Algae: Dairy's next food source?

June 30, 2017

By Jennifer Coyne, Dairy Star

Could algae be the next ingredient used in dairy rations alongside corn and soybeans? Robert Gardner and his research team think so. 

As a room filled with listening ears, Gardner presented his preliminary research findings during the Midwest Farm Energy Conference at the University of Minnesota's West Central Research and Outreach Center (WCROC) June 13 in Morris, Minn.

"There are a lot of different options of products that algae can make - cosmetics, pharmaceuticals, bioplastics, biodiesels, and protein and carbohydrates for animal feed," said Gardner, assistant professor of renewable energy.

Although there are many different strains of the photosynthetic organism - microalgae, macroalgae, cyanobacteria and diatoms, among others - they all work similarly, capturing light and carbon dioxide to produce oxygen.

"Algae is surrounded by a great big world with photosynthesis happening all around it," Gardner said. "Nearly 50 percent of carbon dioxide in the atmosphere is fixed by algae." 
Knowing the strain of algae present in an environment and what they are capable of producing based on their structural characteristics allows scientists to use algae in place of synthetic materials, said Gardner who travels across the United States observing algae environments such as springs in Yellowstone National Park. 

In agriculture, algae blooms have been known to form from nutrient runoff in water reservoirs. This can result in excessive oxygen concentrates and the death of aquatic life. 
"Intensive farming also puts more carbon in the air, and if you don't do a sustainable crop rotation, you can really wreak havoc on the soil," Gardner said.

At WCROC, Gardner's work begins at the dairy lagoon, where wastewater is stored and laden with ample nitrogen and phosphorus. 

"I realize manure waste water is a valuable commodity to farmers, however, eutrophication is still happening," Gardner said. "Maybe there is a way we can be a little smarter and more strategic."

Currently, Gardner and his research team are collecting water from the lagoon and cultivating the algae for dairy feed, removing the nitrogen and phosphorus and treating the water at the same time. 

"We can then take the algae and feed it back to dairy calves to see if there is a pre- or probiotic effect to it ... whether it stimulates the gut microorganisms in the cows and helps them grow better," Gardner said.

The algae being studied are a cyanobacteria type, which can fix nitrogen. This process creates a biofertilizer that can replace synthetic nitrogen products.

Last year, the team created a prototype algae reactor, which cultivates the organisms in a flat-panel setup using recycled plastic. In time, Gardner hopes to add an aquaponic system to further recycle the water. 

"There are a lot of different options," Gardner said. "If we can work with the right strain [of algae], think how we could change dairy farming."

Implementing energy-efficient practices

Although some alternative feed sources are still being evaluated in research settings, there are other ways to transform dairy farms into more efficient operations. 

By evaluating the dairy in a life cycle assessment (LCA), farmers can decide which tool will be most beneficial for the farm. 

"An LCA reviews the impacts of a system on the environment and then organizes the data to determine the possible measures for improvement," said Joel Tallaksen, WCROC renewable energy scientist. 

At the research center in Morris, Tallaksen and his co-workers have used an LCA to evaluate the dairy's impact on fossil fuel use and greenhouse gas emissions. 

"Our ultimate goal is to reduce the impact on the environment and lower our costs associated with the dairy," Tallaksen said. 

The LCA reviewed four entities of the dairy - cropping, manure and herd management and milking operations. Without disturbing much of the dairy operation as a whole, Tallaksen worked with renewable energy scientist Eric Buchanan and other WCROC personnel to re-evaluate energy systems found in the milking operations. 

"We started at the point of smallest greenhouse gas impact, but a significant energy contribution," Tallaksen said. "And almost 30 percent of the total energy used on the dairy comes from milk collection, contributing 4.5 percent of the greenhouse gases."

In the parlor, which is used twice a day to milk 250 cows, more than half of the energy use comes from cow and employee comfort, while another 35 percent is used for cleaning and sanitizing the parlor. 

To reach the goal of net-zero energy use, the dairy implemented a variable frequency drive on the milk pump, replaced one of two reciprocating compressors with a scroll compressor, and carried renewable energy from wind and solar sources to use in the milking system.

By implementing renewable energy systems and tools to reduce overall energy use, the dairy expects to see 80 percent reduction in energy use in the milking parlor. 

"We're doing a good job, but we have a ways to go," Tallaksen said. "Our next step is to identify a new target."

As the LCA identified the parlor as an area of improvement at the WCROC, a similar assessment may show different results and provide different options for improvement on other farms. 
"Before making changes, think of other options, and consider the average payback of each change over time," Buchanan said. "It either makes sense or it doesn't. If it doesn't work for your farm, don't put it on your plan."