Considerations for Drinking Raw Milk and the Threat of Leucosis and Johnes Disease

Reader Contribution by Steve Judge and Bob-White Systems
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Personally, I have absolutely no doubt that raw milk that comes from healthy cows and is properly handled and cooled is safe — period! Just remember to shake the container in your refrigerator once in a while.

If you are trying raw milk for the first time, ease into the tasting. It is so delicious you might be tempted to drink too much! Give your digestive system time to adjust.

Threat of Leucosis and Johnes Disease

Unfortunately there are other very real public health concerns regarding the safety of the milk supply in the U.S. Two bovine diseases are quickly spreading through dairy herds across the nation. One is a virus, commonly known as Leucosis or Leukosis, and the other is a bacterial infection commonly called Johnes. Both can be fatal for dairy cattle and the infection rate in the U.S. is extremely high, likely close to 90% for both diseases.

Currently, they are officially not considered to be an economic threat to dairy herds in the United States because both diseases are not always fatal and if they are it usually takes more than 5 years for an infected and sickened cow to die. The average lifespan of a cow on a commercial dairy is 4.5 years.

However, recent advances in microbiology have allowed researchers to determine that Leucosis can and is being spread to humans, seemingly at an alarming rate. Though no specific disease has been attributed to the Leucosis infection in humans, a recent study done by the CDC has discovered a potential link between the infection and certain forms of breast cancer.

In addition, research has indicated there is a possible link between Johnes disease in cattle and a Crohn’s like disease in Humans. Inexplicably, there are currently no meaningful or effective efforts being undertaken to control the spread of either diseases in cows or humans. In contrast, several European countries have recognized the threat and have eradicated Leucosis from their dairy herds.

Pasteurization’s Role in Controlling Disease

The official position of the Dairy Industry in the U.S. is that standard pasteurization kills both diseases in milk. Although research suggests that pasteurization methods called HTST and vat pasteurization may not kill the Leucosis virus.

Ultra-High Temperature pasteurization (which is heated to higher temperatures than HTST and vat-pasteurized milk) appears to do the trick. All forms of pasteurization appear to kill the Johnes bacteria.

For reasons unknown, farmers who produce raw milk for human consumption are not required to test their cows and milk for either Johnes or Leucosis. Most are required to test their cows for other much less common bovine diseases, such as Brucellosis and Tuberculosis.

I strongly urge all farmers to test their cows for both Johnes and Leucosis, even if you don’t sell raw milk. If you do sell raw milk, I think you owe it to your customers to have your cows tested. I test all my cows for both diseases routinely including every cow I buy – before I agree to buy them. I tell my four kids and five grandchildren to only drink raw milk that has tested negative for Johnes and Leucosis – or – milk that has been UHT pasteurized and it says so on the label.

Safe and delicious milk — it takes work but at the end of the day, it is worth the effort – especially if you are selling your milk directly to your customers. Excellent flavor and a long shelf life can give your milk a strong competitive advantage! If you’re looking for further tips, click here for more articles on best practices, tips and dairy advice.

To learn how to clean dairy equipment, control for disease, and better influence milk flavor profile, read “How to Produce the Safest (and Most Delicious) Milk on a Micro Dairy”.

Steve Judge is a long-time dairy farmer and micro-dairy expert at Bob-White Systems. Driven by a passion for the Slow Food movement and a desire for communities to enjoy locally produced, Steve’s goal is to create appropriately scaled dairy technology and equipment that will give small-scale dairy farmers the opportunity to sell safe, farm fresh milk and dairy products directly from their farms to friends and neighbors. Read all of Steve’s MOTHER EARTH NEWS posts here.

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