GM and algal oil benefits to salmon health studied
Researchers have begun a study into how well omega-3-rich oils from microalgae and genetically modified oilseed crops in salmon feed benefit the health of the fish.
They will compare algal oil from Veramaris, Cargill’s Latitude oil from GM canola (oil seed rape) and oil from GM camelina (a member of the rape family), grown by Hertfordshire-based Rothamsted Research.
The study is being led by fish nutritionists Professor Douglas Tocher and Dr Monica Betancor from Stirling University’s Institute of Aquaculture.
Evaluating the oils
Tocher said the trial would evaluate the oils as sources of the omega-3 long chain polyunsaturated fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).
The study includes monitoring the impact of the new omega-3 sources on the response of the fish to specific disease and parasite challenges.
The IoA researchers are working with Professor Jonathan Napier, of Rothamsted Research, fish immunologists at the University of Aberdeen and the lipidomics group at the University of the Highlands and Islands.
Different levels
The fish oils currently used in salmon feed have different levels of DHA and EPA depending on where they are sourced from, and the researchers explained that that was also the case for alternative oils.
A study was therefore required to evaluate their effects.
Betancor said: “Our new study will test these novel oils as sources of omega-3 in feeds for farmed Atlantic salmon, focusing on their impacts on fish health.
“The study will also define the influence of the novel dietary oils on the detailed biochemical and molecular mechanisms underpinning fish health, and assess and validate the potential of these new oils for use in salmon farming.”
All three oils being tested contain DHA and EPA and were developed specifically for the aquaculture industry.
‘Impact potential’
“This collaborative project is the perfect opportunity to demonstrate the impact potential of our novel plant-based omega-3 technology,” said Rothamsted’s Napier, who is an honorary professor at the IoA.
The study is funded by the Biotechnology and Biological Sciences Research Council (BBSRC), and both feed manufacturer BioMar and the Scottish Aquaculture Innovation Centre (SAIC) are providing support.
The fish will be grown from 20g to 500g in tanks at the IoA and will not enter the food chain.
Grown to 4kg
The study follows on from larger-scale trial started in August last year in which salmon were fed a diet that included oil from Rothamsted’s GM camelina.
The fish were grown successfully from 200g to 4kg in net pens on a Scottish farm. Betancor monitored the health of the fish during the trial, measuring weight and growth and also looking at tissue and molecular samples to compare the results of fish fed the new feed to salmon fed a usual diet.
The GM feed trials are being carried out with research licences. Salmon farmers are not currently allowed to feed GM products to their fish in Scotland but can use algal oil. Chile and North America are likely to be the first markets for GM feed.
