Does raw milk really kill pathogens? — Dr. Amanda Rose weighs the evidence for and against “competitive exclusion”

The short answer, from the research that Dr. Amanda Rose quotes, is “Yes and No”. Several types of common pathogens do seem to decline significantly in numbers over the course of days in a raw milk medium. Others do not.

One common pathogen that IS competitively excluded in raw milk according to studies quoted by Dr. Amanda Rose.

One common pathogen that IS competitively excluded in raw milk according to studies quoted by Dr. Amanda Rose. Others are not excluded.

Amanda is making her complete 24-page report available for purchase at this site. The price is $7. I think this type of research is well worth supporting.

Amanda’s research, however, does leave me with a few unanswered questions such as “under what conditions was the raw milk used in these studies farmed?”. There’s a huge spectrum even from nominally organic to full-blown state-of-the-art biodynamic grass-and-hay-fed dairying. Ontario raw milk farmer Michael Schmidt was a pioneer of grass and hay feeding even back in Germany, the birthplace of Biodynamics and a country where raw milk is established and legal.

And yet, I’d be surprised if you couldn’t, even now, feed a lot of grain to dairy cattle and still be considered “organic”, as long as the grain was organically grown. The argument for restricting feed for cattle mostly to hay and pasture is that roughage is what the ruminant digestive tract of the cow was designed to process and that feeding grains and such distorts the digestive process and give rise to unhealthy conditions in the animal, leading to a lower quality of milk with a higher pathogen count.

As for the possible influence of factors relating to Biodynamic farming practices, consider this story:

Back in the 1980s, an Ontario Biodynamic farmer from Germany, Bernhard Hack, said that after the nuclear disaster in Chernobyl, the German government made aerial surveys of Germany to map the extent of radioactive fallout contamination. What they found was that there were a number of areas where the radiation was much less than in the surrounding regions. Upon closer examination, these reduced-radiation zones turned out to be Biodynamic farms.

Michael Schmidt was able to confirm that German Biodynamic farmers were able to get their cows back out on pasture sooner after Chernobyl than other farmers (because of lower geiger-counter readings on their land). So if Biodynamic farming can make land unusually resistant to radioactive fallout, what exceptional resistance might Biodynamically-produced milk have to foreign pathogens? It’s a sad commentary on the state of our world  that we usually can’t count on governments to publicly acknowledge or disclose this sort of revolutionary information — what I’m saying is, don’t expect to verify this information about Chernobyl fallout from online sources. 

Dr. Carol Vachon showed some slides on competitive exclusion studies at the raw milk symposium in Toronto in January that showed decline in pathogen populations over time in a raw milk medium. Don’t  recall exactly which pathogens he studied, however. We’ll have to look into that further and publish his results here on the Bovine.

And of course raw milk is not primarily used as an antibiotic, so we’re just looking at “side-effects” here. And testing in which pathogens are added to the milk models only contamination, rather than anything that would arise naturally in the course of hygienic production processes. Still, the results and findings are well worth looking at.

Here’s a brief excerpt from the Introduction to Amanda’s paper:

“It is imperative that the citizens of our nation, not just California, have an informed choice in foods.” 
California raw milk dairyman, May 2004 

“Drinking raw milk is like playing Russian roulette with your health.”  
John Sheehan, Food and Drug Administration [Note from blog editor — we’ve heard that same statement from Canadian health officials. Are both following some kind of script, or are they copying each other?]

“Raw milk is great. I used to get it straight from a friend’s small dairy. You just have to know that every five or six years, you are going to puke your guts out. Besides that, it’s great.”
Amanda Rose’s friend Mike, July 14, 2009, Seattle 

Editor’s note: [from Amanda] Your results may vary. 

This short paper was written with no funding from the FDA, CDC, USDA, “big dairy,” or “big ag.” No cows or goats were harmed in the writing of this paper.” 

Another excerpt:

“… Let’s assume that the lactoperoxidase system in raw milk and/or the lactic acid bacteria are as good a killer of pathogens as exercise is of body fat. Knowing that the two are linked still does not give us the answer we need. Raw milk consumers need to know not just whether lactic acid eats away at bad bacteria, but whether the milk ends up pathogen-free in their refrigerator. 

If competitive exclusion is to ensure the safety of raw milk, we need to know that raw milk can kill enough bad bacteria that we can be fairly certain that all of the pathogens have died by the time we consume the milk. 

From the point of view of the consumer, it is important to ask: 

1) If pathogens are killed, are they killed quickly enough that fresh raw milk is safe? 

2) If pathogens are killed, are they killed thoroughly enough that I do not consume an infectious dose in my usual daily consumption of milk? 

With these questions in mind, I describe key studies on pathogen survival in fresh raw milk…”

Once again, here’s that link to the site where you can purchase a copy of the whole 24 page report for $7.


Filed under News

10 responses to “Does raw milk really kill pathogens? — Dr. Amanda Rose weighs the evidence for and against “competitive exclusion”

  1. Thanks for the shout out. In the research I cite, the only two cases in which we know anything about the milk is the BSK study and the current UC Davis study on Salmonella. The BSK study used OPDC milk. The UC Davis researcher has used milk from OPDC and Claravale Farms.


    • N

      I’m looking to find raw milk in Germany, but don’t speak it. Do you know of any place? Thanks. We just moved here and really miss our real milk!

      • Deen

        Here is information for raw milk in Germany
        Let me know how it goes.Deen
        * Contact the following to find regional raw-milk selling farmers: Staatliche Lehr- und Forschungsanstalt fuer Landwirtschaft, Weinbau und Gartenbau, Breitenweg 71, 67435 Neustadt an der Weinstrasse, Telefon 06321-6711.
        * Organic raw milk (and/or other organic products) are available from one of the numerous farms across Germany belonging to the Bioland “group”. Bioland is a reputable brandname that promotes organic agriclture. Call your local chapter for a list of Bioland farms in your area. Interested Germans can contact the headquarters: Bioland-Bundesverband, Bundesgeschäftsstelle, Nördliche Ringstraße 91, 73033 Göppingen, to receive a list of farms in their area. The list indicates which farms sell which products, including raw milk. One can also look it up in the internet at
        * This website tells you where to find producers of Vorzugsmilch:
        * Also see note, “Raw Cheeses?” under Netherlands, below, for a link to a page of raw or “almost raw” cheeses available in Holland and Germany.

  2. Pingback: Nourishing Foods Blog Carnival | Hartke Is Online!

  3. Dana

    FYI, this isn’t about bovine milk, but I once ran across a Dr. Sears piece (William, not Barry) about human milk in which he stated that if you left a bottle of freshly-pumped milk out on the counter for twenty minutes, the milk would kill any germs in it. Apparently it’s biologically active and contains white blood cells as a matter of course.

    I don’t know if cows’ milk works the same way but who knows, maybe it does. Of course if you pasteurize it you kill any living cells in it, including those that belong in it… oops.

  4. I’ve been drinking raw milk for 4 years now, never been sick. Personally, I’m not afraid of
    “pathogens”, as far as I’m concerned they just make my immune system stronger.

  5. Pingback: Does raw milk kill the killer germs? — Dr. Ted Beals responds to Amanda Rose’s paper on competitive exclusion « The Bovine

  6. hazel

    i was wondering if anyone knows how long after the goat was milked the bacteria oxalobacter formigenes would still be alive?

  7. Pingback: Could your Milk Kill you? | Plows and Cows

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