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News Article

Increased use of agricultural byproducts in livestock, fish feeds

Move will free up food for humans 

Producing feed for livestock is using up limited natural resources which could be used to produce food for people. New research from Aalto University, published in Nature Food, shows how changes to the feeding of livestock and fish could not only maintain production but also make more food available for people. Such changes would increase the global food supply significantly, providing calories for up to 13% more people without requiring any increase in natural resource use or major dietary changes.

About a third of cereal crop production is used as animal feed, while about a quarter of fish caught are not used to feed people. Matti Kummu, associate professor of global water and food issues at Aalto, led a team to investigate the potential of using crop residues and food byproducts in livestock and aquaculture production, freeing up the human-usable material to feed people.

Kummu explained that this was the first time anyone had collected the food and feed flows in this detail globally, from both terrestrial and aquatic systems, and combined the data. This allowed them to understand how much of the food byproducts and residues was already in use, the first step to determining their untapped potential.

The research team analysed the flow of food and feed, as well as their byproducts and residues, through the global food production system. Methods for shifting these flows to produce a better outcome were then identified. Livestock and farmed fish, for instance, could be fed food system byproducts, such as sugar beet or citrus pulp, fish and livestock byproducts or crop residues, instead of materials fit for human use.

According to the team, adoption of these changes could lead up to 10-26% of total cereal production and 17 million tons of fish (~11% of the current seafood supply) being redirected from animal feed to human food. Depending on the precise scenario, the gains in food supply would be 6-13% in terms of caloric content and 9-15% in terms of protein content; this lead author of the paper Vilma Sandström says is food for up to about one billion people.

These findings support earlier findings from Kummu’s group on reducing food loss throughout the supply chain, from production, transport and storage through to consumer waste. He explained that in that study, they showed that reducing food loss and waste by half would increase the food supply by about 12%; combined with using byproducts as feed, that would be about one-quarter more food, he says.

Although some of the changes, such as feeding crop residues to livestock, would lead to reduced livestock productivity, the researchers have taken this into account in their analysis. Another challenge is that the food currently used in livestock production and aquaculture is not what people are used to. Feed industries use a different variety of corn, with some of it being of lower quality; fish used in fishmeal production tend to be small, bony fish that are not generally popular with consumers.

It is suggested that overcoming these hurdles could result in substantial gains. Realising these benefits would, however, require some adjustments in supply chains. Sandström pointed out that the food system would have to be reorganised so that the industries and producers with byproducts link up with the livestock and aquaculture producers requiring them.

According to Kummu, what is being proposed is already being carried out on a certain scale and in some areas, and that current practices just need to be adjusted and scaled up.

Sandström, V., Chrysafi, A., Lamminen, M., Troell, M., Jalava, M., Piipponen, J., Siebert, S., van Hal, O., Virkki, V., Kummu, M. Food system by-products upcycled in livestock and aquaculture feeds can increase global food supply. Nature Food (2022) 3:729–740, (open access)

Article details

  • Date
  • 05 October 2022
  • Source
  • Aalto University
  • Subject(s)
  • Animal nutrition
  • Aquaculture