“In human food production realm, fish production provides another option to utilize South Dakota’s agricultural resources for economic development,” said professor Michael Brown, a scientist in SDSU’s Department of Natural Resource Management.
Brown’s latest work finds that some diets using soy protein concentrates, or SPC, perform as well as fishmeal-based diets.
That’s also good news for a hungry world and the world’s ocean fisheries, because production of aquafeeds needed to supply fish farming operations has nearly tripled in recent years, from 14.4 million U.S. short tons in 2000 to 41 million tons in 2010.
“The marine resources necessary to economically support that growth in aquaculture feeds and commercial production of fin fishes, etc., is not sustainable. Given the limited available supply and cost of fish meal and oils, plant-derived replacements are going to be highly valued in the marketplace,” Brown said.
That will give soybean and corn producers opportunities to add value to their crops, said Brown, who uses soybean meal, soy protein concentrates, and corn-based, dry distillers grains with solubles (DDGS) as primary ingredients in his experimental fish diets.
“The latest trials we’ve completed have compared SPC as fishmeal replacers in feeds for rainbow trout and yellow perch. We’ve done these trials with and without amino acid supplements to determine the effects on growth performance, fillet composition and other basic metrics that we use to determine how well a feed is performing,” Brown said. “Recently some of the SPC and DDGS diets that we’ve tested have yielded even better growth than what we saw with fish meal and DDGS controls.”
In a yellow perch feeding trial, one of the SPC diets tested without amino acid additions produced lower weight gain (20 percent) than the control diet (60 percent). However, with amino acids, SDSU researchers achieved the same level of growth performance (60 percent weight gain), Brown said. A different SPC product clearly outperformed fishmeal.
“Combined with selected supplements, that product provided a 175 percent weight gain, and without the amino acid supplements, it did just a touch better (80 percent weight gain) than our fishmeal control,” he said. These results reveal some of the variability that exists in SPC products.
There are several SPC products on the market and soybean processing technology will advance to provide others having different composition and nutritive value. Similarly, with changes occurring in the biofuel industry, alterations in the chemical profiles of corn co-products will occur. Brown’s ongoing work explores how well they perform in fish diets.
“In essence, the idea is, how far can we push soybean and corn products and co-products as diet constituents and still maintain or obtain better performance than we do with the marine-derived fishmeal diets.”
Brown said finding alternative, sustainable feeds to commercially raise fish will be critically important in future decades as the population of humans is expected to near the 9 billion mark. Fish are more efficient at converting feed than any land-based livestock, including poultry and swine, their closest competitors in feed conversion efficiency, Brown said.
“When you think about it, it makes sense. You have fish in this aqueous solution, in water. They require less skeletal support — it’s basic physics,” Brown said. “They require less energy to maintain their position in that medium. Even though there’s higher resistance there due to the viscosity, they also tend to move slower and use less energy. They’re also poikilotherms, so they don’t generate their own body heat — that’s less metabolic energy required to cool or heat themselves. These are some of the primary underlying reasons for the conversion efficiency. They simply make more efficient use of their food.”
The South Dakota Soybean Research & Promotion Council has played a key role in supporting Brown’s research. In addition, the U.S. Department of Agriculture has been funding the DDGS research. The South Dakota Agricultural Experiment Station also supports Brown’s aquaculture studies.
Lance Nixon | Newswise Science News
Kakao in Monokultur verträgt Trockenheit besser als Kakao in Mischsystemen
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Controlling electronic current is essential to modern electronics, as data and signals are transferred by streams of electrons which are controlled at high speed. Demands on transmission speeds are also increasing as technology develops. Scientists from the Chair of Laser Physics and the Chair of Applied Physics at Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) have succeeded in switching on a current with a desired direction in graphene using a single laser pulse within a femtosecond ¬¬ – a femtosecond corresponds to the millionth part of a billionth of a second. This is more than a thousand times faster compared to the most efficient transistors today.
Graphene is up to the job
At the productronica trade fair in Munich this November, the Fraunhofer Institute for Laser Technology ILT will be presenting Laser-Based Tape-Automated Bonding, LaserTAB for short. The experts from Aachen will be demonstrating how new battery cells and power electronics can be micro-welded more efficiently and precisely than ever before thanks to new optics and robot support.
Fraunhofer ILT from Aachen relies on a clever combination of robotics and a laser scanner with new optics as well as process monitoring, which it has developed...
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
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