OP and IP cows showed, that there are - besides common risk factors such as breed and antibiotic udder treatment after calving – specific effects. Thus, in OP farms the average farm SCC as well as alternative medication and in IP farms the antibiotic dry cow therapy and nutritional aspects may be of special importance.

The same group just published another paper in the Journal of Dairy Science comparing the prevalence of antibiotic-resistant mastitis pathogens in organic versus conventional farms. As they explained, they fully expected to find a greater prevalence of resistant pathogens on the conventional farms, but suprisingly found no difference. These tests were done of farms in Switzerland, so I wonder if similar tests done in the US would be the same or different?

There has been a rapid rise in the emergence of multi-drug-resistant pathogens in the past 10 to 15 yr and some bacteria are now resistant to most antimicrobial agents. Antibiotic use is very restricted on Swiss organic dairy farms, and a purely prophylactic use, such as for dry cow mastitis prevention, is forbidden. A low prevalence of antibiotic resistance in organic farms can be expected compared with conventional farms because the bacteria are infrequently or not exposed to antibiotics. The occurrence of antibiotic resistance was compared between mastitis pathogens (Staphylococcus aureus, nonaureus staphylococci, Streptococcus dysgalactiae, Streptococcus uberis) from farms with organic and conventional dairy production. Clear differences in the percentage of antibiotic resistance were mainly species-related, but did not differ significantly between isolates from cows kept on organic and conventional farms, except for Streptococcus uberis, which exhibited significantly more single resistances (compared with no resistance) when isolated from cows kept on organic farms (6/10 isolates) than on conventional farms (0/5 isolates). Different percentages were found (albeit not statistically significant) in resistance to ceftiofur, erythromycin, clindamycin, enrofloxacin, chloramphenicol, penicillin, oxacillin, gentamicin, tetracycline, and quinupristin-dalfopristin, but, importantly, none of the strains was resistant to amoxicillin-clavulanic acid or vancomycin. Multidrug resistance was rarely encountered. The frequency of antibiotic resistance in organic farms, in which the use of antibiotics must be very restricted, was not different from conventional farms, and was contrary to expectation. The antibiotic resistance status needs to be monitored in organic farms as well as conventional farms and production factors related to the absence of reduced antibiotic resistance in organic farms need to be evaluated.

Roesch et al, 2006. Comparison of Antibiotic Resistance of Udder Pathogens in Dairy Cows Kept on Organic and on Conventional Farms. Journal of Dairy Science 89:989-997.