News 270 views last update:6 Aug 2012

Relation feed and immune response in aqua

Øyvind Haugland from the Norwegian School of Veterinary Science studied inflammatory reactions in salmon, and in particular how the ingredients of newer feed sources influence these reactions.

An increased understanding of the cell types of the fish immune system, and how they communicate with each other, is important for the development of better vaccines for salmon farming, and to shed light on the ways that new feed types may influence fish health.

Expression of immune response
The major regulators of the immune response are the cytokines, small proteins that function as messengers among the cells of the immune defence system. One of these cytokines is TNF-a. It was shown that vaccination with oil-containing vaccines leads to a rapid and intense, but temporary, expression of TNF-a and other cytokines. Three weeks after vaccination, however, the levels of cytokines were nonetheless insufficient to alter the amount or expression of genes influencing the presentation of vaccine components to other parts of the immune system.

Alternative feed sources
The study also looked at alternative feed sources and their effect on fish immune defence systems and health. An alternative to the fish meal currently used in feed is soya protein. The results of the work showed that an extract from the soya plant, Glycine tomentella, reduces the level of one of the central chemical messengers in inflammation, none other than TNF-a. Using rapeseed oil leads to significant changes in the fatty acid composition of salmon tissues, but that neither the degree of inflammation nor the bacteria-killing abilities appear to be affected.

Related website:
Norwegian School of Veterinary Science  

Related folder:
Dossier AllAbout Aqua Feed 

[source: ScienceDaily]

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