Fishmealisveryextensivelyused infeedsforfishaswellasother
animals.Arecentglobalsurvey estimatedaquacultureconsumption
offishmealat3724thousandtonnesin 2006(TaconandMetian2008).Nowitis
becoming increasingly evident that such
con-tinuedexploitationofthisnaturalresource will ultimately become
both environmentally and economically
unsustainable.Anysatisfactoryalternativefeedingre-dientsmustbeabletosupplycompara-blenutritionalvalueatcompetitivecost.
Conventionalland-basedcrops,especially
grainsandoilseeds,havebeenfavoured alternatives due to their low
costs, and have provedsuccessfulforsomeapplications
whentheywereusedassubstitutesfor aportionofthefishmeal.Butevenwhen
theseplant-basedsubstitutes cansupportgoodgrowththey can cause
significant changes in the nutritional quality of the fish
produced.Why algae?The reader may wonder why
algae,includingbothmacroalgae (seaweeds) and microalgae (e.g.
phytoplankton),andwhichare popularlythoughtofasplants,
wouldbegoodcandidatesto serveasalternativestofishmeal
infishfeeds.Onefundamental considerationisthatalgaeare
thebaseoftheaquaticfood chainsthatproducethefood
resourcesthatfishareadapt-edtoconsume.Butoftenitis
notappreciatedthatthebio-chemicaldiversityamongdiffer-entalgaecanbevastlygreater
thanamonglandplants,even whenBlue-GreenAlgae(e.g.
Spirulina),moreproperlycalled Cyanobacteria,areexcluded
fromconsideration.Thisreflectsthevery early evolutionary divergence
of different algal groups in the history of life on earth. Only one
ofthemanyalgalgroups,theGreenAlgae,
producedalineofdescentthateventually gave rise to all the land
plants. Therefore it can be difficult to make meaningful
generalisations aboutthenutritionalvalueofthisextremely diverse
group of organisms; rather it is
neces-sarytoconsidertheparticularqualitiesof specific algae.Protein
and amino acidsFishmealissowidelyusedinfeeds
largelythankstoitssubstantialcontent
ofhigh-qualityproteins,containingallthe
essentialaminoacids.Acriticalshortcom-ingofthecropplantproteinscommonly
used in fish feeds is that they are deficient
incertainaminoacidssuchaslysine,
methionine,threonine,andtryptophan(Li et al. 2009), whereas
analyses of the amino acidcontentofnumerousalgaehave
foundthatalthoughthereissignificant
variation,theygenerallycontainallthe essential amino acids. For
example, surveys of19tropicalseaweeds(Lourenoetal.
2002)and34edibleseaweedproducts (Dawczynskietal.2007)foundthatall
species analysed contained all the essential amino acids, and these
findings are consist-entwithotherseaweedanalyses(Rosell
andSrivastava1985,WongandPeter 2000, Ortiz et al.
2006).Analysesofmicroalgaehavefoundsimilar
highcontentsofessentialaminoacids,as
exemplifiedbyacomprehensivestudyof
40speciesofmicroalgaefromsevenalgal classes that found that, All
species had similar amino acid composition, and were rich in the
essential amino acids (Brown et al.
1997).TaurineOneoften-overlooked nutrientisthenon-protein
sulphonicacidtaurine,which issometimeslumpedwith
aminoacidsindiscussions
ofnutrition.Taurineisusu-allyanessentialnutrientfor
carnivorousanimals,including somefish,butitisnotfound
inanylandplants.However, althoughtaurinehasbeen
muchlessofteninvestigat-edthanaminoacids,ithas
beenreportedinsignificant quantitiesinmacroalgaesuch
asLaminaria,Undaria,and Porphyra(Dawczynskietal.
2007,MurataandNakazoe 2001)aswellascertain microalgae,forexamplethe
greenflagellateTetraselmis (Al-AmoudiaandFlynn 1989), the red
unicellular alga The use of algae in fish feeds as alternatives to
fishmealby Eric C. Henry PhD, Research Scientist, Reed Mariculture
Inc., USATable 1: Nutritional profiles of rotifers enriched using
optimized protocols based on culture using Reed Mariculture
RotiGrow Plus and enriched with N-Rich feedsN-Rich feed type High
PROPL PlusUltra PLApplicationsModerate PUFA; overnight gut-load
maintenanceOvernight or 2-6 hr enrichmentExtreme DHA 2 hr
enrichmentComposition of BiomassLipid (Dry wt. % of Biomass)35% 44%
66%DHA (% of lipids)37% 41% 44%EPA5% 2% 0.5%ARA1.0% 1.0% 1.2%Total
PUFAs45% 45% 48%Protein38% 32% 18%Carbohydrate19% 15% 7%Ash8% 9%
10%Dry weight Biomass9% 9% 9%10 | INTERNATIONAL AQUAFEED |
September-October 2012FEATURESeptember-October 2012 | INTERNATIONAL
AQUAFEED | 11Porphyridium (Flynn and Flynn 1992), the
dino-flagellateOxyrrhis(FlynnandFielder1989), and the diatom
Nitzschia (Jackson et al.
1992).PigmentsAfewalgaeareusedassourcesofpig-ments in fish feeds.
Haematococcus is used to produce astaxanthin, which is responsible
for the pink colour of the flesh of salmon. Spirulina is used as a
source of other carotenoids that
fishessuchasornamentalkoicanconvertto
astaxanthinandotherbrightlycolouredpig-ments.Dunaliellaproduceslargeamountsof
beta-carotene.LipidsInadditiontoitshighcontentofhigh-qualityprotein,fishmealprovideslipidsrich
inPUFAs,orpolyunsaturatedomega-3and
omega-6fattyacids.Thesearethefishoil lipids that have become highly
prized for their contributiontogoodcardiovascularhealthin humans.
But it is not always appreciated that algae at the base of the
aquatic food chain in fact originate these fish oil fatty acids.
These desirablealgalfattyacidsarepassedupthe food chain to fish,
and they are indeed essen-tial nutrients for many fish.
Algaehavebeenrecognisedasan obviousalternativesourceofthesefish
oilfattyacidsforuseinfishfeeds(Miller
etal.2008),especiallyeicosapentaenoic
acid(EPA),docosahexaenoicacid(DHA),
andarachidonicacid(ARA).Thereisa
substantialliteraturedevotedtoanalysis
ofthePUFAcontentofmicroalgae,par-ticularly those used in
aquaculture, because theyhavelongbeenrecognisedasthe
bestsourceoftheseessentialnutrients
forproductionofzooplanktonnecessary for the first feeding of larval
fish, as well as filter-feeding
shellfish.Manyshellfishproducersareaware
thesterolprofileoffeedlipidsisofcriti-calimportance,butmuchlessattention
hasbeenpaidtotheimportanceofthe Macroalgae (seaweeds) of many kinds
can form extensive stands with high biomass density10 |
INTERNATIONAL AQUAFEED | September-October 2012 September-October
2012 | INTERNATIONAL AQUAFEED |
11FEATUREwww.evonik.com/feed-additives |
[email protected] challenge is our passion.MetAMINO The
superior methionine source for your aquafeed.
sterolprofileoffishfeeds.Asidefrom
alterationsinthenormalsterolprofileof
thefish,thepossibleendocrineeffectsof
plantphytosterolsinfishfeeds(e.g.soy
phytohormones)haveyettobethor-oughly investigated (Pickova and
Mrkre 2007).Use of algae in
aquacultureManydifferentalgaealreadyplayavital
roleinaquaculture.Itiswidelyknownthat
theadditionofmicroalgaetolarvalfish
culturetanksconfersanumberofbenefits,
suchaspreventingbumpingagainstthewalls of the tanks (Battaglene and
Cobcroft 2007), enhancingpredationonzooplankton(Rocha et al. 2008),
enhancing the nutritional value of
zooplankton(VanDerMeerenetal.2007), as well as improving larval
digestive (Cahu et al. 1998) and immune (Spolaorea et al. 2006)
functions. Furthermore,ithasalsobeenshown
thatlarvaeofsomefishesbenefitgreatly
bydirectingestionofmicroalgae(Reitan
etal.1997).Onestudyhasevenshown that that live zooplankton could be
elimi-nated from the larval diet of Red Drum if
microalgaewerefedalongwithaformu-latedmicroparticulatediet(Lazoetal.).
Itisnotsurprisingthatthebiochemical
compositionsofcertainmarinemicro-algaearewell-matchedtothenutritional
requirementssomemarinefish.Larval
feedsareprobablydeservingofthemost attention in efforts to discover
how algae canbestbeusedinfishfeeds,because
microalgaeareanaturalcomponentof
thedietofmanylarvalfish,eithercon-sumeddirectlyoracquiredfromthegut
contentsofpreyspeciessuchasrotifers and copepods. Existing
protocols that use microalgaetoimprovethePUFAprofile
ofliveprey(Table1)demonstratehow
effectivelyanalgalfeedcanenhancethe nutritional value of these live
feeds.Use of algae in formulated fish
feedsVariousspeciesofmacroalgaeandmicro-algaehavebeenincorporatedintofishfeed
formulationstoassesstheirnutritionalvalue, and many have been shown
to be beneficial: Chlorella or Scenedesmus fed to Tilapia (Tartiel
etal.2008);ChlorellafedtoKoreanrockfish
(Baietal.2001);UndariaorAscophyllumfed to Sea Bream (Yone et al.
1986); Ascophyllum, Porphyra,Spirulina,orUlvafedtoSeaBream
(MustafaandNakagawa1995);Gracilariaor
UlvafedtoEuropeanSeaBass(Valente etal.2006);UlvafedtoStripedMullet
(Wassefetal.2001);UlvaorPterocladia fedtoGiltheadSeaBream(Wassefet
al.2005);Porphyra,oraNannochloropsis-Isochrysis combination fed to
Atlantic Cod (Walker et al. 2009, 2010). Unfortunately,
ithasrarelybeenpossibletodetermine
theparticularnutritionalfactorsrespon-sibleforthesebeneficialeffects,either
because no attempt was made to do so, or poor design of the study.
For example, in one of the few studies that has focused on the
effects of substi-tuting algal protein for gluten protein, the
controlandallthetestdietscontained
caseinplusaddedmethionineandlysine, noanalysisofthealgalproteinwas
provided, and the algal protein (a biofuel
processby-product)containedveryhigh
levelsofaluminiumandiron(Hussein etal.2012).Moreandbetter-designed
studies are necessary before we will have
agoodunderstandingofhowalgaecanbest be used in fish feeds.Choosing
the right algaeOftenthealgaechosenforfishfeeding
studiesappeartohavebeenselectedlargely
forconvenience,becausetheyarelow-cost
andcommerciallyavailable.Forexample,
microalgaesuchasSpirulina,Chlorellaand Dunaliella can be produced
by low-cost open-pondtechnologiesandaremarketedasdry
powders,andtheirnutritionalprofilesare well-documented. Macroalgae
such as the kelpsLaminaria,Undaria,andDurvillea,
andthebrownrockweedAscophyllum,
occurindensestandsthatcanbehar-vested economically, and they have a
long history of use as sources of iodine, as soil amendments, and
animal feed additives to supply trace elements.
Inrecentyearstherehasbeengreat interestinthepotentialofalgaeasa
biofuelfeedstock,andithasoftenbeen proposed that the protein
portion remain-ing after lipid extraction might be a useful
inputforanimalfeeds(e.g.Chenetal.2010). However, the algae chosen
for biofuel produc-tion may not be optimal for use as a feed input,
and the economic pressure for the lowest-cost
methodsoffuelproductionislikelytoresult
inproteinresidueswithcontaminationthat makes them unfit for use as
feed (e.g. Hussein et al. 2012).By contrast, the high-value
microalgae that are used in shellfish and finfish hatcheries are
generally producedinclosedculturesystemstoexclude
contaminatingorganisms,andtheycannotbe dried before use without
adversely affecting their nutritional and physical properties,
greatly reduc-ing their value as feeds. Inevitably their production
costs are higher, but their exceptional nutritional value justifies
the extra expense. Table 2 presents Table 2: Because these algae
are produced using continuous-harvest technology that maintains
exponential growth, their protein and lipid contents are comparable
to those provided by fish feeds.(Dry
Weight)NannochloropsisoculataTetraselmis sp. Pavlova sp.
Isochrysis(T-Iso)Thalassiosira
weissflogiiProtein52%55%52%47%52%Carbohydrate16%18%23%24%23%Lipid17%14%20%17%14%Various
species of microalgae are used as aquaculture feeds, depending on
the cell size and nutritional profile needed for particular
applications12 | INTERNATIONAL AQUAFEED | September-October
2012FEATURESeptember-October 2012 | INTERNATIONAL AQUAFEED |
13typicalnutritionalprofilesofalgaeproducedby Reed Mariculture
Inc.Justasitwouldbesenselesstoarbitrarily
substituteoneconventionalcropplantfor
another(e.g.potatoesforsoybeans)when
formulatingafeed,theparticularattributes
ofeachalgamustbecarefullyconsidered.
Inadditiontotheprotein/aminoacidprofile, lipid/PUFA/sterol profile,
and pigment content, there are important additional considerations.
Thetypeandquantityofextracellular polysaccharides, which are very
abundant in cer-tain algae, can interfere with nutrient absorption,
or conversely be useful binding agents in forming
feedpellets.Thethickcellwallsofmicroalgae such as Chlorella can
prevent absorption of the
nutritionalvalueofthecellcontents.Inhibitory
compoundssuchasthephenolicsproduced
bysomekelps,andbrominatedcompounds
producedbyredalgaesuchasLaurencia,can render an alga with an
excellent nutritional analy-sis unsuitable for use in
afeed.Dependingon growthandprocess-ingconditions,algae
cancontainhighcon-centrationsoftrace elementsthatmaybe
detrimental.Fur thercareful studyoftheprop-er
tiesofnumer-ousalgaewillbe necessaryinorder to optimally exploit
thegreatpotential offeredbythis diversegroupof organisms.Butitis
alreadyapparent thatalgaewillplay animpor tantpar t intheeffor tto
movetheformula-tionoffishfeed downthefood chaintoamore sustainable
future. References available on requestMORE INFORMATION:Eric C.
Henry PhD, Reed Mariculture Inc.Tel: +1 408 426 5456Fax: +1 408 377
3498Email: [email protected]:
www.reedmariculture.com12 | INTERNATIONAL AQUAFEED |
September-October 2012 September-October 2012 | INTERNATIONAL
AQUAFEED | 13FEATURECORPORATE OFFICEP.O. Box 8 100 Airport
RoadSabetha, KS 66534, USAPhone: 785-284-2153 Fax:
785-284-3143extru-techinc@extru-techinc.comwww.extru-techinc.comMany
leading aquafeed manufacturers in the industry count on Extru-Tech
to engineer the perfect aquafeed production solution.Industry
leading equipment and engineered production advantages will give
you the upper hand over the competition. Could you use a cost
effective improvement in performance and fnished product quality?
Contact one of the Aquafeed Consultants at Extru-Tech today at
785-284-2153.ET-221A.indd 1 1/20/12 1:57
PMTheannualglobalproductionof fishmealandfishoiliscurrently
aroundfivemilliontonnesofmeal andonemilliontonnesofoil
(Figure1),exceptinyearswhenthefishing in the South Pacific is
disrupted by the warm waters of an El Nio, most recently in 2010.
Around22milliontonnesofrawmaterial
isused,ofwhichapproximately75percent comes from whole fish and 25
percent from by-productsofprocessingfishforhuman consumption (IFFO
estimates). Themajorityofthewholefishusedare small pelagic fish
such as anchovy, menhaden, sardines and sandeels for which there
are lim-ited markets for direct human consumption. In addition to
the estimated 11.5 million tonnes
ofsmallpelagicfishusedinfishmealthereis also an estimated five
million tonnes of other fish,themajorityfrommixedtropicaltrawl
fisheries in East Asia. Going forward
Theprospectsforincreasingtheproduc-tionoffishmealandfishoilareverylimited,
since most of the underlying fisheries are now
beingwellmanaged,usingtheprecautionary principle with tightly set
and monitored quo-tas. Also increasingly, markets are being found
for at least a proportion of the catches to go for direct human
consumption. Inadditionthereisconcernthatsomeof the mixed tropical
trawl fisheries are not being well managed and that catches will
therefore decrease in the coming years as these become severely
depleted. The prospects for increas-ing volumes of fisheries
by-products do
how-everlookbetterasfishingbecomesconcen-tratedatfewerlandingsitesandaquacultural
production also becomes more concentrated.
Thiswillbefurtherencouragedbytherising price of fishmeal and
stricter laws against the dumping of waste material. So on balance
the production of both fishmeal and fish oil over
thenextfewyearsislikelytoremainabout where it is or possibly
decrease slightly, which will certainly happen in El Nio
years.Thelackofgrowthintheproductionof marine ingredients has led
some to speculate that the growth of aquaculture would in turn be
limited by the shortage of such key ingredi-ents the so-called
fishmeal trap. It is certainly truethatduringthe1990sandearly2000s
asaquaculturegrew,itusedmoreandmore fishmeal, mostly by taking
volumes that in the past had gone into pig and poultry feeds.
However,sincearound2005aquaculture requiring feed has continued its
strong annual growthofaroundsevenpercentbutthe volumes of fishmeal
used in aquaculture have remained steady at around 3.2 million
tonnes andthoseoffishoilhaveevenreduced
toaround600,000tonnes.(Figure2).This
hasledtheFAOtostateintheirrecently released report on the State of
Fisheries and Aquaculture(FAO2012):Althoughthedis-cussion on the
availability and use of aquafeed
ingredientsoftenfocusesonfishmealand
fish-oilresource,consideringthepasttrends
andcurrentpredictions,thesustainabilityof the aquaculture sector
will probably be closely linkedwiththesustainedsupplyofterrestrial
animalandplantproteins,oilsandcarbohy-drates for aquafeeds.Becoming
a strategic ingredientThisgrowthinaquacultureproduction, Fishmeal
& fish oil and its role in sustainableaquacultureby Dr Andrew
Jackson, Technical Director, IFFO, UKFigure 1. The Global
Production of fishmeal and fish oil from 1964-2011 (IFFO
data)Figure 2. The global production of fed aquaculture and the use
in the associated diets of fishmeal and fish oil, millions of
tonnes (FAO FishStat data and IFFO data and estimates)18 |
INTERNATIONAL AQUAFEED | September-October
2012FEATURESeptember-October 2012 | INTERNATIONAL AQUAFEED |
19whilstnotincreasingthetotalamountof
fishmealused,iscomingthroughthepartial replacement of fishmeal in
the diets of almost allspecies(Taconetal2011,Figure3).This
drivetoreplacefishmealisbeingdrivenby the rise in the price of
fishmeal and improving nutritionalknowledge,butalsobyconcern
aboutthefluctuatingsupplyduetoElNio,
etc.Ofcoursethepriceofallcommodi-tieshasrisensteeplyin
recentyearsanditis importanttocompare thepriceoffishmeal with the
alternatives. The most commonly
usedalternativetofish-mealisthatofsoymeal. Figure 4 shows that over
the last twenty years the price ratio of fishmeal to
soymealhasincreased significantly,whichis indicativeofthefact
thatfishmealisbeing reducedinlesscritical areassuchasgrower
feeds,butremainsin themorecriticaland less price-sensitive areas
ofhatcheryandbrood-stockfeeds.Fishmealis therefore becoming less
ofacommodityandmoreofastrategic
ingredientusedinplaceswhereitsunique nutritional properties can
give the best results and where price is less critical. Fish oil
and its fatty acidsAs has been well documented, during the period
1985-2005 fish oil usage moved from
beingalmostexclusivelyusedtoproduce
hydrogenatedmargarinestobeingalmost exclusively used in
aquaculture. Within aqua-culture by far the biggest user was in
salmon feed,indeeditreachedthepoint,inaround
2002,whenover60percentoftheworlds fish oil production was being fed
to salmon. Thereasonforthisveryhighusagein salmon feeds was that
salmon were found to performbestondietswithinexcessof30 percent fat
and at the time fish oil was one of
thecheapestoilsonthemarket.Inaddition
italsogavethefinishedsalmonfilletsavery high level of long chain
Omega- 3 fatty acids, specifically EPA and DHA.
Duringthelast10yearsincreasingevi-dence has been published on the
very impor-tant role these two fatty acids play in human
health.EPAhasbeenshowntobecriticalin
thehealthofthecardiovascularsystemand DHA in the proper functioning
of the nervous system, most notably brain function. This growing
awareness within the medical professionandthegeneralpublichasledto
manygovernmentsproducingrecommended daily intakes for these fatty
acids and
compa-nieslaunchingalargenumberofhealthsup-plements,includingpharmaceuticalproducts,
with concentrated EPA.The importance placed on EPA and DHA
inthehumandiethashadanumberof profound effects on the fish oil
market. Firstly over the last ten years a significant market has
Figure 3. The dietary inclusion of fishmeal (%) in aquaculture
feeds over the period 1995-2010 (after Tacon et al 2011 ) 18 |
INTERNATIONAL AQUAFEED | September-October 2012 September-October
2012 | INTERNATIONAL AQUAFEED |
19FEATURESUBSCRIBEwww.aquafeed.co.uk/subscribe.phpInternational
Aquafeed is published six times a year, bringing you in-depth
features, industry news, events, book reviews and more. As well as
your personal copy delivered direct to your address, subscribers to
International Aquafeed also receive a free copy of the
International Aquafeed Directory worth UK85. For more information
please visit our website.For a complimentary trial issue, please
contact the Circulation & Subscriptions Manager - Tuti Tan -
Email: [email protected] for the sale of crude fish oil
for its refinement and inclusion into capsules etc.
Thishasgrownfromalmostnothing,to thepointwheretodayaround25percent
oftheworldsproductionofcrudefishoilis
soldtothismarket.Thishasoccurredata
timewhenthedemandforsalmonfeedhas
gonefrom1.8milliontonnestonearlythree million tonnes. The other
critical factor is that to obtain fish oil of the right quality
(freshness, lackofoxidationproductsandlevelsofEPA
andDHA)thenutraceuticalmarketpaysa premium of 25-30 percent over
that for feed oil(currentpriceforfeed-gradefishoilis approximately
$1,800/tonne). Inordertoincreasetheproductionof salmon feed in-line
with the market (as well astryingtominimiseanypriceeffect)feed
producershavebeenincreasinglysubstitut-ing fish oil with vegetable
oil. The vegetable oilofchoiceisrapeseed(orcanola)oil,
which,whilenothavinganyEPAorDHA, does at least have short-chain
omega 3 fatty acidsandfeweromega-6fattyacidsthan
mostothercommonlyavailablevegetable
oilssuchassoyaoil.Thepointhasnow beenreachedwhereover50percentof
theaddedoilinsalmondietscomesfrom vegetablesourcesandthistrendseems
likely to
continue.Assalmonarepoorconvertersofshort-chainedomega-3fattyacidstolong-chain
fatty acids the fatty acid profile of the finished
salmonfilletisverymuchareflectionofthe fatty acid profile in the
feed. The result is that the EPA and DHA content of farmed salmon
isdecreasingandtheomega-6contentis increasing.
Thistrendseemssettocontinueinthe years to come. It seems likely
that the salmon marketwilldifferentiateintohighEPAand
DHAsalmondemandingapricepremium and regular salmon, which, while
still contain-ing some EPA and DHA will have levels well below that
found in wild salmon. Is it
sustainable?Oneofthemostoftenaskedquestions
aboutfishmealandfishoiliswhetheror
notthepracticeissustainable.Thisisahuge topic for discussion and
one that is not easily coveredinthelastsectionofashortarticle.
Toanswerthequestiononehastogoback and look at the source of the raw
material and look at the matter, fishery by fishery. The most
widelyacceptedmeasureofsustainabilityfor
afisheryistheMarineStewardshipCouncils
standard.However,whilstthishasbeen
adoptedbyagrowingnumberoffisheries which can be eco-labelled at the
point of sale, there are currently no substantial volumes of
whole-fishfromMSCcertifiedfisheriesbeing made available to fishmeal
plants.Backin2008IFFObecameawarethat
thefishmealandfishoilindustryneededan
independentlyset,third-partyauditedstand-ard,whichcouldbeusedbyafactoryto
demonstratetheresponsiblesourcingofraw
materialandtheresponsiblemanufactureof
marineingredients.IFFOconvenedamulti-stakeholder task force
including feed produc-ers, fish farmers, fish processors, retailers
and environmentalNGOswhooverthenext18
monthscompliedthestandardwhichwas launched late
2009.TheIFFORSstandardhasbeenquickly
adoptedbytheindustryandthepointhas
nowbeenreachedwhereoveronethirdof
theworldproductioncomesfromcertified
factories.Thestandardrequiresthatany
wholefishmustcomefromfisheriesthat are managed according to the FAO
Code of Conduct for Responsible Fisheries. The stand-ard also
demands that the factory can
demon-strategoodmanufacturingpracticeincluding full traceability
from intake to finished product.There are now around 100 certified
facto-ries in nine different countries producing IFFO
RSfishmealandfishoil.Manyoftheworlds
majorfeedfisherieshavebeenapprovedfor use, although some have yet
to produce suf-ficient evidence to convince the auditors. Full
detailsofcertifiedplantsandapprovedraw materials can be found on
the IFFO web site, www.iffo.net . AcontinuingareaofconcernisAsia
where, as discussed earlier, there are
consid-erablevolumesoffishmealproducedfrom
trawledmixedspecies.IFFOisworkingwith
anumberofdifferentorganisationsinclud-ingtheFAOandtheSustainableFisheries
Partnership to investigate how to bring about fisheries improvement
in this critical area. Asia Figure 4. The ratio of the price of
Peruvian fishmeal and Brazilian soymeal based on weekly prices for
the period 1993-2012 and the calculated trend line (IFFO data)20 |
INTERNATIONAL AQUAFEED | September-October
2012FEATURESeptember-October 2012 | INTERNATIONAL AQUAFEED |
21istheregionwhereaquacultureisgrowing fastest and the need for
responsibly produced fishmeal is highest.ConclusionsFishmeal and
fish oil production is expect-edtoremainaroundcurrentlevels,butthis
isunlikelytolimitthegrowthofaquaculture which will continue to have
reducing inclusion levelsofmarineingredientsinthedietsof
mostfarmedfish.Fishmealwillincreasingly
becomeastrategicingredientusedatcritical
stagesofthelife-cyclewhenoptimumper-formance is required. The
growing importance of EPA and DHA
inhumanhealthwillensurethatthereisa
strongdemandforfishoil,eitherfordirect
humanconsumptionorviafarmedfish,such as salmon.
Thereisagrowingneedforfishfeed producersandfarmerstodemonstratethat
alltherawmaterialsintheirfeedsarebeing
responsiblysourced.Thisisbestachievedby
usinganinternationallyrecognisedcertification standard. Increasing
volumes of certified marine ingredientsarenowcomingontothemarket
whichwillallowfishfarmerstodemonstrate their commitment to
responsible aquaculture.ReferencesFAO (2012). The state of the
world fisheries and aquaculture 2012. Rome: FAO.Tacon, A. G. J.,
Hasan, M. R., and Metian, M. (2011). Demand and supply of feed
ingredients for farmed fish and crustaceans -Trends and prospects.
In: FAO fisheries technical paper, Vol. 564. Rome: FAO. MORE
INFORMATION:Website: www.iffo.net"Fishmeal and fish oil production
is expected to remain around current levels, but this is unlikely
to limit the growth of aquaculture which will continue to have
reducing inclusion levels of marine ingredients in the diets of
most farmed fish"20 | INTERNATIONAL AQUAFEED | September-October
2012 September-October 2012 | INTERNATIONAL AQUAFEED |
21FEATUREINFORMATION FOR ADVERTISERSWith circulation of the printed
magazine to key industry decision makers and heavy promotion at key
industry events, working alongside our online distribution
strategies - International Aquafeed is the ideal place to promote
your products aimed at the global aquaculture industry. Call the
team today to hear how we can help you achieve your marketing
goalsTHE BEST WAY TO PREDICT THE FUTURE IS TO CREATE IT. Peter F.
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Wenger12_AQ_210x147mm.indd 1 8/8/12 12:01
PMFeedforfishandshrimpraisedin aquacultureneedshighlevelsof
proteinandenergy.Traditionally
feedforcarnivorousoromnivo-rousfishandforshrimpprovidesthese
mainlyasfishmealandfishoil,which
alsocontributestothehealthpromoting
aspectsoffishandshrimpinthehuman diet.
Aquacultureoffedspeciestodaytakes
6080percentofthefishmealand80per-centofthefishoilproduced,mainlyfrom
the industrial pelagic fisheries or, in a
grow-ingtrend,fromthetrimmingsproduced
duringprocessingforhumanconsumption. Trimmings are defined as
by-products when
fishareprocessedforhumanconsump-tionorifwholefishisrejectedbecause
thequalityatthetimeoflandingdoesnot
meetrequirementsforhumanconsump-tion.TheInternationalFishmealandFish
OilOrganisationestimatestrimmingsare now used for around 25 percent
of fishmeal production. Theindustryis,therefore,heavily
dependentonmarineresourcesbutpro-ductionfromtheseresourcescannotbe
increased sustainably, either for human con-sumption or the
industrial fisheries. At best,
sustainablymanagedfisherieswillcontinue
toyieldaroundthecurrentharvestoffive
milliontonnesoffishmealandonemillion tonnes of fish oil. Feed
producers such as Skretting require
theirmarinerawmaterialsuppliersto document that the fishmeal and
fish oil are derived from responsibly managed and sus-tainable
fisheries and do not include endan-gered species. Therefore, to
meet a growing demandforfish,aquaculturemustidentify alternatives
to these marine ingredients.Rising
demandAnalysesofglobaldemographics,widely
publicisedbytheFoodandAgriculture
OrganizationoftheUnitedNations(FAO), indicate a continuing
expansion of the popu-lation passing nine billion by 2050. In
parallel, economic development is providing a greater
proportionwithanincomethatpermits
themtobemoreselectiveabouttheirdiet.
Themaintrendistoswitchfromvegetable staples to animal and fish
protein. A third, but lesser, factor is the growing awareness
ofthehealthbenefitsoffishinthediet,
providinglongchainomega-3polyun-saturatedfattyacids(LCPUFAs)EPA
andDHA,fishproteinsandimportant vitaminsandmineralssuchasiodineand
selenium.Atthesametime,agrowingpropor-tionofthepelagiccatch,whichincludes
theindustrialfisheries,isgoingtothe
morelucrativemarketsofprocessingfor
humanconsumption,asprocessingtech-nologyimprovesandasnewconsumers
withdifferenttastesenterthemarket.
Simultaneously,theomega-3supplements
industryiscompetingforthebestqual-ityfishoilsandreadilyoutbidsthefeed
producers.AccordingtotheFAOreport TheStateofWorldFisheriesand
Aquaculture2012,aquacultureisset
toremainoneofthefastestgrow-ingfeedsectors.Havingdoubledin
thepastdecadetoalmost60million tonnesglobally,itisexpectedtogrow
byupto50percentinthenext.This makes identifying alternative,
sustainable sourcesofproteinandenergyamajor
priority.Researchersarelookingfor
alternativesthatwillprovidelowfeed
conversionratios,maintainhighfish welfareandproducefishthataregood
toeat,bothintermsofeatingexperience
andnutrition.Ithasbeenamainfocusat Skretting Aquaculture Research
Centre for thepastdecade,forexampledetermining
thenutritionalvalueofmorethan400
rawmaterials.Theseinvestigationsled toAminoBalance,wherebalancingof
aminoacidsincreasesthecontribution such proteins make to muscle
growth.Options and challenges of alternative protein and energy
resources for aquafeedby Dr Alex Obach, Managing Director,
Skretting Aquaculture Research Centre, NorwayFigure 1: Raw material
options for fish feed (Source Skretting)Protein raw
materialsFatsStarch sources Fish meal Fish oil WheatKrill meal
Krill oil BarleyAlgal meal Algal oil SorghumSoya products Rapeseed
oil TapiocaSunflower meal Soybean oil Potato starchRapeseed meal
Sunflower oil PeasCorn gluten Corn oilFaba beansWheat gluten
Linseed oil OatsFaba beansPalm oilLupinsCamelina oilPea meal
Poultry fatRice products LardPoultry mealFeather mealBlood mealMeat
and Bone mealMicrobial proteinInsect meal Worm mealDDGS Marine
origin Vegetable raw materials Animal by-products Other raw
materials22 | INTERNATIONAL AQUAFEED | September-October
2012FEATURESeptember-October 2012 | INTERNATIONAL AQUAFEED |
23Recent advanceResearch progress to date means fishmeal
levelsinfeedsforspeciessuchasAtlantic salmon have been reduced.
Until recently 25 percent appeared to be the limit below which
performance suffered, in terms of growth rate and feed conversion
ratio. In 2010 researchers at Skretting ARC final-ised a new
concept known as MicroBalance. MicroBalancetechnologyisbasedonthe
identificationofseveralessentialmicro-nutri-entsinfishmealthatwereshowntobethe
limitingfactors,nottheamountoffishmeal.
Supplementingthedietwiththerightbal-anceofessentialmicro-nutrientsandother
functionalmicro-ingredientshelpedreduce fishmeal content in fish
feed.ApplyingtheconceptenabledSkretting companies to produce
commercially success-fulfeedswithaslittleas15percentfishmeal
withoutdetractingfromfeedperformance,
fishwelfareorendproductquality.Akey
advantageofMicroBalanceistheflexibil-itytoadapttherawmaterialcombinationin
responsetoprices,lesseningforfarmersthe impacts of price
volatility. TodaySkrettingcanformulatefishfeed
withlevelsoffishmealaslowas510
percent.Fishmealcanbereplacedsolelyby vegetable raw materials or by
a combination of vegetable raw materials and non-ruminant
processedanimalproteins(PAPs).Itshould be noted that PAPs are
widely used in coun-triesoutsidetheEUandprovideextremely
goodquality,safenutritiontosupplement fishmeal.
Typicalexamplesincludebloodmealalso
knownashaemoglobinmeal,poultrymeal,
andfeathermeal.PAPswerebannedfrom
animalfeedandfishfeedintheEUfollow-ingtheBSEcrisisinthe1990s.Recentlya
proposalforthereintroductionofPAPsin
fishfeedwasapprovedbyaqualifiedmajor-ityofEUmemberstates,meaningthatnon-ruminant
PAPs will be authorised for fish feed from June 1, 2013. Trial
resultsA 22-month trial with Atlantic salmon in
acommercialscalefarminNorwaydem-onstratedthe practicalityof
MicroBalance.It followed a com-pletegenera-tionofsalmon fromsmoltto
harvest. The trialwasjointly organi sedby MarineHarvest andSkretti
ng andconducted attheCentre forAquaculture Competence (CAC)i n
Norwayfrom May2009to February2011 inclusive.CAC is a
commercial-scaleR&Dfarm managedby MarineHarvest andisequipped
tomeasureall operational parametersjust aspreciselyas
inasmall-scale researchsta-tion.Atotal of 780, 000 Atlantic salmon
provided were divided and fed on one of three feeds:
Conventionalgrowerfeed(pre MicroBalance):25percentfishmealand13
percent fish oil with EPA + DHA comprising about 10 percent of
total fatty acids.OptiLinefromSkrettingNorway(using
MicroBalance):15percentfishmealand13 22 | INTERNATIONAL AQUAFEED |
September-October 2012 September-October 2012 | INTERNATIONAL
AQUAFEED | 23FEATUREpercent fish oil with EPA + DHA comprising
about 10 percent of total fatty acids.Experimental OptiLine(using
MicroBalance):15percentfishmealandnine percent fish oil with EPA +
DHA comprising about eight percent of total fatty acids.
Theparametersmonitoredwere growth,FCR,quality,health,sustainability
andfoodsafety.Thetotalharvestweight
was3,517tonnes.Aftertheharvestthe
taste,smellandtextureofthefilletswere
testedbyapanelofprofessionaltasters. The results showed that both
low fishmeal feedsgavethesamegrowthandFCRas
thecontroldiet.Therewerenoobserved
differencesinfishhealth,orinthequality parameters.
Thesalmonfedwiththelowestpropor-tion of marine products (15%
fishmeal, 9% fish oil)onlyneeded1.07kgoffishintheirfeed to produce
1 kg at harvest. Calculating protein
aloneshowedapositiveratio,withfishout exceeding fish
in.MicroBalanceisnowappliedinthediets of several other commercial
species, including seabass,seabream,rainbowtrout,turbot and
yellowtail.Fish
oilResearchtodatehasenabledproduc-ersoffishfeedtosupplementfishoilwith
vegetable oils in the diets of carnivorous
spe-ciesbyasmuchas50percent.Lowerlevels
havebeentestedinexperimentaldietswith
nonegativeeffects.Muchoftheprogress results from the EU RAFOA
project. RAFOA standsforResearchingAlternativestoFish
OilinAquacultureandtheprojectfocused
onfourspecies;Atlanticsalmon,rainbow
trout,seabassandseabream.Ledbythe
InstituteofAquacultureattheUniversityof
Stirling,partnersincludeNIFES(theNational
InstituteofNutritionandSeafoodResearch)
andSkrettingARC,inNorway,theINRA
(NationalInstituteforAgronomicResearch)
inFranceandtheUniversityofLasPalmas,
intheCanaryIslands(Spain).Themainchal-lengeistomaintainadequatelevelsofEPA
and DHA, both for the fish and for the health benefits of fish as
food. Secondly the EU AquaMax project, coordi-nated by NIFES in
Norway with 32 international partners around the world including
Skretting ARC, addressed this issue directly, developing
dietswithlowlevelsofbothfishmealand
fishoilandthusreducingthefish-infish-out
ratios.Thiscom-plementswork at Skretting ARC todevelopthe
LipoBalance concept,which allowscombina-tionsofoilsto be prepared
that willprovidethe correctbalance ofenergyand
nutrients,includingEPAandDHA,atlowest cost.Performance
ratiosFeedconversionratios(FCRs)have
advancedsignificantlyoverthepastthree decades. In Atlantic salmon,
for example, the FCRhasdecreasedfrom1.30inthe1980s
toslightlyabove1.00today,mainlydueto the development of
high-nutrient-dense diets andtoimprovementsinfeedmanagement
(reducingfeedwaste).Thisrepresentsmore
efficientuseoffeedrawmaterials;especially as fishmeal and fish oil
contents were reduced in the same period (Table
1).Anothercontributorhereistheemer-gence of functional diets that
maintain or even improveperformanceinadverseconditions
suchashighorlowwatertemperaturesand outbreaks of disease. Better
growth, reduced FCRandhighersurvivalwillallcontributeto improve the
utilisation of feed resources.FeedFishDependencyRatio(FFDR)is
thequantityofwildfishusedperquantityof
culturedfishproduced.Thismeasurecanbe
weightedforfishmealorfishoil,whichever
componentcreatesalargerburdenofwild fish in feed. In the case of
Atlantic salmon for example,followingtheintroductionofthe
MicroBalance concept, the fish oil will certainly
bethedeterminingfactorfortheFFDR.The
dependencyonwildforagefishresources
shouldbecalculatedforbothFMandFO using the following formulae.
FFDRm = (% fishmeal in feed from forage fisheries) x (eFCR) /
22.2FFDRo=(%fishoilinfeedfromforage fisheries) x (eFCR) /
5.0Where:eFCRistheEconomicFeedConversion
Ratio;thequantityoffeedusedtoproduce the quantity of fish
harvested.Onlyfishmealandfishoilthatisderived directly from a
pelagic fishery (e.g. anchoveta) is to be included in the
calculation of FFDR.The amount of fishmeal in the diet is
calcu-lated back to live fish weight by using a yield of 22.2%.
This is an assumed average yield. If
theyieldisknowntobedifferentthatfigure should be used.The amount of
fish oil in the diet is calcu-lated back to live fish weight by
using a yield of five percent This is an assumed average yield. If
the yield is known to be different that figure should be
used.Usingtheseformulaeitcanbeseenthat
theFFDRsforAtlanticsalmon,forexample,
werehalvedbetween2004and2011.The FFDRmwasreducedfrom1.24to0.56and
theFFDRofrom4.28to2.05.Thisdoubles the quantity of salmon produced
from a given quantity of fishmeal and fish oil.Health
benefitsAsmentioned,maintaininghealthbenefits is a key objective
when reducing dependency on marine raw materials. It is being
addressed inseveralways.Thefirstistodeterminethe minimum levels of
EPA and DHA that the fish require.Thefeedswithhighlevelsofmarine
ingredientsproducedfishwithhighlevelsof
longchain(LC)poly-unsaturatedfattyacids
(PUFAs);morethanneededbythefishso that a proportion was metabolised
for energy. At lower inclusion levels the use of these lim-ited
nutrients can be optimised, since a higher proportion will be
retained in the muscle. At even lower levels (close to nutritional
require-ment)thefishcanmaximiseitscapacityto elongate and
desaturate, and could become a net producer of LC PUFAs. Figure 2:
Supply and use of fish oil (Source IFFO and Skretting)Table 1:
Total production of fed species in 2000, 2005, 2010, with total
feed used, total fishmeal and total fish oil (x 1,000 tonnes).Year
Total production of fed speciesTotal of feeds usedTotal fishmeal
usedTotal fish oil used1995 4,028 7,612 1,870 4632000 7,684 14,150
2,823 6082010 21,201 35,371 3,670 764Source:Tacon et al. FAO
Fisheries and Aquaculture Paper 56424 | INTERNATIONAL AQUAFEED |
September-October 2012FEATURESeptember-October 2012 | INTERNATIONAL
AQUAFEED | 25Onaverage100gofsalmonfillethas
around16goffatofwhichatleastfourto five percent is omega-3 EPA and
DHA (DHA beingthemainfattyacidinthephospholipid fraction). Thus a
130 g portion would provide around930mgofEPAandDHA.Thatis
equivalenttoseveralsupplementcapsules. Two portions a week
adequately provide the recommended dietary levels of LC PUFAs and
importantvitaminsandmineralsinaneasily assimilated form.
Asecondapproachistoexplorewaysof formulatingfeedsothattheLCPUFAsare
retained in the fillet flesh. Further research at
SkrettingARCintothefunctionsofmicro-ingredients recently led to a
new salmon feed that significantly improves the feed conversion
ratio and fillet yield. Fillet analysis revealed the
micro-nutrientsalsoraisedtheproportionof EPA and DHA in the muscle.
The third approach is to identify alternative
resources.Therearetwomajorcontenders:
geneticmodificationstocropplantsand
micro-algae.Progressisbeingmonitoredby feed producers keen to
reduce their depend-enceonmarineingredients.Someplants produce
PUFAs, for example rape (canola) or soya, but the carbon chains are
too short. The EPAcarbonchainhas20carbonatomsand DHA 22. The
ambition is to introduce genes
toextend18-carbonchainsalreadypresent. Limited progress has been
with EPA. DHA is a greater challenge.Some micro-algae species are
natural syn-thesisersofthelongerchainfattyacids.The
challengehereiseconomic;togrowthem
inbulk,eitherbyseafarmingorinvatson
land,insufficientvolumestomakethem
competitiveasafeedingredient.Thereare
alsoreportsofextractingLCPUFAsfrom yeast cultures and these would
face the same economic
challenge.ConclusionAquafeedproducersmustfindalterna-tivestothemarineingredientsfishmealand
fishoilwhilemaintainingfishwelfareand
aquacultureperformanceasahighlyeffi-cientmeansofproducingnutritiousprotein.
Eating quality and health benefits are equally important. However,
although the supply of marine ingredientsfromthewildcatchislimited,
with appropriate controls they will continue
tobeavailable.Akeytaskfortheindustry is to ensure they are used in
a manner that spreads the benefits through a combination
ofsupplementation,feedformulationand
feedmanagementonfarm.Thiswaythe growing demand for fish can be met
and the benefitssharedsustainablyforgenerations to come.About the
authorAlexObachhasheldtheposition ofManagingDirectoratSkretting
AquacultureResearchCentresince May 1, 2007. Originally from
Barcelona, Spain, he is a veterinarian with a Master
inAquaculturefromtheUniversity ofGirona(Spain)andaPhDinfish
pathologyandimmunologyfromthe University of West Brittany (France).
He started working at Skretting Aquaculture Research Centre in 1993
as a research-er,initiallywithinfishhealththenas
anutritionist.HeHepreviouslywas ManagerofARCsFishHealthdepart-ment.
Between 1993-1995, he was also engaged as lecturer at the
University of Barcelona,andworkedfortwoyears
asManageroftheMarineHarvest Technical Centre.24 | INTERNATIONAL
AQUAFEED | September-October 2012 September-October 2012 |
INTERNATIONAL AQUAFEED | 25FEATURETheworlddemandforseafoodis
increasingdramaticallyyearbyyear, althoughanannualupperlimitof
100milliontonsissetsoasnotto exhaust reserves. It is for this
reason that there isaconsiderablemovetowardsmodernising and
intensifying fish farming. To be economically viable, fish farming
must be competitive, which meansthatfeedcostsamongstothersmust be
carefully monitored as the operational cost
goes60percentforfeedalone.Therefore
selectionofcheaperandqualityingredients
isofparamountimportanceforsustainable
andeconomicalaquaculture.Identificationof suitable alternate
protein sources for inclusion infishfeedsbecomesimperativetocounter
the scarcity of fishmeal. Inadditiontoitsscarcityandhighcost,
oftenfishmealisadulteratedwithsand,salt
andotherundesirablematerials.Allthese factors have forced fish feed
manufactures all over the world to look for alternate sources.
Inthiscontexttheyhavebeenleftwithno protein but to substitute
animal protein with plantproteinsources.Avarietyofplant
proteinsourcesincludingsoybeanmeal,leaf
proteinconcentrateandsinglecellprotein
havebeentested.Thetestshaveshown
thatthesecanbeincludedasalternatives
tofishmeal(Oginoetal,1978,Applerand Jauncy, 1983). Of various plant
protein sources, soybean meal(SBM)isoneofthemostpromising
replacementsforpartorwholeoffishmeal.
Soybeanmealistheby-productafterthe
removalofoilfromSoyabeans(glycine
max).Atpresentsoybeanmealisthemost
importantproteinsourceasfeedforfarm
animalsandaspartialorentirereplacement of fishmeal?
Theproductsobtainedfromsoybeansand their processing are as
follows:-Soybean meals, solvent
extractSoybeanmealfromdehulledseeds,sol-vent extracted,Soybean
expellerSoybean expeller from dehulled seedsFull fat soybean
mealFull fat soybean meal from dehulled seedsThe chemical
composition of soybean meal is fairly consistent (Figure
1).Thecrudeproteinleveldependsonthe
soybeanmealquality.Soybeanhasoneofthe
bestaminoacidprofilesofallvegetableoil meals. The limiting amino
acids in soybean meal aremethionineandcystinewhilearginineand
phenylalanine are in good supply (New, 1987).The fat content of the
solvent extracted soy-beanmealisinsignificantbutsoybeanexpeller
hasoilcontentbetweensixandsevenpercent, whilefullfatsoybeanexpeller
has oil content between 18 to 20 percent. Soybean meal and
soybeanexpellerarelowerin macro and trace elements than fishmeal.
There is no substantial
differencebetweentheindi-vidualsoybeanmealproducts. The calcium
content is low and thephosphoruslevelisrather higher. However, the
phospho-rus is bound to phytic acid and its availability for
aquatic animals is, therefore, limited. Soybeanmealsandexpel-lers
are reasonable source of B-vitamins. For most vitamins there are
insignificant differences between
thedifferentproducts.Howeverthefullfatsoy-beanmealtendstobehigherinsomevitamins.
Whiletheproductsaremainlyhigherincholine content, the vitamin B12
content is low and pan-tothenic acid is mainly damaged by heat
treatment.The digestible energy of soybean meal over all fish
species ranges from 2572 to 3340 Kcal/kg (10.8 to 14.0 MJ/kg). The
metabolisable and digestible energy of full soybean meal increases
with the increase heating temperature at a given time due to the
inactivation of trypsin inhibitors.Deleterious constituents of
soybean productsTrypsin inhibitors: - About six percent of the
totalproteinofsoybeansreducesactivitiesof
trypsinandchymotrysin,whicharepancreatic enzymes and involved in
protein digestion (Yen etal.,1977).Theactivityoftrypsininhibitoris
notfullyunderstood,butisresponsibleforthe poor performance of
certain fish species (Alexis et al., 1985, Balogum and Ologhobo.,
1989).Lectins: - This type of toxic protein is
chemi-callyhemagglutinin,whichcausesagglutination
ofRBC's(Liener,1969).Thereareindications that lectins reduce the
nutritive value of soybean meal for Salmonids but are inactivated
by treat-ment of the meals (Ingh et al,
1991).Otherproperties:-Soybeanisunpalatable for some fishes such as
Chinook salmon. While as herbivorous and omnivorous species are
less choosy.Thesizeorageofthefishmayalso affect the palatability of
soybean meal.Utilisation of Soybean Products in
AquacultureComprehensive researchworkhasbeen donetoevaluatesoy-bean
meals as a replace-mentofanimalprotein sources in diets for fishes
butthereplacementof allfishmealbysoybean mealhasnotbeenvery
successfulperhapsdue tothelimitingamino acids and insufficient heat
treatment of the soy-bean meals. Smith et al (1980) claimed success
infeedingrainbowtroutadietbasedalmost
entirelyonrawmaterialsofvegetableorigin containing 80 percent full
fat roasted soybean. In a similar report, Brandt (1979) evaluated a
diet basedentirelyonplantingredients(containing 50 percent heated
full fat soybean + 10 percent maize gluten meal to overcome a
possible defi-ciency of S-amino
acids).Reinitzetal(1978)observedthatrainbow
troutfryfedadietcontaining72.7percentfull fat soybean had a greater
daily increase in length andweightwithanimprovedfeedconversion
ratiocomparedwiththosefedacontroldiet based on 25 percent herring
meal, five percent fish oil 20 percent soybean oil meal. The
mortal-ity rate for both groups was similar. Taste panel
studiesindicatedthattherewasnoeffectof
dietarytreatmentonfirmnessandflavourof the fish.Kaneko (1969)
reported that 1/3rd of white fishmealcouldbereplacedbysoybeanmeal
withnonegativeeffectsongrowthofwarm Use of soybean products in
aquafeeds: a reviewby T. H.Bhat, M. H.Balkhi and Tufail Banday
(Sher-e-Kashmir University of Agricultural Sciences and Technology
of Kashmir)Figure 1: The chemical composition of Soyabean meal40 |
INTERNATIONAL AQUAFEED | January-February
2012FEATUREJanuary-February 2012 | INTERNATIONAL AQUAFEED |
41waterfishes.Viola(1977)iso-nitrogenously reduced the fishmeal
content in the diet of carps containing25percentproteinsupplemented
bysoybeanmealwiththeadditionofamino
acids,vitaminsandmineralsandopinedthat
soybeandietdidnotinducegoodgrowthin carp. Similarly Atack et al
(1979) reported poor utilisationofsoybeanproteinbycarpwhenit formed
the sole protein source. Gracek (1979) used different qualities of
soybean meal to sup-plement ground maize for feeding carp fry and
recorded better survival.No difference in growth was observed when
common carp (Cyprinus carpio) were fed either
with45percentsoybeanmeal(+10percent
fishmeal)or20percentsoybeanmeal(+22 percent fishmeal). Other trails
however showed that the growth performance and feed efficiency
ofcommoncarpwerereducedwhendietary fishmeal was replaced by soybean
meals. Therewerenodifferencesinperformance
betweenextrudedfullfatsoybeanmealand
oilreconstitutedsoybeanmeal(Inghetetal; 1991). A better weight gain
was reported when soybeanmealwasincorporatedinthedietsof carp fish
(Cristoma et al; 1984). Similarly sklyrov
etal(1985)successfullyusedsoybeanmealin rearing carp fish
commercially. It is claimed that
soybeanmealisdeficientinavailableenergy
andlysineaswellasmethionineforcarps.
Supplementationofsoybeanmealdietswith methionine coated with
aldehyde treated caesin significantly improved utilisation of amino
acid by common carp (Murai et al; 1982).Lack of phosphorus rather
than the sulphur amino acids may be the cause for poor
perform-anceofcommoncarpswhen40percentsoy-bean meal diets were fed
to them. Addition of 2.0 percent sodium phosphate did not improve
their performances (Viola et al; 1986). Kim and
Oh(1985)attributedthepoorperformance
ofcommoncarpfedwithadietcontaining40
percentsoybeantolackofphosphorusrather than sulphur and amino
acids, since addition of twopercentsodiumphosphatestosoybean meal
diet improved their performance to a level obtained with the best
commercial feed.Nour et al (1989) studied the effect of heat
treatmentonthenutritivevalueofsoybean
mealascompletedietforcommoncarpby autoclaving the soybean seeds for
0, 15, 30, or 90minutesandrecordedmaximumaverage
dailyweightgainwithdietscontainingsoybean seeds autoclaved for 30
minutes. Nandeesha et al (1989) incorporated soybean meal in the
diets of Catla and indicated the possibility of utilising soybean
meal in carp diets. Keshavapa et al (1990) used soybean flour in
the diet of carp fry and recorded better survival. Senappa (1992)
studied protein digestibility from soybean-incorporated diets and
recorded better digestibility when fed to fingerlings of Catla.
Naik (1998)studiedtheeffectofSoyaflourand fishmeal based diets in
the diet of Catla catla & Labeo rohita and observed a better
growth and survival of carps when reared together and also in
combination with fresh water prawn.Channel cat fish (Ictalurus
punctatus) fed on all plant protein diets grew significantly less
than fishfeddietscontainingfishmeal(Lymanetal, 1944). Growth was
substantially reduced when menhadenfishmealwasreplacedbysoybean
mealatanisonitrogenousbasis(Andrewsand Page, 1974). Full fat
soybean meal heat treated differently replaced fishmeal at low
levels in diets forchannelcatfishshowedthatreplacement gave
satisfactory results (Saad,
1979).Growthandfeedefficiencyoffingerling
hybridtilapia(Oreochromisniloticus)was
significantlydepressedwhensoybeanmeal
replacedfishmealattheoptimumlevel(30 percent) in their diet (Shiau
et al, 1988). The growthdepressionofthehybridtilapiawas reduced
when a 30 percent crude protein diet containing soybean meal but by
adding two to three percent dicalcium phosphate to the diet, growth
rate of tilapia was comparable to the control (Viola et al, 1986).
Soybean meal with supplemental methionine could replace up to
67percentfishmealinthedietsformilkfish (Chanos chanos) (Shiau et
al, 1988).Growth,feedconversionandsurvivaloftiger prawn (Penaeus
monodon) juveniles fed two levels of soybean meal under laboratory
conditions were lowerwithhigherlevelsofsoybeanmeal(Piedad, Pascual
and Catacutan, 1990). No significant
differ-encesingrowthandsurvivalcouldbeestablished whensoybeanmeal
atlevelsfrom15-55 percent replaced par-tially or completely fish
mealinthedietsfor tigerprawnsstocked incagesinpondsat 10to20shrimps
persquaremeter (Piedad,Pascualet al,1991).Limand Dominy(1991)
obtainedcompara-bleresultsinfeeding PenalusVannamel
withdietscontaining upto17percentof dryextrudedfullfat
soybeanmealasa partialreplacement for fish protein.Generallythe
studiesoutlined abovetogether withseveralothers indicatethatthereis
anadvantagetobe gainedfromusing properlyprocessed soybeanproducts
forformulatingdiets forfishduetotheir better quality protein and
higher dietary energy value in full fat soybean which is more
advantageous with cold water fish
speciesbecausewarmwaterfish(Carp,Catfish
etc)canutilisecarbohydratesmoreefficiently.
Theonlyrecommendationrelatingtothelimit of inclusion of full fat
soybean in fish diets is not
toexceedtheknownpracticallimitsrelatingto fats in general in order
to avoid problems of feed preparationandtoreducetheriskofhighfat
levels in the meal.Recommended Inclusion RatesSoybean may replace
animal protein in diets for aquatic animals to a certain extent.
However, with increasing substitution of e.g. fish meal by soybean
meal the performance of fish decline. Herbivores may tolerate
higher levels of soybean meal than carnivores. It appears that full
fat soybean meal is more beneficial for cold-water fish than for
warm water species due to the better utilization of the energy from
the soybean products. Only properly
heat-treatedsoybeanproductsshouldbeused
foraquaticfeeds.Furthermore,itisadvisableto use only soybean meals
processed from dehulled seeds in order to reduce the crude fisher
content in the diet. This article originally appeared on40 |
INTERNATIONAL AQUAFEED | January-February 2012 January-February
2012 | INTERNATIONAL AQUAFEED | 41FEATUREAquaculture UK 201223-24
May 2012Aviemore, ScotlandThe UKs major Aquaculture exhibition and
conference featuring the latest aquaculture products and
innovations. Visit www.aquacultureUK.com for further information or
contact [email protected]_Farming Int_1/8_107X146.indd 1
17/10/2011 12:45Asmoreofworldsnatural fisheriesaredepletedand
demandoffishcontinues torise,aquaculturewill continue to grow, thus
raising demand forhealthy,commerciallyprepared fish Mostly,
aquaculture relies upon extrusion cooking to produce feeds that are
good mix and nutritionally available, but also in a form
thatiscapableofmovingthroughwater column very slowly (floating) to
be ingested. Thus,thebigdependencyinaquacultureis
selectingingredientsthatwhenextruded will possess just right
buoyancy, not migrate nutrientsintowater,withhighpalatability for
specific fish species.Fishfeedpelletsarepreparedeither
bypressedcutsheetsorbyExtrusion methods.Thisarticlewilldiscussabout
IngredientsandExtrusionprocessforpro-ducing the pellets.Main
ingredients include: 1) Fish & Bone Meal 2) Soy protein (though
it is not preferred byfarmersbeingnoteasilydigestible by many fish
species) 3) Wheat 4) Starch 5) Blood Meal Other ingredients like
Vitamins, Minerals andLipids(FatOil)arealsoaddedin producing
pellets.FishmealFishmealisawell-knownsourceof
proteinswhichisstronglydemandedby the animal feeds industry. This
is due to its balancedaminoacidcontent,whichmakes it an ideal feed
for many domestic animals. Moreover,itsusetoadjust
(improve)theaminoacidcon-tentofotherdietaryprotein
sourcesalsocontributesto increasedemandforfishmeal. As its name
points out, fishmeal isderivedfromcapturedfish,
includingwholefish,fishscraps fromfillets,andpreservesof
industries. Mostofthemaincapture fisheryproducersdevotethe
mainpartofthisactivitytofish meal production. The raw
mate-rialsusedinfishmealmanufac-turecomealmostentirelyfrom species
which are not often used forhumanconsumption(either
duetheirsize,orbecausethey are very abundant).
Thefishmealprocessing systemconsistsofpreserving
initialfishproteinsbymeansof acontrolleddehydration,which
extractsaround80percentof thewaterandoilscontained when fresh from
fish. Thisleadstotheproduc-tionofadryproduct,easyto preserve and
easier to transport than the initial product.Fresh fish entering
the manu-facturing plant is first ground and
thencookedinacontinuousheatingoven
at90-95percent,whichin-turncoagulates proteins and lose their
water-holding capac-ity. The hot mash is then transported to an by
R V Malik, CEO, Malik Engineers, Mumbai, IndiaAquaculture:
Producing aqua feed pellets10 | INTERNATIONAL AQUAFEED |
March-April 2011 March-April 2011 | INTERNATIONAL AQUAFEED | 11F:
Feed pelletsendlessscreworoilexpellerthatpresses
itandsqueezesoutmostoftheremaining water and oils.
Pressedfishcomingoutofthepress (press cakes) then cut into smaller
portions and placed into a dryer on a steam heated surface. During
the drying period, the mash isinconstantmotionandsubjecttoan
airjetthatremovesallthesteamemitted. The dried mash obtained is now
called 'fish meal'andcontainsfrom8to10percent of water.
However,ifthemoisturelevelismore than11-12percent,thereisariskofthe
fishmealdevelopingmoulds.Generally,
antioxidantsareaddedwhenfishmealis introduced and taken out of the
dryer, and by so doing ensuring the stability of the oils remaining
within the fish meal.Soy proteinNot all fish species have easy
digestibility ofsoyprotein,primarilyduetoincreased
carbohydratecontentfraction.Itisusually used as supportive additive
with other eas-ily digestible protein like fish meal which is rich
in fish proteins.Beanprocessingconsistsessentiallyof
extractingtheoilsoastoconcentrate theproteins.
Thisprocessprovidesavery importantby-product,namelysoyaoil,
whichiswidelyusedasarawmaterial andoilforhumanconsumption.
Thisproc-essalsocontributestotheeliminationof
certainanti-nutritionalfactorspresentin the raw
bean.Thefirststepinprocessinginvolves
theremovaloftheshell(cellulose)from thegrain.Thebarebeansarethen
heated,ontheonehandtoreducethe activityofcertainenzymes,andonthe
othertobreakthecellulosestrandsand facilitatethefollowingsteps.
Theheated beansarethenmashedtoformthin
paste-likeslices,whichfurtherfacilitates the destruction of the
cellulose structure and oil
extraction.Theproduct,nowtermedwholesoya cake, still contains its
oil and has around 40 percent protein, and as such is sold directly
for animal feeding.Next, the oil can be extracted from the
wholecakebymeansofasolvent(such ashexane).
Aftertotalevaporationofthe solvent, there remains the solvent
extracted soya cake, which in turn is widely used for animal
feeding, and contains 45 - 50 percent
protein.BloodmealAbattoirsorslaughterhousesproduce
manyimportantby-products,suchas bloodandbones, etcwhichare
oftendifficultto commercialize. N o w a d a y s ,
however,theseby-products constitute the basic raw mate-rial of the
bone and blood meals widely used in industry for animal
feeding.Consi derabl e amountsofblood areproducedby
abattoirs,andthis productisusu-allytransported todryingovens
andconverted intobloodmeal. Bloodfromdiffer-entoriginssuch
as,sheep,goat,and poultryareusually storedandproc-essedseparately.
However,soasto complywithbasic sanitarymeasures, it is generally
com-pulsorytostore bloodwithincool-ingchambersand toensurethatthe
levelofbacteriais keptwithinpre-scribedmaximum limits.The
manufacture of bloodmealFreshblood iskeptcoolat thefactory,and
sizeableparticles filteredandthe bloodmassstirred soastoseparate
thefibrillarphase fromtheliquid mass.Thefibrinis thenheatedupto
coagulation and the coagulatedmass dividedanddried throughahotair
stream(thatisby spraydrying).This methodisparticu-10 |
INTERNATIONAL AQUAFEED | March-April 2011 March-April 2011 |
INTERNATIONAL AQUAFEED | 11F: Feed pelletsQuality control and
testing ofraw materialsProduct development and recipe
optimizationSmall-scale productionQuick change of test
conditionsBrabenderGmbH & Co. KGE-Mail:
[email protected] www.brabender.comLaboratory Extruderfor
Food and FeedFind us on booth no. G 061Extruder_90x270_Kopie von 90
X 27010.02.201116:18Seite 1Formulation of
fishfeedAswehaveseen,feedformulatorscan resort to a wide assortment
of raw materi-alstomakeupafoodmixturesoasto
meetthenutritionalrequirementsofthe
fishforenergy,aminoacids,fattyacids, carbohydrates, vitamins and
minerals.Theserawmaterialsaregenerallyused
inflourorliquidform,andwillhaveto undergo binding by means of a
technologi-cal process to obtain a food mixture in the
formofdrypellets,whichareeasytouse and preserve.As a guide, salt
water marine aquaculture isdependantuponhighlevelsofproteins with
high digestibility. The fresh water
aqua-culturereliesuponmorecarbohydrates,
thatishighlevelsofgrainscoupledwith
modesttohighqualityproteins,minerals, vitamins with little or no
fiber.Thefirstfactortobeconsideredfor
feedformulationisthetotalenergyand
protein/energyratioofthefinalproduct. After this, the protein
content must be cal-culated according to the amino acid balance
desired,andthelipidsincludedtosatisfy
thebestfattyacidprofileforthespecies concerned and the energy level
desired. All this must be considered taking into account the
vitamin and mineral requirements of the cultured
species.Thisformulationisnoteasilyreached
andsocomputerisedlinearprogramming
techniquesmustbeused.Furthermore,
itisalsonecessary,aftercoveringallthe
nutritionalrequirementsofthespecies within the formula to also
produce a range of tasty feeds of different pellet sizes for the
different age classes.Manufacturing stages- StorageThe raw
materials coming into the feed manufacturing plant are generally
stored in silos with an ideal height calculated so as to allow the
raw material flow to be conveyed downwards, during the
manufacturing proc-ess, until the final product is produced. This
is in order to avoid having to pull the
prod-uctsupbyverticalconveyorsthatusually cause breaks and dust in
the final product.- GrindingGrindingrawmaterialsreducesparticle
sizeandincreasesingredientsurfacearea, thus facilitating mixing,
pelleting and digest-ibility.Themostcommonlyusedgrinders are
hammer-mills, for fish feed manufacture,
asplate-grindersdonotgenerallyproduce fine enough ground
materials.TheExtrusioncookingprocessutilizes
LipidsFishoilsareco-productsofthefish-mealindustry.
Theirnutritionalcharac-teristics regarding fatty acids make them
indispensableforfishfeedmanufacture,
andinparticulartheircharacteristic highcontentofn-3unsaturatedfatty
acids (first double bond linkage in
posi-tion3),whichareessentialforawell
balancedfoodformulaforcarnivorous fish
species.Alargeamountoffishoilarisingfrom
fishmealmanufacturesisre-processedin
specializedfacilitiesfordiversepurposes;
partofitbeinghydrogenatedandmixed with other lipids, and
transformed into mar-garine, mayonnaise and bakery compounds, and
the other part used directly by the feed industry.
MineralsMineralsaremeasuredasashinthe recipe.
Thoughtheyservenofunctionality in extrusion (on the contrary their
abrasive naturewillacceleratewearandtearof
workingpartsinextruder),theseareusu-ally added in proportions <
5 percent. They include phosphorous, calcium (from calcium
carbonateorgroundlimestone),sodium chloride (salt), magnesium,
potassium, etc.Vitamins:They can be water soluble or soil solu-ble.
Vitamin B and C are water soluble, A, D, E,andKarefatsoluble.
Theyareaddedin proportions