Alternative and more sustainable feed ingredients

The exceptional nutritional value of fish, including Atlantic salmon, is largely due in part to the high content of 'omega-3' (n-3) long-chain polyunsaturated fatty acids (LC-PUFA). These essential fatty acids are known to have numerous health benefits, and play a key role in the prevention of common human diseases, including cardiovascular, inflammatory and neurological conditions particularly prevalent in the UK population. The primary source of these fatty acids in our diet is fish and seafood and, with declining fisheries worldwide, an increasing proportion is now being supplied by aquaculture. High levels of omega-3 LC-PUFA in farmed fish were ensured by the use of fish oil and fishmeal as feed ingredients, but this is not sustainable and, in recent years, alternatives have been sought. Vegetable oils can replace fish oils as energy sources but they are devoid of omega-3 LC-PUFA and high replacement levels can impact and compromise the health-promoting properties of farmed fish. The Nutrition Group is taking a radical new approach in a project with considerable potential to enhance sustainability of aquaculture. The project entitled 'Evaluating novel plant oilseeds enriched in omega-3 LC-PUFA to support sustainable development of aquaculture' addresses the fundamental problem with substitution of fish oil, the global lack of omega-3 LC-PUFA. The aim of this innovative £1.1 million Biotechnology and Biological Science Research Council (BBSRC) Industrial Partnership Award is to produce novel vegetable oils, specifically enhanced for aquaculture by containing high levels of omega-3 LC-PUFA, which can be used to replace fish oil in aquafeeds. The project, an interdisciplinary collaboration between Stirling, plant scientists at Rothamsted Research, and the major international fish-feed company, BioMar, represents an integrated approach to the supply chain underpinning the aquaculture industry. The oilseed crop, Camelina sativa, a relative of rapeseed, is being modified using a synthetic biology approach to produce plants metabolically engineered by the inclusion of algal genes to manufacture omega-3 LC-PUFA, usually produced only in marine phytoplankton. Oils will be trialled in feeds for Atlantic salmon and, in addition to providing a more sustainable supply of omega-3 LC-PUFA, the project would also benefit UK arable agriculture. Although GM plant technology currently has a limited role in Europe, the opportunities and markets for aquaculture are global and, in these terms, GM products already have wide application in animal feeds in many parts of the world.

A second project, 'Development of protein-rich and starch-rich fractions from faba beans for salmon and terrestrial animal production respectively' or Beans4Feeds for short, is developing replacements for fishmeal rather than the current over-reliance on imported soybean products. This project will process faba (field) beans to produce a protein concentrate for use in salmon feeds, and a starch concentrate for use in pig and poultry feeds, and thus replace a significant proportion of imported soy and fishmeal. In addition to economic benefits, increased bean cultivation will reduce the use of artificial fertilisers, relying on beans’ nitrogen-fixing properties as natural fertiliser and soil improvers, reducing costs and providing environmental benefits through reduced carbon and nitrogen usage. The £2.6 million award from the UK Technology Strategy Board involves six industrial partners including feed companies (EWOS, BioMar, Harbro), a fish producer (Marine Harvest Scotland), crop trader (WN Lindsay), and plant breeder/seed company (Limagrain UK), and five academic partners including Stirling, Aberdeen and St. Andrews Universities, the James Hutton Institute and Scottish Agricultural College. The project represents an almost unique, holistic approach involving all key players in the animal feed supply chain, combining critical commercial drivers with sustainability and food security.