Latest study says raw milk not worth risk

Latest study says raw milk not worth risk

A new European study presents the risks and benefits related to the consumption of raw cow's milk.

SOCIETY seems to be trending toward more "natural" products, and a preference for raw milk consumption is becoming increasingly popular.

That's because raw milk is associated with several perceived health benefits that are believed to be destroyed upon heating during pasteurization.

However, many pathogens can be isolated from raw cow's milk. The prevalence of foodborne pathogens in raw milk varies, but their presence has been demonstrated in many surveys, and foodborne infections have been repeatedly reported due to campylobacter, salmonella and human pathogenic verocytotoxin-producing Escherichia coli.

In industrialized countries, milk-borne and milk product-borne outbreaks represent 2-6% of bacterial foodborne outbreaks.

An ongoing debate about the risks and benefits of raw milk has ensued.

Non-scientific information is typically used to support the consumption of raw milk, but results of a new European study published in the journal Food Control present scientifically sound data regarding the risks and benefits related to the consumption of raw and heated cow's milk.

The study considered both microbiological aspects (e.g., the prevalence of milk-borne pathogens, pathogen growth inhibition by antimicrobial systems and by lactic acid-producing bacteria, probiotic bacteria, etc.) and nutritional or health aspects (nutritional value, immunity, allergies, lactose intolerance, diabetes, milk digestibility, etc.).

Because regulations, management and pathogen pressure from both the environment and the animals differ substantially among countries around the world, the researchers decided to limit the review study to European countries because they all follow the same regulations.

Raw milk advocates claim that it has probiotics that are beneficial for the body. However, to have any beneficial effect, the researchers said these probiotics need to be ingested in large quantities in order to survive intestinal transit.

In fact, researchers have found that the amount of probiotics that must be ingested in order to have an effect needs to be 1,000-10,000 times higher than the amount actually present in raw milk.

Given that these probiotic bacteria represent only certain specific strains that are potentially present in milk, and given that their growth is inhibited at the refrigeration temperature used to store raw milk, the study concluded that the relevance and the number of these bacteria are too limited to have any physiological effect for consumers. Consequently, the destruction of these probiotics by pasteurization or sterilization has no net health effects.

With respect to vitamins, the researchers pointed out that milk contains vitamins in varying amounts. The difference in vitamin concentrations between raw milk and pasteurized milk is so small that the researchers concluded that there is no difference in the levels of minerals and trace elements between the two.

Milk is a particularly good source of calcium and phosphorus (with the other minerals and trace elements being less relevant). The review found that heat treatment (and homogenization) appears to have no significant effect on the bioavailability of calcium in milk.

According to the review, a number of epidemiological studies suggested that early-life exposure to unprocessed cow's milk could reduce a person's risk for developing asthma, allergic rhinitis, hay fever, pollen allergy and atopic sensitization.

The researchers pointed out that most of these studies alluding to a possible protective effect of raw milk consumption did not provide any objective confirmation of the raw milk status (home-cooked or not) or a direct comparison with heat-treated milk.

Additionally, the researchers suggested that the increased resistance observed seems to be related to the person's exposure to a farm environment or animals rather than to raw milk consumption.

The only argument for raw milk supported through the review was the change to the organoleptic profile of raw milk.

Various sources, ranging from chemicals to enzymetic or microbial in nature, can alter the flavor profile of milk. Some of these flavor "defects" can be reduced by heating, while others are induced by heating.

However, the researchers noted that new processing techniques and packaging materials can minimize off-flavors or produce pasteurized milk with a similar taste to raw milk.

The study demonstrates that consuming raw milk poses a realistic health threat due to its possible contamination with human pathogens. People most at risk are the very young and elderly, pregnant women and people with compromised immune systems. However, anyone can be affected, including healthy young adults, so the researchers recommended that milk should always be heated before consumption.

With the exception of an altered organoleptic profile, heating (particularly ultra-high-temperature and similar treatments) will not substantially change the nutritional value of raw milk or other benefits associated with raw milk consumption.

"Almost all arguments put forward by raw milk proponents for not heating milk can be refuted, and the only substantial disadvantage of heating is the change in the organoleptic profile of milk," the researchers said. "It is clear that this 'detrimental' effect of heating does not countervail the risk posed by raw milk consumption, namely of a milk-borne pathogen infection, which can have serious health consequences."


New DFA facility

Dairy Farmers of America (DFA) recently broke ground on an ingredient processing facility in Cass City, Mich.

The $40 million plant will serve a region where milk production is steadily outpacing local plant capacity. At completion next fall, the 33,000 sq. ft. plant will process up to 3 million lb. of fresh milk each day, which will be supplied by DFA member farms in the Michigan Thumb area.

Initially, the plant will produce condensed whole and skim milk, as well as cream. A phased construction plan will allow for growth among current and future DFA members and the potential to manufacture value-added demand products.

"This plant will provide a local home for our members' milk, answering the growing need for Michigan plant capacity while building a base for value-added processing in the future," said Mark Korsmeyer, executive vice president of DFA. "Furthermore, the project is consistent with DFA's strategic plan, creating supply chain efficiencies and increasing commercial investments to bring increased value to our farmer owners."

Numerous partner agencies contributed substantial support to the plant. The Michigan Strategic Fund (MSF) approved a $500,000 Michigan Business Development Program grant and a $1 million Community Development Block Grant, while the Michigan Economic Development Corp. is contributing $300,000 in corporate funds. MSF also awarded Tuscola County and Cass City a new 15-year Agriculture Processing Renaissance Zone designation for the project.

The village of Cass City also offered support by providing revenue bonding valued at approximately $6.7 million for a wastewater pretreatment system and public infrastructure improvements.

In addition to creating at least 25 full-time positions at the facility, increased employment opportunities are expected to occur on member farms and in agricultural support industries, the announcement said.


Heat detection system

Dairy companies Afimilk and ABS Global announced that they are teaming up to market the next generation of automatic heat detection solutions, AfiAct II.

AfiAct II uses long-range radio to collect behavior data anywhere on the farm from herds of any size and updates results at short intervals. Highly scalable and adaptable, the system is available as a stand-alone solution or can be integrated with Afimilk's farm and milking parlor management system. AfiAct II is also web accessible on any type of device.

Afimilk, a global dairy management company, developed the first heat detection system and recently launched this next-generation solution. As part of this collaboration, ABS will further extend its portfolio of reproduction offerings by introducing the AfiAct II system to customers in the U.S. and Canada.

With the initial AfiAct heat detection system, U.S. customers were reporting achieving pregnancy rates above 25%. Operating wirelessly, AfiAct II reduces open days and operating costs, resulting in savings of $100-150 per cow per lactation, the announcement said.


Heat Stress Road Show

The Dairy Heat Stress Road Show was a hit two years ago, and the road show will travel again this fall and in the spring of 2014, bringing new answers to the problem of heat stress in dairy cows.

Dr. Todd Bilby, dairy technical services manager with Merck Animal Health, said heat stress on dairies not only affects cow comfort but also lowers milk production and fertility, which costs the dairy industry millions of dollars annually.

Surveys conducted of participants in the last Dairy Heat Stress Road Show found that heat stress costs dairy operators more than $81 per cow per year.

The event teaches producers how to overcome some of the negative effects of heat stress by implementing strategies such as nutritional changes, hormonal treatments and facility improvement.

Producers at a road show event also reported that, by attending, they estimated that implementing the strategies they learned about could save their dairy operation more than $40 per cow per year.

The dates and locations of the road show this fall will be:

* Dec. 3 at the County Extension Office in Okeechobee, Fla., and

* Dec. 5 in Camuy, Puerto Rico, which will be delivered in English and Spanish.

The 2014 dates and locations will be:

* April 1 at the Texas A&M AgriLife Research & Extension Center in Stephenville, Texas;

* April 2 at the Hilton Garden Inn in Phoenix, Ariz., and

* April 4 at the Consumer Education Pavilion of the Vet Medicine Center in Tulare, Cal.

Topics and speakers for the road show include:

* Nutritional Additives & Facility Modifications to Reduce Heat Stress by Dr. Robert Collier, professor at the University of Arizona;

* Should We Cool Dry Cows? by Dr. Geoffrey Dahl, professor and department head at the University of Florida;

* Current & Future Opportunities to Reduce the Impact of Heat Stress by Dr. Pete Hansen, distinguished professor with the University of Florida, and

* Tools & Technologies to Assess Heat Stress on Commercial Dairies by Bilby.

Volume:85 Issue:42

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