Development of alternative sustainable fish feeds to promote human health using novel non-conventional indigenous ingredients

Omega-3 (n-3) long-chain polyunsaturated fatty acids (Omega-3), eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids, are essential dietary nutrients with key roles in neural development, immune and inflammatory responses, and beneficial effects in several pathological conditions, including cardiovascular and neurological diseases, and some cancers. Many national and international bodies recommend a daily intake of up to 500 mg of Omega-3 for optimum health. It is known that in countries with low economic status the availability of Omega-3 in the food supply is low and often below the minimum recommended intake. It is now appreciated that improvement of human nutrition in terms of fatty acid composition is an important goal and so the primary objective of the project is to address this nutritional deficiency in poor populations in India, Kenya and Tanzania.
Almost all long-chain Omega-3 is produced by microalga in marine and freshwater ecosystems and thus fish are the predominant source of these nutrients in the human diet with farmed fish now accounting for around 50% of consumption. However, the only sources of Omega-3 for feeds for farmed fish are fishmeal and fish oil that are also finite and limited resources derived from wild fisheries. Projecting recommended dietary intakes for Omega-3 to a population of 7 billion shows a large gap between supply from fish/seafood (whether wild or farmed) and demand. Therefore, supply of Omega-3 for optimal human nutrition is a global problem that transcends geographical and political boundaries. Conventional plant proteins and vegetable oils do not contain long-chain Omega-3 but their precursor, ALA (short-chain omega-3), can be abundant in terrestrial and freshwater plants. In addition, many freshwater fish species including common carp and Nile tilapia have the metabolic capacity to convert dietary ALA to EPA and DHA. Therefore, one potential option for increasing the amount of Omega-3 available to human populations is to exploit the endogenous ability of freshwater fish species to produce EPA and DHA from ALA. Fish farming in India and Africa is dominated by carp and tilapia production - the species of greatest interest for the production of Omega-3 in farmed fish. Intensification of carp and tilapia aquaculture with associated increased use of supplementary and manufactured feeds provides the opportunity to enhance nutritional quality of the farmed products through higher Omega-3 contents derived from dietary ALA. This must be done sustainably and thus without the use of finite and/or expensive global commodities or competing with existing human food resources or animal feedstuffs represented by current agricultural crops.
The aim of the present proposal is to improve Omega-3 status of farmed carp and tilapia in India and Africa (Kenya and Tanzania) for the benefit of poor local populations using indigenous, non-conventional feed ingredients. In this context, we aim to apply and expand current knowledge of nutrient and fatty acid compositions of a range of local, indigenous materials including freshwater plants, microbes and seaweeds and assess their availability, feasibility and potential as feed ingredients in terms of nutritional quality, supply level, and socio-economic viability. Selected novel ingredients will be tested in carp and tilapia feeding studies for ability to support growth, development and health of farmed fish and to enhance nutritional quality through increased the Omega-3 content. The potential of the novel feed ingredients for further widespread application and industrial and commercial scale-up will also be assessed in order to facilitate their exploitation as novel indigenous feed ingredients.

The proposal aims to improve n-3 (Omega-3) long-chain polyunsaturated fatty acid (LC-PUFA), eicosapentaenoate (EPA) and docosahexaenoate (DHA), contents of farmed carp and tilapia in India and Africa for the benefit of poor local populations consuming the fish. n-3 LC-PUFA are essential dietary nutrients with beneficial effects in several pathological conditions and many international bodies recommend daily intakes of up to 500mg for optimum health. However, availability of n-3 LC-PUFA in the food supply is low and often below minimum recommended intake in countries with low economic status. Furthermore, there is a large gap between supply and demand for n-3 LC-PUFA showing this is a global problem that transcends geographical and political boundaries. Higher plants do not contain n-3 LC-PUFA but their precursor, linolenic acid (ALA), can be abundant in terrestrial and freshwater plants and many freshwater fish species including carp and tilapia, that are farmed in India and Africa, have the metabolic capacity to convert dietary ALA to EPA and DHA. Therefore, one potential option for increasing the amount of n-3 LC-PUFA available, particularly to poor populations, is to exploit the endogenous ability of farmed freshwater fish to produce EPA and DHA from ALA. In this context, we aim to apply and expand knowledge of nutrient and fatty acid compositions of sustainable, local, indigenous materials including macrophytes, microbes and macroalgae to assess their availability, feasibility and potential as feed ingredients in terms of nutritional quality, supply, and socio-economic viability. Selected novel ingredients will be tested in carp and tilapia feeding studies for ability to support growth and health of fish and to enhance nutritional quality through increased n-3 LC-PUFA content. The potential of the novel ingredients for widespread application and industrial and commercial scale-up will be assessed to facilitate their sustainable use as feed ingredients.

This project will benefit a broad range of local people in Africa, India and the UK. It will principally benefit small-scale fish farmers in India, Kenya and Tanzania by providing them with alternate fish feeds that do not contain expensive and increasingly scarce ingredients such as fishmeal and fish oil. This will increase the economic sustainability of their fish farms, helping to support reduction in poverty and increasing food security for the local communities. The inclusion of locally sourced ingredients will enable this to happen two ways, first the cost of the fish feed will be reduced and, secondly, it will ensure that that prices of the fish feed are more stable, allowing the fish farmer to plan better for the future. In addition to benefitting the fish farmer directly there will be additional benefits to the local community. The new ingredients for the fish food will all be produced in the same community as the fish farmer. This will create more jobs and livelihoods not just from those who will produce the new raw materials, but also for those who process and transport those raw materials. This will potentially increase wealth in the community and help to reduce poverty. This research will not only increase food security at a community level but will also increase it at a national level, by reducing the reliance on imported food materials such as fishmeal and oil, soybean products etc. and this could have knock on benefits to the balance of trade within these countries.
The alternate feed ingredients are also being chosen specifically to promote the content of n-3 long-chain polyunsaturated fatty acids (LC-PUFA) in the farmed fish. These fatty acids are crucial for good health but countries like Kenya and Tanzania have some of the lowest consumption rates for these fats of anywhere in the world. By including these new feed ingredients in fish produced locally these beneficial fatty acids are passed on from the raw ingredients to the fish and then on to the people who eat them. This has the potential to improve the health of these poor populations through cheap locally produced foods that have the potential to reduce diseases such as heart disease, dementia and some cancers. Therefore, the development of alternate fish feeds rich in these ingredients will reduce the suffering and economic cost of these diseases in countries with poorly developed health services.
In addition to the health, social and economic benefits this research project will also increase the level of scientific knowledge in all the countries involved. This will be of particular benefit to countries like Kenya and Tanzania where this project will work to ensure that the scientists and students involved with the project will be trained in the latest scientific skills and techniques. This will ensure that the project leaves a legacy within these countries of highly skilled scientists, networked to the international scientific community, who will be able to then develop another generation of high quality scientists. This knowledge exchange will also be of direct benefit to UK and Indian scientists, allowing them to learn from their colleagues in other countries and bring back that knowledge to help their domestic economies. In the UK we face similar issues with our fish farming industry, which is reliant on imports of fishmeal and oil, and expensive soybean protein concentrates, all mainly from South America and other countries outside the EU. The concept of a holistic approach to solving this problem through development of new potential feed ingredients from indigenous plants/crops is equally relevant in the UK. Therefore, the technology and information developed within this project will be applicable within the UK fish farming industry and provide valuable information for ongoing UK research into finding alternate ingredients for fish feeds.