Avian Flu and Raw Milk: Where is the Evidence?

We are pleased to share with you this balanced analysis of the risks of avian flu from raw milk, from medical microbiologist Peg Coleman. Peg serves on the Advisory Board for Raw Milk Institute and she will be presenting a free webinar about Milkborne Risk Analysis (including a discussion of avian flu and raw milk) on Thursday May 9 at 11am Pacific / 2pm ET.

Recent risk communications from CDC , FDA, and USDA regarding transmission of highly pathogenic avian influenza virus or HPAI (subtype H5N1) to humans via raw milk include no supporting evidence of viral transmission from raw milk to humans in the peer-reviewed literature. CDC and USDA reported that the HPAI strains recently isolated in the US lack the genetic markers for viruses adapted to infect humans. An extensive body of scientific evidence from the peer-reviewed literature introduced herein does not support the assumption by these US government agencies that HPAI transmits to humans via milkborne or foodborne routes and causes disease. Nor does the scientific evidence support the recommendation that consumers should avoid raw milk and raw milk products.

One Detected Case: Worker Had Contact with BOTH Dead Birds and Affected Cows

In March of 2024, dead wild birds on a TX dairy farm and unusual symptoms in older dairy cows (decreased lactation, low appetite, other clinical signs) triggered sampling of affected cows (oropharyngaeal swabs) and their milk. On March 25th, Texas Animal Health Commission confirmed samples were positive for HPAI. A dairy worker on this farm with eye inflammation was also confirmed positive for HPAI, though it is unclear if the worker had contact with both the dead birds and the affected cows.

On April 9th, the World Health Organization (WHO) stated the following about the TX case. “This is the first human infection with [HPAI (H5N1)] acquired from contact with infected cattle and the second confirmed human case of influenza A(H5N1) detected in the country. No additional associated cases of human infection with influenza A(H5N1) have been identified. Since the virus has not acquired mutations that facilitate transmission among humans and based on available information, WHO assesses the public health risk to the general population posed by this virus to be low and for occupationally exposed persons, the risk of infection is considered low-to-moderate.” In addition, the American Association of Bovine Practitioners (AABP) now recommends a new name, Bovine Influenza A Virus (BIAV) because the virus is not highly pathogenic in dairy cows.

The WHO lists the following factual information about avian influenza: i) “Direct contact with infected animals (through handling, culling, slaughtering or processing) or indirect contact (through environments contaminated with bodily fluids from infected animals) represent a risk for human infection.“; ii) “animal influenza viruses are distinct from human influenza viruses and do not easily transmit to and among humans;” and iii) sustained person-to-person transmission is not demonstrated.

Animal Contact is the Only Demonstrated Transmission Source

Of all the transmission sources reported in surveillance systems by CDC and other government agencies (animal contact, environmental, foodborne, person-to-person, and waterborne), the only demonstrated transmission source for HPAI transmission to humans is animal contact. In light of the body of evidence on HPAI transmission to humans by direct animal contact, not by foodborne transmission, risk communications to avoid consumption of raw milk and raw milk products do not appear to be based on scientific evidence, but on other factors.

An earlier risk assessment conducted by FDA and USDA (2010) determined that HPAI “is not considered to be a foodborne pathogen although virus had been isolated from poultry muscle and the interior of eggs”. This is consistent with current facts compiled by the WHO about avian influenza transmission to date: i) “Direct contact with infected animals (through handling, culling, slaughtering or processing) or indirect contact (through environments contaminated with bodily fluids from infected animals) represent a risk for human infection.“; ii) “animal influenza viruses are distinct from human influenza viruses and do not easily transmit to and among humans;” and iii) “sustained person-to-person transmission is not demonstrated”. Although HPAI was detected in milk from ill cows in TX, as in poultry muscle and eggs, no evidence supports foodborne transmission of HPAI to humans.

Antiviral Properties of Raw Milk

While no evidence supports milkborne or foodborne transmission of HPAI to humans, evidence does exist that demonstrates a multitude of well-characterized mechanistic factors that inactivate viruses and prevent foodborne illness. Key studies in the peer-reviewed literature are cited in brackets, with full references appended.

First, consider peer-reviewed studies demonstrating antiviral properties of a suite of bioactive components of raw mammalian milks, including bovine milk [4,5,7-9,12-14,16,17,19]. Multiple researchers note that some of the antiviral components of milk are likely function synergistically, meaning effects are greater in combination than independently, an observation particularly relevant in complex gut ecosystems of humans that include innate and adaptive immune systems. Many of these bioactive components of raw milk are also sensitive to heat and may be absent, inactive, or present in lower concentrations in pasteurized milks. Considering the extensive literature on antiviral activity in milk, clinical researchers [3] applied deep scientific knowledge to recommend that infants not be deprived of raw breastmilk due to the presence of viruses. The benefits of feeding raw breastmilk including its antiviral components to infants outweighs the very small risk of infection, from their perspective as clinical researchers, one associated with the Italian Association of Human Milk Banks.

Defense Against Pathogens in the Human Digestive Tract

Next, consider the gauntlet of defenses against foodborne pathogens in the human digestive tract [1,6,18]. These defenses include physical (stomach acidity, peristalsis), chemical (digestive enzymes), and cellular (innate and adaptive immune system, microbiota) factors that, acting simultaneously or sequentially, inactivate pathogens, including viruses, and/or suppress infectivity and virulence of ingested pathogens. Researchers [11] note that HPAI is an enveloped virus, susceptible to disruption and degradation in stomach acids, unlike the 16 viruses known to be transmitted to human by the oral route [6]. Further, FDA and USDA determined in 2010 that HPAI “is not considered to be a foodborne pathogen” even though virus was isolated from poultry muscle and the interior of eggs.

Host chemical and cellular defenses include:  complement; defensins; enzymes; interferons; interleukins; pattern recognition receptors (Toll-like receptors 3, 4, and 7; NOD-like receptors; RIG-1 receptors); and an array of host cells (dendritic cells, B cells, intestinal epithelial cells, macrophages, monocytes, natural killer cells, T cells) and cells of the gut-associated microbes or microbiota. Also, the gut microbiota include not only commensal (non-pathogenic) bacteria, but also commensal viruses that can modulate infectivity and virulence of pathogens [10].

CDC Data on Transmission Sources

Now, consider that the microbial ecology of raw milks including antiviral activity as described briefly above aligns with recent CDC data for all transmission sources from 2005 to 2020 [15]. This CDC dataset included 3,807 milkborne illnesses (2,111 associated with pasteurized milk) linked to bacterial pathogens, but lacks any viral illness associated with milk, raw or pasteurized. The predominant virus in this CDC dataset was norovirus, associated with 8,199 illnesses from leafy greens reported over this 16-year period. No norovirus illnesses or any other viral illnesses were reported in milk.

What is known about HPAI transmission to humans is that it is rare, requiring prolonged direct contact with infected, sick, and dead animals, generally birds, now dairy cows, that can lead to mild flu-like symptoms or eye inflammation, some progressing to fatal infections, according to WHO. Again, HPAI in humans is linked to transmission via animal contact, not by foods.

It seems that occupational exposure resulted in infection of a farm worker handling ill cows, with developed of one symptom in the worker, eye redness (conjunctivitis), consistent with transmission by animal contact. HPAI has been detected in dairy cows in Texas, Kansas, New Mexico and Michigan as of April 2. The dairy animals and rare humans affected have recovered.

Cross-disciplinary evidence demonstrates that raw milk from healthy cows is not inherently dangerous, consistent with the CDC evidence of trends for 2005-2020 [15] and evidence of benefits and risks [2]. There is no scientific evidence that HPAI in raw milk causes human disease.

Please consider the references below and pose questions in the comments. You may be interested to learn more about these recent peer-reviewed publications.

• Trends in burdens of disease by transmission source (usa, 2005–2020) and hazard identification for foods: focus on milkborne disease.
  Journal of Epidemiology and Global Health.

• Suppression of pathogens in properly refrigerated raw milk.
  PLOS ONE

• Lessons identified from applications of the Risk Analysis Quality Test Release 1.0.
  Risk Analysis

This article was originally published on Peg Coleman’s website here: https://www.colemanscientific.org/blog/2024/4/7/where-is-the-evidence

References

1.           Buchanan RL, Havelaar AH, Smith MA, Whiting RC, Julien E. The key events dose-response framework: its potential for application to foodborne pathogenic microorganisms. Critical Reviews in Food Science and Nutrition. 2009 Sep 22;49(8):718-28.

2.           Dietert RR, Coleman ME, North DW, Stephenson MM. Nourishing the human holobiont to reduce the risk of non-communicable diseases: a cow’s milk evidence map example. Applied Microbiology. 2021 Dec 30;2(1):25-52.

3.           Francese R, Peila C, Donalisio M, Lamberti C, Cirrincione S, Colombi N, Tonetto P, Cavallarin L, Bertino E, Moro GE, Coscia A. Viruses and human milk: transmission or protection?. Advances in Nutrition. 2023 Aug 20.

4.           Gallo V, Giansanti F, Arienzo A, Antonini G. Antiviral properties of whey proteins and their activity against SARS-CoV-2 infection. Journal of Functional Foods. 2022 Feb 1;89:104932.

5.           Gallo V, Arienzo A, Tomassetti F, Antonini G. Milk bioactive compounds and gut microbiota modulation: the role of whey proteins and milk oligosaccharides. Foods. 2024 Mar 16;13(6):907.

6.           Lockhart A, Mucida D, Parsa R. Immunity to enteric viruses. Immunity. 2022 May 10;55(5):800-18.

7.           Kaplan M, Şahutoğlu AS, Sarıtaş S, Duman H, Arslan A, Pekdemir B, Karav S. Role of milk glycome in prevention, treatment, and recovery of COVID-19. Frontiers in Nutrition. 2022 Nov 8;9:1033779.

8.           Oda H, Kolawole AO, Mirabelli C, Wakabayashi H, Tanaka M, Yamauchi K, Abe F, Wobus CE. Antiviral effects of bovine lactoferrin on human norovirus. Biochemistry and Cell Biology. 2021;99(1):166-72.

9.           Panon G, Tache S, Labie C. Antiviral substances in raw bovine milk active against bovine rotavirus and coronavirus. Journal of Food Protection. 1987 Oct 1;50(10):862-7.

10.         Pavia G, Marascio N, Matera G, Quirino A. Does the human gut virome contribute to host health or disease?. Viruses. 2023 Nov 17;15(11):2271.

11.         Sangsiriwut K, Uiprasertkul M, Payungporn S, Auewarakul P, Ungchusak K, Chantratita W, Puthavathana P. Complete Genomic Sequences of Highly Pathogenic H5N1 Avian Influenza Viruses Obtained Directly from Human Autopsy Specimens. Microbiol Resour Announc. 2018. 7(22):e01498-18. doi: 10.1128/MRA.01498-18. PMID: 30533850; PMCID: PMC6284082.

12.         Santos I, Silva M, Grácio M, Pedroso L, Lima A. Milk antiviral proteins and derived peptides against zoonoses. International Journal of Molecular Sciences. 2024. 25(3):1842.

13.         Schlusselhuber M, Godard J, Sebban M, Bernay B, Garon D, Seguin V, Oulyadi H, Desmasures N. Characterization of milkisin, a novel lipopeptide with antimicrobial properties produced by Pseudomonas sp. UCMA 17988 isolated from bovine raw milk. Frontiers in Microbiology. 2018. 9:355822.

14.         Singh P, Hernandez‐Rauda R, Peña‐Rodas O. Preventative and therapeutic potential of animal milk components against COVID‐19: A comprehensive review. Food Science & Nutrition. 2023. 11(6):2547-79.

15.         Stephenson MM, Coleman ME, Azzolina NA. Trends in burdens of disease by transmission source (USA, 2005–2020) and hazard identification for foods: focus on milkborne disease. Journal of Epidemiology and Global Health. 2024 Mar 28:1-30.

16.         Tache S, Benkaddour M, Corpet DE. Rotavirus inhibitor and recovery in raw bovine milk. Journal of Food Protection. 1995 Apr 1;58(4):434-8.

17.         Taha SH, Mehrez MA, Sitohy MZ, Abou Dawood AG, Abd-El Hamid MM, Kilany WH. Effectiveness of esterified whey proteins fractions against Egyptian Lethal Avian Influenza A (H5N1). Virology Journal. 2010 Dec;7:1-4.

18.         Wan T, Wang Y, He K, Zhu S. Microbial sensing in the intestine. Protein & Cell. 2023 Nov 1;14(11):824-60.

19.         Wang X, Yue L, Dang L, Yang J, Chen Z, Wang X, Shu J, Li Z. Role of sialylated glycans on bovine lactoferrin against influenza virus. Glycoconjugate Journal. 2021 Dec 1:1-8.

Avian Flu and Raw Milk: A Common Sense Approach

Breaking News!  There is a concern among dairymen and biosecurity experts about a multistate outbreak of avian flu that is affecting cattle in Texas, Kansas, Michigan, New Mexico, and Idaho. Various Federal and state government agencies are using this cow illness outbreak as a stage to warn consumers against drinking raw milk. 

According to the US Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS), in cattle this illness causes decreased lactation and low appetite, but the cattle generally recover without dying. Cows who have contracted this illness have recovered “with little to no associated mortality,” according to the USDA.

The press and media information released by the USDA and others warns against drinking raw milk from affected cows. They further state that pasteurization protects consumers from the illness.  

Raw Milk and Breastmilk are Very Similar

As a premed-trained dairy farmer who is a 12-year member of the UC Davis International Milk Genomics Consortium (IMGC), I have studied viral infections in cows and the immunologic and biomechanics of antibody creation.  Based on what is known about antibodies and raw milk, there are deep flaws in the warnings about consuming raw milk related to avian flu.  

Dr David Dallas PhD is an IMGC researcher who studies milk genomics. At the 2023 IMGC Symposium, Dr Dallas reported that raw milk from cows and goats is “qualitatively similar” to human breast milk.  However, “quantitatively” bovine raw milk and human breast milk have “different levels” of various milk components.  

This is why raw milk from cows and goats is so well-digested and compatible by human consumers. We can thus compare human mammals with bovine mammals in how mothers protect their babies. 

Mammals Protect Their Young Through Antibodies in Raw Milk

In 2004, the state of California Veterinarian visited our dairy to perform tuberculosis testing of our cows. He told me something I will never forget: “Mammals protect their young.”  

What he meant was that, in general, when a mother becomes infected by a virus or bacterial infection, she will produce antibodies in her raw milk that will provide her young with protection from the illness.  This is part of why breastfed babies are known to have stronger immune systems than babies raised on formula.  Antibodies in raw milk are one way that Nature assures the strength and survival of the next generation.  

The CDC readily acknowledges that mothers should continue to breastfeed their infants because “flu is not spread to infants through breast milk.” They know that breastmilk contains “antibodies and other immunological factors that can help protect her infant from flu.” Similarly, studies performed at the UC Davis dairy lab during COVID found that exposing a cow to coronavirus resulted in antibodies to coronavirus in her raw milk.  

These studies were a further confirmation of what doctors and the owners of Alta Dena dairy knew way back in the 1960’s: cows that have been exposed to illnesses create antibodies to the illnesses which are then passed through their raw milk.  Decades ago, Alta Dena dairy would purposely make immune milk for certain consumers and doctors by intentionally exposing cows to specific illnesses. This raw milk was used to help heal sick people.  Now the FDA does not allow this practice and threatens anyone who uses it with criminal charges. They consider it to be equivalent to creating a new drug without oversight, which is a crime in the USA under the Food Drug and Cosmetic Act.  

Further back in history, it was observed that the milk maidens of the 1700-1800s did not catch smallpox because of their exposure to cowpox by being around dairy animals and drinking raw milk.

Common Sense Approach to Avian Flu in Cattle

The warnings against raw milk related to avian flu are clearly fearmongering.  The FDA acknowledges that “there is limited information available about the transmission of bird flu in raw, unpasteurized milk.” Then they go on to use the same fearmongering tactics they’ve been using for decades against raw milk, despite the fact that there is now ample evidence that raw milk can be carefully produced as a low-risk food.  

Conscientious raw milk producers already monitor their herds for illness and ensure that raw milk from unhealthy animals is not used for direct human consumption. Additionally, biosecurity measures such as maintaining a closed herd and quarantining any new animals are implemented.   

These are common sense measures that are already recommended by the Raw Milk Institute and used by diligent raw milk farmers. We have no reason to suspect that any further measures are necessary in the current Avian flu outbreak in cattle.  Mammalian milk is uniquely designed to protect and strengthen the immune system, and those systems will continue on as new threats arise.

FDA Demonstrates Bias Against Raw Milk in Unfounded Raw Cheese Recall

Government agencies in many countries have been biased against raw milk and raw dairy products for over a century.  This is true in the United States as well, even though Dr Henry Coit and the American Association of Medical Milk Commissions demonstrated that raw milk could be produced carefully and hygienically as a low-risk food all the way back in the late 1800’s.

Anti-raw milk smear campaigns and propaganda have been used continually to make people fearful of raw milk and raw milk products. In reality, raw milk can be produced as a low-risk food when farmers are trained and use careful production practices.

Of course, there is no such thing as a perfectly safe food, as evidenced by the ongoing illness outbreaks linked to foods such as cantaloupes, leafy greens, and chicken. Pasteurized milk is not perfectly safe, either, and is implicated in foodborne illnesses and outbreaks every year. For instance, in 2007, there was an outbreak of Listeriosis in Massachusetts which was associated with pasteurized milk.  Overall, there were five cases identified and three deaths occurred.

Nonetheless, only raw milk and raw milk products are targeted by government agencies as being unsafe.

My Family’s Farm is Being Targeted

In the latest example of anti raw milk bias, the Food and Drug Administration (FDA) has recently targeted raw cheese from my family’s farm (RAW Farm). On February 15th 2024, the Centers for Disease Control (CDC) and the FDA urgently demanded to speak with us. We had 30 minutes notice for a call that was attended by about a dozen people from the CDC and FDA.

Our raw cheeses are sold nationally at over 1,300 grocery stores.  We were told that the CDC’s PULSENET database had associated 10 illnesses to our raw cheese products over the last 5 months. The CDC and FDA admitted that, out of these 10 illnesses, half of those who became ill denied ever having consumed our cheese.

Nonetheless, the FDA gave us two alternatives: either 1) voluntarily recall all of our cheese sold in the USA, or 2) they would force a mandatory recall of all our cheeses.

Our own internal tests performed on every batch of raw cheese were all negative for pathogens.  The state of California’s tests on our cheeses were also all negative for pathogens.  Nonetheless, we chose to fully comply with a voluntary recall of all raw cheeses within a specified date range. Although we needed a lot more information and answers to questions, out of an abundance of caution we recalled all of our cheeses on February 16th 2024. 

Searching for Answers to Many Questions

Over a 10-day period during our voluntary recall, we dug into the data to see what we could learn.  We were patient and did not comment, but instead we just collected information and considered every piece of data in our investigation.

We asked the FDA to provide the Whole Genome Sequencing (WGS) test data gathered by PULSENET. We conferred with experts from a testing lab who concluded that the WGS data was inconsistent from person to person and did not match as having a single cause. The CDC appears to have picked and selected data to match a narrative and ignored other data and date ranges. 

By February 25th, we had considered all the data from the FDA as well as mountains of internal test data and state test data. There was never any evidence that our cheese contained pathogens.

Clear Bias from the FDA and CDC

In handling this situation, the FDA broke their own rules in numerous ways.  They did not comply with their own Food Safety Modernization Act requirements or procedures. 

The timing of this whole situation was conspicuous considering that it was in the middle of a nationwide recall of pasteurized cheeses due to Listeria.  That outbreak is affecting 11-states and is associated with dozens of illnesses and two deaths. 

Additionally, on February 17th despite lack of evidence, FDA Director Dr Stic Harris posted on his personal LinkedIn page a photo of our cheese along with a warning that “While my personal opinion is you should never drink raw milk or eat raw milk products, you certainly don’t want to eat raw milk cheese linked to an ongoing outbreak.” Raw milk was never even involved in this recall, only raw cheese.  The bias against raw milk and raw milk products is clear.

The Accusations Were Baseless

It is clear from investigating all of the data that the FDA’s accusations against RAW Farm’s cheese were baseless. We stand with our consumers and our test data. The FDA can provide no evidence what so ever of any pathogens in any of our products.

As of February 26, we have now lifted our Voluntary Recall on our cheeses. You can read our full press release here:

Suffice it to say that as pioneers in the raw milk movement, we wage many battles.  Some are scientific, some are political, and some are educational. In this case, the FDA refuses to acknowledge science and is protecting themselves and big industry. They are demonstrating extreme political bias and continue to refuse to become educated about how raw milk can be produced as a low-risk food.

NEW Raw Milk Research: Suppression of Pathogens in Properly Refrigerated Raw Milk

We are pleased to announce that a new peer-reviewed paper has been published about pathogen growth in raw milk.  The paper is "Suppression of pathogens in properly refrigerated raw milk" by primary authors Peg Coleman and Dr Tom Oscar. 

This paper documents the results of a pilot study aimed at gaining insights into how well pathogens can grow in refrigerated raw milk. This study was commissioned by the Raw Milk Institute, with pathogen growth tests being performed at Food Safety Net Services (FSNS), an independent 3rd party lab.

Inapplicable Data Has Been Used to Vilify Raw Milk

Some of the data cited by Government agencies against raw milk includes pathogen growth studies where it was found that pathogens multiply greatly over time.  However, these studies are not actually applicable to carefully-produced raw milk because they were performed in nutrient-rich broth instead of milk, they used tremendously high amounts of pathogens (such as 10 log 7, which corresponds to ten million pathogenic colony-forming units (CFU) of bacteria per mL), or they did not account for cold temperature storage.

Pathogens Were Purposely Added Into Raw Milk

In this new pilot study, samples of well-produced raw milk were purposely inoculated with the four main pathogens of concern for raw milk: E coli 0157:H7, Salmonella spp., Campylobacter spp., and Listeria monocytogenes. The raw milk was inoculated at two levels (high and moderate counts per mL).

Pathogen Growth Was Measured Over Time

The objective of this new pilot study was to document growth characteristics of these pathogens in carefully produced raw milk over a period of 14 days when stored at the refrigeration temperature recommended by FDA and USDA: 40°F (4.4 °C). The number of pathogenic bacteria present in the raw milk were counted on days 0, 3, 6, 9, 12, and 14.

Study Found No Growth of Three Types of Pathogens

The study authors concluded that:

"The major finding of the pilot study is statistical evidence of no growth at 4.4°C for the major foodborne pathogens causing illness associated with raw milk in the US (Campylobacter, E. coli O157:H7, and Salmonella). For listeriosis, rarely associated with illness from raw milk, the pilot study documented evidence of pathogen growth in 8 of 12 replicates (P = 0.001 to P = 0.028, significant by ANOVA in the second week of refrigerated storage)."

These results indicate that, when stored at the recommended refrigerator temperature, moderate to high counts of E coli 0157:H7, Salmonella spp., and Campylobacter spp. did not multiply over time in raw milk.

Listeria monocytogenes exhibited some growth in the second week of refrigeration. It is important to note that a recent systematic review found that the risks of severe listeriosis were greater for pasteurized milk than for raw milk.

Challenging Incorrect Assumptions of the Past

Although more data is needed, the results of this pilot study serve to provide an initial basis for challenging incorrect assumptions of the past that overestimated the growth of pathogens in clean, cold raw milk produced for direct human consumption by careful, trained producers.

Special thanks to Peg Coleman and Dr Tom Oscar for their work on this statistical analysis and paper.

You can read the full paper here: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0289249

New Raw Milk Research From the 2023 IMGC Symposium

A Farmer’s Takeaways from the 2023 Symposium of the International Milk Genomics Consortium (IMGC)

“If you are the smartest person in the room, you are in the wrong room.”

Introduction

Well…I was in the right room at IMGC with a huge opportunity to learn and grow. Just like all prior years.

The 20th International Milk Genomics Consortium (IMGC) Symposium was held on September 6-8 2023. This was the 12th year that I have attended the IMGC Symposium. For the last several years, the Raw Milk Institute has been an official Bronze Level Sponsor of the conference. These conferences have taken me all over the world, including Cork Ireland, Quebec Canada, Aarhus Demark (twice), Sydney Australia, and UC Davis in California several times. I am nearly always the only farmer in the room filled with dairy processing scientists, PhD students, dairy science professors and university professors, and other milk researchers.

Over 12 years, I have made some great friends and created some important collaborations and alliances. I am approached by PhDs, especially after I speak at the microphone after a particularly engaging presentation that begs questions. They say things like, “Keep on asking those great questions!”  I am the only one that can ask those questions because everyone else would potentially lose their NIH or industry grants if they dared to asked those kinds of questions.

Time and interest are ushering in a new generation of open-minded PhD researchers, many of whom are women. They all want to talk about raw milk and its bioactive elements. Raw milk is truly a miracle of nature.  Being an event sponsor has allowed greater access to insider information about all things milk.  Below are my main takeaways from three intensive days of meetings, interactions, meals and dinner parties, and presentations in Cork Ireland at the University of Cork.

Raw Milk Institute was a Bronze Level Sponsor of the 2023 IMGC Symposium

Raw Milk Nourishes, Protects, and Directs

Raw milk is incredibly complex and perfectly designed to nourish, protect, and direct. We all know that raw milk is designed as the first food of life for babies to thrive and grow, yet as researchers continue to study raw milk, they discover many more benefits.

For instance, raw milk serves as a delivery system for immune-bioactive proteins. Peptides (which are chains of amino acid proteins) are protective of the baby by not allowing pathogens to cause illness. These functional proteins serve many roles, including protection of the baby.

Other specialized-proteins in breastmilk include natural mRNA, which provide the genetic information to direct cellular metabolic processes in the baby.  Breastmilk also contains stem cells for repair of damaged cells or tissues.

Raw milk also contains everything needed for its digestion. Raw milk has proteases, peptidases (for digesting proteins), lipases (for digesting fats), and bacteria that make lactase (for digesting lactose).

Additionally, when people drink milk, over time there are changes in the composition of the gut bacteria that make milk digestion easier. Lactase-producing bacteria found in the gut become the probiotic and as they feed on lactose, that becomes their selected prebiotic (food that bacteria chose to digest or eat). Over time the populations of these lactose-loving probiotic bacteria increase when they are fed lactose from dairy products.

The various milk proteins, immunoglobins, enzymes, fats and sugars are “qualitatively similar” between human breastmilk and cow milk. However, they are “quantitatively different” and appear at different levels and amounts in cow milk versus human milk. The same would be true for other bovine milks. The similarities are why humans can drink raw milk from cows, goats, and other animals. 

Milk’s Benefits Can’t Be Extracted

Many raw milk researchers are focused on finding ways to extract beneficial elements from raw milk. However, these elements are designed to work together with the full complement of many different macro- and micro- nutrients, enzymes, probiotics, etc in whole raw milk.

New products made with bio-actives extracted from raw milk will likely be met with suspicion, as well they should. The health benefits from whole, raw milk are the result of a complex interplay of bio-actives. Outside of the whole food matrix, those bio-actives are incomplete and not as effective as in their natural state.

Milk Fat is Essential to Its Beneficial Properties

Butterfat in milk is an essential part of milk’s overall beneficial properties. This fat is known to benefit brain development, immune system development, intestinal development, and the composition of the gut microbiota.

Butter fat globules are three-layer thick capsules that come in different sizes. The three-layered capsules are used by the gut as fiber; they also provide butyrate and butyric acids which are highly beneficial and healing to the lower gut. 60% of the bioactive elements found in raw milk are “carried on or inside” the fat globule. This says so much about skim milk, which has lost much of its beneficial value with the removal of the fat.

Researchers discovered that the fat globules in the milk are smaller in cows fed a high energy diet with high stress levels, such as cows being kept in concentrated animal feeding operations (CAFOs). The smaller fat globules in the milk do not contain bacteria inside that could ride through the stomach to the lower gut.

In contrast, the fat globules are larger in cows fed a low energy diet and under low stress levels (such as cows in pasture-based operations).  These larger fat globules carry bacteria inside of them. It is thought that the fat cell may act as a protective carrier vessel to carry bacteria though the stomach acid environment into the lower gut where they may be beneficial.

Pasteurization Damages and Denatures Milk

Pasteurization damages milk such that it becomes oxidated, highly allergenic, and hard to digest. It is a common protocol to pasteurize milk up to 3 or 4 times to achieve longer shelf life and assure that the milk is completely dead, with no regard for the essential and beneficial bio-actives that are destroyed in the process. 

Raw milk contains everything it needs to digest itself. Raw milk contains enzymes and bacteria that help create more enzymes to digest raw milk and all the sub elements. Milk maldigestion has been over simplified. It is not just lactose; it is the proteins and fats that also need help with digestion.

After pasteurization the bioactive elements needed for milk to digest itself are missing! Fats, proteins, and sugars all need digesting, but their enzymes and digestive bacteria are denatured or dead.  Without active enzymes, digestion of fat (via lipase) and proteins (via protease) is inhibited. This results in maldigestion in some consumers. 

Whereas raw milk helps to build immune system strength, pasteurized milk does not build up the immune system. Heat denatures the functional proteins and does not allow cellular direction. This can result in cellular confusion and chaos.

Raw whey proteins are highly anti-inflammatory and have many health benefits. The raw whey health benefit findings are consistent with other researchers in the Netherlands, including Dr. Ton Baars’ research on whey proteins showing that they stabilize MAST cells, control histamine release, and reduce allergies.

However, all whey is required to be pasteurized in the USA as per the Food and Drug Administration (FDA) and Pasteurized Milk Ordinance. Whey proteins are destroyed by processing and are highly sensitive to heat. One researcher has been frustrated in trying to extract the beneficial components from pasteurized whey. The heating of whey makes the components “sticky” such that they plug up the ultrafiltration micropores. Therefore, ultra filtration cannot be used to extract whey components from pasteurized whey.

New Pasteurization Technologies Cause Less Damage Than Traditional Heat Pasteurization

As an alternative to heat-based pasteurization, researchers are studying other methods such as high pressure (HPP), ultrafiltration, and ultraviolet (UV) light. These methods are effective at inactivating bacteria and less harmful to milk than heat-based pasteurization. For instance, both high pressure processing and ultraviolet processing preserve some of the bioactive milk proteins better than heat-based pasteurization.

Nonetheless, milk processors in the USA are resisting the use of these new technologies. In some other countries, UV and HPP are being successfully used, but in the USA the FDA continues to represent processors’ interests and thereby block the ability to innovate with these alternatives to heat processing. This failure to innovate with HPP, UV or Ultrafiltration is creating a loss of consumer interest in pasteurized milk as people continue to suffer from maldigestion when consuming pasteurized milk.

In Studies, 20,000+ Kids Drank Raw Milk With NO Milk-Related Illnesses

The pioneering PARSIFAL and GABRIELA studies of more than 55,000 kids in Europe really set the international high bar for studies on raw milk. The overall findings included reduced rates of asthma, eczema, respiratory illnesses, fevers, allergies, and ear infections in children who drank raw milk.

At the symposium, it was emphasized that during all of those studies and over twenty years of research, there was never a “red flag event.” A red flag event would be a reported illness from raw milk consumption. The studies included data from more than 20,000 children who drank raw milk, and there was not a single red flag event!

Yet, at the end of each of the peer reviewed and journal published articles, there is a disclaimer that says something such as, “even though there are health benefits to consuming raw milk, the researchers can not recommend raw milk because of the risks of raw milk consumption.” This disclaimer was included because peer review and journal publication political pressures demanded it, despite the fact that there was no basis in the research data.

Dr. Markus Ege MD and Mark McAfee, in Cork Ireland at the IMGC symposium 2023

Raw Milk Provides Sustainability for Farmers and Superb Nutrition for Consumers

Farmers have been denied fair markets for their dairy products for more than a century. All of the value-added efforts are happening after products leave the farm. Milk processors continue to ensure that farmers are paid low prices for their milk, resulting in the loss of thousands of family farms. However, raw milk provides a pathway to sustainability and life satisfaction for dairy farmers.

Raw milk presents a unique farmstead product that brings all the added value back to the farmer with an incentive to work on quality. By selling directly to consumers, raw milk farmers are able to obtain greater financial rewards for their work, while consumers benefit from the improved flavor and nutrition. It’s a win-win for farmers and consumers!

Raw milk that is carefully and intentionally produced for direct human consumption is a low-risk food. This type of raw milk is wholly different from raw milk being produced in unhygienic conditions. Raw milk intended for direct human consumption is produced in sanitary conditions, with much care to ensure that the animals are healthy and that the milk is clean. This type of raw milk is tested often and held to rigorous standards to ensure that it is being produced in a way that discourages pathogen growth.

By combining nature’s blueprints, the bio-actives found in whole raw milk, standards for good production practices and modern testing systems, RAWMI Listed farmers are nourishing consumers safely. Congrats to all of the RAWMI Listed pioneers! 

Texas Raw Milk Training: For World-Class, Low-Risk Raw Milk!

Raw Milk Institute (RAWMI) recently taught a full-day intensive farmer training class on Production of Low-Risk, World-Class Raw Milk in Mount Pleasant Texas. RAWMI President Mark McAfee and Vice President Sarah Smith traveled to Texas to teach this class in collaboration with Northeast Texas Community College (NTCC).

There were 25+ attendees from Texas, Louisiana, and Arkansas. Attendees included farmers who are already producing raw milk, prospective farmers considering raw milk production, and students who were interested to know more about raw milk.

RAWMI presented our full 5-hour training presentation in the NTCC Ag Complex classroom, complete with catered snacks and lunch from local businesses.

A Texas state dairy inspector also presented and answered questions about Texas raw milk laws. She provided invaluable information about Texas’ Raw for Retail statute as well as the allowance for herdshares in Texas.

Following our classroom presentation, we took the students for a farm tour at Udder Delight Dairy, which is a raw milk micro-dairy that is operated by Tom and Brenda Ramler. Their dairy is currently working through our free one-on-one mentoring process to become a RAWMI Listed dairy.

Overall, this class was a resounding success! The students were engaged and appreciative of the opportunity to learn more. Several farmers who attended the class have expressed interest in becoming RAWMI Listed as well.

RAWMI extends special thanks to Tom Ramler, Jimmy Smith, and Northeast Texas Community College for sponsoring and coordinating this important step for safe, low-risk raw milk in Texas!

Managing the Increased Risks of Calf-Sharing on Raw Milk Farms

Calf-sharing, i.e. allowing a cow’s offspring to nurse directly from its mother, is a common practice on small dairy farms.  Many farmers and consumers think that calf-sharing is ideal for the health and well-being of both the cow and calf, and it does present an idyllic picture of farm life. Calf-sharing can also reduce the workload for farmers, who don’t have to bottle-feed the calves.   

However, farmers who are producing raw milk need to be aware that calf sharing increases the risk of pathogens being present in the raw milk. The same is true for kid-sharing with goats.

Pathogens, Calves, and Kids

You may wonder: Why do calf-sharing and kid-sharing increase the risk of pathogens in raw milk?  Just like human babies, calves and kids explore the world with their mouths and can then directly transfer harmful bacteria to the udders as well as to the inside of the teat canals. Calves and kids have immature immune systems and are therefore more likely to harbor pathogens themselves.

Although pathogens in well-produced raw milk are rare, they are still an important consideration and we encourage all raw milk farmers to take pathogens seriously.  Pathogenic bacteria that can be carried by calves and kids include E coli 0157:H7, Salmonella spp., Campylobacter spp., and Listeria monocytogenes. Illnesses from these pathogens can be serious or even fatal. 

Many scientific studies have verified that calves and kids are more likely to carry pathogens than their fully-grown counterparts. Below are a couple of the studies; additional studies are listed in the references section at the end of this article.

• A longitudinal study of Shiga-toxigenic Escherichia coli (STEC) prevalence in three Australian dairy herds -

  https://www.sciencedirect.com/science/article/pii/S037811359900173X?via%3Dihub -

  "In concurrence with previous studies, it appears that cattle, and in particular 1–14-week-old weanling calves, are the primary reservoir for STEC and EHEC on the dairy farm."

• Age related differences in phylogenetic diversity, prevalence of Shiga toxins, Intimin, Hemolysin genes and select serogroups of Escherichia. coli from pastured meat goats detected in a longitudinal cohort study - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7391229/ - "Overall, virulence genes and STEC [virulent e coli] were detected in isolates from goat kids in higher proportions than adult animals. Additionally, isolates with 2 or more virulence genes were significantly higher in pre-weaned and goat kids around weaning than in adult goats."

Illness outbreaks from petting zoos provide further confirmation that calves and kids can transfer pathogens in real-world conditions.

• Animal petting zoos as sources of Shiga toxin-producing Escherichia coli, Salmonella and extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae -   https://pubmed.ncbi.nlm.nih.gov/33382208/ - “Animal petting zoos and farm fairs provide the opportunity for children and adults to interact with animals, but contact with animals carries a risk of exposure to zoonotic pathogens and antimicrobial-resistant bacteria... Of 163 faecal samples, 75 contained stx1, stx2 or stx1/stx2 genes, indicating the presence of STEC. Samples included faeces from sika deer (100%), sheep (92%), goats (88%), mouflons (80%), camels (62%), llamas (50%), yaks (50%), pigs (29%) and donkeys (6%)…”

This information makes some farmers and consumers uncomfortable, yet it is still important to consider in developing a plan for minimizing the risk of pathogens from raw milk.   

Staph aureus, Calves, and Kids

In addition to pathogens that can cause human illness, calf-sharing (and kid-sharing) can increase the chance that Staph aureus will be widespread in the dairy herd.  Staph aureus is a type of bacteria that colonizes inside the mammary tissue, thereby increasing the risk of recurrent mastitis. The presence of Staph aureus can also cause scar tissue in the udder, which may result in lower milk production over time.  Cows and dams can transfer Staph aureus to suckling calves and kids, such that Staph aureus can become widespread in the dairy herd.  

Bottle-Feeding Has the Lowest Risk for Pathogens

At the Raw Milk Institute, our goal is to help farmers better-understand the potential risks in raw milk production so that they can then take steps to minimize the risks.  We are not the raw milk police, and we do not forbid anyone from calf-sharing. However, we want to make sure that farmers are aware of the risks and can then plan for how to reduce the risks.  

To achieve the lowest risk-profile, calves and kids would be bottle-fed.  It is nonetheless very important to ensure that the calves and kids receive the colostrum in order to help build up their immune systems. Be aware that the manure from calves and kids can also be a source of pathogens.  

Studies and farmer experience have shown that early separation (within 24 hours of birth) reduces the stress of the separation on both calves and cows. Leaving the cow and calf together for longer periods increases the stress related to separation.

• Effects of early separation on the dairy cow and calf: 2. Separation at 1 day and 2 weeks after birth - https://pubmed.ncbi.nlm.nih.gov/11179551/ - “Behavioural observations were conducted on 24 Holstein dairy cow-calf pairs during the first 24h after separation. Before separation, cow-calf pairs were generally inactive. After separation, cows from the late-separation treatment group showed higher rates of calling, movement and placing the head outside the pen, than cows in the early-separation group.”

Calves who have been separated from their mothers will do best if they are kept with at least one other calf rather than in isolation. 

• The effect of individual versus pair housing of dairy heifer calves during the preweaning period on measures of health, performance, and behavior up to 16 weeks of age - https://pubmed.ncbi.nlm.nih.gov/33358809/ - Pair housing of dairy heifer calves during the preweaning period helps meet the natural social needs of the calf and has been shown to improve growth and starter intake during the preweaning period as compared with individual housing.

Raising calves can be time-intensive, so some farms choose to instead have their calves raised offsite at farms that specialize in calf-rearing.  

Managing the Risks of Calf-Sharing

For farms that choose to calf-share or kid-share, below are some risk management strategies that have been employed successfully in small dairy farms that have participated in the Raw Milk Institute’s Listing program.  

• Apply extra diligence to udder preparation and stripping.  Ensuring that the teats are well-cleaned, pre-dipped, and stripped prior to milking will reduce the chance of pathogens being present. (See our Udder Prep for Raw Milk article for more information.)

• Closely monitor the calves/kids for any signs of illness.  If the calves/kids are ever showing signs of illness (such as diarrhea, runny nose, etc.), the milk would potentially have a greater risk of pathogens.  The milk should then be either diverted and not used for direct human consumption or the calves/kids should be separated from the herd until the illness has cleared.

• Perform regular milk culture testing of your herd for Staph aureus to make sure it is not present. Staph aureus can show up intermittently so one test does not necessarily clear the herd.

• Have a "nurse cow" or “nurse dam” to feed the calves or kids, whose milk is not used for human consumption.  This method needs to be utilized carefully, as too many calves/kids per nurse cow/dam can result in a loss of body condition and health problems for the nurse cow/dam.

• As they grow to a few months old, some calves/kids can be especially hard on the teats when nursing.  This can result in damage or injury to the teats. If this occurs, it is best to separate the offspring from their mothers.

It is also worth noting that calf-sharing (or kid-sharing) will reduce the amount of milk that is available to sell to customers. This can become especially problematic as the calves/kids reach 5+ months of age.

Choosing not to calf-share or kid-share is a good option for farmers who want to have the lowest risk of pathogens in their raw milk.  However, calf-sharing and kid-sharing can be done successfully when farmers acknowledge and manage the risks. The techniques listed above will reduce the likelihood of anything going wrong, for the benefit of both the customers and farmers.

A less-detailed version of this article was published in the June-July 2023 issue of Graze Magazine.

References

1. Age related differences in phylogenetic diversity, prevalence of Shiga toxins, Intimin, Hemolysin genes and select serogroups of Escherichia. coli from pastured meat goats detected in a longitudinal cohort study - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7391229/ - "Overall, virulence genes and STEC [virulent e coli] were detected in isolates from goat kids in higher proportions than adult animals. Additionally, isolates with 2 or more virulence genes were significantly higher in pre-weaned and goat kids around weaning than in adult goats."

2. Role of calf-adapted Escherichia coli in maintenance of antimicrobial drug resistance in dairy calves - https://pubmed.ncbi.nlm.nih.gov/14766551/ - "The prevalence of antimicrobial drug-resistant bacteria is typically highest in younger animals, and prevalence is not necessarily related to recent use of antimicrobial drugs. In dairy cattle, we hypothesize that antimicrobial drug-resistant, neonate-adapted bacteria are responsible for the observed high frequencies of resistant Escherichia coli in calves."

3. Antibiotic resistance and transferable antibiotic resistance of Escherichia coli isolated from Swedish calves 5 and 30 days old - https://pubmed.ncbi.nlm.nih.gov/1094406/ - "In comparison with the 30-day-old calves, the 5-day-old calves had significantly more strains with transferable antibiotic resistance (95.8 percent as against 63.4 percent)."

4. Enterotoxigenic Escherichia coli Infections in Newborn Calves: A Review -

   https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7130746/pdf/main.pdf - "Diarrhea caused by enterotoxigenic Escherichia coli is an infectious bacterial disease of calves that occurs during the first few days of life. The Escherichia coli that cause the disease possess special attributes of virulence that allow them to colonize the small intestine and produce an enterotoxin that causes hypersecretion of fluid into the intestinal lumen. These enterotoxigenic Escherichia coli are shed into the environment by infected animals in the herd and are ingested by newborn calves soon after birth."

5. Prevalence of Escherichia coli O157:H7 in range beef calves at weaning -

   https://www.cambridge.org/core/journals/epidemiology-and-infection/article/prevalence-of-escherichia-coli-o157h7-in-range-beef-calves-at-weaning/EBD00C9EB16D36476F75D825C05139B0 - "This study was designed to determine the prevalence of Escherichia coli O157:H7 infection of beef calves at weaning, prior to arrival at the feedlot or mixing with cattle from other sources. Fifteen range cow-calf herds, which weaned calves in October and November, were sampled in Kansas, Missouri, Montana, Nebraska and South Dakota... Thirteen of the 15 herds (87%) were found to have at least one positive isolation of E. coli O157:H7 in faecal samples...This study indicates that E. coli O157:H7 infection before weaning, prior to entry into feedlots, is widespread. Furthermore, serologic evidence suggests that most calves (83%) and all herds (100%) have been exposed to E. coli O157.

6. Diversity, Frequency, and Persistence of Escherichia coli O157 Strains from Range Cattle Environments -

   https://www.ncbi.nlm.nih.gov/pmc/articles/PMC152399/ - "The number of XbaI-PFGE subtypes, the variable frequency and persistence of subtypes, and the presence of identical subtypes in cattle feces, free-flowing water sources, and wildlife feces indicate that the complex molecular epidemiology of E. coli O157 previously described for confined cattle operations is also evident in extensively managed range cattle environments."

7. A longitudinal study of Shiga-toxigenic Escherichia coli (STEC) prevalence in three Australian dairy herds -

   https://www.sciencedirect.com/science/article/pii/S037811359900173X?via%3Dihub -

   "In concurrence with previous studies, it appears that cattle, and in particular 1–14-week-old weanling calves, are the primary reservoir for STEC and EHEC on the dairy farm."

8. Comparison of Diversities of Escherichia coli O157 Shed from a Cohort of Spring-Born Beef Calves at Pasture and in Housing - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1065151/ - "Overall, there was no demonstrable difference in shedding between calves when housed and at pasture. However, when shedding occurred, the rate of shedding was greater among calves in pen S (0.025 < P < 0.05) and pen N (0.05 < P ≤ 0.10) than when at pasture"

9. Persistence of verocytotoxin-producing Escherichia coli O157:H7 in calves kept on pasture and in calves kept indoors during the summer months in a Swedish dairy herd -

   https://pubmed.ncbi.nlm.nih.gov/11407548/ - "The objective of this part of the study presented here was to examine the persistence of VTEC O157:H7 in calves that were kept on pasture and indoors, respectively, during the summer...The faecal samples from the calves kept on pasture were negative during the whole period...This suggests that calves on pasture may be less exposed to the bacteria or that they clear themselves. In the pen group, there were between one and six culture positive individuals per sampling occasion. One of the calves that was housed indoors was positive in faecal culture on four consecutive samplings." (One big limitation on this study is the very small sample size. There were only 6 calves in each group, which is a very small number so that makes this data somewhat less able to be used to draw widely-applicable conclusions.)

10. Animal petting zoos as sources of Shiga toxin-producing Escherichia coli, Salmonella and extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae -   https://pubmed.ncbi.nlm.nih.gov/33382208/ - “Animal petting zoos and farm fairs provide the opportunity for children and adults to interact with animals, but contact with animals carries a risk of exposure to zoonotic pathogens and antimicrobial-resistant bacteria. The aim of this study was to assess the occurrence of Shiga toxin-producing Escherichia coli (STEC), Salmonella, extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae and methicillin-resistant Staphylococcus aureus (MRSA) in animal faeces from six animal petting zoos and one farm fair in Switzerland. Furthermore, hygiene facilities on the venues were evaluated. Of 163 faecal samples, 75 contained stx1, stx2 or stx1/stx2 genes, indicating the presence of STEC. Samples included faeces from sika deer (100%), sheep (92%), goats (88%), mouflons (80%), camels (62%), llamas (50%), yaks (50%), pigs (29%) and donkeys (6%), whereas no stx genes were isolated from faeces of calves, guinea pigs, hens, ostriches, ponies, zebras or zebus. Salmonella enterica subsp. enterica serovar Stourbridge (S. Stourbridge) was detected in faecal samples from camels. A total of four ESBL-producing E. coli strains were isolated from faeces of goats, camels and pigs... This study provides data that underscore the importance of hygiene measures to minimize the risk of transmission of zoonotic pathogens and MDR, ESBL-producing E. coli to visitors of animal petting venues.” 

11. Investigations on Transfer of Pathogens between Foster Cows and Calves during the Suckling Period - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8469241/ - “The present study aimed to compare the pathogens detected in the mammary glands of the foster cow with those in the oral cavities of the associated foster calves and to evaluate the resulting consequences for udder health, calf health and internal biosecurity... Transmission of P. multocida and S. aureus probably occurred during suckling. For S. sciuri and Sc. suis, environmental origins were assumed. Transmission from dam to foster cow with the suckling calf as vector could not be clearly demonstrated.”

12. Effects of early separation on the dairy cow and calf: 2. Separation at 1 day and 2 weeks after birth - https://pubmed.ncbi.nlm.nih.gov/11179551/ - “Behavioural observations were conducted on 24 Holstein dairy cow-calf pairs during the first 24h after separation. Before separation, cow-calf pairs were generally inactive. After separation, cows from the late-separation treatment group showed higher rates of calling, movement and placing the head outside the pen, than cows in the early-separation group.”

13. The effect of individual versus pair housing of dairy heifer calves during the preweaning period on measures of health, performance, and behavior up to 16 weeks of age - https://pubmed.ncbi.nlm.nih.gov/33358809/ - Pair housing of dairy heifer calves during the preweaning period helps meet the natural social needs of the calf and has been shown to improve growth and starter intake during the preweaning period as compared with individual housing. 

Managing Pathogen Risks from Fresh Cows and Does

For farmers who are producing raw milk for direct human consumption, it is important to understand the risks related to fresh cows and does. Freshening is a time of tremendous change as the udder moves into the production of colostrum and milk.  During this time of transition while the milk supply is being established, there is a higher likelihood of mastitis and pathogens being present in the udder. Although pathogens in well-produced raw milk are rare, they are still an important consideration and we encourage all raw milk farmers to take pathogens seriously.  

Fresh Cows and Pathogens

Our understanding of the increased pathogen risks in fresh cows/does is largely based on test data from RAW Farm in California. This dairy was founded by RAWMI Chairman Mark McAfee over 20 years ago, and it operates on a different scale than most raw milk dairies.  RAW Farm is milking over 800 head of cattle and serving thousands of customers with distribution to over 400 stores in California. With this relatively large scale of raw milk production, RAW Farm has implemented some unique risk management strategies to ensure that the milk they provide is ultra-low-risk.

RAW Farm utilizes frequent pathogen testing as part of their risk management strategy. After having a positive E coli 0157:H7 test in a fresh cow’s milk years ago, RAW Farm started performing more frequent testing on individual fresh cows.  The overall test dataset shows that although pathogen detections are still rare, nonetheless fresh cows are more likely to test positive for pathogens than cows whose milk supply is well-established.

Based on this experience, RAW Farm chooses to err on the side of being extra careful, so they withhold the milk from fresh cows from their bulk tank for a minimum of 28 days and do multiple sets of pathogen tests on each fresh cow before adding her milk to the bulk tank.  However, we would not expect small-scale farms to undergo the same rigorous, expensive protocol. 

Withhold Milk for 5-7 Days, Then Check To Make Sure All is Well

Our general recommendation is for raw milk farmers to ensure that milk from fresh cows/does is not used for direct human consumption for a minimum of 5-7 days after freshening. After that period, we recommend that intentional methods be used to ensure there is no inflammation or mastitis present. Some methods that have been used successfully at other farms include:

• udder inspection for signs of inflammation

• testing such as mastitis, coliform, pathogen, and/or somatic cell count tests

There are several types of on-farm mastitis tests available, including 4-Way California Mastitis Test, Mas-D-Tec, and Udder Check.  When combined with visual inspection, these tests serve as a verification step prior to using the milk for direct human consumption.

Milk Fresh Cows and Does Last

Another risk management strategy is to make sure that the fresh cows/does are milked last, to ensure that any potential pathogens do not contaminate the milk from other animals.  After milking the fresh cows/does last, the milking machine should be rigorously cleaned, with special care taken for any complex parts such as valves.

What to Do With The Withheld Milk

Right after freshening, the colostrum should ideally be fed to calves/kids, who will benefit from its immune-system strengthening properties. Once the colostrum has cleared, and assuming that the milk looks healthy, this milk can be used for making inherently-low-risk foods such as butter or aged-cheeses. Due to their low moisture content and low pH, these foods are very unlikely to harbor pathogens.   

Acknowledge the Risk and Make a Plan

Managing the increased pathogen risks for fresh cows/does need not be complicated.  Just as for other potential risks, we recommend that farmers acknowledge the risk and make a plan for how to handle it.  This will reduce the likelihood of anything going wrong, for the benefit of both the customers and farmers. With proper risk management, low-risk raw milk is achievable.

Want help in optimizing your own production of raw milk? Check out our FREE Listing Program for farmers!

This article was published in the May 2023 issue of Graze Magazine.

Join Us for Raw Milk Training in Oregon June 17-18

On June 17-18 2022, the Raw Milk Institute (RAWMI) will be providing Raw Milk Risk Management training in Oregon. This training is will be done in collaboration with Cast Iron Farm (RAWMI Listed farm in Oregon).

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About the Training

This 2-day intensive RAWMI training workshop will focus on the benefits of raw milk, grass-to-glass identification of risks, development of a risk management plan, and lessons learned from other raw milk dairies. It is our goal to assure that raw milk is safe and continues to be freely available for both farmers and consumers in Oregon.

The training will be hosted at Cast Iron Farm in McMinnville, Oregon. We'll be providing lots of practical tips for the production of safe raw milk. The training will include formal presentations as well as demonstrations and tours at Cast Iron Farm. This training has been shown to reduce outbreaks and illnesses, increase safety, and lower insurance costs.

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Cost and Registration

The cost for this 2-day training workshop is only $35.

If the cost is a barrier, feel free to contact Christine at Cast Iron Farm to learn about potential scholarships.

You can register for the class here:

http://castironfarm.com/rawmi-training-june-2023/

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Class Schedule

Saturday June 17th

• 9:30am - Arrival and introductions

• 10:00am - 45 minute presentation by Oregon Department of Ag outlining the new CAFO regulations for anyone owning dairy animals.  This will include time for Q&A. If you do not feel comfortable attending a presentation given by the state agency, feel free to join us after lunch.

• noon-1pm - Light lunch and snacks

• 1pm-3pm - RAWMI presentation by Mark McAfee on health benefits of raw milk, safety and risks of raw milk

• 3pm-3:20pm - Stretch break

• 3:30pm-5pm - RAWMI presentation on raw milk risk management from grass-to-glass

Sunday June 18th

• 9:30am - Milking demonstration and tour of Cast Iron Farm

• 10:30am-noon - RAWMI presentation about raw milk testing and and building a successful raw milk business

• noon-1pm - Light lunch and snacks

• 1pm - One-on-one questions and consultations with RAWMI to answer all your questions

Sunday afternoon tours of Godspeed Hollow, another RAWMI listed farm 20 minutes from Mcmminnville, can be arranged by appointment for those interested.

Rapid Chilling of Raw Milk Lowers Pathogen Risks and Improves Shelf-Life

For raw milk production, risk management and customer satisfaction go hand-in-hand.  Many of the strategies that result in low-risk raw milk also work well to keep customers happy with delicious, long-lasting milk. Rapid chilling is one such strategy that lowers the risk of pathogens while also improving the flavor and shelf-life of raw milk.

Although pathogens in well-produced raw milk are rare, they are still an important consideration and we encourage all raw milk farmers to take pathogens seriously.  The four main pathogens of concern that can be found in raw milk are E coli 0157:H7, Salmonella spp., Campylobacter spp., and Listeria monocytogenes. Illnesses from these pathogens can be serious or even fatal. 

In the rare case when pathogens are present in well-produced raw milk, illness will still not occur unless the pathogen load (or amount of pathogen present) is high enough to produce illness. If it is present in a small enough quantity, even the most virulent pathogen will not produce illness.  Generally, the presence of a single virulent bacterium is not sufficient to cause illness, and different pathogens have varying thresholds at which they must be present to induce human illness. 

However, bacteria multiply rapidly at warm temperatures and can double their count in as little as 20 minutes. At cold temperatures, bacteria growth slows down dramatically.  This means that farmers can greatly reduce the number of bacteria present in raw milk by quickly chilling the milk right after milking time. 

Aim for Chilling to 35-40 °F in Less Than an Hour

Our general recommendation is for farmers to chill their raw milk to 35-40 °F within an hour of milking.  This helps in ensuring that any bacteria present in the raw milk do not have much time in which to multiply.

Refrigerators do not generally work well for rapidly chilling raw milk.  Depending on the size of the milk jar or jug, it may take a few hours for warm milk to cool down to under 40 degrees in the refrigerator. Freezers also do not generally work well for chilling milk because the milk may freeze and break the glass jars. 

In order to achieve cold milk in a short time, other methods are needed. We work closely with dozens of farmers, and have seen that rapid milk chilling is achievable no matter the size of the farm.  Here are some of the different ways in which farmers can rapidly chill their raw milk to 35-40°F in an hour or less.  

Ice-and-Water Bath for Rapid Milk Chilling on Micro-Dairies

For small-scale farms, an ice-and-water bath can work well for milk chilling. A chest cooler can be used to hold the ice-and-water bath.  When using this method, there are a few important things to pay attention to:

• The milk jars should be submerged in the cold ice-and-water, but make sure that the water level does not reach lid of the milk container. Otherwise, there may be problems with water comingling with the milk in the jars.

• The size of the milk jar will make a big difference in how long it will take the milk to chill down.  We recommend that farmers use milk jars that are no larger than ½ gallon, or else the chilling time will be too lengthy.

• Some farmers who do not have ice maker machines have preferred to use either stainless steel ice cubes (which can be sanitized in the dishwasher) or frozen water bottles which can be reused over and over again.

• Make sure there is enough cold ice water to rapidly chill the milk.  If there are too many milk jugs in relation to the amount of ice water, then the chilling will not be quick enough.

• Some farmers like to add in a small submersible water pump (such as an aquarium or pond pump) to circulate the water in their ice water bath for quicker chilling. 

• Whatever method you use, you can check to see whether the milk is chilling rapidly enough by measuring the temperature in the middle of your milk jars after an hour.   
  

Bulk Milk Tanks

Bulk tanks are another option for milk chilling. Small bulk tanks can hold up to 15 gallons of milk, and many other sizes are available for farmers who are producing larger quantities of milk.  Bulk tanks with integrated cooling systems can quickly chill the milk to the desired temperature. When using a bulk tank, farmers need to be aware of the following:

• Bulk tanks need to be sized appropriately, or else there can be problems with the milk freezing if there is too little quantity of milk relative to the size of the tank.

• Milk stacking occurs when milk from multiple milkings is poured into the bulk tank. This can result in increased bacteria counts as the milk in the tank is re-warmed each time fresh milk is added.  Furthermore, milk stacking increases the risk of contamination from one batch of milk to another, thereby increasing the potential damage done by the presence of any undesirable bacteria/pathogens. We recommend that farmers minimize milk stacking by bottling their milk after every 1-3 milkings.

• Bulk tanks must be thoroughly cleaned after each time the milk is bottled.  The valve on the bulk tank, in particular, needs to be completely disassembled and scrubbed clean to ensure that it does not harbor bacteria. 

Sophisticated Chilling for Larger Farms

Larger farms may choose to use sophisticated chilling equipment, such as plate chillers.  These chillers will cool the milk down rapidly in just a few minutes before it even enters the bulk tank.  Farmers using plate chillers need to be aware of the following:

• Complex equipment can create more opportunities for bacteria biofilms to grow in nooks and crannies. Therefore, thorough cleaning is essential for plate chillers in between milkings.

• A clean-in-place (CIP) system will be required for thoroughly cleaning the plate chiller.  We recommend that farmers work with a dairy supply consultant to optimize the CIP for their individual pipeline systems. This should include a tepid rinse, followed by a hot wash with alkaline detergent, followed by a warm acid rinse. 

• The temperature of the water used for the hot alkaline wash will decrease as the water flows through the system, thereby reducing the effectiveness of the cleaning solution. It is recommended to ensure that the temperature of the wash water is at least 120 degrees at the outlet of the system.

• Over time, bacteria biofilms can become resistant to specific cleaners, especially in pipeline systems.  Therefore, it is recommended to periodically “shock” pipeline systems by using different alkaline and acid cleaners about once a month.

Rapid Milk Chilling is Achievable

Rapid milk chilling is an important strategy for risk reduction with raw milk.  As we have described, rapid chilling is achievable no matter the size of the farm. Besides reducing the risk of high bacteria counts in the milk, rapid chilling can also result in a longer shelf-life for the milk and help in preventing off flavors. Rapid chilling is a Win-Win for both farmers and customers.

This article was published in the April 2023 issue of Graze Magazine.