Wednesday, February 10, 2010
Barley Feed for Aquaculture
The potentialities of feed grain for fish feed has been known to myself for two decades. The question was if someone would do something about it. The answer of course is in this item. Wild supply has been flat and now needs to be augmented by grain.
The obvious approach is to blend the feedstock with as much barley product as suitable to maintain a healthy stock. This would allow the use of barley fairly early.
As I have posted earlier, the advent of fresh water Coho husbandry in particular opens the door to exploitation of lakes in the boreal forests. There the feeding needs will be concentrated over the winter months, while during the summer it will be augmented by insect larvae. Trout should also prosper as well as less commercially attractive species.
This appears to be a fairly serious effort and it is hopefully implemented in the feed cycle somewhere to have it proven out.
Implementing a successful fish husbandry program in the boreal lakes opens up seventy percent of the world’s fresh water for commercial aquaculture in an environment that is presently overwhelmed with insect hordes. I would not want to put a production potential calculation out, because we simply do not have good working numbers, not least since no one has actually tried to do it the way I think it has to be done to optimize production.
What is however obvious is that the fresh water resource is so huge as to dwarf anything we can imagine. I suspect that without ever going to the ocean, that we can supply sufficient fish protein to satisfy the global population if we want to, or at least a serious fraction of it.
Barley Examined as Source for Potential Fish Feed
Fish physiologists Rick Barrows (left) and Gibson Gaylord (right) inspect pellets made of barley protein as technician Jason Frost (background) loads an extruder with raw materials.
Millions of tons of menhaden and other small fish are removed from the oceans each year to feed fish, poultry, and swine. The total amount of fish harvested for fishmeal has not changed in the last 20 years, but the demand has increased sharply. This pressure is thought by some to presage ecological problems and higher feed costs. So the search is on for alternative feed ingredients.
ARS scientists, led by fish physiologist Rick Barrows, are attacking the problem from many angles, one of which is to use barley protein as a main ingredient in feeds. Researchers at the Small Grains and Potato Germplasm Research Unit in
, are examining barley’s genes to improve the grain’s protein yield and nutritional composition and developing ways to concentrate the protein. At the research unit, which is co-located at the Aberdeen, Idaho ’s Hagerman Fish Culture Experiment Station, geneticist Ken Overturf is identifying genes in trout that may allow the fish to better utilize fishmeal-free diets. University of Idaho
The research team is pursuing several approaches to enhance the use of barley protein in aquafeeds. One is to produce a highly valuable co-product, beta-glucan, for the human nutraceutical industry while also producing barley protein for fish. Geneticist Gongshe Hu has selected varieties that will yield high levels of beta-glucan as well as protein.
Another approach is to concentrate the protein in standard field barley into a form usable in aquaculture feeds. Keshun Liu, a chemist at
, is evaluating both wet and dry fractionation methods of concentrating the protein. Barrows and researchers with cooperative research and development agreement partner Montana Microbial Products (MMP) of Butte, Montana, applied for a patent on a new enzymatic method that concentrates barley protein and produces raw material for another valuable commodity—ethanol. Aberdeen
“This process has provided a high-protein ingredient that may replace other, more expensive protein sources,” says Barrows.
“We conducted feeding trials to determine the digestibility of macronutrients and amino acids in the barley protein concentrate. The data from these trials allowed us to formulate trout feeds with varying levels of barley protein concentrate, and we successfully replaced both fishmeal and soy protein concentrate.
“There is no current commercialization of barley protein concentrate in place, but MMP is producing pilot quantities for feeding studies in trout, salmon, and other species. MMP projects that the concentrate will sell for $700 to $1,200 per ton,” says Barrows. Since fishmeal costs about $1,200 per ton, and fish oil costs about $2,200 per ton, the projected costs of barley protein concentrate compare favorably.
“Feed is part of a complex interplay of genetics, nutrition, and economics,” says Barrows. “We believe barley protein concentrate can completely replace fishmeal if other essential nutrients are supplemented. We will also examine oats as another fish-feed alternative.”—By Sharon Durham,Agricultural Research Service Information Staff.
This research is part of Aquaculture, an ARS national program (#106) described atwww.nps.ars.usda.gov.
Rick Barrows is in the USDA-ARS Small Grains and Potato Germplasm Research Unit, 3059 F National Fish Hatchery Rd., Hagerman, ID 83332; (406) 994-9909.
"Barley Examined as Source for Potential Fish Feed" was published in the February 2010issue of Agricultural Research magazine.