Disease-fighting Milk

Posted on Monday, March 11th, 2019

Written by Sydney Pearce

Dairy cows eating feed through stall bars with one cow looking at camera
Dairy producers can use high immune response technology to identify cows with superior immunity and disease resistance.

Milk can do more than build strong bones—it could potentially reduce the risk of disease in humans, with help from new technology developed at the University of Guelph.

High Immune Response (HIR) technology, developed by professor Bonnie Mallard, is a management and breeding tool created for producers to identify cows with inherently superior immunity and disease resistance.

HIR cows have stronger immune systems than average- and low-responder cows. HIR cows also respond better to vaccination and have better quality colostrum and milk. Healthier cows not only mean less disease, but also less money spent on treatment.

Now, researchers at the Mallard Lab are using HIR technology cows to improve human health as well. Dr. Heba Atalla from the department of pathobiology is looking at microRNA (also called miRNA, small RNA molecules regulate proteins) found in cows’ milk and colostrum.

Atalla is interested in miRNA that are located within capsules called exosomes. She found certain miRNAs are more abundant in colostrum of HIR cows compared with average- and low-responders. These miRNAs have a crucial role in the development of the immune system and intestinal health.

After placing these exosomes that contain miRNA in an environment with human cells in a lab setting, they were taken up by human cells, despite originating from cows’ bodies. This suggests their bioavailability to humans similar to other important protein molecules in milk.

These exosomes, especially those from milk of HIR cows, made human cells healthier.

Further, exosomes from colostrum promoted the death of cancerous cells, suggesting their potential role as natural therapy to humans with a high risk of colon cancer.

“This research has many downstream applications,” Atalla says. “We can produce milk from HIR cows with natural value-added health benefits to humans, or disease-specific milk products tailored for individuals who are at risk for allergy, cancer or other chronic illness. It will also lead to economic benefits for the agricultural and health sectors in Canada.”

Previous studies have shown that HIR cows produce higher amounts of a specific antibody (produced in response to an immunization or infection) within the blood and in colostrum and milk.  This is extremely beneficial to calves that are born with a naïve immune system, and require passive immunity from the colostrum produced by their dam.  

In addition to cows, the HIR technology is used to identify sires with a high immune response. Semen from these sires is marketed as Immunity+ by The Semex Alliance. Immunity+ semen makes the HIR technology behind it available to producers across Canada and in 120 countries around the world to breed for enhanced immune response in the next generation.

Recent industry data shows that daughters of Immunity+ sires have lowered disease rates and mortality compared with daughters from non-Immunity+ sires. These results are proof HIR technology works in the field for producers, but more importantly, animals are benefiting from it, Mallard says.

In related research, Dr. Lauri Wagter-Lesperance from the department of pathobiology is measuring the presence of certain innate proteins not previously investigated in the colostrum and milk of HIR cows and Immunity+ daughters.

Natural antibodies are antibodies that are naturally present in cows’ blood and are produced by the immune system without immunization or exposure to infection. Defensins are peptides produced by certain cells of the immune system. Natural antibody and defensins can readily bind to bacteria so that certain cells of the immune system, called phagocytes, can engulf the bacteria to destroy it, and develop an acquired memory response for enhanced protection on future exposure.

“We are taking a natural approach to creating better milk products and enhancing our knowledge,” Wagter-Lesperance says. “There are plenty of good things in milk. It sometimes gets a bad rap and we are working to show consumers more of the benefits of milk.”

Atalla’s research is in collaboration with Mallard and professor Niel Karrow. Her projects are funded by Dairy Farmers of Ontario, the Natural Sciences and Engineering Research Council - Collaborative Research Development and the Ontario Ministry of Agriculture, Food and Rural Affairs. Wagter-Lesperance is a post-doctoral fellow working with Mallard, with funding provided through the Mitacs Elevate Program and The Semex Alliance.

This story was written by SPARK and originally published in the Milk Producer.

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