nofima.no
Creating value
2013
17
financed by:
The Norwegian Seafood
Research Fund
The physical and chemical properties of fishmeal influence both the production of fish feed and the physical feed quality.
photo: Jon-Are Berg-Jacobsen © nofima
High physical feed quality is important for the salmon
farmers. This new knowledge about the complexity
of the protein sources can help the feed producers to
achieve better control of their production process and
the quality of the feed.
Fishmeal is used extensively in fish feed and is
purchased based on a limited number of specifications.
Nofima has now demonstrated that these specifications
are inadequate in order to predict the physical quality of
the fish feed. This new knowledge may also be applied
to plant and other animal-based feed raw materials.
Extrusion technology and bread baking:
Salmon
feed is currently produced by extrusion technology – a
rapid kneading and cooking process at high temperature,
similar to preparing dough in your kitchen to bake bread.
This process results in a series of physical and chemical
changes in the feed raw materials. The quality of the
fish feed may be controlled and improved by adding
starch and other binding agents, but the proteins in the
fishmeal will also contribute to the physical quality of the
feed.
Major stress on feed:
The physical quality of fish feed
has become more important in recent years because the
feeding system blows the feed through long pipes from
storage bins to the fish cages. This exposes the feed to
mechanical stress and may lead to crushing. Crushing of
the feed pellets is a problem since the fish cannot eat
small particles or dust, and dust clogs up the feeding
system.
“We have documented for the first time that variation
in the physical and chemical properties of fishmeal influ-
ences both the extrusion process and the physical quality
of the feed,” says Project Manager and Senior Scientist
Tor Andreas Samuelsen at Nofima.
The physical and chemical properties of fishmeal influence both the
production of fish feed and the physical feed quality.
Proteins influence pellet strength
