SEAFOODNEWS.COM [SCOM] July 15, 2014 — Scientists at the USDA and at Montana Microbial Products (MMP) have engineered barley to serve as a nutritional, high-protein fish feed ingredient for farmed salmon and trout diets.
Researchers were able to substantially increase barley's protein content. Barley typically contains 10 to 12 percent protein, but 40 to 60 percent protein is needed in diets of carnivorous fish like rainbow trout and salmon. But the new enzymatic process patented by the Agricultural Research Service (ARS) and MMP concentrates protein by removing the carbohydrates in barley and turning them into an ethanol coproduct, utilizing all the nutrients in the grain.
According to Rick Barrows, a fish physiologist with the ARS's Small Grains and Potato Germplasm Research Unit in Aberdeen, Idaho, this new high-protein product produced by this technology should help fill the gap for more plant-based protein sources as alternatives to fishmeal, which is typically made from small ocean fish. He added the barley protein concentrate has less variability in composition and is less expensive than most fishmeals.
Barrows, who works in Bozeman, Montana, and his team tested barley protein concentrate in rainbow trout and found digestibility—the percentage of nutrients available to the fish—to be as high as 95 percent. The product also was tested in Atlantic salmon by research leader William Wolters and fish physiologist Gary Burr at the ARS National Cold Water Marine Aquaculture Center in Franklin, Maine.
Atlantic salmon were fed a diet containing either 11 percent or 22 percent barley protein concentrate. The growth of those salmon was not significantly different from salmon fed a standard fishmeal diet. Also, the fish that ate the 22 percent barley protein concentrate diet had significantly greater energy retention compared to fish fed the other diets. Higher energy retention demonstrates that the fish are using the feed more efficiently.
MMP has built a commercial prototype plant in Montana to produce barley protein concentrate for trout feeding trials. The company also plans to build a commercial facility in the near future.
This story originally appeared on Seafood.com, a subscription site. It is reprinted with permission.