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 enough to 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 every 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.

WEBINAR VIDEO: Let's Talk About Raw Milk

Over 100 people attended our recent Let’s Talk About Raw Milk webinar. We had attendees from coast-to-coast across the United States, including Arizona, California, Delaware, Florida, Georgia, Indiana, Iowa, Massachusetts, Michigan, New Hampshire, New Jersey, New Mexico, New York, Oregon, North Carolina, South Carolina, Texas, Virginia, Washington, Wisconsin, and Wyoming. We also had international attendees from Bedfordshire England, Sussex England, and Mexico.

This was a great opportunity for our Board of Directors at the Raw Milk Institute to share our passion for raw milk and connect with raw milk consumers and farmers. In the wake of our presentation, we’ve been contacted by many who missed the webinar as well as attendees who want to share it with others. We are pleased to share with you this recording of the webinar!

About the Webinar

Below is our 50-minute webinar (followed by 25 minutes of Q&A), which covers:

• 00:00 - Introduction

• 05:59 - Top 5 Reasons to Drink Raw Milk

• 09:10 - History of Raw Milk

• 13:42 - Health Benefits of Raw Milk

• 22:01 - Two Types of Raw Milk

• 25:46 - Safety and Risks of Raw Milk

• 31:40 - RAWMI Method for Low-Risk Raw Milk

• 40:03 - How to Find a Good Raw Milk Farmer

• 44:07 - How to Take Care of Your Raw Milk

• 48:27 - Help Your Farmer Achieve Excellence

• 49:00 - Interactive Q and A

Presented by:

• Mark McAfee - Raw Milk Institute President and CEO of Raw Farm

• Sarah Smith - Raw Milk Institute Vice President and Natural Healthcare Practitioner

• Dr Joseph Heckman - Raw Milk Institute Board Member and Professor of Soil Science

• Kelsey Barefoot - Raw Milk Institute Board Member and Owner of The Barefoot Cow

• Esther Arkfeld - Raw Milk Institute Board Member and Owner of Dairy on Orange

Build Immune System Strength With Whole Foods: Drink Raw Milk!

America invested $3 billion dollars and spent 13 years between 1990 and 2003 to figure out what makes us genetically human. The research project focused on discovery of the genes and genetic code that makes us what we are.  This work was funded by Congress and led by the Department of Energy and the National Institutes of Health. The findings were not quite as expected.  

Our parents gave us each about 20,000 genes that give us our basic structure and shape. That was the easy part.  That is our “hardware”. However, the “software” that runs our human machine gets a little tricky. It becomes very complicated and even inconvenient.

Rob Knight, founder of the Center for Microbiome Innovation and Professor of Pediatrics at the University of California San Diego, describes that,

“You’re more microbe than you are human.”

On a cellular level, we are only 43% human, with the balance of our cells being bacteria, viruses, and fungi. Genetically, our 20,000 human genes are vastly outnumbered by 2,000,000 to 20,000,000 microbial genes, which are mainly coming from bacteria. And most of these bacteria make their home in our gut.

At the cellular level, genetic information is shared between human cells and microbial cells. Genetic information is freely traded, exchanged and swapped around as an essential part of life and cellular function. The essential bacterial genetic information acts as “software” for the human cells, regulating the immune system, digestion, and manufacture of vital vitamins. This is how our human micro-biome functions.  

I like to say “we are Bacteriosapiens”.  What does this mean in real terms? How do we apply advanced science and use this information to better our lives? The bottom line is this:

We have great control over our optimal health.

We are not narrowly driven by the genes our parents passed to us. Those genes are important, but they are only a sliver of the genetics that truly drive our human machine. How we live our lives has tremendous impact on our microbiome and therefore our health. Were we breast fed, were we born by C-Section, did we receive heavy antibiotics early on? That’s just for starters. What we were fed as children and how do we continue to eat today? Don’t get into a guilt trip. That’s all old history. You can start fixing it today.

According to Dr. Anahid Jewett PhD at UCLA:

The healthy gut biome needs two things to reduce inflammation and keep you healthy:

• A load of biodiverse bacteria

• The whole foods that feed them

It comes down to nurturing our beneficial bacteria!  How do we get good bacteria to hang out, colonize our bodies, and become our very best genetic friends? How do we get and keep our genetic software so our human cells can make good decisions and keep us healthy?  Beneficial bacteria don’t hang around very long if we don’t offer them breakfast, lunch and dinner.

What nourishes our beneficial bacteria?  Whole foods do. What is a whole food? A whole food is a food that is unprocessed and complete. Nothing taken away and nothing added. Whole foods grow right out of good healthy soils which are teaming with earthworms, fungi, and bacteria. Whole foods come right out of the cow or straight from a well-nourished animal.

Americans don’t eat many whole foods. Instead we eat the Standard American Diet (SAD). In doing so, we starve and deprive our beneficial bacteria! In fact, we Americans love our antibiotics, pharmaceutical drugs, preservatives, sugar rich foods, long shelf life foods and GMOs. Highly processed foods and chemicals are destructive to our gut biome and the bacterial diversity required for genomic health. So what does that leave us? Its leaves us with “hardware and no software to drive it”. We become genetically inept at the cellular level.  We develop a whole range of diseases, including allergies, leaky gut, autoimmune disorders, depression, autism, and more. It’s really SAD.   

Nourishing and healing our gut microbiome requires moving away from processed foods and pharmaceuticals, and instead moving towards whole foods.

Raw milk, raw cheese, raw butter, raw cream and raw kefir are whole gut biome superfoods. They seed the gut with diverse beneficial bacteria, while providing the enzymes, proteins, minerals, and good fats that bacteria love to eat. They are whole foods with biologically active elements and protein systems that protect the gut, and build and maintain our immune system. They are the first foods of life!  Add fresh or fermented vegetables, grass-fed beef, chicken, eggs, and other direct-from-the-farm foods to make your bacteriosapien thrive!

Follow-on studies to the Human Genome Project continue today, including the Human Microbiome Project and the American Gut Project. It has become quite the clash of titans. The current medical and food processing establishments find this information to be extremely inconvenient. If bacteria are critical to life, then what are we doing with all the antibiotics? Sugars grow candida yeast and disrupt normal healthy bacterial colonization. Preservatives kill off bacteria in foods to extend shelf life and cause damage to the gut bacterial colonies. So does the widely-used glyphosate Round-up!

In the Coronavirus Pandemic, we witnessed lack of resilience in our gut biomes and immune systems.

While some people were not affected by Coronavirus others became deathly ill or worse.  We don’t know exactly why there was such a difference in these outcomes and pathways. We have been given a big hint, though: in general, COVID19 illness seriously affected those with compromised immune systems and poor health status.

New threats will continue to emerge. Viruses and bacteria continually evolve and adapt. Our immune system and gut biome must dynamically do the same. We must be adaptive and resilient to be able to address the ever present and evolving threats that will come to visit us. Will your immune system and genomics be up to the new threat?  Vaccines are always late, come after the fact, and don’t have the most effective track record. A healthy adaptive resilient immune system is with you and working all the time.

There is a long list of studies that confirm the health benefits of raw milk. These benefits include significantly fewer colds (which are viral illnesses), less asthma, fewer ear infections, reduction of eczema, less allergies, and stronger general health. These findings confirm that:

Those who eat a whole food diet and consume raw dairy products have more adaptive and resilient immune systems.

Get to know your bacterial self. You are not alone. Give your new best friends breakfast, lunch, and dinner. They won’t ever let you down if you feed them well.

Drink your raw milk and eat your whole foods! Cherish your new bacterial friends. They are the healthy you!

Welcoming Farms in Washington, Idaho, and New York to RAWMI Community

The Raw Milk Institute (RAWMI) sends a warm welcome to three more farmers who have completed our Listing program!

RAWMI offers free mentoring to all dairy farmers. Whether they are milking one cow, a handful of goats, or a large herd, the principles of safe raw milk production form a foundational toolset that benefits all dairy farmers and their customers. 

Some of the farmers we mentor choose to keep it casual, and are satisfied to just ask us a few questions before continuing their raw milk journeys. There is another set of farmers, though, that is not content to just dip their toes in the water; they want to dive right in and take their entire milk process to the next level. 

For these farmers, we offer our (free) RAWMI Listing program, wherein we assist farmers in developing their own unique on-farm Risk Analysis and Management Plan, documenting their processes with written Standard Sanitary Operating Procedures, and identifying the Critical Control Points that are essential to their production of safe raw milk. RAWMI Listed farmers test their milk at least monthly for ongoing assurance that their processes are working well to produce low-risk raw milk. RAWMI Listing is the gold standard for raw milk producers.

Three raw milk farms have recently completed the RAWMI Listing process, and we extend them a warm welcome into our growing community!

• #67 - G&G Dairy - Churchville, New York, USA

• #68 - Renegade Ridge Creamery - Prescott, Washington, USA

• #69 - Blue Wildrye Dairy - Princeton, Idaho, USA

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G&G Dairy - Churchville, New York, USA

Grace Zuber is the owner and operator of G&G Dairy. She grew up on a conventional dairy, family-owned farm. Once her dad had retired, she knew her passion and love for dairy cows wasn’t going to stop. The idea of producing raw milk comes from Grace’s love of one cow she was already milking separately from the main heard of a few thousand. When her dad retired, she started with just a handful of cows, but a year and a half later she now has 18 altogether of various ages. With a lot of help a new raw milk facility was built. After getting the approval from NYS, Grace was given the certification to start selling raw milk in November of 2024. Her cows are all grass-fed girls and she grows her own hay for winter.

Grace has a small storefront for her customers to come pick up milk. Along with raw milk, she offers eggs, homemade soaps, and fresh raw honey (when in season).

You can check out G&G Dairy’s Risk Management Plan and test results here: https://www.rawmilkinstitute.org/listed-farmers/#gg

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Renegade Ridge Creamery - Prescott, Washington, USA

Renegade Ridge Creamery, located on the Pedersen Family Ranch, was established in 2025 with one simple mission: bringing fresh, healthy raw milk to families throughout Southeast Washington.

They started by milking a single Jersey cow to provide wholesome food for their own family. As the ranch grew, so did their passions. They began raising Pyredoodle puppies and, ultimately, turned Gretchen's lifelong love of cattle and dairying into a family-owned microdairy.

Today, Renegade Ridge Creamery is proud to be Washington State's first RAWMI Listed dairy, reflecting their commitment to producing raw milk with exceptional safety, quality, and transparency. Their herd consists primarily of Jersey cows, along with a few carefully selected Jersey crosses.

All five of the Pedersen children help care for the animals and participate in the daily work of the ranch and creamery. They believe that knowing your farmer matters, and enjoy educating their members about raw milk, responsible farming practices, and the importance of supporting local agriculture.

You can check out Renegade Ridge Creamery’s Risk Management Plan and test results here: https://www.rawmilkinstitute.org/listed-farmers/#renegade

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Blue Wildrye Dairy - Princeton, Idaho, USA

Blue Wildrye Dairy grew out of an unexpected love affair with raw milk. Because Suzanne’s father was a public health physician—and naturally cautious about raw milk—she never tasted it while growing up. When she finally did, years later, it was love at first sip.

When Suzanne and her husband began building Blue Wildrye Farm, their pasture-based regenerative farm in the rolling hills of northern Idaho, she knew this extraordinary food fit naturally within their mission: caring for the land, raising animals with respect, and producing deeply nourishing food for their community. Suzanne set out to learn how they could produce raw milk that was not only exceptionally rich and delicious, but also as clean and low-risk as possible.

RAWMI provided the knowledge, mentorship, and rigorous framework they needed to build their microdairy from the ground up. Today, their small herd of A2A2 Jersey cows grazes rotationally managed pastures. They combine careful animal husbandry, meticulous sanitation, rapid chilling, and weekly milk testing to ensure that every jar reflects their commitment to both quality and safety.

After seeing the lengths Suzanne goes to in order to produce clean milk, even her public-health-doctor dad is now willing to drink raw milk—as long as it comes from her dairy.

You can check out Blue Wildrye Dairy’s Risk Management Plan and test results here: https://www.rawmilkinstitute.org/listed-farmers/#bluew

REGISTRATION IS NOW OPEN! August 11th - Let's Talk About Raw Milk - FREE Webinar

On Tuesday August 11th at 12pm Pacific / 1pm Mountain / 2pm Central / 3pm Eastern, the Raw Milk Institute will present a free 1-hour Let’s Talk About Raw Milk webinar. This presentation will be livestreamed, so that everyone can conveniently attend from their own locations.

About the Webinar

This RAWMI presentation will focus on:

• Top 5 reasons to drink raw milk

• History and benefits of raw milk

• Safety and risks of raw milk

• How to find a good raw milk farmer

• How to take care of your raw milk

How to Register

This webinar is FREE and registration is now open! You can register to attend at this link:

Space is limited, so make sure to register now if you want to attend. We look forward to seeing you on Zoom!

SAVE THE DATE! August 11th - Let's Talk About Raw Milk - FREE Webinar

On Tuesday August 11th at 12pm Pacific / 1pm Mountain / 2pm Central / 3pm Eastern, the Raw Milk Institute will present a free 1-hour Let’s Talk About Raw Milk webinar. This presentation will be livestreamed, so that everyone can conveniently attend from their own locations.

About the Webinar

This RAWMI presentation will focus on:

• Top 5 reasons to drink raw milk

• History and benefits of raw milk

• Safety and risks of raw milk

• How to find a good raw milk farmer

• How to take care of your raw milk

How to Register

We will soon be accepting registrations for this event! In July, we will announce when you can register via our website, email list, and social media accounts.

We're Making Low-Risk Raw Milk a Reality!

We’ve recently analyzed our database of over 11,000+ sets of coliform and standard plate count data and the results are in: RAWMI Listed farmers are surpassing the bacteria standards for pasteurized milk!

Our Raw Milk Test Database

Every month, we receive raw milk test data from dozens of Raw Milk Institute (RAWMI) Listed farmers. In order to become Listed, these farmers have completed our free intensive mentoring program, developed individualized Risk Analysis Management Plans for their farms, and committed to ongoing bacterial testing of their milk. To date, over 65+ farms have completed our Listing program.

Listed farmers are required to test their milk at least once per month for coliforms and Standard Plate Count (SPC). Many Listed farmers choose to test their milk more often, such as once per week or even daily. As a result, we collect hundreds of raw milk test data points every month from our Listed farmers and have compiled a huge test database over the last 14 years. We have now amassed over 11,000 test data points each for coliforms and SPC tests in raw milk.

About Coliform and Standard Plate Count Tests

The SPC is a measure of the total number of aerobic bacteria in the milk. High SPC numbers can indicate dirty milking equipment, poor milk chilling, udder inflammation, and/or poor udder preparation.

Coliform count measures the amount of coliform bacteria present in the milk. Coliform counts measure the overall hygiene and cleanliness of the milk. High coliform counts generally indicate the presence of manure or other environmental contaminants on the udders or milking equipment. They can also indicate the presence of udder inflammation. High coliform counts are likely to correspond to the presence of harmful pathogens in the milk.

Although these two tests do not directly detect the presence of pathogens, they serve as general indicators that the milk is being produced hygienically and in such a way that pathogens are less likely to be present. No food can ever be perfectly safe, but nonetheless these tests can help to dramatically decrease the risk of having pathogens present.

Standards for Pasteurized vs Raw Milk

Below is a summary of the coliform and SPC standards for raw, pre-pasteurized, and pasteurized milks, in units of colony-forming units per milliliter (cfu/mL).

Standard Plate Count

• Federal Pasteurized Milk Ordinance (PMO) - Allows up to 100,000 cfu/mL in pre-pasteurized milk.

• Federal PMO - Allows up to 20,000 cfu/mL in pasteurized milk.

• Raw Milk Institute Common Standards - Allows up to 5,000 cfu/mL in raw milk for direct human consumption.

Coliforms

• Federal PMO - Allows unlimited number of coliforms in pre-pasteurized milk.

• State of California - Allows up to 750 cfu/mL coliforms in pre-pasteurized milk.

• Federal PMO - Allows up to 10 cfu/mL in pasteurized milk.

• Raw Milk Institute Common Standards - Allows up to 10 cfu/mL in raw milk for direct human consumption.

RAWMI Listed Farmers Are Surpassing Pasteurized Milk Standards

Intentionally-produced raw milk is measurably quite different from pre-pasteurized raw milk and even meets stricter standards than pasteurized milk. Our large dataset of thousands of test results shows that raw milk farmers who have been properly trained can routinely meet the stringent standards set forth in the RAWMI Common Standards.

In analyzing all of the test data from RAWMI Listed farmers over the last 14 years, we found the following for raw milk that was to be used for direct human consumption.

Coliforms

• 11,826 total tests

• Average of all tests = 2.1 cfu/mL

Standard Plate Count

• 11,470 total tests

• Average of all tests = 960 cfu/mL

In over 11,000+ tests, RAWMI Listed Farmers averaged <1,000 cfu/mL for SPC and 2 cfu/mL for coliforms.

Making Low-Risk Raw Milk a Reality Across the USA, Canada, and Beyond!

There are now RAWMI Listed Farmers in 21 states of the USA, 2 Canadian Provinces, and Lebanon. You can check out their Risk Analysis Management Plans and monthly test data here.

Managing Potential Pathogenic and Herd Health Risks in Raw Milk Herds

The demand for raw milk is growing as more farmers and consumers  learn about its nutritional benefits, delicious flavor, anti-inflammatory functional proteins, bioactive compounds, farm sustainability and beneficial animal and environmental stewardship.[i, ii] Raw milk farmers can thrive in this emerging market and help their customers achieve robust health with strong immune systems, less inflammation, and less asthma and allergies.[iii, iv, v] 

Unfortunately, that service to consumers can be overshadowed if farmers aren’t diligent about managing the real food safety risks that can come along with raw milk and the farm environment. There is no such thing as perfectly safe food. Like other foods, if not properly produced and handled, raw milk may contain pathogens that may make customers sick. The resulting illnesses can be serious or, on rare occasions, even fatal.

People are depending on farmers to manage the food safety risks. Although the risks are small, they are real, and we encourage all raw milk farmers to take these risks seriously with ethical and moral commitment. The health of the individual cows/goats/sheep (or other mammals) and the overall raw milk dairy herd is of prime importance in ensuring that raw milk is low-risk and safe to drink. As more farmers become focused on producing low risk raw milk for direct human consumption, there is an increased interest in learning which specific human pathogens and herd health conditions may be of concern.  

Pathogens and Zoonotic Diseases Versus Herd Health Concerns

The main microorganisms that may be of concern for raw milk dairy herds include different types of bacteria and viruses.  Some of these microorganisms cause illness or disease that can be transmitted from animals to humans or vice versa (also known as zoonosis or zoonotic disease). We generally refer to these microorganisms as human pathogens.

Some other microorganisms of concern can cause health problems in the dairy herd, but are not generally considered to pose human health risks and/or are not transmissible through food. There is uncertainty about several microorganisms and possible connections to human health risks.

We recommend that every raw milk farmer build a good relationship with a veterinarian who can be trusted for advice in herd health management. As a helpful guide, this article provides an overview of the following microorganisms of concern.

• Zoonotic microorganisms (known human pathogens): Verotoxin-producing Escherichia coli (VTEC, such as E. coli 0157:H7, Salmonella enterica spp., Campylobacter spp., Listeria monocytogenes, Shigella spp., Yersinia spp., Mycobacterium bovis (tuberculosis), Brucella bovis (brucellosis), Coxiella burnetii (Q Fever), Avian Influenza H5N1, Staphylococcus aureus (S. aureus).

• Herd disease microorganisms (those not generally considered as human pathogens): Bovine Leukemia Virus (BLV), Mycobacterium avium subsp. paratuberculosis (MAP, Johne’s disease or paratuberculosis).

The guidance in this document is intended for educational purposes. Local disease conditions are important in determining the appropriate course of action, so it is recommended to consult with a local veterinarian in making decisions about herd health monitoring and testing.  

Three Variables for Illness

Bacterial, fungal, and viral pathogens need a host to survive and thrive, yet pathogens do not cause illness in every host. For a pathogen to cause illness, three variables must align:

• A pathogen must be present which is virulent and capable of producing harmful effects

• The pathogen load must be high enough to trigger illness

• The host must be susceptible to the pathogen

Farm families tend to have strong immune systems that are adapted to the microbial flora of the animals and the farm environment, so they are less likely to become ill from raw milk that could possibly contain some of these microbes. However, it is important for farmers to recognize that many consumers may have compromised immune systems or immune systems that have not been adapted to the farm microbial flora, such as those living in urban areas, those taking medications such as antibiotics, chemotherapy or other immune-suppressing drugs, and those exposed to toxins in the environment or in the food. Unlike the farmer and the farm family, these consumers may be at a higher risk of illness from exposure to pathogens that can be found routinely in the farm and animal environment.   

Sampling Techniques for Microorganisms

Determining whether there are microorganisms of concern in the raw milk dairy herd generally requires observation, physical assessment, and specialized laboratory testing. It is important to work with the herd veterinarian, the diagnostic laboratory, and/or consultants to evaluate the presence of microorganisms of concern on the farm. The aim of testing is to determine the presence of specific microorganisms on the farm, where the hazards are present within the farm, and whether the microorganisms are present in the raw milk.

Depending on the goals of testing, the samples may come from numerous sources such as slurry, manure, water, milk from individual teats, milk from a single animal, blood, urine, animal tissue, milk filters, bulk tank milk, bottled milk, or vending machines. Some tests determine the presence of microorganisms directly in the milk.  For some microorganisms, samples such as blood and milk are taken to detect antibodies or immune response in the animals against the microorganisms, rather than the microorganisms themselves.  

Risk Reduction Strategies

Healthy goats and cows can produce healthy milk that will nourish farm families and customers, but diseased or unhealthy animals can pass illness through their milk or through milk contaminated with feces.  With due diligence and care, raw milk can be a low-risk food for the nourishment of people.

Farmers can reduce the risks of human pathogens being present in the milk through various strategies including biosecurity measures, herd management strategies, milking practices, and milk handling measures. Some specific risk management strategies include:

• maintaining a closed herd or implementing testing and quarantine of any new animals before they are introduced to the herd,

• ensuring the animals are healthy and kept in comfortable conditions,

• monitoring for signs of mastitis (udder inflammation),

• monitoring for fever as a possible indicator of systemic disease,

• thoroughly cleaning the teats prior to milking,

• rigorously cleaning all equipment that will be in contact with the milk,

• rapid chilling the milk to <40ºF (<4°C) within an hour (or less) or milking, and

• performing bacterial testing of the milk on a regular basis for early detection of problems and to assure compliance with RAWMI Common Standards.[vi]

Regardless of the specific microorganisms that are present, conscientious raw milk producers should monitor their herds for illness and ensure that raw milk from unhealthy animals is not used for direct human consumption. Signs of illness can include poor appetite, lameness, poor body condition, rough fur or coat, runny nose, cough, watery eyes, diarrhea or discolored feces, fever, discolored urine, uterine discharges, swollen udder or quarter, reddened udder or teats, high somatic cell count (such as detected in the California mastitis test, even if not detected in every quarter), and/or abnormal milk (even if not detected in every quarter) such as milk that is thick, discolored, stringy, or salty.   

Human Pathogens of Concern for Raw Milk in Western Countries

Currently in the western world, the four most common human pathogens that have been associated with raw milk-related illness in humans are verotoxin producing Escherichia coli (VTEC, such as E. coli O157:H7), Salmonella enterica spp., Campylobacter jejuni, and Listeria monocytogenes. Less commonly, Shigella spp. and Yersinia spp. have been associated with raw milk-related illness in humans. When any of these bacteria are present in the milk at levels that are sufficient to cause infection, susceptible people may experience intestinal illness that may include severe illness or death.

VTEC (such as E. coli 0157:H7) are of particular concern because these pathogens can produce severe illness even with a low pathogenic load (few bacteria are needed to cause disease). For instance, although “the total case numbers of E. coli O157:H7 infections are lower than those of other enteric pathogens such as Salmonella or Campylobacter spp., the diseases caused by E. coli O157:H7 showed much higher hospitalization and fatality rates... Human infection caused by E. coli O157:H7 can present a broad clinical spectrum ranging from asymptomatic cases to [in rare cases] death. Most cases initiate with non-bloody diarrhea and self-resolve without further complication. However, some patients progress to bloody diarrhea… In 5–10% of [these] patients, the disease can progress to the life-threatening sequelae, HUS [hemolytic uremic syndrome, leading to kidney failure] or thrombocytopenic purpura [blood clots that can restrict flow of oxygen to the organs].”[vii]

Thus, pathogens in raw milk need to be taken very seriously. Some of the most common sources of pathogens in milk are manure, mastitis, and improper cleaning of milking equipment resulting in biofilms of bacteria. Researchers from Canada and Europe have studied the safety of raw milk intended for direct human consumption and found that raw milk can be a low-risk food when farmers are trained in risk management practices, implement careful production practices, and test their milk regularly.[viii, ix]

Pathogen testing of raw milk can be used to determine whether pathogens are present, however this testing can be expensive and is only meaningful if it is performed frequently. For small-scale farms that cannot afford frequent pathogen testing, Raw Milk Institute recommends bacterial testing at least monthly for hygiene indicators by testing for coliforms and Standard Plate Count (SPC). The RAWMI Common Standards aim for a rolling three-month average of <5,000 cfu/mL for SPC and <10 cfu/mL for coliforms. [vi]

Although these two tests do not directly detect the presence of pathogens, these tests serve as general indicators that the milk is being produced hygienically and in such a way that pathogens are less likely to be present. Coliform and Standard Plate Count testing can be performed at an offsite lab or with an on-farm lab (with results in 24-48 hours). After an initial investment in equipment, on-farm labs can greatly reduce testing costs in the long-term because the on-farm test cost is only $1-3 per test.

Now, we will proceed to a description of some of the common herd health or zoonotic pathogens.

Mycobacterium bovis (Tuberculosis or TB)

Tuberculosis (TB) is a serious disease both in animals and humans. Cattle who are infected with Mycobacterium bovis (TB) may show no outward signs of infection or vague symptoms such as weight loss and low energy.[x] TB can infect humans through contact with infected cattle or through consuming raw products from infected animals. In humans, tuberculosis can cause prolonged cough, lung, kidney, brain, and spine damage, and ultimately death if not successfully treated.[xi] 

In some continents and regions, bovine tuberculosis is one of the biggest challenges to low-risk raw milk production. For instance, many areas in Asia, Africa and South America have relatively high rates of tuberculosis in cattle and problems with TB contamination of raw milk.[xii, xiii, xiv, xv] For farmers in high-risk TB areas who want to produce raw drinking milk, a rigorous TB testing program of the entire herd and workers, combined with careful control to ensure that animals are kept out of contact with potential disease carriers, would be essential.

Nearly all states in the United States of America (USA) have successfully eradicated tuberculosis in dairy animals through national programs, involving extensive testing and culling of TB infected animals.[xvi] Canada is officially free of bovine tuberculosis.[xvii]  In the European Union, 17 countries are officially TB-free.[xviii, xix]

There are wildlife reservoirs of TB in many countries that may have TB-free dairy herds. For instance, badgers in the United Kingdom and Ireland, white-tailed deer in the USA, elk and bison in Canada, and brushtail possums in New Zealand are common carriers of tuberculosis in the wild.[xx]  Limiting interactions with wild animals is a very important strategy for protecting your herd from this disease.

In states and countries that have legal access to raw milk, annual TB testing for raw milk herds is commonly required by regulatory agencies. The Raw Milk Institute’s Common Standards recommend testing the dairy herd for TB at least annually.[vi] Farmers living in TB-free areas, where the herd has no contact with wildlife, may choose to rely on the tuberculosis-free status of their region in consultation with a local veterinarian. In some areas, it may be appropriate to test more often than annually, such as if TB is common in the region or known to commonly affect wildlife populations.

TB testing is generally performed by a trained veterinarian and involves giving a subdermal injection of TB antigens followed by measuring the swelling of skin at the injection site. Regulatory agencies take tuberculosis very seriously. Positive TB tests lead to immediate restrictions of movement of animals and suspension of raw milk dairy production.

If an animal is a reactor in the skin sensitivity test, then additional tests need to be performed on the animal and the whole herd. If the additional tests come back positive, then the animal is euthanized to investigate organs for disease involvement in a necropsy. Depending on local policies, if the autopsy finds no tissues affected by tuberculosis, the rest of the herd may be able to be spared.

Brucella bovis (Brucellosis)

Brucellosis is a serious zoonotic disease that also can cause disease in animals. In cattle, brucellosis can cause fertility problems including miscarriage, abortion, and retained placenta.[xxi]  In people, brucellosis can cause undulant fever which can have serious short term and long term health effects.  Brucellosis in people may include chronic fevers, liver inflammation, fatigue, bone and joint inflammations, and more serious inflammation of the heart and brain tissues.[xxii] There are brucellosis vaccines for cattle and some countries have official brucellosis vaccination programs. In the USA, the brucellosis vaccine may be required in some localities. Several years ago in the USA, this vaccine was improperly produced and caused Brucellosis to be contracted by those who drank raw milk from vaccinated animals.[xxiii]  

In some countries, brucellosis is one of the biggest challenges to low-risk raw milk production.  For instance, India and Central African countries have relatively high rates of Brucellosis in cattle.[xxiv, xxv] A rigorous brucellosis testing program, combined with careful control to ensure that animals are kept out of contact with potential disease carriers, are essential in areas such as these.

In the USA, nearly all states have successfully eradicated brucellosis in dairy animals.[xxvi] Canada is officially free of bovine brucellosis.[xxvii, xxviii] In the European Union, most countries are officially declared free of  brucellosis.[xxix] However, there are still wildlife reservoirs of this disease in some parts of Europe.

In the USA, states have varying requirements for Brucellosis testing. For instance, Pennsylvania requires annual brucellosis testing whereas California requires quarterly brucellosis testing for raw milk herds. The Raw Milk Institute’s Common Standards generally recommends testing the dairy herd for brucellosis regardless of location.[vi] However, farmers living in brucellosis-free areas whose animals have no contact with wildlife may choose to rely on the brucellosis-free status of their region in consultation with a local veterinarian. In some areas, it may be appropriate to test more often than annually if brucellosis is common or known to commonly affect wildlife populations.

Generally, brucellosis testing is performed on bulk tank milk using the “ring test” which detects the presence of Brucella antibodies. Brucellosis is taken very seriously by regulatory agencies. If the milk tests positive, then further testing can be performed to determine which animals in the herd are affected. If it is verified that animals have Brucellosis, the affected animals must be culled from the herd. This decision is driven by local animal health regulations. Beware that the ring test is not generally considered to be effective for goats or sheep due to a high rate of false positive tests.[xxx]

Although brucellosis is mainly associated with domestic ruminants and pigs, there are wildlife reservoirs for the disease in bison and elk in the USA, buffalo in southeast Africa, and Alpine ibex in the French Alps.[xxxi] Limiting interactions with wild animals is an important strategy for protecting your herd from this disease.

Coxiella burnetii (Q Fever)

Q Fever is an illness caused by the bacteria Coxiella burnetii. In dairy herds, Q fever can lead to reproductive problems such as infertility and abortions. In humans, most Q fever cases are asymptomatic, but some people can develop mild flu-like symptoms. Rarely, some people can develop serious illness with chronic Q fever.[xxxii]

The primary way people are exposed to Coxiella burnetti is through breathing in dust or air that is contaminated by manure or the animals’ bodily fluids. Transmission can also occur through direct contact with mucus, aborted fetuses, amniotic fluid, placenta, milk, or ticks. In some areas, cases of Q Fever are required to be reported to public health agencies.

Coxiella burnetti testing of raw milk dairy herds is not typically required by regulatory agencies. Coxiella burnetti testing is typically performed with serum antibody testing to evaluate whether the animal has been exposed to Coxiella burnetti. Thus, a positive test does not necessarily indicate that an animal is contagious or virulent at the time of testing. Further testing may be needed to determine whether Q fever is currently present. When animals have positive antibody tests, it is recommended to work with a veterinarian to determine if there is an active infection ongoing in the herd.

For overall herd health, Raw Milk Institute generally recommends testing for Q Fever prior to purchasing animals.  For existing herds with no clinical signs of illness, it is recommended to consult with a local veterinarian who is knowledgeable about local conditions in order to determine whether Q Fever testing is recommended.

Avian Influenza Virus H5N1

Avian influenza virus primarily affects birds and is spread across the globe with migratory birds. Avian influenza H5N1 is a type that has recently crossed over from wild birds into some bovine and porcine herds in the USA. Although avian influenza H5N1 can be highly pathogenic in birds, according to the US Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS), in cattle this illness primarily causes decreased lactation and reduced appetite.[xxxiii] The illness is generally mild, where many cattle in the herd show no signs of illness, and those who do generally recover within a couple weeks. Symptoms include weakness, dehydration, fever, lower milk production, and yellow-tinged, thick milk. The first symptom of Avian influenza H5N1 in cows is generally a fever which appears a few days prior to becoming clinically sick.

Knowledge about H5N1 avian influenza is limited. Like other flu viruses, H5N1 is a respiratory illness and not generally considered to be a foodborne illness. There have been reports of cats dying from exposure to H5N1 in milk, however it is not clear whether those cats had exposure to wild bird or poultry sources of the virus.

It is recommended to monitor the herd for illness and ensure that raw milk from unhealthy animals is never used for direct human (or pet) consumption. If there is an H5N1 outbreak in the herd, it is recommended to quarantine all symptomatic animals from the rest of the herd for 2-3 weeks, until all signs of illness have passed. It is recommended to consult with a local veterinarian to determine the best course treatment and any other precautions that should be taken. For existing herds with no clinical signs of illness, it is recommended to consult with a local veterinarian who is knowledgeable about local conditions in order to determine whether H5N1 testing is recommended.

Staphylococcus aureus (Staph A)

Staphylococcus aureus (S. aureus) is a common cause of mastitis in ruminants. It can be present in raw milk, but it is not generally considered to be a pathogen of human concern. However, it is a major and serious cause of chronic mastitis and degradation of the herd’s productivity.[xxxiv] S. aureus bacteria colonize the mammary glands and teats. Over time, scar tissue and abscesses develop in the udder and teats, thereby reducing milk volume and the infection may remain in the udder, even after numerous antibiotic treatments.

Milk culture testing can be used to determine if S. aureus is present in your herd. Most regulatory agencies do not require testing for S. aureus. However, there are exceptions such as New York, where the presence of S. aureus at low levels is allowed in raw milk, but high levels are not allowed. 

Animals infected with S. aureus may initially show no clinical signs, whereas thereafter clinical mastitis (udder swelling, udder hardness, abnormal milk, and elevated somatic cell counts) may appear and result in chronic infection.  S. aureus may be passed from mother to offspring through raw milk or nursing. S. aureus can also be spread among the lactating cows through milking equipment, teat dip cups, and the hands of farm workers. Flies may also transfer the bacteria.[xxxv]

S. aureus is generally resistant to many types of antibiotics and is difficult to eradicate from the herd. Not uncommonly, S. aureus can appear to be wiped out as determined via testing, but then it may appear again in later testing. Some small-scale farmers have reported success in treating S. aureus with the use of homeopathic medicines but it is not clear whether this could work in larger herds with widespread S. aureus. [xxxvi]

Because S. aureus can degrade the herd’s milk supply and cause recurrent mastitis, many farmers choose to perform herd milk culture testing.  Strategies for managing S. aureus include: [xxxv]

• Culling animals who test positive and maintaining a herd that is negative for S. aureus

• Bottle feeding calves and kids to ensure that S. aureus is not passed from mother to offspring (and ensuring that milk from infected animals is not fed to offspring)

• Segregating the milking herd to separate those who test positive for S. aureus

• Milking S. aureus-infected animals last, to ensure that the bacteria are not passed to uninfected animals via the milk machine and hands of farm workers

• Ensuring teat cups used on S. aureus-positive animals are not used on other animals (or rinsing and sanitizing such cups after milking infected animals)

Bovine Leukemia Virus (BLV)

Bovine Leukemia Virus (BLV) can affect the health and productivity of your herd. Although some animals with BLV may have signs of illness (such as labored breathing, loss of appetite, or tumors), nearly two-thirds of infected animals are sub-clinically infected (i.e. they show no signs of illness).[xxxvii] Some recent studies have theorized that BLV may be linked to breast cancer in humans.[xxxviii, xxxix] However, the research on this is inconclusive and was not able to make clear associations. 

BLV is destroyed by pasteurization. Raw milk naturally contains bioactive anti-viral and anti-carcinogenic compounds (which are destroyed by heat).[xl] These bioactive compounds affect human immunity and it is not known how they would affect any potential interactions with BLV. According to one of the studies investigating the link between BLV and breast cancer, “Numerous prospective studies on dairy consumption in various defined populations, however, including one study that carefully evaluated unpasteurized milk consumption, found no significant relationship between cow’s milk consumption and breast cancer incidence.”[xxxix]

BLV testing of the raw milk dairy herd is not typically required by regulatory agencies. For overall herd health, Raw Milk Institute recommends testing for BLV prior to purchasing animals. In existing herds with no clinical signs of illness, it is recommended to consult with a local veterinarian who is knowledgeable about local conditions in order to determine whether BLV testing is recommended.  Some types of BLV testing measure the relative levels of viral loads, with the results given as ‘Undetected, Low, Moderate, or High’. Animals who have no symptoms and test as Undetected or Low are considered to be low-risk animals for raw milk production.   

Mycobacterium avium paratuberculosis (MAP, Johne’s disease, Paratuberculosis)

Johne’s disease is an infection in the small intestine of cows and other ruminants. It is caused by Mycobacterium avium subspecies paratuberculosis (MAP) and can easily spread in the herd. Johne’s disease is a chronic gut infection that leads to weight loss, diarrhea, loss of body condition, and reduced milk production. Animals may contract MAP or already be infected with MAP at birth, yet it is possible that no signs of illness may appear for years.[xli] Johne’s is generally not considered to affect humans, thus it is primarily a herd health issue.

Some researchers have theorized that MAP may be linked to Crohn’s disease in humans, however the research is inconclusive. For instance, a study looking for connection between MAP and Crohn’s found that “The results do not support the hypothesis that Map plays a causative role in the etiology of Crohn's disease.” [xlii] According to another study, “Despite numerous attempts to demonstrate causality by researchers, direct microbiological evidence of MAP involvement in [Crohn’s disease] remains elusive. Importantly, it has not been possible to reliably and reproducibly demonstrate mycobacteria in the tissue of [Crohn’s Disease] patients.” [xliii] 

MAP testing of the raw milk dairy herd is generally not required by regulatory agencies in North America. For overall herd health, Raw Milk Institute generally recommends testing for MAP prior to purchasing animals.  For existing herds with no clinical signs of illness, it is recommended to consult with a local veterinarian who is knowledgeable about local conditions in order to determine whether MAP testing is recommended.

When cows or goats have the clinical signs of diarrhea, weight loss, and poor body condition (skinny-looking) while still eating a normal ration, it should be considered that they may have MAP and testing is recommended. The milk test that is generally used for MAP indicates relative amounts of antibodies to MAP that are present in the milk, and does not strictly indicate that an animal has Johne’s disease. To protect the rest of the herd, culling should be considered for any animal that shows ongoing signs of Johne’s illness or tests positive on antibody screening tests. 

My Herd Came Back Positive. Now What Do I Do?

We hope the above information clarifies some of the most common pathogens and herd health concerns. Be aware that testing results are not always clear. There are many kinds of testing protocols and different tests reveal different kinds of data. Depending on the type of test performed, a positive test result may be detecting the presence of antibodies against a disease (which would indicate a prior immune response to the illness rather than a current, active infection).

Additionally, some cows or goats may test positive for illness while appearing perfectly healthy with no signs of illness. In those cases, the farmer may choose to monitor the cows/goats closely and wait to cull until such time as there may be actual signs of illness. This is a decision to be made in consultation with a veterinarian. 

When culling is necessary, it should be done at a USDA-approved slaughter plant. Slaughtered animals that are suspected to have been diseased will be inspected by a USDA inspector to determine if the animal is fit for human food consumption. At that time, an official USDA determination is made about the disease status of the animal that will either confirm or nullify the initial assumption or diagnosis of disease. 

As an ethical raw milk producer, one of your most important and highest responsibilities is to assure that your raw milk herd is healthy and not spreading illness unto itself or any of your raw milk consumers. Whatever it takes to achieve and protect the optimal herd and consumer health will be the best decision. Be sure to have a good veterinarian to assist in these decisions. There are many kinds of tests, and being able to understand the specific test results will be critical to making the right decisions. The broader raw milk production community may also have answers to your challenge. Thus, stay connected to the larger community and its greater experience.  

Thanks to the RAWMI Advisory Board for reviewing this document.

References

[i] Lin T, Meletharayil G, Kapoor R, Abbaspourrad A. Bioactives in bovine milk: chemistry, technology, and applications. Nutr Rev. 2021 Dec 8;79(Suppl 2):48-69. doi: 10.1093/nutrit/nuab099. https://pmc.ncbi.nlm.nih.gov/articles/PMC8653947/

[ii] Abbring S, Xiong L, Diks MAP, Baars T, Garssen J, Hettinga K, van Esch BCAM. Loss of allergy-protective capacity of raw cow's milk after heat treatment coincides with loss of immunologically active whey proteins. Food Funct. 2020 Jun 24;11(6):4982-4993. doi: 10.1039/d0fo01175d. https://pubmed.ncbi.nlm.nih.gov/32515464/

[iii] The protective effect of farm milk consumption on childhood asthma and atopy: The GABRIELA study. Loss, Georg et al. Journal of Allergy and Clinical Immunology, Volume 128, Issue 4, 766 - 773.e4 https://www.jacionline.org/article/S0091-6749(11)01234-6/fulltext

[iv] Lallès JP. Dairy products and the French paradox: Could alkaline phosphatases play a role? Med Hypotheses. 2016 Jul;92:7-11. doi: 10.1016/j.mehy.2016.04.033. Epub 2016 Apr 20. https://pubmed.ncbi.nlm.nih.gov/27241245/

[v] Consumption of unprocessed cow's milk protects infants from common respiratory infections. Loss, Georg et al. Journal of Allergy and Clinical Immunology, Volume 135, Issue 1, 56 - 62.e2 https://www.jacionline.org/article/S0091-6749%2814%2901274-3/fulltext

[vi] Raw Milk Institute, “Common Standards.” 2020. https://www.rawmilkinstitute.org/common-standards

[vii] Lim, J. Y., Yoon, J., & Hovde, C. J. (2010). A brief overview of Escherichia coli O157:H7 and its plasmid O157. Journal of microbiology and biotechnology, 20(1), 5–14. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3645889/

[viii] Whitehead J, Lake B. Recent Trends in Unpasteurized Fluid Milk Outbreaks, Legalization, and Consumption in the United States. PLoS Curr. 2018 Sep. https://pubmed.ncbi.nlm.nih.gov/30279996/

[ix] Berge AC, Baars T (2020). Raw milk producers with high levels of hygiene and safety. Epidemiology and Infection 148, e14, 1–7.  https://www.cambridge.org/core/services/aop-cambridge-core/content/view/ACCC5FD0AC2CEAB12379DFA902491115/S0950268820000060a.pdf/raw_milk_producers_with_high_levels_of_hygiene_and_safety.pdf

[x] Daly, R. (2020) “Tuberculosis in Cattle: What You Need to Know.” South Dakota State University Extension. https://extension.sdstate.edu/tuberculosis-cattle-what-you-need-know

[xi] World Health Organization. “Tuberculosis Fact Sheet.” November 2023. https://www.who.int/news-room/fact-sheets/detail/tuberculosis 

[xii] Ramanujam, Harini, and Kannan Palaniyandi. “Bovine tuberculosis in India: The need for One Health approach and the way forward.” One health (Amsterdam, Netherlands) vol. 16 100495. 30 Jan. 2023. https://pubmed.ncbi.nlm.nih.gov/36817978/

[xiii] Firdessa, Rebuma et al. “High prevalence of bovine tuberculosis in dairy cattle in central ethiopia: implications for the dairy industry and public health.” PloS one vol. 7,12 (2012): e52851. https://pubmed.ncbi.nlm.nih.gov/23285202/   

[xiv] Carneiro, P A M et al. “Milk Contamination by Mycobacterium tuberculosis Complex, Implications for Public Health in Amazonas, Brazil.” Journal of food protection vol. 85,11 (2022): 1667-1673. https://pubmed.ncbi.nlm.nih.gov/34788443/

[xv] Basit A, Hussain M, Shahid M, Ayaz S, Rahim K, Ahmad I, Rehman AU, Hassan MF and Ali T, 2018. Occurrence and risk factors associated with mycobacterium tuberculosis and mycobacterium bovis in milk samples from North East of Pakistan. Pak Vet J, 38(2): 199-203. http://dx.doi.org/10.29261/pakvetj/2018.038

[xvi] Animal and Plant Health Inspection Service. “Status of Current Eradication Programs.” United States Department of Agriculture. April 2024. https://www.aphis.usda.gov/livestock-poultry-disease/status-eradication-programs

[xvii] Canadian Food Inspection Agency. “Bovine tuberculosis.” Government of Canada. March 2024. https://inspection.canada.ca/animal-health/terrestrial-animals/diseases/reportable/bovine-tuberculosis/eng/1330205978967/1330206128556

[xviii] European Health and Digital Executive Agency. “Brucellosis (Brucella abortus, B. melitensis and B. suis).”  European Commission. 2022. https://hadea.ec.europa.eu/programmes/single-market-programme-food/veterinary-programmes/brucellosis_en

[xix] European Union Reference Laboratory. “Tuberculosis in bovine animals eradication in Europe.”  Visavet Health Surveillance Centre. Jan 2024. https://www.visavet.es/bovinetuberculosis/animal-tb/eradication.php

[xx] Miller, R. S., & Sweeney, S. J. (2013). Mycobacterium bovis (bovine tuberculosis) infection in North American wildlife: current status and opportunities for mitigation of risks of further infection in wildlife populations. Epidemiology and infection, 141(7), 1357–1370. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3684113/

[xxi] Larsen, J. (May 2023) “Overview of Brucellosis in Large Animals.” Merck Manual Veterinary Manual.  https://www.merckvetmanual.com/reproductive-system/brucellosis-in-large-animals/overview-of-brucellosis-in-large-animals

[xxii] Corbel M, editor. Brucellosis in humans and animals: Food and Agriculture Organization of the United Nations, World Organisation for Animal Health, World Health Organization. 2006 editor. https://iris.who.int/rest/bitstreams/51770/retrieve

[xxiii] Gruber JF, Newman A, Egan C, et al. Notes from the Field: Brucella abortus RB51 Infections Associated with Consumption of Raw Milk from Pennsylvania — 2017 and 2018. MMWR Morb Mortal Wkly Rep 2020;69:482–483.  https://www.cdc.gov/mmwr/volumes/69/wr/mm6915a4.htm

[xxiv] Holt, H. R., Walker, M., Beauvais, W., Kaur, P., Bedi, J. S., Mangtani, P., Sharma, N. S., Gill, J. P. S., Godfroid, J., McGiven, J., & Guitian, J. (2023). Modelling the control of bovine brucellosis in India. Journal of the Royal Society, Interface, 20(200), 20220756. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9991488/

[xxv] Imadidden Musallam, Andrée Prisca Ndour, et al.Brucellosis in dairy herds: A public health concern in the milk supply chains of West and Central Africa, Acta Tropica, Volume 197, 2019, 105042, ISSN 0001-706X. https://www.sciencedirect.com/science/article/pii/S0001706X19303304

[xxvi] Animal and Plant Health Inspection Service. “Status of Current Eradication Programs.” United States Department of Agriculture. April 2024. https://www.aphis.usda.gov/livestock-poultry-disease/status-eradication-programs

[xxvii] Canadian Food Inspection Agency. “Bovine tuberculosis.” Government of Canada. March 2024. https://inspection.canada.ca/animal-health/terrestrial-animals/diseases/reportable/bovine-tuberculosis/eng/1330205978967/1330206128556

[xxviii] Canadian Food Inspection Agency. “Fact Sheet - Brucellosis.” Government of Canada. May 2016.  https://inspection.canada.ca/animal-health/terrestrial-animals/diseases/reportable/brucellosis/fact-sheet/eng/1305673222206/1305673334337

[xxix] European Health and Digital Executive Agency. “Brucellosis (Brucella abortus, B. melitensis and B. suis).”  European Commission. 2022. https://hadea.ec.europa.eu/programmes/single-market-programme-food/veterinary-programmes/brucellosis_en

[xxx] Godfroid J, Nielsen K, Saegerman C. Diagnosis of brucellosis in livestock and wildlife. Croat Med J. 2010 Aug;51(4):296-305. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2931434/  

[xxxi] Godfroid J. (2017). Brucellosis in livestock and wildlife: zoonotic diseases without pandemic potential in need of innovative one health approaches. Archives of public health = Archives belges de sante publique, 75, 34. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5592711/

[xxxii] Wisconsin Department of Health Services. “Q Fever (Coxiella burnetii infection)” Oct 2021. https://www.dhs.wisconsin.gov/disease/qfever.htm

[xxxiii] United States Department of Agriculture, Animal and Plant Health Inspection Service. Mar 2024. “USDA, FDA and CDC Share Update on HPAI Detections in Dairy Cattle.”  https://www.aphis.usda.gov/news/agency-announcements/usda-fda-cdc-share-update-hpai-detections-dairy-cattle

[xxxiv] Cheng, W. N., & Han, S. G. (2020). Bovine mastitis: risk factors, therapeutic strategies, and alternative treatments - A review. Asian-Australasian journal of animal sciences, 33(11), 1699–1713. https://doi.org/10.5713/ajas.20.0156

[xxxv] Jones GM, Bailey TL, Roberson JR. (1998) Staphylococcus Aureus Mastitis: Cause, Detection, and Control. Virginia Cooperative Extension, Virginia Tech. https://www.thecattlesite.com/articles/679/staphylococcus-aureus-mastitis-cause-detection-and-control

[xxxvi] Macleod, G. The Treatment of Cattle by Homeopathy. Random House. 2012. https://books.google.com/books/about/The_Treatment_Of_Cattle_By_Homoeopathy.html?id=d92E1MECc48C

[xxxvii] Animal and Plant Health Inspection Service. “Bovine Leukemia Virus.” United States Department of Agriculture. Feb 2024. https://www.aphis.usda.gov/livestock-poultry-disease/cattle/bovine-leukemia

[xxxviii] Delarmelina E, Buzelin MA, Souza BSd, Souto FM, Bicalho JM, Câmara RJF, et al. (2020) High positivity values for bovine leukemia virus in human breast cancer cases from Minas Gerais, Brazil. PLoS ONE 15(10): e0239745. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0239745

[xxxix] Buehring GC, Shen HM, Jensen HM, Jin DL, Hudes M, Block G. Exposure to Bovine Leukemia Virus Is Associated with Breast Cancer: A Case-Control Study. PLoS One. 2015 Sep 2;10(9):e0134304. https://pmc.ncbi.nlm.nih.gov/articles/PMC4557937/

[xl] Lin T, Meletharayil G, Kapoor R, Abbaspourrad A. Bioactives in bovine milk: chemistry, technology, and applications. Nutr Rev. 2021 Dec 8;79(Suppl 2):48-69. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8653947/

[xli] Animal and Plant Health Inspection Service. “Johne’s Disease.” United States Department of Agriculture. Apr 2024. https://www.aphis.usda.gov/livestock-poultry-disease/cattle/johnes

[xlii] Jones PH, Farver TB, Beaman B, Cetinkaya B, Morgan KL. Crohn's disease in people exposed to clinical cases of bovine paratuberculosis. Epidemiol Infect. 2006 Feb;134(1):49-56. https://pmc.ncbi.nlm.nih.gov/articles/PMC2870362/

[xliii] John M. Aitken, Khoi Phan, Samantha E. Bodman, Sowmya Sharma, Anthony Watt, Peter M. George, Gaurav Agrawal, Andrew B.M. Tie, A Mycobacterium species for Crohn's disease?, Pathology, Volume 53, Issue 7, 2021, Pages 818-823,ISSN 0031-3025, https://www.sciencedirect.com/science/article/pii/S0031302521002348

Allergies and Raw Milk

Modern Lifestyles and Allergies

Although allergies were rare prior to the 1800’s [1], they are a common affliction in our modern lifestyles.  As people have moved further from their agricultural roots, allergies have become more prevalent.  Several studies have found that exposure to diverse bacteria and potential allergens in the environment makes a big difference in preventing the development of allergies.

For instance, in a study looking at allergies and asthma in northern Europe, allergy prevalence was much higher in Finnish people as compared to Russians, even though they lived in geoclimatically similar areas [2]. 27% of Finnish school children demonstrated allergic sensitization to pollen, as compared to only 2% of their Russian counterparts. In unraveling the causes for this disparity, the study found a striking result: “the epidemic of allergy and asthma results from reduced exposure to natural environments with rich microbiota, changed diet and sedentary lifestyle.” Basically, exposure to environments with high bacterial and microbial diversity is associated with lower rates of asthma and allergies.   

North Karelia in Finland and Pitkäranta region in the Republic of Karelia in Russia. The dashed lines are Finnish borders before 1944. Haahtela, et al, 2015.

Several other studies have found similar results, and have concluded that living in a farm environment provides protection from asthma and allergies. Contact with farm animals was found to be associated with lower rates of allergies [3], as was “exposure to stables and farm milk” [4]. Although several studies identified that consumption of raw milk (aka “farm milk”) was an integral part of the farm environment, it was argued that allergy protection was from the farm environment and not from raw milk consumption.  However, further research has revealed that raw milk is indeed a key factor in protecting against allergies and asthma.

Children Who Drink Raw Milk Have Less Allergies

Several large epidemiological studies of European children have found correlations between raw milk consumption and decreased rates of allergies.

PARSIFAL Study

The PARSIFAL study was designed to look at allergy risk factors in children. This large study of over 14,800 European children (from Austria, Germany, the Netherlands, Sweden, and Switzerland) investigated allergic diseases in relation to children’s exposure to different environments (farms, rural, suburban) and farm-fresh foods (such as raw dairy products, eggs, and vegetables). The PARSIFAL data relating to allergies and raw milk were published in December 2006 in the Journal of Clinical and Experimental Allergy [5].

The PARSIFAL study concluded that there is a “significant inverse association between farm [raw] milk consumption and childhood asthma, rhinoconjunctivitis, sensitization to pollen, a mix of food allergens, and horse dander." The study found that, regardless of which environment the children lived in, those children who drank raw milk had significantly lower rates of allergies and asthma than children who did not drink raw milk. These effects were “most pronounced in children drinking farm milk since their first year of life.”

GABRIELA Study

The GABRIELA study was designed to investigate the genetic and environmental causes of asthma and allergies.  This study included over 8,000 European children (from Germany, Austria, and Switzerland), and was published in the Journal of Allergy and Clinical Immunology in August 2011 [6]. In this study, raw milk consumption was compared to consumption of boiled/pasteurized milk, and the level of exposure to raw milk in utero through school age was also accounted for. The study also looked into the children’s exposure to farm environments as a possible variable related to rates of asthma and allergies.

The GABRIELA study found that raw milk consumption is associated with significantly lower rates of allergies and asthma, and that this beneficial effect is independent of other farm exposures. It was found that early exposure to raw milk (at <1 year of age) and daily consumption of raw milk increased the beneficial effect in children who drank a mixture of raw milk and pasteurized milk. The consumption of only pasteurized milk “was not associated with any health outcome.”

It’s Not the “Farm Effect,” It’s the Raw Milk!

The above-referenced studies specifically analyzed the effects of living environments, and found that the beneficial effects of raw milk on allergies and asthma were indeed present even in children who did not live on farms. Furthermore, a recent meta-analysis of eight health studies related to raw milk was published in the November 2019 issue of the Journal of Allergy and Clinical Immunology [7]. A meta-analysis is a quantitative statistical analysis which combines the results of multiple scientific studies, thereby allowing the researchers to derive overall conclusions about that body of research.

The recent meta-analysis, written by a team of researchers from the Netherlands and Germany, concluded that when taken as a whole, the body of data from the previous studies shows that raw milk consumption in childhood has a protective effect on allergies and asthma “independent of other farm exposures and that children not living on a farm can theoretically profit from this effect.” 

Why Does Raw Milk Protect Against Allergies and Asthma?

Although it was originally postulated that raw milk’s bacterial content was responsible for its allergy-protective effects, research has not found this to be the case.  For instance, the GABRIELA study found that, “Contrary to our expectations, we did not observe an association between total viable bacterial counts in milk and investigated health outcomes” [6].

More recent research has investigated whether the whey proteins in raw milk could be responsible for the beneficial effect on allergies. A study published in the June 2020 Food and Function Journal “aimed at achieving a better understanding of the underlying mechanism between heat damage to whey proteins and allergy development” [8]. In this study, “raw cow’s milk was heated for 30 min at 50, 60, 65, 70, 75, or 80 °C [122, 140, 149, 158, 167, or 176 °F]… The allergy-protective effect of differently heated milk samples were tested in a murine OVA-induced food allergy model.” 

Heat treatment at 65 °C or higher destroyed allergy-protective capacity of raw milk in murine OVA-induced food allergy model. Abbring, Xiong, et al, 2020.

This study found that allergy protection ceases when raw milk is heated to 149 °F, which is the same temperature at which the whey proteins are denatured.  It was concluded that the whey protein in raw milk provides protection from allergies, asthma, and inflammation.  When heated above 149 °F, these properties are dramatically reduced or eliminated. This finding is an important confirmation of the unique beneficial properties of whole, unprocessed raw milk. 

Low-Risk Raw Milk as a Therapeutic Tool Against Allergies

The research is clear that raw milk consumption is correlated with protection from allergies and asthma. Although a living environment that is rich in bacterial diversity is helpful, it has been demonstrated that the allergy-protective benefits of raw milk are present in both rural and urban environments.  The immunologically active whey proteins are likely the cause of this protective effect.  There is a growing body of evidence that raw milk is a low-risk food when it is produced carefully and intentionally [9, 10]. Thus, low-risk raw milk can be a powerful therapeutic tool for allergy and asthma protection.

References

[1] Hay Fever and Paroxysmal Sneezing: Their Etiology and Treatment. 1887. Mackenzie M. https://archive.org/details/b20406757/page/n7/mode/2up

[2] Hunt for the origin of allergy – comparing the Finnish and Russian Karelia. Clinical and Experimental Allergy. 2015; (45) 891– 901. Haahtela T, Laatikainen T, Alenius H, Auvinen P, Fyhrquist N, Hanski I, von Hertzen L, Jousilahti P, Kosunen T U, Markelova O, Mäkelä M J, Pantelejev V, Uhanov M, Zilber E, Vartiainen E. https://onlinelibrary.wiley.com/doi/full/10.1111/cea.12527

[3] Farming exposure in childhood, exposure to markers of infections and the development of atopy in rural subjects. Clinical and Experimental Allergy : Journal of the British Society for Allergy and Clinical Immunology vol. 34,8 (2004): 1178-83. Radon K, Windstetter D, Eckart J, Dressel H, Leitritz L, Reichert J, Schmid M, Praml G, Schosser M, von Mutius E, Nowak D. https://pubmed.ncbi.nlm.nih.gov/15298556/

[4] Exposure to farming in early life and development of asthma and allergy: a cross-sectional survey. Lancet. 2001;358(9288):1129-1133. Riedler J, Braun-Fahrländer C, Eder W, Schreuer M, Waser M, Maisch S, Carr D, Schierl R, Nowak D, von Mutius E; ALEX Study Team. https://pubmed.ncbi.nlm.nih.gov/11597666/

[5] Inverse association of farm milk consumption with asthma and allergy in rural and suburban populations across Europe. Clinical and Experimental Allergy. 2007; 37(5):661-70. Waser M, Michels KB, Bieli C, Flöistrup H, Pershagen G, von Mutius E, Ege M, Riedler J, Schram-Bijkerk D, Brunekreef B, van Hage M, Lauener R, Braun-Fahrländer C; PARSIFAL study team. https://www.ncbi.nlm.nih.gov/pubmed/17456213

[6] The protective effect of farm milk consumption on childhood asthma and atopy: The GABRIELA study. Journal of Allergy and Clinical Immunology. 2011; 128 (4): 766-73. Loss G, Apprich S, Waser M, Kneifel W, Genuneit J, Büchele G, Weber J, Sozanska B, Danielewicz H, Horak E, Joost van Neerven RJ, Heederik D, Lorenzen PC, von Mutius E, Braun-Fahrländer C; GABRIELA study group. https://www.jacionline.org/article/S0091-6749(11)01234-6/fulltext

[7] The Beneficial Effect of Farm Milk Consumption on Asthma, Allergies, and Infections: From Meta-Analysis of Evidence to Clinical Trial. Journal of Allergy and Clinical Immunology: In Practcice, 2019. 8 (3): 878-889. Brick T, Hettinga K, Kirchner B, Pfaffl MW, Ege MJ. https://www.ncbi.nlm.nih.gov/pubmed/31770653

[8] Loss of allergy-protective capacity of raw cow's milk after heat treatment coincides with loss of immunologically active whey proteins. Food and Function. 2020 Jun 24;11(6):4982-4993. Abbring S, Xiong L, Diks MAP, Baars T, Garssen J, Hettinga K, van Esch BCAM. https://pubmed.ncbi.nlm.nih.gov/32515464/

[9] Recent Trends in Unpasteurized Fluid Milk Outbreaks, Legalization, and Consumption in the United States. PLOS Currents. 2018; 10. Whitehead J, Lake B. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6140832/#ref27

[10] Raw milk producers with high levels of hygiene and safety. Epidemiology and Infection, 2020; 148, e14, 1-7. Berge AC, Baars T. https://www.ncbi.nlm.nih.gov/pubmed/32000877 

Welcoming Farms in Wyoming and Texas to RAWMI Community

The Raw Milk Institute (RAWMI) sends a warm welcome to two more farmers who have completed our Listing program!

RAWMI offers free mentoring to all dairy farmers. Whether they are milking one cow, a handful of goats, or a large herd, the principles of safe raw milk production form a foundational toolset that benefits all dairy farmers and their customers. 

Some of the farmers we mentor choose to keep it casual, and are satisfied to just ask us a few questions before continuing their raw milk journeys. There is another set of farmers, though, that is not content to just dip their toes in the water; they want to dive right in and take their entire milk process to the next level. 

For these farmers, we offer our (free) RAWMI Listing program, wherein we assist farmers in developing their own unique on-farm Risk Analysis and Management Plan, documenting their processes with written Standard Sanitary Operating Procedures, and identifying the Critical Control Points that are essential to their production of safe raw milk. RAWMI Listed farmers test their milk at least monthly for ongoing assurance that their processes are working well to produce low-risk raw milk. RAWMI Listing is the gold standard for raw milk producers.

Two raw milk farms have recently completed the RAWMI Listing process, and we extend them a warm welcome into our growing community!

• #65 - Country Meadows Dairy - Lander, Wyoming, USA

• #66 - Little Dairy on the Prairie - Dalhart, Texas, USA

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Country Meadows Dairy - Lander, Wyoming, USA

Country Meadows Dairy is a family-run micro dairy located just outside Lander, Wyoming. Operated by Jan Francisco, this dairy raises Jersey cows and provides delicious dairy products to Meadowlark Market, including raw milk, yogurt, and cheeses.  

Jan’s cows are healthy and raised on pasture. She follows the best practices created by the Raw Milk Institute to create a clean, safe product.  Jan loves the freedom that comes from being a producer, the skills she has learned in this venture, and the connection with the animals.  

You can check out Country Meadows Dairy’s Risk Management Plan and test results here: https://www.rawmilkinstitute.org/listed-farmers/#countrymeadows

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Little Dairy on the Prairie - Dalhart, Texas, USA

Located in the Texas Panhandle, Little Dairy on the Prairie is a family-owned micro dairy operated by Jeff and Christiana Kawich. With lifelong experience in dairy farming, they focus on producing high-quality A2A2 raw milk from their herd of Jersey cows. Their approach blends traditional dairying practices with a strong commitment to modern food safety.

Little Dairy on the Prairie is dedicated to providing clean, nutritious milk while maintaining a close connection with the families they serve! 

You can check out Little Dairy on the Prairie’s Risk Management Plan and test results here: https://www.rawmilkinstitute.org/listed-farmers/#littledairy