High time for Scottish salmon with new plant-based protein feed trials
22 August 2022
In a global first, a UK producer of hemp crops is taking its first steps into the aquaculture sector that could see the alternative plant-based protein source used as a key ingredient for Atlantic salmon feeds.
Rare Earth Global, growers of industrial hemp for a range of sustainable products, has received £50,000 funding from the UK Seafood Innovation Fund (SIF) to explore how hemp seeds could be integrated into the diets of farmed salmon in Scotland.
With support from the Sustainable Aquaculture Innovation Centre (SAIC) and the University of Stirling’s Institute of Aquaculture, the project team has begun an initial feasibility trial to assess the impact of hemp protein on fish health and wellbeing, looking at factors such as digestibility and nutritional value.
Hemp-based protein is already sold for human consumption as a plant-based nutritional supplement as well as being used in cattle and poultry farming. However, the results of this study could see locally grown hemp being introduced as a core feed ingredient in aquaculture for the first time.
Initial indications suggest that a protein content of up to 50% could be achieved from the plants grown on UK soil, exceeding producers’ minimum requirements of 35%, as well as reducing the sector’s reliance on imported ingredients such as soy and fish meal.
The concept of using the hemp seeds as an effective protein source forms part of Rare Earth Global’s zero-waste approach to hemp farming, which ensures that every part of the plant is used for maximum value. Hemp plants are known to have multiple uses, with the stems widely used for sustainable insulation, paper, textiles and other materials.
By 2024, Rare Earth Global expects to be the largest UK-based hemp processor, contracting up to 5,000 hectares and the team said they have already had positive discussions with some of Scotland’s major seafood producers and feed manufacturers.
Suneet Shivaprasad, managing director and co-founder of Rare Earth Global, said: "There are lots of novel feed ingredients coming into the aquaculture sector, but the hemp seed trial is about making the best use of local ingredients. Hemp is one of the fastest growing plants, using minimal water and capturing up to eight times more carbon than most trees, which makes it a highly sustainable choice for so many different products and materials.
"Our aim is to ensure that every part of the plant delivers maximum impact, which is why we are focusing on aquaculture. Our studies show that protein conversion rates in salmon are much higher than for cattle or poultry, highlighting significant potential for the sector to introduce it as a new, sustainable feed ingredient. The process could be scaled up very quickly and we could see an entirely new UK-based supply chain for fish feed emerging in the near future.”
Researchers from the Institute of Aquaculture will be conducting trials at the University of Stirling’s facilities to assess how salmon react to different varieties of the hemp plant and any impact that the ingredient has on gut bacteria and the digestive system.
Monica Betancor, lecturer at the Institute of Aquaculture, said: "We already know that hemp protein is suitable for human consumption, which is highly promising, but this trial will help us better understand its impact on fish diets including gut health and digestibility. There may also be additional nutritional benefits, such as anti-inflammatory properties, and our aim is to gather appropriate data that can be used to inform future decisions about the suitability of this new feed ingredient.”
There are around 100 different types of hemp plant that can be grown worldwide, from the harsh climates of the Himalayas to the warmth of the Caribbean, and a further goal of Rare Earth Global is to determine which varieties will deliver the best results in terms of both crop yield and fish health and growth.
Sarah Riddle, director of innovation and engagement at SAIC, said: "With rising demand for sustainable healthy protein across the globe, aquaculture has a responsibility to reduce the environmental footprint of seafood production while also increasing its capacity to feed a growing population. Rare Earth Global’s entry into the sector represents an exciting opportunity for a new low-carbon feed source that could see reductions in imports from overseas. The circular model of production is equally important, highlighting the opportunity for a range of different sectors to make use of ingredients that may have otherwise been considered as waste.”