These stories are about treatment of on-farm milk for use in feeding calves. Of course, if it works for calves, why wouldn’t it work for people? Though probably the bar of surety is set higher when we’re dealing with food for humans. Michael Schmidt’s two-calf study comparing the effects of feeding calves raw milk vs store-bought pasteurized milk comes to mind as well, in connection with this news. Michael’s “Tale of Two Calves” remains the single most popular post ever published on The Bovine. Did you know that some farmers actually do pasteurize milk before feeding it to calves? Either that, or throw the “surplus” milk out and buy milk replacer from the feed store. You learn something every day. Thanks to Deb for the news tips:
“AT A 3000-cow dairy farm near Ithaca, New York, Rodrigo Bicalho wrestles a 3-week-old calf onto a scale. The calf totters about; the scale reads 52 kilograms, a healthy weight. Bicalho makes a note. He is trying to find out what happens if he gives his calves milk that, instead of being pasteurised, is treated with ultraviolet light.
While pasteurisation of foodstuffs has led to dramatic declines in foodborne illnesses, including tuberculosis, it does not kill all pathogens and candestroy some of the nutrients in milk, such as proteins and vitamins.
That can be a problem when using colostrum, for example. This is the first milk a mammal produces for its offspring, and it provides vital immunoglobulins to prevent disease in the newborn. Pasteurisation denatures these proteins, rendering them useless, says Bicalho, a veterinary scientist at nearby Cornell University. His is the first study to look at whether UV-treated milk might provide a viable alternative.
Exposure to UV light does not kill pathogens, but it damages their DNA enough to prevent them from reproducing. Although the technique can be used to purify water, it is still fairly new technology and it is not yet clear how effectively it deals with viruses and protozoans such as Giardia. What’s more, the technique relies on light reaching all parts of the liquid; that’s easy with water, but tricky with liquids such as milk and juice because of their opacity and coloration.
To get around this problem, Bicalho is using a device called the Turbulator, made by SurePure of Zug, Switzerland. It consists of a series of grooved cylinders with UV lamps running down the centre and a space 1.5 millimetres wide in between, through which the milk is passed. The grooves create a turbulent flow, and this ensures that all of the milk is exposed to UV light as it travels through the pipes.
Replacing pasteurisation with UV treatment promises to both inactivate pathogens and preserve a food’s beneficial properties. The technology also uses a fraction of the energy of heat treatment, and could knock out those microbes that are unaffected by, or even thrive on pasteurisation….”
“It’s been 150 years since Louis Pasteur perfected the process that bears his name. Pasteurization was at first used to extend the shelf life of beer and wine, but dairy processors soon saw its value and pasteurization became an industry-wide practice.
Many dairy farmers currently pasteurize the waste milk they feed to their baby calves. But the process of heating and holding milk at a particular temperature can be both energy and time-consuming. Errors can result in a product that has a burnt flavor or milk that still contains unacceptable levels of bacteria.
Recent developments have moved milk purification into the 21st century, with new tools that kill bacteria with ultraviolet light.
Mike Hulstein and his family milk 500 head on their farm located near Edgerton, Minn. Hulstein had an ultraviolet milk purifier installed on their dairy a year and a half ago.
“We were having a lot of problems with clostridia when we were feeding milk replacer,” Hulstein said. “That was all but eliminated after we switched over to feeding UV purified milk.”
With an average of 40 to 60 baby calves to feed at any one time, Hulstein was spending $100 per day for milk replacer.
“We were throwing away up to 600 pounds of waste milk each day,” Hulstein said. “Putting in a UV purifying system that would enable us to feed our waste milk seemed like a good solution for both problems.”
After a year and a half of use, Hulstein reports that his UV milk purifier has been operating trouble-free.
“We had some issues with curdling in the beginning,” he said. “After about a week, we figured out that we needed to hold the waste milk at 50 degrees or less. We installed a separate cooler to hold our waste milk and that solved the problem.”
The Hulsteins house their baby calves in a converted tiestall barn. Sue, Mike’s wife, handles the bulk of the calf feeding.
“Sue really likes our UV milk purifying system,” Hulstein said. “Using purified waste milk has simplified calf feeding chores for her. She used to spend a lot of time and effort measuring and mixing milk replacer. Now, when it’s time to feed calves, the milk has been purified and is being held at the proper feeding temperature.”
Hulstein said not only are their calves healthier, but they also have heavier weaning weights.
“We have a lot less scours now and fewer problems with mycoplasma,” he said. “Plus, we are making good use of the milk from cows that have been treated and milk from cows that have high somatic cell counts.”
Ultraviolet light is deadly to most microbes. In a UV milk purifier, milk is passed multiple times over a set of florescent tubes that produce a specific wavelength of UV light. The milk is never heated above feeding temperature, which helps preserve the milk’s beneficial immunoglobulins. Proteins and vitamins in the milk are unaffected by the UV purification process….”
“Waste milk from the cows in your hospital barn is oftentimes discarded. But every pound of waste milk or colostrum milk that has been properly treated to lower its bacteria levels can replace milk sources you would otherwise need to purchase. By turning waste milk into a valuable feed stuff for your calves, you not only save money, but you also provide a nutrient-rich and energy-filled product that can jump-start calf growth.
In the past, the primary concern with feeding waste milk to calves was the high level of bacteria contained within the milk that could make them sick. At such a young age, calves are very susceptible to pathogens such as Salmonella, E.coli, Staphylococcus species, and more. Bacteria loads in waste milk need to be reduced for optimal calf health.
Pasteurization Limitations – In recent years, on-farm heat pasteurization of waste milk has become common. Heating the milk and holding it at 145°F for 30 minutes, and then cooling the milk to 106°F, transforms the waste milk into a suitable food source for calves. While heat pasteurization is effective at killing bacteria, it can be time consuming and utilize a significant amount of energy. In addition, the heat pasteurizer can waste a lot of water, which is needed to cool the hot milk to an acceptable feeding temperature.
Heating the waste milk to pasteurization temperature can also degrade the nutritional value of the milk. And heat pasteurizers can be cumbersome pieces of equipment that are difficult to use.
Comparing the UV Pure to Conventional Heat Pasteurizers – The patented UV Pure technology allows the UV light to be used effectively on opaque liquids, such as milk. The UV light penetrates into the bacteria cells contained within the milk, destroying their DNA bonds – killing the bacteria and eliminating their ability to reproduce and grow….”