New uses for alfalfa: Aquafeeds
To help Minnesota producers put alfalfa back on the landscape, researchers at the University of Minnesota and U.S. Department of Agriculture (USDA) Agricultural Research Station began studying alfalfa’s value-added products. The Minnesota Department of Agriculture funded the research.
They studied alfalfa protein concentrate (APC) production methods as well as its potential as an aquafeed with different species of fish (Figure 1). They hope this will increase the demand for APC production.
APC is a product in limited production with good potential as a feed additive for the aquaculture industry. APC contains higher amounts of the limiting amino acids lysine, methionine and threonine than other high-protein plants. Plus, it’s a source of omega 3 fatty acids, another requirement for fish health.
A million acres across Minnesota harvested alfalfa in 2016 according to the USDA annual crop production reports. This amount has been declining for more than 30 years; in 1986, nearly 2 million acres were harvested for alfalfa.
This decline is mainly due to demand. Dairy and farming practices have changed over the years, and these agricultural changes have changed 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. However, we may need to shift our thinking to a new species.
As aquaculture grows, it’ll expand the aquafeeds market. Aquaculture, the farming of fish, has been growing since 1995 and is a significant portion of the world food fish supply. 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 United States is growing in response to this demand. However, one concern is that we still need to provide high-quality protein diets traditionally 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 to decrease the demands on ocean fish.
The USDA partnered with the University of Minnesota to initiate this project in 2016, beginning with recruitment of a graduate research assistant and APC production research (Figure 2).
In winter 2017, we began a feeding trial with yellow perch replacing the fishmeal in the pellets for half of our tanks with APC. Researchers monitored the fish for growth throughout the spring. Also in 2017, we began examining the economics of commercially producing APC 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.
Reviewed in 2018