By Susan Hall
The potential for grains, and in particular lupins, to meet the increasing global demand for feed ingredients for aquaculture, is being boosted by a concerted research push in Western Australia.
The aim is to reduce aquaculture"s dependence on fishmeal and replace it with high-protein grain products.
While there is growth in Australian demand for feeds for tuna, prawns, Atlantic salmon, trout and barramundi, this project is targeted at the global market for aquafeeds.
“Australia produces 80 percent of the world"s lupins, so this represents a huge opportunity for Australian growers,” says Dr Brett Glencross from the WA Department of Fisheries.
A Centre for Legumes in Mediterranean Agriculture (CLIMA) project, supervised by Dr Glencross, is examining value-added plant protein products as ingredients for aquafeeds.
The $4 million project is being supported by the GRDC and the Fisheries Research and Development Corporation (FRDC).
The program was recently joined by scientists from CSIRO Marine Research, the Tasmanian Aquaculture and Fisheries Institute and Norway"s AKAVFORSK.
The potential rewards are high. There is an opportunity to include Australian lupin kernal meal (LKM) in the annual 3.6 million tonnes of aquafeeds for farmed salmon, trout and prawn industries around the world.
Aquaculture feed manufacturer Skretting Australia so far uses about 5000 tonnes of LKM, with Skretting Norway now also using Australian LKM.
Dr Glencross says his research will identify production processes that are nutritionally, economically and practically viable.
“Nutritional evaluation with key aquaculture species, such as rainbow trout, salmon and prawns, will demonstrate the potential advantages of specific lupin products,” he says.
The commercial phase of the project will then involve the transfer of processing knowledge to the manufacturing sector, and an assessment of market awareness.
Aquafeed manufacturers generally favour lupins because they are easily pelletised and have better pellet characteristics.
A modern fish diet should contain 45 percent protein, with a typical formulation being about 42 percent fishmeal (65 percent protein) and 11 percent legumes.
“High protein lupins would therefore be a great advantage in feed formulations,” Dr Glencross says.
“Although LKM can substitute for soybean meal, a preferred strategy is to position LKM as a high-quality, niche ingredient with some important advantages over soybean meal, including better digestibility, improved functionality and fewer anti-nutritional factors.”
While lupinus angustifolius (narrow-leaf lupin) is the main lupin grown in WA, researchers will also assess the potential benefits of new varieties, including lupinus mutabilis (pearl lupin) and lupinus luteus (yellow lupin).
“We need to look at the amount of nutrients and energy an animal can derive from the specific ingredient, the palatability of that ingredient and the animal"s capacity to utilise the nutrients and energy,” says Dr Glencross.
“The major value in yellow lupin is the protein component, while in narrow-leaf lupin it is fibre and protein.
“To maximise prices, breeding should aim to increase protein, perhaps by reducing the fibre content, and the proportion of hull.”
Yellow LKM has several sought-after attributes, which could command a premium of 30 to 40 percent, or about $100 per tonne.
Dr Glencross says it has a slightly better protein and energy level than soybean meal, making it potentially more competitive in the international aquafeed ingredient market.
Yellow LKM also has a high protein and phosphorus digestibility and a reasonably good energy digestibility (comparable to soybean meal).
However, Dr Glencross says a key limitation to development of the market for yellow LKM is availability and that much more will need to be grown to make aquaculture feed companies confident enough to make the switch.
He says that to lift yellow lupin production, the yield and cost differential between yellow and narrow-leaf lupin must decrease.
GRDC has also been working with the WA Department of Agriculture, where Sofia Sipsas heads a team investigating other new lupin opportunities in human foods (see Ground Cover issue 49).
For more information:
Dr Brett Glencross, WA Department of Fisheries, 08 9239 8103, firstname.lastname@example.org
GRDC Research code: CSM 1, program 5