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Nutraceuticals: what’s all
the buzz about?
Obviously, fish owners want their fish to eat healthy.
But can the ingredients in the fish’s food cures what
ails them just as effectively as a trip to the vet?
There are always plenty of disease-causing bacteria, viruses,
fungi and other organisms lurking, either in a fish’s
body or in the environment, waiting for an opportunity to
attack a susceptible fish. They are a part of life that cannot
be avoided, however fish do have a system for coping with
them – armies of immune cells that recognise these invaders,
attack them and hopefully, destroy them before they destroy
the fish. If a fish’s immune system is overstressed,
inefficient or undernourished, it cannot sustain an army able
to recognise the enemy and destroy it – that’s
when they develop disease. By maintaining their immune system
in peak condition, it is possible, at best, to avoid symptoms
of illness completely and, at worst, to put together an effective
fighting quickly so that the illness is less severe.
Because of crowding and associated stressors encountered
in fish keeping, they are more susceptible to disease than
free-ranging fish. Poor nutrition management practices are
often cause of these infections. Because these infections
are usually opportunistic, it is sometimes possible to control
the spread of infection by correcting housing problems that
precede disease outbreak (e.g. poor water quality.) In severe
cases, control of these infections often requires the use
of medicated feed such as feed supplemented with antibiotics.
Alternatively, the fish’s food can be their first medicine.
Instead of giving a drug to cure the invasion of pathogens,
“functional” fish foods can be fed to minimize
or prevent it. These foods are enriched with specific natural
food ingredients with properties to reinforce the fish’s
natural ability to fight the invasion of pathogens. These
ingredients are called neutraceuticals and specifically aid
body-protecting functions, thereby offering a health benefit
over and above simple nutrition or basic fortification. Proven
nutraceuticals include:
- BIOFLAVONOIDS act as natural antioxidants,
i.e. scavengers of active oxygen species that may adversely
effect fish health
- PROBIOTICS, the fish gut’s first
line of defense against disease, are health promoting bacterial
supplements, which improve the intestinal microbalance by
selectively suppressing the harmful bacteria in the gut
of fish.
- PREBIOTICS refer to a group of natural
sugars that is resistant to digestion by fish but can exclusively
be utilised by specific friendly beneficial bacteria (the
probiotics), causing them to outgrow their pathogenic competitors
in the fish’s gut. In other words, prebiotics act
as food for probiotics.
- IMMUNESTIMULANTS stimulate the macrophage
immuno-force of the fish to eliminate unwanted pathogens
in their bloodstream. Furthermore it also relieves allergies
that may occur due to not fully functional immune system.
Additionally, the use of functional fish foods will help
control the potential pathogenic bacteria and fungal growth
and digestive problems commonly occurring after antibiotic
treatment or prolonged stress conditions. It may therefore
be successfully used as a prophylactic, but it does not replace
the therapeutic value of antibiotics - however it may minimise
its use.
Functional foods are an emerging trend in fish foods –
fish enthusiasts are looking for products to maintain and
improve their fish’s quality of life. They seek the
targeted health benefits functional foods can offer, - “changing
the medicine cupboard for the food cupboard” - and often
want to see immediate results. Unfortunately, when they do
not see immediate results, they often become skeptical about
these foods and consequently believe that the “health
claims” are just marketing hype. Most of these products
will benefit their fish’s health in the long run and
after extended use.
Lourens de Wet
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