Milk contains approximately 88 percent water, and when it is transported from the farm to the processor that water is transported, too. But, what if you could remove some of that water and save it for use on-farm?
The concept is basic: remove water from milk and concentrate the solids prior to transport.
Reverse osmosis (RO) and ultrafiltration (UF) are the two methods of removing water from milk that are feasible for on-farm use, says Vikram Mistry, dairy scientist at South Dakota State University. Both processes use similar equipment; the difference is the pore size in the membrane. With RO or UF, raw milk is pumped under pressure over different-sized membranes to remove the water. Typical on-farm applications concentrate milk two and one-half to three and one-half times depending upon application.
The development of these two technologies has evolved over the past 35 years. The very first membranes required milk to be heated to 135 degrees F, which created shelf-life, bacteria and taste issues, says Mistry. It wasn’t until around 1997 that a membrane system was developed for cold milk, eliminating bacteria count, shelf-life and taste problems.
There are a handful of on-farm units across the country, but it is a technology that is piquing the interest of more and more dairy farmers.
Here is a look at the opportunities that these technologies could offer.
Recycle that water
For every 100 pounds of milk shipped, it is possible to remove 88 pounds of water, which can be recycled for other uses on-farm.
Since the pore size of the membranes used in reverse osmosis and ultrafiltration are different, the water by-product is slightly different. Water removed through RO contains some water-soluble vitamins and very little else, says Bob Fassbender, technical director at TC Jacoby and Company and manager of North American Milk. The water by-product from RO can be used to water cows, irrigate crops or wash equipment, among other things.
The by-product of ultrafiltration is water which contains minerals and lactose. The water reclaimed through UF is best utilized by watering cows, as it contains lactose which is a good energy source for dairy cattle.
The reclaimed water through RO or UF can replace up to 20 percent of the water used from ground or municipality, says Fassbender. “In areas where water resources are scarce, this could provide a huge benefit.”
Shrink the carbon footprint
Removing the water from milk prior to transport can shrink the number of trucks needed to haul milk from three and one-half down to one.
This reduction in trucks lowers the cost of transportation for milk, but it also takes vehicles off the road, which reduces the number of greenhouse gases emitted. And the dairy industry has made a commitment to reduce its greenhouse-gas emissions by 25 percent by the year 2020.
The Good Cow Company in Boise, Idaho, has developed its environmentally friendly marketing strategy around reverse osmosis. Their Web site promotes the fact that RO takes place directly on farm; no diesel is used to haul milk to the processing site, and water is recycled to irrigate crops on-farm.
The Good Cow Company isn’t the only one becoming more sustainable and lowering its carbon footprint. Every business is looking to mitigate its exposure to greenhouse-gas emissions and minimize its carbon footprint, says Michael Lichte, director of dairy marketing at Dairy Farmers of America.
And, transportation is the single largest expense in marketing milk, says Lichte. Anything that can be done to reduce transportation costs is a huge benefit. “These technologies would divide transportation costs in three, and get the same functional milk components to places cheaper.”
Increases cheese yield
The demand for RO or UF milk hasn’t just been growing from the “sustainable” aspect, either. The concentrated solids have benefits to cheese- and ice cream-makers.
UF and RO milk gives cheese-makers the ability increase product yields and increase plant capacity without expanding. An addition of 10 percent of UF or RO milk can increase cheese yields by as much as 20 percent, says Fassbender. Both sets of concentrated solids can be used in Grade A manufacturing.
Dairy Farmers of America has had steady demand for this type of product since it invested in RO technology at its plant in Colorado, says Lichte.
Fassbender concurs. “We have a waiting list of people who want UF milk,” he says.
Opens the door to opportunities
Because transportation costs are cheaper, shipping milk farther becomes more feasible.
Dairies located in remote areas may have a limited marketplace for their milk, explains Fassbender. “This opens up the marketplace for that dairy and could allow them to ship into milk-deficit areas.”
Two years ago, when California had a surplus of milk, the processors placed caps on milk production, limiting growth. RO or UF could be an option if that situation occurs again for producers to stay under base if they exceed their allotted base or wish to expand.
Installing an on-farm system in Wisconsin, where there are 210 dairy plants, may not make much sense. But there are a lot of locations west of the Mississippi River where it would be applicable, notes Fassbender.
It could also be possible for several farms to work together and install this type of set-up. “Southeast Milk in Georgia has made this work. Several dairies run their milk through one system prior to transport,” notes Fassbender.
This technology continues to evolve and so do the uses for separated solids or permeates. As more technology emerges, the value will continue to increase.
Quality is important
Producing high-quality milk is always important, but it becomes crucial when it comes to reverse osmosis (RO) or ultrafiltration (UF).
RO and UF milk both have to meet Grade A standards for somatic cell counts of 750,000 cells per milliliter. (California has a more-stringent standard at 600,000 cells/ml.)
Somatic cell count can be problematic if a farm has a SCC of 300,000 cells/ml or higher before concentration, says Bob Fassbender, technical director, TC Jacoby and Company. Bacteria levels of 100,000 must also met, but Fassbender says he’s never seen bacteria counts to be an issue.
Antibiotic testing can also be an issue, as the current antibiotic tests were designed for raw milk and must be performed on the raw milk, not concentrated solids. Antibiotic tests must be performed on raw milk prior to it running through the RO or UF system. If it’s not tested prior to concentration, the milk may have a false/positive reading at the plant, explains Fassbender. “This method has been accepted by the U.S. Food and Drug Administration for RO and UF milk,” he says.
Economics of it all
There are several items that impact the feasibility of a reverse osmosis (RO) or ultrafiltration (UF) system on-farm. Variables include how far milk is transported, current milk price and fuel costs, to name a few.
Because milk hauled by three and one-half trucks can be shrunk into one, there are significant hauling savings.
Trip distance: 300 miles
Cost charged per tanker: $2.25 per loaded mile
Cost per tanker: $675
Cost per hundredweight: $1.35 (based on 50,000-pound load)
Cost to haul 175,000 pounds of milk (3.5 tankers): $2,362.50
Cost to haul UF or RO milk: $675 (at 3.5 times the concentration, the equivalent fat and protein of 175,000 pounds of milk)
Cost per hundredweight (milk equivalent): 39 cents
Savings per hundredweight: 96 cents per hundredweight
Savings in dollars: $1,687
There is a cost of 50 cents to 75 cents per hundredweight to run the equipment on-farm. The biggest expense in operating the equipment is the chemicals needed to clean the system.
The total footprint, including the cement pad to load a truck out on, is 50-feet by 80-feet. The equipment itself is very small, says Fassbender. Cost of the equipment varies depending upon the size of the system and the different bells and whistles, but a basic system, geared for 350,000 pounds of milk per day would cost $3 million. This includes the building and facility to put it in.
Again, multiple farms might want to work together on this.