Fish meal has been used as a feedstuff since the 19th century in Northern Europe and is now used worldwide. Global production of fish meal has been stable for the past two decades at around 5 to 6 million tons, Peru and Chile being the main producers. A major portion (more than 60%) of fish meal produced globally is used for aquaculture (farming of finfish and shrimp). The intensification of aquaculture in Asia, and particularly in China, is increasing the demand for fish meal even though the supply cannot grow accordingly. Natural phenomena such as the El Niño-Southern Oscillation affect the fisheries along Central American Pacific coasts, leading to seasonal scarcities and increased prices. Due to these factors, the fish meal market is volatile and prices often shoot up. The search for suitable and cost-effective alternative protein sources for use in industrial aqua feeds will be the most critical factor in the development of intensive aquaculture in Asia (Kaushik, 2010; Steinfeld et al., 2006).

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FishMeal
Fish meal or fishmeal, is a commercial product made from fish and the bones and offal from
processedfish.Itisa brown powderor cake obtainedbydryingthe fishorfishtrimmings,oftenafter
cooking, and then grinding it. If it is a fatty fish it is also pressed to extract most of the fish oil.
Fishmeal isanutrient-richandhigh-proteinsupplementfeedingredientthatstoreswell, and is used
primarily in diets for domestic animals and sometimes as a high-quality organic fertilizer.
Fishmeal can be made from almost any type of seafood, but is generally manufactured from wild-
caught,small marine fishthatcontaina highpercentage of bonesandoil,andis usually deemed not
suitable for direct human consumption. The fish caught for fishmeal purposes solely are termed
"industrial". Other sources of fishmeal are from by catch of other fisheries and by-products of
trimmings made during processing (fish waste or offal) of various seafood products destined for
direct human consumption. Virtually any fish or shellfish in the sea can be used to make fishmeal,
although a few rare unexploited species may produce a poisonous meal.
What is fishmeal?
In the UK the termfishmeal meansaproduct obtainedbydryingand grinding or otherwise treating
fishor fishwaste towhichno othermatterhas beenadded.The termwhite fishmeal isreserved for
a product containing not more than 6 per cent oil and not more than 4 per cent salt, obtained from
white fish or white fish waste such as filleting offal.
These are semi legal definitions, and for convenience fish meal can be defined as a solid product
obtainedbyremovingmostof the waterandsome or all of the oil from fish or fish waste. Fish meal
is generally sold as a powder, and is used mostly in compound foods for poultry, pigs and farmed
fish; it is far too valuable to be used as a fertilizer.
What raw material is used?
Virtuallyanyfishorshellfishinthe seacanbe used to make fish meal, although there may be a few
rare unexploitedspecieswhich would produce a poisonous meal. The nutritional value of proteins
fromvertebrate fishdifferslittle fromone speciestoanother;wholeshellfishwould however give a
nutritionally poorer meal because of the low protein content of the shell. Most of the world’s fish
meal is made from whole fish; the pelagic species are used most for this purpose. Where a fishery
catches solely for the fish meal industry, it is known as an industrial fishery.
Countrieswithmajorindustrialfisheriesare Peru, NorwayandSouthAfrica.Some countries like the
UK make fish meal from unsold fish and from offal that is the heads, skeletons and trimmings left
over when the edible portions are cut off. Other countries like Denmark and Iceland use both
industrial fishandprocessingwaste.Fishmeal made mainlyfromfilleting offal usually has a slightly
lower protein content and a higher mineral content than meal made from whole fish, but a high
proportion of small whole fish in the raw material can have the same effect.
The following points are important when selecting species for an industrial fishery:
1. The speciesmustbe inlarge concentrationstogive ahighcatching rate;thisis essential because
the value of industrial fishislessthanthatof fishfordirecthumanconsumption.

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2. The fisheryshouldpreferablybe basedon more thanone speciesinordertoreduce the effectof
fluctuationsinsupplyof anyone species.
3. The total abundance of longlivedspeciesvarieslessfromyeartoyear,and
4. Specieswithahighfat contentare more profitable,because the fatinfishisheldatthe expense
of waterandnot at the expenseof protein.
Manufacturing fishmeal
There are several ways of making fish meal from raw fish; the simplest is to let the fish dry in the
sun.Thismethodisstill used,insome parts of the world where processing plants are not available,
but the product is poor in comparison with ones made by modern methods. Almost all fish meal is
made by cooking, pressing, drying and grinding the fish in machinery designed for the purpose.
Althoughthe processissimple inprinciple,considerable skill andexperienceare necessary to obtain
a high yield of high quality product, and to make the plant efficient. A typical process is shown
diagrammatically in figure 1:
Fig.1. A typical fish meal process diagram.

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Hygiene inthe Factory
Contamination of the material during processing may seriously affect quality; microorganisms
like Salmonella thatmayultimatelycause disease in man have to be kept out. Much can be done by
good housekeeping in the plant, for example by keeping floors, walls and conveyors clean and by
separating‘wet’and‘dry’areasof the plant,butthe processingmachineryitself is often less readily
accessible for cleaning. Contaminated water, from a dock for example, should not be used for
cooling or other purposes if it can come in contact with the fish or the fish meal.
Storage and transport of fishmeal
Fishmeal isnot readilyspoiledbybacterial actionbecauseof itslow watercontent, and it has a very
small bulkcomparedtothe fishfromwhichit ismade;indeed,these are twoof the mainreasons for
making fish meal. There is no need to refrigerate the meal in storage.
Fish meal is usually stored and transported either in sacks made of paper, hessian or plastics, or in
bulk.Fishmeal inbulkissometimespelletizedtomake mechanical handlingeasier,since it does not
flow readily as a powder.
Fishoil presentinthe storedmeal canreact withoxygeninthe atmosphere;the heatgeneratedmay
damage the meal nutritionallyand,onoccasion,cause the meal tocatch fire.Fortunatelythisis now
a rather rare occurrence, due to the widespread use of antioxidants. Not all fish oils are equally
reactive; some oily meals seem to require antioxidant treatment; whilst others do not. The most
commonlyusedantioxidantisethoxyquin;the amountused varies but is normally in the range 200-
1000 mg/kg.Sacks of newlymade oilymeal are frequentlystoredinventilated stacks, particularly in
hot climates. White fish meal, with a low oil content, does not require antioxidant treatment.
Compositionand nutritional value
Before examiningthe compositionof the finishedmeal it is interesting to consider the composition
of the intermediate products. Figure 2 shows the composition of the material at each stage of its
flow through the process and is based on the assumption that the raw fish contain 70 per cent
water, 18 per cent solids and 12 per cent fat. It can be seen that more drying occurs in the
evaporators than in the dryer. The composition of the intermediate products in this example is as
follows:
Water Solid Fat
Materials % % %
Raw Fish 70 18 12
Press Cake 53 44 3
Press Liquor 78 6 16
Dilute Stick water 95 1 <1
Conc. Stick water 65 33 2
Fish Meal 9 85 6
Fig. 2. Composition of material during the process.

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How is fishmeal used?
Fish meal in the UK was used mainly as a fertilizer until about 1910, but since then its high
nutritional value hasbeenfarbetterutilizedinanimal feeding.The demand in the UK for fish as fish
meal isfar greaterthan the demandforfishfordirecthuman consumption;thereforeimportsof fish
meal to the UK are high.The pig andpoultryindustries producing large amounts of bacon and eggs,
pork and chicken, at relatively low prices could not survive without large scale use of high protein
animal foodslike fishmeal.Usually about 10 per cent of the diet of pigs and poultry consists of fish
meal;10 percent is the upper limit for meal containing 10 per cent fat, because more than about 1
per cent of fish oil in the diet of the animal may taint the taste of its flesh. Much of the UK
production is of white fish meal with a fat content low enough to eliminate any risk of taint. Fish
meals with an extremely low fat content are sometimes made for certain specialized purposes.
Distribution
Fish meal has been used as a feedstuff since the 19th century in Northern Europe and is now used
worldwide.Global productionof fishmeal hasbeenstable forthe past two decades at around 5 to 6
million tons, Peru and Chile being the main producers.
A majorportion(more than60%) of fishmeal produced globally is used for aquaculture (farming of
finfishandshrimp).The intensificationof aquaculture inAsia,andparticularly in China, is increasing
the demandforfishmeal eventhoughthe supplycannotgrow accordingly.Natural phenomenasuch
as the El Niño-SouthernOscillationaffectthe fisheriesalongCentral AmericanPacific coasts, leading
to seasonal scarcitiesandincreasedprices.Due tothese factors,the fishmeal market is volatile and
pricesoftenshootup.The search forsuitable and cost-effective alternative protein sources for use
inindustrial aquafeedswillbe the mostcritical factor in the development of intensive aquaculture
in Asia (Kaushik, 2010; Steinfeld et al., 2006).
Advantages of using fishmeal in animal feeds
Natural and sustainable, fishmeal provides a concentrated source of high quality protein and a fat
rich in omega-3 fatty acid, DHA and EPA.
Protein:The proteininfishmeal hasahighproportionof essential amino acids in a highly digestible
form,particularlymethionine pluscistine, lysine, threonine and tryptophan. Present in the natural
peptide form,theycanbe usedwith high efficiency to improve overall balance of dietary essential
amino acids.
Fat: The fat will generally improve the balance of fatty acids in the feed to restore the ratio of
omega-6: omega-3 forms towards 5:1; which is believed to be optimum; in the fat in many diets
currentlythisratioisconsiderablyhigher.Withthe optimumratioand omega-3 fatty acids provided
as DHA and EPA, general health of the animal is improved, especially where there is to be less
dependence on routine medication.
A dietarysource of DHA and EPA resultsintheirdepositioninanimal products. This in turn will help
to balance omega-6: omega-3 ratios in the human diets and provide pre-formed DHA and EPA
requiredforinfantdevelopmentandforpreventionof numerousdisordersof the circulatorysystem,
the immune system and to reduce inflammatory conditions.

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Energy: Fishmeal is a concentrated energy source. With 70% to 80% of the product in the form of
digestible protein and fat its energy content is higher than of many other proteins.
Minerals and Vitamins: Fishmeal has a relatively high content of minerals such as phosphorus, in
form with good availability to the animal. It also has a wide range of trace elements. Vitamins too
are presentatrelativelyhighlevels –Bcomplex vitamins,includingcholine,biotinandvitamin B12 as
well as A and D.
Conclusion
Fishmeal isrecognizedasa valuable animal protein supplement and a source of vitamins, minerals
and unknowngrowthfactors.Fishmealsare addedtothe dietas highqualitysupplements to obtain
efficient diets, particularly for aquaculture & animal feed.

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References:
1. http://janathafishmeal.com/index.php/fish-meal/
2. http://www.feedipedia.org/node/208
3. http://en.wikipedia.org/wiki/Fish_meal
4. http://www.fao.org/wairdocs/tan/x5926e/x5926e01.htm