Canola role for aquaculture
The flow-on effect of this growth means fish feed providers are looking increasingly to the grains industry to supply raw material.Two major ingredients of fish feed are protein and oil or fat. Currently most fish feeds comprise 20 to 30 per cent of combined fish oil and poultry fat. Australia’s leading supplier of aquaculture feed, Skretting Australia, has recently begun substituting some of the fish oils and poultry fat used for farmed salmon diets with Australian canola oil. The company’s research has discovered:
- faster fish growth rates in winter because canola oil is more digestible;
- better conversion rates – more fish for less feed;
- canola oil maintains a favourable balance of omega-3 and omega-6 fatty acids in salmon flesh; and
- less wastage of the valuable ‘healthy’ long-chain omega-3‘EPA and DHA’ oils from fish oils, as a higher proportion remains in the fish flesh rather than being used by the fish for energy.
He anticipates the company will use about 10,000 tonnes of canola oil per year in the future, with usage increasing as demand for Australian farmed fish increases.
“We introduced canola oil into one of our new salmon feed ranges, Optiline Premium, in August but we are likely to do the same for all our feeds in future,” Dr Hauler says.
However, fish meal and poultry meal are the main protein source for aquaculture. Dr Hauler says his company would be interested in an Australian grain-based product if the protein can reach the same levels as fish meal and poultry meal – 60 to 65 per cent.
“We are quite limited in Australia in what is available to us,” he says.
Skretting Australia currently uses de-hulled lupin meal (which is about 38 per cent protein), wheat gluten and minor quantities of imported soybean meal as supplementary protein sources.
In 2008, the Western Australian Department of Fisheries completed a GRDC and Fisheries Research and Development Corporation project that investigated increasing the protein concentration of lupin meal for the aquaculture industry. However, these protein concentrates have not yet proved economical for fish feed manufacturers.
However, with further research Dr Hauler says Australian de-hulled faba beans, soybeans or canola meal have the potential to be alternatives to fish meal and poultry meal. “It would be a good story for the aquaculture industry if we could have an Australian grain-based raw material that could compete with animal proteins,” he says.
The GRDC is supporting research into producing commercial canola with oils containing the same long-chain omega-3 fatty acids found in fish oil. The price of fish oil is at a premium. Over the past decade it has risen four-fold to $2500 a tonne. The aquaculture industry currently consumes 75 per cent of the world’s fish oil production, while demand for pharmaceuticals and fish oil capsules is growing at roughly 15 per cent a year.
GRDC Project Code UWA00062
Region National, West