This Brief discusses potential alternative sources for feeds in
aquaculture fish diet, and explains that the future of aquaculture's
development is dependent on the costs of fishmeal and fish oil.
Considering that the increasing costs of traditional feeds constrain
this development, research is looking into alternatives, which can
ensure adequate nutrition for animals' growth.
This work reviews the use of alternative plant, microbial and insect
protein sources, evaluating in particular their impact on growth,
nutrient digestibility, fillet quality traits and sensorial perception
in the most important farmed marine and freshwater fish species. The
Brief specifically summarizes the pros and cons of plant oils from
oilseeds, which can on the one hand be a sustainable substitute for fish
oil, but which are on the other hand less rich in omega-3 long-chain
polyunsaturated fatty acids. The feeding might therefore result in an
undesired reduced nutritional value of the flesh of farmed fish. The
authors also explore the possible use of fishery discards as potential
aquaculture feed source. Since the landing of by-catch will with the new
Common Fisheries Policy (CFP) become obligatory (instead of simply
returning it to the sea, often dead), suitable uses of what must not be
used for human consumption can be investigated. The authors give an
outlook whether this might become a sensible alternative to improve the
management of discards and create more sustainable fisheries.
The Brief also addresses the issues of additives to aquafeeds, such as
vitamins, minerals, and antioxidants, but also immunostimulants and
enzymes. The authors discuss which effects these additives may have on
fish growth, welfare, reproduction and health status in aquacultures.
