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

欧米伽-3 （n-3）长链多不饱和脂肪酸（欧米伽-3）、二十碳五烯酸（EPA）和二十二碳六烯酸（DHA）是必需的膳食营养素，在神经发育、免疫和炎症反应中起关键作用，并对包括心血管和神经系统疾病以及一些癌症在内的几种病理状况有有益作用。许多国家和国际机构建议每天摄入500毫克的Omega-3才能达到最佳健康状态。众所周知，在经济地位较低的国家，食品供应中Omega-3的可用性很低，通常低于最低推荐摄入量。现在人们认识到，从脂肪酸组成方面改善人类营养是一个重要目标，因此该项目的主要目标是解决印度、肯尼亚和坦桑尼亚贫困人口的营养缺乏问题。几乎所有的长链Omega-3都是由海洋和淡水生态系统中的微藻产生的，因此鱼类是人类饮食中这些营养素的主要来源，养殖鱼类目前约占消费量的50%。然而，养殖鱼类饲料中Omega-3的唯一来源是鱼粉和鱼油，这也是来自野生渔业的有限资源。预计70亿人口的膳食中ω -3的推荐摄入量表明，鱼类/海产品（无论是野生的还是养殖的）的供应与需求之间存在巨大差距。因此，为人类提供最佳营养的Omega-3是一个超越地理和政治界限的全球性问题。传统的植物蛋白和植物油不含长链Omega-3，但它们的前体ALA（短链Omega-3）在陆生和淡水植物中含量丰富。此外，包括鲤鱼和尼罗罗非鱼在内的许多淡水鱼具有将膳食ALA转化为EPA和DHA的代谢能力。因此，增加人类可获得的Omega-3量的一个潜在选择是利用淡水鱼从ALA中产生EPA和DHA的内源性能力。印度和非洲的养鱼业以鲤鱼和罗非鱼为主，这两种鱼类对养殖鱼类中Omega-3的生产最感兴趣。鲤鱼和罗非鱼水产养殖的加强，以及相关的补充饲料和加工饲料的使用增加，通过从膳食ALA中获得更高的Omega-3含量，提供了提高养殖产品营养质量的机会。这必须以可持续的方式进行，因此不使用有限和/或昂贵的全球商品，也不与现有的人类粮食资源或以当前农作物为代表的动物饲料竞争。本提案的目的是改善印度和非洲（肯尼亚和坦桑尼亚）养殖鲤鱼和罗非鱼的Omega-3含量，以使使用本土非传统饲料成分的当地贫困人口受益。在此背景下，我们的目标是应用和扩展目前对一系列当地、本地材料（包括淡水植物、微生物和海藻）的营养和脂肪酸组成的知识，并从营养质量、供应水平和社会经济可行性方面评估它们作为饲料原料的可用性、可行性和潜力。选定的新成分将在鲤鱼和罗非鱼喂养研究中进行测试，以支持养殖鱼类的生长、发育和健康，并通过增加Omega-3含量来提高营养质量。还将评估新型饲料成分进一步广泛应用和工业和商业规模扩大的潜力，以促进其作为新型本土饲料成分的开发。

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.