New uses for alfalfa: Aquafeeds
In 2016, alfalfa was harvested from 1 million acres across Minnesota. That amount has been declining for more than 30 years where in 1986 nearly 2 million acres were harvested for alfalfa. (USDA Annual Crop Production Reports). This decline is mainly due to demand as dairy and farming practices have changed over the years. The changes in the agricultural landscape have resulted in changes in our field soils and waterways as well. Increasing the feed industry’s demand for alfalfa may help farmers plant and harvest alfalfa on buffer acres and turn a profit while buffering the waterways from soil and nutrient loss, but we may need to shift our thoughts to a new species.
Alfalfa protein concentrate potential
The Minnesota Department of Agriculture has funded research at the University of Minnesota and USDA Agricultural Research Station to study value added products of alfalfa in order to help farmers across the state put this valuable crop back on the landscape. Alfalfa protein concentrate (APC) is a product in limited production that has good potential as a feed additive for the aquaculture industry. APC not only contains higher amounts of the limiting amino acids lysine, methionine, and threonine than other high protein plants, it also has a source of omega 3 fatty acids which is a requirement for fish health as well. In order to stir increased production of APC, University researchers are studying the production methods as well as the feed potential with different species of fish (Figure 1).
Aquafeeds have an expanding market as aquaculture grows. Aquaculture, the farming of fish, has been a significant portion of the world food fish supply and growing since 1995. According to the National Oceanic and Atmospheric Administration:
"The United States is the leading global importer of fish and fishery products, with 91 percent of the seafood we eat (by value) originating abroad – half of which is from aquaculture. Driven by imports, the U.S. seafood trade deficit has grown to over $11.2 billion annually. Although a small producer, the U.S. is a major player in global aquaculture, supplying a variety of advanced technology, feed, equipment, and investment to other producers around the world."
Aquaculture in the US is growing in response to this demand, however one of the concerns is that we still need to provide high quality protein diets that have traditionally been supplied by fish from the ocean. Researchers around the globe are pursuing the development of sustainable ingredients for aquafeeds to find replacements for fishmeal and fish oil in order to decrease the demands on ocean fish.
Dr. Samac, of the USDA and partnered with the University of Minnesota, initiated this project last year beginning with recruitment of a graduate research assistant and APC production research (Figure 2). This winter we began a feeding trial with yellow perch replacing the fishmeal in the pellets for half of our tanks with APC. The fish will be monitored for growth throughout the spring. Also this year, we will begin to examine the economics of producing APC commercially in the Midwest. This project will continue through 2018 while we conduct further feed and production trials with different cultivars and protein production methods to optimize this ingredient for fish feed.
Want to learn more?
Please join us at the 3rd annual Minnesota Aquaponics Symposium on May 2nd to learn more about the progress of the yellow perch feeding trial.
Dr. Jeff Coulter is a University of Minnesota Extension corn agronomist and advises farmers on the relationship of rotating alfalfa in corn production fields. Dr. Coulter can be reached at firstname.lastname@example.org. To learn more about growing and harvesting alfalfa in buffer strips please contact Dr. Scott Wells, University of Minnesota Extension forage agronomist. Dr. Wells can be reached at email@example.com.