British scientists have genetically engineered camelina plants to produce high levels of omega-3 oils in their seeds which were successfully fed to Atlantic salmon.
The breakthrough could eventually provide a more sustainable source of omega-3-producing crops to substitute fish oil in fish feeds.
The scientists at Rothamsted Research say oil derived from camelina plants that have been genetically modified to produce 20% EPA in their seeds is entirely suitable for feeding Atlantic salmon.
In a joint research project between the University of Stirling and Rothamsted Research, scientists developed GM plants that can produce up to 20% of the omega-3 oil eicosapentaenoic acid (EPA).
“We have always worked towards providing a sustainable source for the omega-3 fish oils – our results here confirm another step in that direction.”
Johnathan Napier, Rothamsted Research
The extracted oils from the plants grown in the glasshouse were used as a replacement for marine fish oil in feeds for Atlantic salmon.
The results of the study demonstrated that growth performance, feed efficiency, fish health and nutritional quality for the human consumer were unaffected when dietary fish oil was substituted with oil from the GM plants.
Omega-3s are polyunsaturated fats found naturally in oily fish, nuts, seeds and leafy green vegetables. They are associated with many health benefits including prevention of heart disease and stroke.
But wild stocks of oily fish, such as mackerel and salmon, are under pressure.
The scientists hope fish oils extracted from GM plants could replace fish oil in salmon farming.
Rothamsted scientists, funded by the Biotechnology and Biological Sciences Research Council (BBSRC), have being carrying out research in metabolically engineering plants to produce omega-3 fish oils for more than 15 years.
For the latest study, published in the journal Scientific Reports on Thursday (29 January), they used five microalgal and fungal genes to engineer camelina plants (Camelina sativa) in order to generate a renewable, terrestrial, sustainable source of omega-3 fish oils.
The oil extracted from these glasshouse-grown GM plants was then used to test effective incorporation in fish feeds and the suitability of these feeds for Atlantic salmon.
Lead researcher professor Johnathan Napier, of Rothamsted Research, described the results as “very encouraging”.
He said: “We have always worked towards providing a sustainable source for the omega-3 fish oils – our results here confirm another step in that direction.”
Professor Douglas Tocher, leading the salmon feeding study at the University of Stirling, said: “The development of these novel plant oils, tailored to human requirements, represent a sustainable way to farm fish with high levels of omega-3 fish oils that maintain their high nutritional value to the human consumer while preserving wild fish stocks.”
Rothamsted is currently evaluating the results of a field trial of GM camelina plants engineered to produce omega-3s (see link above).