Thursday, October 17, 2019

Zinc and omega-3 fatty acids

by Dr Neil Auchterlonie, Technical Director, IFFO

Researchers from Nofima, the Norwegian research organisation, reported last month that the barrier tissue of salmon is affected by zinc and omega-3 levels in feed, in a recent piece of scientific work that was funded by the Norwegian Seafood Research Fund (FHF).

Why is this important? Well, the integrity of salmon skin, intestine and gill tissues is vital for the health of the fish. These barriers are recognised as important first lines of defence against pathogens, as well as being important in helping the organism handle physical stressors such as fluctuations in temperature, salinity, or water quality in general.
 

The article that has been presented on the Nofima website points out the importance of these compounds nutritionally, and particularly in relation to the changes we are seeing in feed formulations such as new feeds specifically for recirculation systems, as well as the obvious dominance of plant-based raw materials in modern feed formulations.

The research set out to investigate whether changes in feed composition would affect the health and robustness of farmed salmon, and the scientists looked specifically at the interaction of zinc and marine source omega-3 fatty acids in feed, for parr to post-smolt in recirculation systems.

It seems to be a part of an ongoing programme of work that has looked at the general robustness of fish in the aquaculture environment, which is highly applied and very relevant work. The results are described in the context of the health and welfare of the fish, and those are obvious impacts related to the ability of the salmon to cope with a pathogen challenge, whether it is ISA virus or sea lice.

This science is important in the context of declining marine ingredient inclusions in aquafeeds. Fishmeal and fish oil are excellent sources of many micronutrients, and among the many different compounds present that contribute to fish (and consumer) health are zinc and the long chain fatty acids, EPA and DHA.

Read more, HERE.


The Aquaculturists

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