The Future of Aquafeeds :: Office of Aquaculture - NOAA Fisheries

Fed aquaculture is using more plant-based feeds as the industry expands.
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The concurrent trends of increasing consumption of seafood and decreasing natural harvests will dictate that a larger portion of seafood must be derived from aquaculture in the 21st century. The difficulty of producing economically large quantities of microalgal feeds is currently one of the major impediments to the further development of the aquaculture industry. Traditional methods, which rely on photosynthetic growth in outdoor ponds or indoors under artificial lights, suffer from the phenomenon of light-limitation of biomass density. Certain species of microalgae are capable of heterotrophic growth to high density utilizing sugars or other organic compounds for energy and cell carbon. This paper reviews work with strains of heterotrophic algae that have demonstrated potential as both nutritional feeds and for economical production by fermentation.

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Aquaculture feeds made with fishmeal and fish oil pack a powerful nutrient boost. But fish farmers are seeking alternatives to fishmeal and fish oil because of concerns that grinding up millions of tons of wild anchovies, sardines and other forage fish to the demands of a growing aquaculture industry isn’t sustainable. Trout Production: Feeds and Feeding Methods. 1999. Southern Regional Aquaculture Center, Fact Sheet # 223. Web Site:
Photo provided by FlickrAlso in 2015, it was reported that  would soon be available as a protein source for Ghanaian poultry, pig and aquaculture feeds.
Photo provided by FlickrAquaculture Feeds | Nutrition | National Renderers Association
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The findings, which appear in the open-access journal , are a major breakthrough in the quest to develop sustainable, fish-free feeds for aquaculture, the world's fastest growing food sector. The Dartmouth study is the first report of a marine microalgae species being successfully used as a complete replacement of fish oil in feed for Nile tilapia, which thrived on the new diet and bulked up despite eating less. A PDF is available on request."Our study shows that Schizochytrium is a high quality candidate for complete substitution of fish oil in juvenile Nile tilapia feeds, providing an innovative means to formulate and optimize the composition of feed while simultaneously raising feed efficiency of tilapia aquaculture," says Sarker, a research assistant professor in Dartmouth's Environmental Studies Program.Aquaculture feeds characteristically contain a higher percent of protein than feeds used in agriculture for poultry, swine, and beef. A typical commercial production diet formulated for tilapia or catfish contains approximately 32–40% protein, while one formulated for trout or salmon contains as much as 44–50% protein, on a dry weight basis. A commercial grower diet formulated for most terrestrial animals rarely exceeds 20% in total protein, and even for carnivorous species such as cats, the total protein rarely exceeds 38%. The use of higher protein levels in fish feeds is accepted because fish require less energy for maintenance of normal body functions than warm blooded animals such as poultry, swine, cattle, horses, and other terrestrial animals. Also, several species such as salmon and trout derive their energy from protein and fats more efficiently than from carbohydrates; similar to cats.Reducing the amount of total protein in fish feeds can increase profitability and minimize nitrogen pollution. Selecting proteins with high digestibility and formulating feeds with the appropriate balance of amino acids can easily accomplish this. The use of nutrient-dense feeds can also decrease costs and minimize nitrogenous waste from aquaculture facilities. A nutrient-dense feed will supply a significant amount of a particular nutrient or nutrients relative to the amount of energy occupying space in a feed pellet. Both of these approaches are being successfully implemented for poultry and swine, with significant improvements in feed conversion ratios and reductions in nitrogenous waste.