november december international aquafeed full edition

7/30/2019 November december International Aquafeed full edition

1/56


2/56

WHO CARES...If prots in the aquaculture industry are as appetising as a salmon dinner?As feed prices soar and formulation moves towards sustainability, aquaculture producers

must think differently to stay on the menu.

In all phases of the shs life, proper nutrition will improve health. With decades of dedicated research,

the Aqua AdvantageProgramme responds to the challenges of todays aquaculture producersthrough nutritional innovation, addressing issues such as growth and performance, feed efciency,

esh quality and immunity.

So, when asked who cares about your protability? Remember

DOES!

alltech.com | facebook.com/AlltechNaturally | @Alltech

Visit us at booth #219

Nashville, Tennessee

February 21-25, 2013


3/56

An internAtionAl mAgAzine for

the AquAculture feed industryCONTENTS

aqua

I n t e r n a t I o n a l

feed

Volume 15 / Issue 6 / November-December 2012 / Copyright Perendale Publishers Ltd 2012 / All rights reserved

International Aquafeed is published six times a year by Perendale Publishers Ltd of the United Kingdom.

All data is published in good faith, based on information received, and while every care is taken to prevent inaccuracies, the publishers accept

no liability for any errors or omissions or for the consequences of action taken on the basis of information published. Copyright 2012

Perendale Publishers Ltd. All rights reserved. No part of this publication may be reproduced in any form or by any means without prior

permission of the copyright owner. Printed by Perendale Publishers Ltd. ISSN: 1464-0058

Aqua News

3 Lindeopensworldleading

aquacultureinnovationcentreinNorway

4 VIVChina:

Wildcaughtfishstilltoplayacriticalroleinfeedingpeopleintherunupto2050

5 Newglobalpartnershiptopromoteaquacultureinfightinghunger

6 AQUACULTUREUPDATES

7 AnewpartnershippromisesamoreefficientandsustainablefutureforEuropeanaquaculture

8 Expertsclosingthenetontargetedfishgenes

9 AcquisitioninEcuadortakesNutrecotoglobaltopthreeshrimpfeedproducer

Features

10 AnoverviewoftheUKfishvaccinationindustry

14 Yeastinaquaculture

20 Extrusiontechnologyfortheproductionofmicro-aquaticfeedsandshrimpfeeds

26 Whycheckselenomethioninelevelsinseleniumyeast?

28 EffectofSangrovitonthegrowthandperformanceofseabass

38 INDUSTRYPROFILES

Regular items

8 THEAQUACULTURISTS

24 PHOTOSHOOT

30 EXPERTTOPIC-SALMON

42 INDUSTRYEVENTS

BiominWorldNutritionForum2012

Aqua2012

ISRMAXIndia49 CLASSIFIEDADVERTS

50 THEAQUAFEEDINTERVIEW

52 INDUSTRYFACES

Cover image courtesy of Bryce Groark - brycegroark.com

www.perendale.co.uk


4/56

Editor

ProfessorSimonDavies

Email: [email protected]

Associate Editors

ProfessorKrishenRana


AliceNeal


Editorial Advisory Panel

Abdel-FattahM.El-Sayed(Egypt)ProfessorAntnioGouveia(Portugal)ProfessorCharlesBai(Korea)ColinMair(UK)DrDanielMerrifield(UK)DrDominiqueBureau(Canada)DrElizabethSweetman(Greece)DrKimJauncey(UK)EricDeMuylder(Belgium)

DrPedroEncarnao(Singapore)

Subscription & Circulation

TutiTan


Design & Page Layout

JamesTaylorEmail: [email protected]

International Marketing Team

DarrenParris


LeeBastin


Latin American OfficeIvnMarquetti


More information:International Aquafeed

7 St George's Terrace, St James' Square

Cheltenham, GL50 3PT

United Kingdom

Tel: +44 1242 267706

Website: www.aquafeed.co.uk

Forme,thislastmonthhasbeenquitehectichavingcrossedseveraltimezonesmakingtwoseparatevisitstoSEAsia,attendingVIVinBeijingandtheBIOMINWorldNutritionForuminSingapore.IhadthepleasuretooofmakinganinterimbriefvisittoNottinghamTrentUniversityinEnglandwhereIwastheexaminerforaPhDstudentworkingonpoultrynutritionwhichisactuallysosimilarinmany

waystomyspecialisedsubjectoffishnutrition.Wecaninterchange

manygoodideasherewithapplicationsinaquaculturebyappreciatingthe fundamental biochemistry and physiology common to avianspeciesandfish.AsIsettheclocksbackforwinter,thedaysaregettingdistinctlyshorterandthewarmthandmemoryoftropicalSingaporeisalasfadingawayasIreachformycardiganandmugofcocoa.NomoreSingaporeSlingsforawhile,justtheoddweedram!

NonethelesstheBiominmeetingwasamostexcitingeventandverywellorganisedindeedwithmanyfriendsattendingtheaquaculturesessionincludingmyformerstudentShaneHunterwhooperatesahighlysuccessfulbusinessfromMaltaasanaquacultureconsultantandwhogaveamostenlighteningtalkon21stcenturyaquaculturelisting

anddiscussingnewsystemsandtechnologiesthatcouldrevolutionisetheindustry.IattendedthecompleteBIOMINprogrammeand learnedsomuchabouttheirformidableportfolioofactivities forallfarmedlivestockandIamsogratefulfortheirinvitation.Iwillreportlater.AnothergreattreatwastheBioMarineBusinessConventionheldinLondonatFishmongersHallandareceptionintheHousesofParliamentontheterracesoverlookingtheThames.IwasabletohelparrangethelocationforthisprestigiousvenueandIoweaspecialthankstotheRightHonourableDouglasCarswellMPrepresentingClactonuponSeaforhissupportandwhotakessuchaninformedinterestinaquacultureespeciallytilapiaandfishnutrition.

BioMarineattractedmorethan200delegatesandwaslastheldinNantes,France.Thismeetingwasabletosetanagendaforasustainableaquacultureindustrywithahostofleadingexpertsfromacrossthespectrumofdisciplinesrangingfrommacro-algae,microalgae,shellfish,fishandtheaquafeedindustry.Stake-holdersfromgovernment,legalandfinancialorganisationstogetherwithcommercewereabletoshareanddebateideasandbringaboutanagreedvisionandstrategythatcanbeforwardedtothose

whocanbringaboutchangeandmakedecisionsforthefuture.NextyearitwillbeheldinHalifax,NovaScotiaandIcantwaitsincetheCanadianHighCommissionersaysthelobstersaresogood!!

Turningtoourcurrentissue,weannouncenewsaboutauniqueInnovationCentreforAquacultureinNorwaybytheLindeGrouptoserveR&Dandtoactashubforthedisseminationofadvancedtech-nologiesandademonstration/facilityplatform.Thisisthetypeofvisionaryapproachthatothersshouldbeundertakingifwearetoseeaquacultureprosperandwouldbeattractiveforuniversityinvolvementonawiderlevel.WegetanindustryreviewfromDominiqueBureauandanoverviewoftheUKfishvaccinationindustrybyKathyTaylorofSalmovacwhereitisvitaltonotethathealthyfisharecentraltoefficientproductionandutilisationoffeed.Theinteractionofdietandimmunologyisincludedlater.

AcomprehensivefeatureontheuseofvariousyeastsispresentedbyPhilippeTaconPhDofLesaffreFeedAdditives,Franceandthisisamosttimelyarticlegiventhemassiveinterestsinprebiotics,probioticsandSCPtypefeedingredientsderivedfromspecificfermentationprocesses

suchapotablealcohol(beerandwhisky)andnowtherapidexpan-sion of bioethanolrefineriesusing cornorwheat as substrates.Talkingofyeastitisimportantthatwemakenoteofthespeciationoftraceelementsandthattheformofseleniumandothermineralsmust be correct.Wilbert Litjens,Technical manager Optimin &Betaine and Paul Perucchietti, Product manager Optimin, SelkoFeedAdditives adviseusof these facts in their technicalarticlefocusingonseleniuminyeastasseleno-methionine.

Fish nutrition and feed technology is a complex blend ofsciencesandasaneditorandacademic,Ilearnmuchfromthistradeand technical journal.Itcanbe heavyreading buthighlyinformative,itisourlastfor2012andsohaveagood

festiveseasonandwewillmeetagainin2013.

Professor Simon Davies

Croeso (Welcome in Welsh)

InthelastissueofInternationalAquafeed,themainpictureonpages26and27wascaptionedincorrectly.Thecorrectcaptionreads,theCACisjointlyownedbyMarineHarvestNorway,SkrettingandAkvaGROUP.Itisalargescaleexperimentalfishfarmusedfordocumentationpurposes,locatedinHjelmelandintheCountyofRogalandinNorway,anditisoperatedfortheownersbyMarineHarvestNorwayregionSouth.Thedocumenta-

tionpurposesareprimar ilyrelatedtodiets,butalsotechnicalequip-

mentandproduction(inlinewiththeinterestsofthe owners).ThereisclosecollaborationwithNIFES(NationalInstituteofNutritionandSeafoodResearch)andNVI(theNorwegianVeterinaryInstitute).

A big thank you to all of our supporters

in 2012 ......wewishyouallahappyandprosperousnewyear.


5/56

Linde Gases, a division ofT he L inde G ro up , ha sannouncedtheopeningoftheir state-of-the-ar t InnovationCentreforAquaculture,apio-

neering R&D and testing unitlocatedatlesundinNorway.ThecentrewasformallyopenedbyNorway'sViceMinisteroftheMinistryofFisheriesandCoastalAffairs, Kristine Gramstad, atan inauguration ceremony onSeptember20,2012.

Theinnovationcentre,withitslocationbasedintheheartofthe wor ld's most industr iali sed

fishfarmingcommunity,willbealeadingaquacultureR&Dcentreglobal ly. In addit ion to highlyequippedlaboratories,thecentrewillfeatureanumberoftestand

demonstrationaquaculturetanks,the largest of which is 55 cubicmetresandhasbeenbuilttoahighly innovativespecification.Ahighlightoftheinnovationcentre,the tank will allow both aquac-ulture technologists and cus-tomersalike toobservehowthelatestoxygenationtechnologiesimpactfishdevelopmentwithinanoptimalon-landfarmingenclo-

sure.Inadditiontoanoverhead wa lkway

e xt end ing t he f u lldiameterlengthofthetank,Linde has max-imisedobservationalo p po r t u n i ti e s v i aeye-level inspectionwindowsandunder-waterlighting.

"Both the researcha n d d e ve l op m en tand the subsequenttes ting of the lat est

oxygenationtechnolo-giesisunquestionablyneededtoensurethefuturesuccessofland-based aquaculture,"saysStefanDullstein,

HeadofAquacultureandWaterTreatment,LindeGasesDivision."Linde's dedicated InnovationCentreforAquaculturewillplayaleadingroleinthedeliveryofsuchtechnologiesandgivecus-tomer s the oppor tunity to seefirsthandpioneeringoxygenationsystemsinoperation."

L inde 's advanced aquacul-ture technology has been devel-

opedinresponsetoaprogres-sivetrendthatisseeingaquacul-tureproductionbeingtransferredfromseacagestoland-basedsitesforthefulldurationofamarinefishs life. Itis this changethat

hasconfrontedthefishfarmingindustrywiththechallengeofefficientlyoxygenatinglargefishtankstoaccommodatefish stockfrominfancytomaturity.

Inparticular,thelesundcentrefeaturesLinde'sinnovativefishfarmingoxygenationtechnology,SOLVOXOxyStream,aunique

low-pressureoxygenationsystemwhichsignificantlyincreasesfish

production volume, optimisesfishmeatqualityandconsider-ablyimprovesfishfarmingoper-ations from an environmentalstandpoint.

www.linde.com

Linde opens world leadingaquaculture innovation centre in Norway

Along with the Linde

aquaculture specialists, the

inauguration of the centre was

attended by Kristine Gramstad,

Norwegian Vice Minister of

Fisheries and Costal Affairs

In addition to highly equipped

laboratories, the innovation centre

will feature a number of test and

demonstration aquaculture tanks.

A highlight of the innovation centre, the 55 cubic metre

tank, with its overhead walkway and inspection windows

will allow aquaculture technologists and customers to

observe how the latest oxygenation technologies impact fish

development.

Nvmb-Dcmb 2012 | INterNatIoNal AquAFeed | 3

Aqua News


6/56

Wildcatchhasawrongimage, says GorjanNikolik, AssociateadirectorAnimalProteinwithR a bo b an k I n te r na ti o na l i nSingapore.

It 's being seen as i f we arerobbingnatureandasaresultisindecline,hetoldaninternationalaudience attending a one-dayInternationalChinaSummiton

the day preceding the openingofVIVChina,whichtookplaceintheNewChinaExhibitionCentreinBeijing.

"Thesectorischangingandisdynamicandshouldbecomparedwith forestry rather than anexploitativeoperation.Wecanremoveacertainamount."

Hesaidthatwherepressurehadbeenappliedtoafisheryandthefishingoperationsweresubstan-

tial there was a vested interestinmaintainingstocks,managingthe resource and adopting reg-ulationstocontroloverfishing.HepointedtofisheriesinNorthAmerica, Australia, Japan andotherswhereregulationscontrol-lingindustrymeantthatindustrycould invest in larger vessels,operatesecurelywithquotasandbecomeprofitableandsustain-ablebusinesses.

"Unfortunately,thatisnotthe

norm.ThroughoutAsiaandAfricainparticularthereisstillaneedfor regulation.Anywhere whereyouhavesmallartisanfisheriesyou have damageto sustaina-bility.Wearedoingagoodjobinseveralplacesbutmoreneedstobeachieved."

Withoutthedevelopmentofaquacultureoverthepast40-50years,therewouldnothavebeenanygrowthinfishconsumption,

hetoldtheaudienceof300rep-resentativesfromtheintensivelivestockindustries.Hesaidaqua-culturenowmakesupabouthalfofallfishprocessedforhumanconsumption.

Whilewildcapturefishwouldnotincreasein the years ahead,aquaculturewouldseethetotalfishproducingindustryincreasebyfourtosixpercentgrowthforthenextfourtofiveyears.However, after that growthwould declineto about threepercentperyear.

He says the FAO forecaststhe world needing between 20

millionto25milliontonnesoffishby2020.That'saone-thirdincreaseinlessthanadecade;atarget that is unlikely to bemet,hesuggested.

However,MrNikolikdoesseefish playingan increasing roleinthehumandietastheworldaddressesthefoodneedsofninebillionpeopleby2050.Hesaysthere are some 300 species offishworldwidethatarecurrentlyincludedinthehumandietofwhichsome50-60speciesareof primary importance.Whilethe west and Japan havea pref-erenceformarinespeciesintheirdiets,Chinainparticularenjoysfreshwaterspeciesandcarpinparticular.Sixtypercentoftheworld'saquaculturetakesplaceinChinaandthemajorityofthefishproducediscarp.

Whencomparedwithterres-trial animals, fish are particular ly

efficientinconvertingfeedintoflesh.Whilethefeedconversionrateforpigsisnowaround2.5:1andpoultryat1.8:1andleaderinthe animal world, tilapia records1.6:1,shrimpat1.5:1andsalmonat1.1:1.Thelatteristhemostadvancedandmaysoonachievea1:1conversionrate!

"Whyisitpossibleforfishtoachievetheseextraordinarycon-versionrates?"heposedrhetor-

ically.F ish l ive in a world wherethere's littleeffectof gravity andasaresultexpendnoenergytofightgravity.Thereforethereisnoneedtobuildmassivebonestruc-

tures to support their weight. Inaddition,fishareendothermic-meaningtheyneedtoexpendnoenergytowarmtheirbodies.

"Everythingtheyeatgoesintomotion and growth. Also theyhavehighfecundity,meaningtheyhavelotsofoffspring."Pigsmightbeabletoachieveanimpres-sive27pigletsperyear,butfishcanproduce50,000eggstwiceayearwithmortalityratesof

betweentwoandthreepercent,"headds.

OtherfactorsthatMrNikolikfeels with swingthe balanceinfavouroffishistheimpos-s i bi l it y o f d i se a se s m ov i ngacross thespecies barrier ascanhappenbetweentesterialanimals; "Thereis no diseasethat canmovefromfish speciesto a human."The str ucture ofthe res ource also favours fish

suchassaltwater,"whichcan'tbeusedforanythingelse";manyland-basedfishfarmingopera-tions do not need fresh watersupplies;aminimalCO2andmethanegasemissioncontri-

butionisalsoanadvantageoverterrestr ial species.

For aquaculture to achievei ts p o te n ti a l, t h e i n du s tr yneeds huge investments. It 'sanindustrythatisfragmented,ranges f rom the deve lopedto de ve lo pi ng co un tr ies, ha sno g l ob al o r r eg io nal m ar-ketingpolicyandisuncoordi-nated.Therearecurrentlytoomany spec ies be ing farmed

and resources into researchanddevelopmentisspreadtoothin,he adds. "Wehaven't evenchosenthespeciestofocuson,"hetoldtheaudience.

Mr Nikol ik says terrestr ia lan ima l product ion systemshave been deve loped over2000yearswhileaquacultureislessthan40yearsoldandforsomespeciesjust15yearsold.Whileaquaculturedoesoffera

valuablesourceofproteinforthe human diet in the decadesahead,ithasmanyobstaclestoovercomewiththeaccesstoresourcessuchascoastlineallo-cation,beinglimitingfactors.

VIVChina:Wildcaughtfishstilltoplayacriticalroleinfeedingpeoplein

therunupto2050

4 | INterNatIoNal AquAFeed | Nvmb-Dcmb 2012

Aqua News

Mr Gorjan Nikolik of Rabobank International (right) with the

editor of International Aquafeed, Professor Simon Davies at the

International China Summit in Beijing


7/56

Aqua News

TheAquaculturistblog is a great placeto keepup-to-datewith the latest aquaculture news inbetween printeditions ofInternationalAquafeedmagazine. Theblog, likethemagazine,hasan internationalfocuswitharangeofstories,newsandevents.

SamoaTheRedwoodRegionEconomicDevelopmentCommission,Samoaissetto receive$70,000fromtheHumboldtCountyBoard

ofSupervisorstoestablishanaquaculturecentreinSamoa.Thecenterwillpotentiallygrowbothfreshwaterandsaltwaterspeciesofplantsandanimals,includingabalone,fishandvegetables.-http://bit.ly/TCA5Ys

JamaicaJamaica'saquacultureindustr yissettoreceiveaboostthanksto30millionEU-fundeddevelopmentplan.Thefourandahalfyear

ACPFishIIProgrammeincludesplansforlandandwateruseandablueprintforaquaculture.TheaimistorevitaliseJamaica'saquac-ulturesub-sector,whichhasdeclinedbyalmostfiftypercentinthepastfiveyears- http://bit.ly/PlMKnt

USANewYorkis knownforits experimentalfoodscene soit comesas nosurpriseto learnthatproductsfrom vertical farmsare

appearingonmenusacrossthecity.Verticalfarminginvolvesgrowsamultitudeofaqualifeinacolumn.Seaweed,mussels,andscallopsgrowatthetopofthewaterwithshellfishsuchasclamsandoystersbelow.Besidessavingspace,verticalfarmersclaimthepracticehelpsrestockmarinelife.Verticalfarmingisgrowinginpopularitysolookoutforproductsinarestaurantnear

yousoon.-http://bit.ly/T6WHQl

KenyaNormallywereportonthegulfbetweenfishdemand

andsupplybutinKenyathestoryisreversed.Kenyansare not eatingenoughfishtosustainthe fishfarmingindustry.Thegovernmenthasbeenpushingaquacul-turedevelopmentforsometime,investingSh5.7billionoverthreeyears.ButthishasnotpersuadedKenyanstoserveupfishathome;theaveragefishconsumptioninthecountryisjust3.7kgperpersonayear.-http://bit.ly/QNH0gY

ScotlandAnewworld-classsalmonfarmatLochailort,Scotland

issetforcompletionin2013.TheMarineHarvestsitewillhousea smolthatcherywhich willbeoneof thebiggestfacilitiesintheworld.-http://bit.ly/RgLv5L

SwedenResearchersattheUniversityofGothenburg,Sweden

arestudyingthepotentialeffectsofaccumulatingantibi-oticsintheseabed.Morethan10,000tonnesofantibi-oticsareconsumedinEuropeeachyear,30-60percentofwhichpassthroughanimalsandhumanscompletely

unchanged.Thedifferentsubstancesthenreachtheocean viahospitals, municipal sewage, fish farms andrun-offfromagricultureandlandfills.- http://bit.ly/Rpvdar

www.theaquaculturists.blogspot.com

Aregularlookinsidetheaquacultureindustry

i i i i ii

ii

ii

ii

i

ii

iiiiiiii

iiiiiiiiii

iiiii i i i i

ii

ii

i

ii

i

ii

ii

iiiiiiiii

iiiii

i

ii

ii i


8/56

view

AQUACULTURE

by Dominique P Bureau, member

of the IAF Editorial Panel

On the Estimationof the DigestibleNutrient Contentsof Finished Feeds

Averylargeproportionofaquaculturefeedmanufacturers

arenowformulatingtheirfeedsonadigestiblenutrientbasis.Thisprogressivemovefromformulatingonatotalnutrientbasistoformulatingondigestiblenutrientsispraiseworthysinceitisprovidingamorerationalbasisfortheproductionofcost-effectivedietsadequatelymeetingthenutrientrequirementsofanimals.

Everyyear,anincreasingamountofinformationof

thedigestibilityofnutrientsofdifferentingredientsisbecomingavailable.Thisinformationisinformallycompiledinanumberofreferencedocumentsandincreasinglyusedbycommercialfeedformulators.Thequestionarisesastohowreliableistheavailableinformationandhowitisbestused.Inacontextofveryhighfeedcommoditiesprices,theimpactofoverestimatingorunderestimatingdigestiblenutrientcontentsoffeedingredientscantranslateintosignificanteconomicalimpacts.

Forexample,variationsaslowastwoorthreepercentage

pointsinthedigestibilityofproteinorlipidsourcescantranslateintovariationsofasmuchas$10to30pertonneoffeedproduced,clearlynotsomethingnegligible.

Foryears,thedebatearoundestimatesofapparentdigestibilitywasonmethodologicalissues(e.g.,fecescollectionmethods)and

perhapsmoreimportantissueshavebeenneglected.Iwishtobrieflyhighlighttwooftheseissuesinthiscolumn.

Ingredients,suchaspoultryby-productsmeal,feathermeals,meatandbonemeals,andDDGSareincreasinglyusedincommercialaquaculturefeedformulations.Asubstantialamountofinformationoftheapparentdigestibilityofprotein,aminoacidsandenergyoftheseingredientsisavailableinthereferenceliterature.However,theseingredientsareproducedusingawidevarietyofequipmentandprocessinganddryingconditions.Consequently,significantdifferencesmayexistintheapparentdigestibilityofnutrientsamongstlots(batches)oftheseingredients.Verylittleworkhasbeendonetomeaningfullycharacterisethevariabilityofthedigestibility

andnutritivevalueofdifferentlotsofthesameingredient.Thisisamajorissueforfeedmanufacturerssincetheseingredientsarefrequentlysourcedfromseveraldifferentsuppliers(brokers)andthesesuppliers,inturn,frequentlysourcetheseingredientsfromdifferentmanufacturingfacilities.

Anotherimportantissueisthewaybywhichthedigestiblenutrientcontentsoffinishedfeedscanbecomputed.In

feedformulation,thenutrientcontributionsofdifferentingredientsareusedtopredicttheconcentrationofnutrient(orenergy)inthefinishedfeed.Thecontributionofnutrientsofdifferentingredientisthusassumedtobeadditive.Itiscommonfornutritioniststoassumethatthedigestiblenutrientsandenergycontentsoffeedscanalsobecalculatedasthesumofdigestiblenutrientandenergycontributionsofdifferentfeedingredients(calculatedfromthequotientofincorporationlevelinthefeed,theapparentdigestibilitycoefficient(ADC)andthenutrientcontentofthe

ingredient).Whilepracticalandgenerallyeffective,anincreasingamountofevidencesuggeststhatthistypeofapproachmaynotbesuitableforseveraltypesofnutrients.

AseriesofpublicationsfromtheUniversityofGuelph(HuaandBureau.2006.Aquaculture,254:455-465;HuaandBureau.2009.Aquaculture,294:

282-287;HuaandBureau.2009.Aquaculture,286:271-276;HuaandBureau2010.Aquaculture,308:152-158)showedthatthedigestiblephosphorus(P),starchandlipidcontentsoffinishedfeedscouldnotbecomputedfromthesumofexpecteddigestiblenutrientcontributionsofthedifferentingredients.Thisresearchindicatedthattheformsunderwhichthesenutrientsweresupplied(or

foundinthefinishedfeeds),thelevelsandinteractionsbetweendifferentformsofthenutrients,andtheeffectofsomeexogenousfactors(e.g.,watertemperature,%gelatinization)hadtobetakenintoaccounttoaccuratelypredictthedigestiblenutrientcontentsoffinishedfeeds.

Fortunately,thisresearchalsoshowedthatmultipleregressionequationsprovided

asimpleandpracticalapproachofaddressingthischallenge.EquationswherethusdevelopedforpredictingthedigestibleP,starchandlipidcontentoffeedsmanufacturedusingawidearrayoffeedingredients.Unfortunately,mostleast-costfeedformulationsoftwarepackagesarenotcurrentlydesignedtocarryoutanoptimization(least-costing)ofthedigestibleP,starchand

lipidcontentsoffeedsonthebasisoftheseequations.However,thesesimpleequationscanbeprogrammedintofeedformulationsoftwareandtheeffectsofchangesinfeedformulationonthedigestibleP,starchandlipidcontentsofthefinishedfeedsbeeasilycomputed.

Theseissuesshouldbeontheradarscreenoffeedmanufacturersandmoresystematicandcommerciallyrelevantworkneedstobedonebyfishnutritionresearchersontheimportanttopicofestimatingthedigestiblenutrientcontentsoffeeds.

AQUACULTUREUPDATES

Climate change may make the

bodiesoffishsmaller,reportstheBBC.Scientistspredictthatfishcouldshrinkbyupto24percentifwatertemperaturescontinuetorise.Warmerwatermeanslowerlevelsofoxygenwhichreducefish

bodyweight.AstudypublishedbytheInstituteofFoodTechnologistshasfoundthat using fish oil as an alternativeto cano la oi l in nutr it ion barscanprovideomega-3fattyacidswithoutchangingthetaste.

Anindooraquaculturefacilitywiththecapabilitytoproduce17millionpounds offish a yearcould becoming to Montgomery County,NewYorkState,USA.Ifgiventhego-ahead, 'ProjectAqua' wouldcreate175jobsandreceivemorethan $175 million in initial privateinvestment.

An abalone trafficker in New

SouthWales,Australiahaslandedthetoughestsentenceinthestate'shistoryforfisheriesoffences.The55-year-oldmanwassentencedtofouryearsinjailandaAU$1000f ine after being convicted onfourcountsofabalonetraffickingandonecountofthreateninganfisheriesofficer.

The Ukrainian parliament hasapprovednew aquaculture laws.Thelawswillmapoutplansforaquaculturedevelopmentandthelegalframeworkforbodiesinvolvedinit.

Salmon farmexpansiongiventhegoaheadinwestcoastTasmania.ThethreemajorsalmonproducersinTasmania ,Tassal, Petuna andHuonAcquacultureplantoalmostdoublethesizeoftheirfarmsin

Macquar ie Harbour from thecurrent5.5squarekilometrestoninesquarekilometres.

TheGlobalAquacultureAlliance

hascertifieditsfirstsalmonfarmsinAustralasia.TheBestAquaculturePracticesprogrammehascertifiedtwo Mt.CookAlpine Salmon Ltd.farmsintheMackenzieBasinareanearTwizel,NewZealand.

TheBritishColumbiaaquacultureindustryistoreceiveacashinjectionof$1.25millionfromtheHarperGovernment.Elevencompanieswillbenefitfromthemoney,whichisearmarkedforsustainableandinnovativeaquacultureprojectsintheprovince.


9/56

Anewpartnershippromisesamore

efficientandsustainablefutureforEuropean

aquaculture

Itiswelldocumentedthataqua-culturefacesincreasingpres-suresasdemandforseafoodproductsgrowswhiletraditionalwildfisheriesareindecline.

A new European researchprojectcalledIDREEM(IncreasingIndustrialResourceEfficiencyinEuropeanMariculture)hasbeenlaunchedtoprotectthelong-term

sustainabilityofEuropeanaquac-ulturebydevelopinganddemon-stratinganewinnovativeproduc-tiontechnology,Integrated Multi-TrophicAquaculture(IMTA).

The 5 .7 mi ll ion project ,whichstartedinOctober2012,iscoordinatedbytheScottishAssociationforMarineScience(SAMS) and delivered in col-

laborationwithfourteenindus-trial and research partners fromacrossEurope.

For the next four years, theIDREEMconsortiumwilldeveloptools and methods to help theEuropean aquaculture industryadoptmoreenvironmentallyandeconomicallyefficientpracticesusing

IMTAonacommercialscale.IMTA is the combined culti-

vationofmultiplecommerciallyfarmedspeciesthatbelongtodif-ferentlevelsonthefoodchain.InanIMTAsystem,fisharefarmedto ge th er wi th ot herspecies includingshellfish (suchas musse l s)andalgaeors e a w e e d ,

creat ing amore e f fi -cient,cleanera n d l e s swasteful pro-duction system.IMTAallowsnutrientsfromfishfarmsthatareoth-erwiselosttotheenvironmenttobeturnedintousefulproducts

astheyareutilisedbytheseaddi-tionallygrownspecies.

IMTAaddressesconcernsaboutthe future sustainability of aqua-culture by increasing produc-tivity and profitabili ty while alsoreducingwasteandover-relianceonrawmaterialsfromwildfishstocks.

TheIDREEMprojectwilldem-onstrate the benefitsof IMTAthrough pilot commerc ial -scaletesting, field research and mod-elling.InterdisciplinaryresearchwithinIDREEMwillexaminethe

obstaclesandriskstotheuseofIMTAsystems

anddeveloptoolsto ov ercomet h e s e c o n -

s t r a i n t s ,

whethertheyareeconomic,environmental,

t e c h n i c a l ,socialorregula-

tory.IDREEMpairsaquac-

ulturebusinessesandresearchinstitutionsinstrategicpartner-shipstopromoterapidimple-

mentat ion , a l lowing ins tanttr ans fe r bet we en researchfindings and commercial appli-

cations.Thetoolsandmethodsdevelopedwithin IDREEM willhelpaquacultureenterprisesandpolicymakersgainabetterunder-standingoftherisksandbenefitsassociatedwithIMTA.

Theendresultoftheprojectwillbethecreationofamoreefficient Europeanaquacultureindustry,basedonthedevelop-

mentofmoreeconomicallyandenvironmentally efficient tech-nology. IDREEM wil l delivertools and evidence to suppor tthe adoptio n of IMTA acrossthe aquaculture industry,helpingcreateemploymentandwideningamarketnicheforIMTA-grownseafoodproducts.

www.sams.ac.uk

"The end result of the projectwill be the creation of amore efficient European

aquaculture industry"


Aqua News

ASIAN GATEWAYTO ANAQUATIC WORLD OF WONDER

www.aquarama.com.sgFor more information, please contact:

Iman Tam [email protected]

co-located with

The 4th International Pet

& Accessories Exhibition


10/568 | INterNatIoNal AquAFeed | Nvmb-Dcmb 2012

Aqua News

Scottish scientists are

hominginontheelusive

genes that could create

the perfect salmon and

revolutioniseaquaculture.Experts

at Landcatch Natural Selection,

basedinArgyll,andtheirresearch

partners,areaimingtobethefirst

intheworldtolocatethegenes

that determine how susceptibleindividualAtlantic salmon are to

certaindiseases.

ItisanotherpioneeringadvancefromLandcatchwhoin2007werethe first aquaculturecompanytobeinvolvedinworktopinpointa gene influencing InfectiousPancreaticNecrosis(IPN)whichposesamajorthreattoAtlanticsalmon.Theylateralsoprovedthatsealiceresistanceisinherited,sub-

sequentlyproducingjuvenilefishwhichwerelesssusceptible.Thisallowedbreeding fromselectedpedigree families and increasedgeneticresistanceineachnewgen-eration.

ThenewworkmeansLandcatchand partners are getting evernearertotheall-importantgenesandare on target to have thisscienceforsaleandalreadyappliedtotheirsalmoneggsby2014.

Healthier, diseaseresistant salmon

Inwhatwillbeamajorbreak-throughforthe industry, eggsandsmoltswillthenbeproducedto

selectivelybreedhealthier,diseaseresistantsalmonandotherfishas

thetechnologycancrossover tootherspecies.

It will mean improved qualityproductsandanaccelerationofgenetictechniquesinfarmedfishwhichtheindustryandcommenta-torsbelieveisnecessarytoaddress

worldfoodshortagescausedbyclimatechange.Theworkacceleratesthepaceof

progressandwillhelpbreedersandresearchersexaminetraitsinindi-vidualfishandbetterunderstandtheirgeneralsurvivability, omega-3levelandgrilsingormaturingrates.

This involves a cutting-edgegenomicselectiontooltheSNPChipaglassslideusedtoanalysevariationsinDNAsequences,or

SingleNucleotidePolymorphisms(SNPs), which act as biologicalmarkersandhelpscientistslocatearangeofgenesassociatedwithdisease.

Hundreds of thousandsof genetic markers

Therearemanymillionsofthesevariationsin every species, andthesecanbeusedasmilestonesontheDNAmap.Scientists,whopre-

viouslyexaminedonlyfivemarkersfor one salmon gene, can nowinterrogatehundredsofthousandsof markers for 20,000-30,000genes.

Inessence,Landcatchcandiscover

moreinformationononefishthanwaspreviouslyavailableonthou-sands.Thislevelofbreedingexper-

tise would normally take manydecadestoreach,butLandcatchwilldoitinjusttwo.

DrAlanTinch,directorofgeneticsatLandcatchse-centreinAlloa,saysexpertshavenarrowedthesearchdowntoabout100possiblegeneshaving identifiedQuantitativeTraitLoci(QTL)stretchesofDNAcontainingorlinkedtothegenesthatunderlieatrait.Hesays,Weareclosinginonthegenesallthetime. Itsabitlikeus knowingthe

street where they live but wejust dontknow yetwhichhouses,whereaspreviouslyweonlyknewwhattowntheylivedin.

Weknowthatinthatarea(ofDNA)thereissomethingthathasaneffectondiseaseresistanceandthere is a technicalargument fortherebeingagenethere.

TheprogresshasbeenwelcomedbyArgyllandButeconstituencyMSPMichaelRussellwhosays,I

amverypleasedtoseeanArgyll-basedcompanyattheforefrontofimportantresearchthatshouldhavestrongcommercialandenvi-ronmentalbenefit.

Landcatch suppl ies genet ic

servicesandAtlanticsalmoneggsand smolts to the aquacultureindustry.Itusesselectivebreedingto develo p stra ins of sa lmo nwhichcanperformtoever-higherlevelsateverystageofproduc-tion fromeggs to adult fish. ThefirmispartoftheglobalHendrixGeneticsmulti-speciesfoodpro-duct ion organisat ion whosemissionistohelptheworldmeetitsfoodneedsthroughinnovativeandsustainablegenetictechniqueswhichinformtheirbreedingproc-esses.

Theworktofindthegeneis

beingundertakenwithanumberof commercial and academicpartners, including EdinburghUniversity,RoslinInstitute,StirlingInstitute of Aquaculture andGlasgowUniversity,withsupportfromtheUKTechnologyStrategyBoard.

LandcatchgeneralmanagerNeilManchestersays,ThemissinggenesarelikeourHolyGrailandfindingthemwillhavewidespreadpositive

implications.Breedingfishthatareresistanttoliceanddiseasewillbeanincredibleachievementandamajorcommercialbreakthroughforaquacultureandeffortstofightthewaronhunger.

Expertsclosingthenetontargetedfishgenes


11/56

2012ReedMariculture,Inc.

AllRightsreserved.

InstantAlgae,

InstantZooplankton,

RotiGrow,S

hellfishDiet,ReefNutrition,andAPBreedaretrademarksorregistere

dtrademarksofReedMaricultureInc.

Provid

ingSuperio

rFeed

s

fo

rSup

erior Result

s

TOLL-FREE: 1-877-732-3276 | VOICE: 408-377-1065 | FA X: 408-884-2322 | www.reed-mariculture.com

Factory direct and distributor sales.Experts in international logistics. See how easy it is.

The Future of FeedsReed Mariculture has earned a reputation forbeing on the cutting edge when it comes todeveloping innovative nutrition solutions for

organizations building sustainable practices.

Customers in over 80 countries depend on ReedMariculture for timely delivery of superior nutritionproducts and world class customer service.

Commercial Aquaculture ProductsOur Instant Algae including RotiGrow andShellsh Diet products are the most convenientand effective feeds on the

market for growth, enrichmentand greenwater productivity.

We also offer InstantZooplankton products.

Hatcheries:Bivalve Shellsh,

Finsh, and Shrimp

Our New, APBreed Product LineAPBreed provides proven hatchery technologies

designed for marine ornamentals feeds and products.We currently offer zooplankton, microalgal and high-quality dry feeds with more products in development.

University Research Labs

Public Aquariums

Marine Ornamental Breeders & Hobbyists

Reef NutritionWe provide a full line of the

highest quality and freshestornamental products in theindustry, backed by our customerservice guarantee.

Marine Ornamental Breeders & Hobbyists

Let us know how we can helpyou create the future today.

Instant Algae in our10 Liter Cubitainer

Reef Nutrition Products


12/56

Iamsure everyone involvedin any fish

vaccinationwould really rather prefer

thattheydidnthavetovaccinate.Itis

an expensive, timeconsuming, hazard-

ous and stressful process. So why do we

vaccinatefish?

CertainlyinthesalmonfamingIndustry,ithasbecomeapartofthefreshwaterproduc-tionprocessformanyyearsnowanditisonlysomeof the mostmaturemembers ofthesalmon industry remember what it was likebeforeoil-basedvaccinesweredeveloped.

Priorto theseeffectiveoil-basedvaccines,salmonproducerscouldbeexpectedtoloosemaybe50percentoftheirstockstothemaindiseasethreat,Furunculous.Somefarmssuf-

feredmorethanothersbutallhadproblemsofsomeformorother.Theonlyrealsolutionwastreatmentwithantibiotics,whichwasnotonlyextremelyexpensivebutledtoproblemswithresistance.

The other problem was the negativepublicperceptionofhighusageofantibioticsinafoodanimal.This,inconjunctionwithafew high profile cases of use of unlicensedantibiotics on fish farms, led tothe industryseekingafreshapproachtodiseasemanage-ment.Theoil-basedvaccinesusedtodayinthe aquaculture industry are all multivalent,

meaningtheypreventavarietyofdiseases,abitliketheMMRvaccineinhumans.

Why vaccinate?Economics, logistics and risk involved

in injection mean that many alternativeapproacheshavebeentried.Dipvaccinesandin-feedvaccineshaveallbeentrialledbutdueto the nature of how fish immune systemswork, these only have limited effects. If itwerethateasy,Iamsurehumanwouldprefertohave atablet insteadof aninjection when

theygoonholiday!The problem with putting vaccines in-feed is that the in order for vaccines toworktheyneedtocreatearesponseintheimmunesystem-thebodyhastoreacttoaforeignsubstanceinthebodytoproduce

the ant igens to give the immunesystem the correct defences. If thesubstancethatcreatesthisreactionin

thebodyisput intothefeed,thebodyisdesignedtodealwiththisbydigestingand

excreting it through the digestive system,and i t does not stimulate the immunesystemandthushasnoeffectinpreventingdisease.

Who vaccinates?The Atlantic salmon industry through-

out the world has been familiar with intra-peritoneal (by injection)vaccinations for manyyears. Trout farmersoccasionally vaccinate

for Enteric RedmouthDisease(ERM)onhigh-risksitesbutbecausetheproductioncycleismuchquicker for trout thansalmon, most diseasecanbemanagedthroughdipvaccination.

The sea-bass industryin the Mediterranean isabiggrowthareaatthemoment but is sufferinginthe same way salmon

farmersdid25yearsagowith many sites loosingmaybe 50 percent oftheirstocks.Recentcom-mercialproduction of aneffectiveoil-basedvaccinehaveledtomanyseabassfarmers now consideringvaccinationbyinjectionastheonlyeffectivemethodtocontroldisease.Thosefew that have invested

in a vaccination strat-egyhaveseenbigfinancialbenefits from it and aswordspreads,itislikelytobecomecommonplaceinthisindustrytoo.

How is the procedure

carried out?The fish are starved for 24 or 48 hours

(depending on time of year) prior to vac-cinationtoemptythegut.Thefisharethencrowded in the tank or cage before beingpumpedorhandnettedintoananaestheticbath. The fish take one to two minutes tobecomefullyanaesthetised.Thisisextremely

An overviewof the UK fish vaccination industryby Kathy Taylor, Salmovac, UK

Melanisation (a permanent bruise like mark in the

flesh of the fish) causing downgrades at harvest.

Permanent damage and scarring inside the fish due

to damage by needle movement during vaccination

process.


FEATURE


13/56

important for vaccinator safety but also the

safety and welfare of the fish.

The fish are then delivered onto a stainless

steel table where the fish then are vaccinated

in a very specific area, with only a 3 mm toler-

ance. The team must achieve a 96 percent

accuracy target and considering most vaccina-

tors handle between 15-20,000 fish each this

is quite some achievement!

The fish are then returned to a recovery

tank and should come round from the anaes-

thetic within about two to three minutes.

There is always some level of mortality after

this high risk, stressful process but usually it is

just a few fish, around 100 for every 100,000

fish vaccinated. High mortalities immediately

after vaccination are usually attributed to poor

anaesthesia rather than the injection.

The consequences of poor vaccination

usually only become apparent months after

vaccination and can last up until harvest where

the financially consequences become appar-

ent. The main problems are:Incorrect needle depth resulting in either

intra-muscular injection (needle too short) or

internal organ damage, including granuloma

(needle too long) which results in the fish not

growing properly due to damage to the gut.

Fish not being immune to the disease

because of incorrect dosage (or no vaccine)

being delivered.

Two of the main problems Salmovac

encounters as a

contract vaccina-

tion team, is poor

anaesthesia of the

fish and also poor

grading, prior to vac-

cination of the fish.

Poor anaesthesia of

the fish can lead to

high mortalities. If

fish are under anaes-

thetised, the whole

process becomes

stressful and danger-

ous for them (imag-

ine having a major

operation whilst

only partly sedated!).

On the other hand,

if they are over

anaesthetised, they

risk not recover-

ing quickly enough,resulting in piles of

fish in the recovery

tank causing suffoca-

tion or even worse,

not recovering at all.

The other risk

factor here is to the

vaccinators. If the

mineral oils used in

november-December 2012 | IntnatInal AquAFeed | 11

FEATURE


14/56

thevaccines areaccidentally injectedinto thefinger,thevaccinatorwillrequireurgentmedi-calattention.Thefingerwillhavetobecutopenandthevaccineflushedout,otherwisethe resulting inflammation could result inthe blood supply to the finger tissues beingreducedandpossiblelossofthedigit.

How has vaccination developed?

Whenthefirstoil-basedvaccinesbecameavailable for the salmon industry, quite afewcompaniesstartedvaccinatingtheirownfish believing (mistakenly) that this wouldkeep costs down, as they wouldnt haveto contract in extra labour. The problems

encountered and thesometimes devastatingresults of this quicklyled to most companiesemploying contract vac-cinationspecialists.

The main problemswere a lack of knowl-edge about needledepths and the results

of inaccurate vaccina-tion, along with theprocess taking a longtime because of theinexperienceandslow-ness of untrained vac-cinators. An inexperi-encedteamofsixcouldprobably manage tovaccinatebetween150-200 ,000 f ish a weekwhereasourteamscan

do 400-500,000 fish aweek!

Vaccines havedevel-oped tremendously inthe past 20 years, thedoseperfishusedtobe0.2mlandthevaccineswerevery thick, difficulttoadministerandcauseshigh side effects in thefish.Theyarenow0.1mlandmuchthinnerandcausefewersideeffects.Someofthenewervac-cines are now a 0.05mldoseandagainhavereduced side effects forthe fish while also giv-ingincreasedprotectionagainstdisease.

Theimprovementsinvaccinetechnologyhavenot only reduced theside effects for the fishbut have also improved

theeaseofuseforvacci-nators.Thesmallerdosesize is much easier to

administer,resultinginfewercasesofrepeti-tivestressinjuryandcarpeltunnelsyndrome.

Which species areworth vaccinating?

Allspeciesareworthvaccinatingiftheeco-nomicsofpreventingdiseaseratherthantreatingitstackup.Withthesalmonindustry,itisessen-tialthatallfisharevaccinatedandastheseabass

industryexpandsandimprovesitislikelythatallseabasswillhavetobevaccinatedto.Thekeytowhetheritisworthvaccinatingornot,reliesonwhetherthenisaneffectivevaccineatapricethat makes itviableto vaccinate andpreventsthelostofmarketsizefishtodisease.

How does vaccinationprovide value for money?

The expense and hassle ofvaccinationisfaroutweighedbypotentiallossesatseaorthe heavy costs and logistics involved withtreatingfish atsea. The otherfactor tobearin mind is fish welfare and the associatedregulations.MostScottishsalmonfarmsnowsubscribe to the RSPCA freedom foodsstandard,whichlaysdownwelfarestandards

for the aquaculture industry and vaccinationplaysakeyroleinthis.Itcostsafewpencetovaccinatea smoltat 30gbut theprice oflosingamarketsizesalmontoapreventabledisease is many, many times that amount.Prevention isnot only preferable,but finan-ciallyessential,tocure.

Vaccination in action at Salmovac

The fish are delivered onto a stainless steel table

where the fish are vaccinated in a very specific area,

with only a 3 mm tolerance. The team must achieve

a 96 percent accuracy target and considering most

vaccinators handle between 15-20,000 fish each this

is quite some achievement!

About the authorSalmovac was founded in 2003 in

the north of Scotland in response to

agrowingdemandforqualitycontractvaccinationserviceswithintheScottishsalmon industry. The directors, KathyandJohnFosterbothhadhadpreviousvaccination experience and a wealthof knowledge of both fish health andaquaculturepracticesalongwithaback-groundinqualityandbusinesssystems.Theystartedwithjustoneteamoffivepeople and successfully vaccinated fivemillionsalmoninthefirstyear.Becauseof the high quality and professional-

ismdeliveredbySalmovac,wordsoonspreadandcontractscamefloodingin.However,theywerecarefulnottooverstretchthemselvesinthefirstfewyears,preferringtoincreasethebusinessatasustainable rate, in order to keep thequalityofserviceandreputationofthecompanyhigh.

Asaresultofthissustainablegrowthof the business, they currently employover40peoplefromallovertheworldand successfully vaccinated 60 millionfishlastseason!

In2010,KathyFoster(nowTaylor)purchased the business from her ex-husband and now is the sole directorofSalmovac.Whatwasadifficulttimeforthebusinessbackthenhasprovedtobeabenefit forthe longertermandthe business has continued to growandprosperwithcontractsnotonlyinScotland but also in Ireland, Norway,Spain,FranceandSwitzerland.

More InforMatIon:

Kathy Taylor, SalmovacTel: +44 1381 621914


Website: www.salmovac.com


FEATURE


15/56

No hollow spaces | No cross contamination

Excellent cleaning access | Filtered air inletTemperature control | Moisture control | Cleaning in Place

C L E A N C O N T R O L

Swivel Valve Cooler MkII

c o o l a n d d r y

clean and lean

[email protected]

www.geelencounterflow.com

T +31-475-592315

Geelen Counterflow

Holland / USA / Argentina / China


16/56

Yeast products are getting more

andmorepopularinaquaculture.

However many products (as a

wholeorasfractions)areonthe

aquaculturemarketatthemomentanddif-

ferentiatingbetweenonefromanothercan

bedifficult.Thissmallarticleaimsatshadingsomelightsonthesubjectandexplainsthat

allyeastproductsarenotequal.

Yeastisaunicellularorganismbelongingtothekingdomof Fungi.Morethan athousandspecieshavebeenfoundintwomajorphyla:Basidiomycota and Ascomycota in whichbelongspeciesabletoduplicatebybuddingsuchasSaccharomycescerevisiae.

Due to their unique properties to growunder aerobic conditions and produce gas

andethanolunderanaerobicconditions,someyeast (mostly S. cerevisiae) have been usedforthemanufactureoffermentedfoodssuchasbread , beer and wine for a long time.Yeasts are also used as single sell proteinsourceinanimalnutritionandinaquacultureundervariousformsandspecies(Torulaspora,Torulopsis,Kluyveromyces, Saccharomyceetcaetera). It can be found for example in

shrimpandmarinefishlarvalfeedsorincludedasaproteinsourceinaquafeeds.

The reasons for this extensive use is itsexcellentnutritionalcontents,itseasysupplyin dried form or under liquid form whenbakery yeast plants or breweries are near

aquafeedplants,andnowadaysacompetitivepriceinregardstootherproteinsourcessuchasfishorsoybeanmeal.Furtherapplicationsare being developed for yeast as functionalfeed additives as probiotic live yeast, yeastfractions(yeastcellwalls,yeastextracts)orasasourceformorepurifiedproductssuchasbeta-glucansandnucleotides.Theproductionprocess ofyeast canallow the possibilitytoincorporatetracemineralsandthenproducehighlybioavailableorganictraceminerals,alsoknownasseleniumandchromiumyeast.

ThepinkyeastPhaffiarhodozyma,isnatu-rallyrichinastaxanthinandhasbeenusedforsometimeasnaturalsourceofthepigmentin salmonids. Although now it tends to bereplacedbybacterialproductswhichhaveahigher concentration and whose cell wall ismoreeasilydegraded.WewillonlyreferinthefollowingarticleonproductscomingfromS. cerevisiaeorigin.

Nutritional properties of yeast:Typical dry yeast composition is 93-97

percentdrymatterandcancontainfrom40%to60percentcrude proteinnitrogen, 35-45percentcarbohydrates,and5-9percentlipids.Aquiteimportantfractionofthenitrogenis

undertheformonnucleicacids(upto12%)that can lead to produce significant level ofuric acid if consumed at high concentra-tion, like meat. The Amino acid profile ofyeastisclosetosoybeanmealandthereforewelladaptedto animal nutrition; itis richinGlutamic acid and Lysine (up to8%).YeastisnaturallyrichinBvitaminssuchasbiotin,thiamineandfolicacid. ItalsoproducesniacinbutcontrarytosomebeliefdoesnotproduceB12Vitamin.Ergosterolwhichisasignificantfractionofyeastcellwall,alsoisalsoaprecur-

sorofVitaminD2byusingUVtreatments.

Bakers yeastEveniftheirnameremainsSaccharomyces

cerevisiae (cerevisiae for beer), mostof thestrains of Bakers yeast have been selectedfortheirhighfermentativepower,particularlyuseful for bakers.Strains are specific to the

typeofbreadandtheregionwhereitissold,inordertorespondtodifferentbreadmaking

conditions (French bread, white bread, flatbread,croissant,etc.)andresisttodifferentprocess conditions (osmotic pressure from

highsugaredbread,freezing,acidityofsourdough,).

Bakers yeast comes as a pure and pri-maryculturegrownonsugarsubstratesuchas molasses. The production is performedunderverystrictconditionsinordertomain-tainthegeneticpurity,consistency,specificityandefficacyofthestrains.(Figure1).Itcanbesoldunderdifferentformsandpackaging(instant dried yeast, active dry yeast, com-pressed,cream).

The primary grown culture controlled

processmakesalsoaveryconsistentbaseforthe production of yeast extracts, autolysedyeast, yeast cell walls and their derivate:nucleotides and beta-glucans. Yeast cellwalls produced from Bakers yeast usuallyhaveahighcontentofmannans.Theyare

Yeast in aquacultureby Philippe Tacon PhD, Lesaffre Feed Additives, France


FEATURE

Figure 1: Yeast manufacturing process (primary grown culture)


17/56

recognised as good toxin binders. Fractionscomingfrombakersyeasthavealightbeigecolour.

ThemostpopularaquacultureapplicationofBakersyeastisinhatcherieswhereitisamajorfeedsourceforartemiaandrotifer(seeforexampleCouteauetal1990).

Brewers YeastBrewers yeast can be identified either

as the ferment used in brewery industries(Yeastprimaryproduction)ortheby-productofthese industries which istheformmainlyusedinaquaculture.Inthelattercase,yeastbiomass is harvested from the fermentationvatsattheendofbeerfermentation.Itcanbesoldunderliquidform(18-20%ofdrymatter)but preferentially as inactive yeast spray or

drum dried. It canalsobeengrownasamorecontrolled product andspecific strains and finditswaytohumancareasafoodsupplementandholistictherapeutic,alsoknownasnaturalbrewersyeast.

Brewers yeast for aquafeed applications

issoldbytradingcompaniesasacommoditybased on the protein content, or by localbreweriesinneedtodispatchtheirslurry.Thequalityandthesupplyoftheseproductscanbe inconsistent and depends greatly on thesourceofsupply.

The nutritional content is similar as theoneinbakersyeast,butcontainsmoretraceminerals such as selenium and chromium.Theproteincontentofbreweryeastisrela-

tively high and and its amino acid content issimilar to bakers yeast. Numerous workshaveshowntheefficacyofBrewersyeasttoreplacepartiallyortotallytheproteinsfound

infishandvegetablemealinfishandshrimp.Shrimpfeedsformulatorstypicallyincorporatebrewersyeastintheirformulaattherateoftwotofourpercent.

Brewers yeast can be used to produceyeastfractions,howeverduetothenatureofbrewersyeastandthespecificityofthepro-ductionprocesses,thequalityislessconsistentthan inbakersyeast. Productscoming frombreweryyeasttendtohaveadistinctivebitter

table 1: ffect of live yeast ctisaf on growth parameters in tilapiaunder stress conditions. (n=3, P


18/56

smellandtasteandadarkercolourthantheonescomingfrombakersyeast.

Ethanol YeastEthanol Yeast are harvested after hav-

ing performed alcoholic fermentation anddistillation for the conventional productionof Bioethanol from sugarcane, beet sugaror grains syrup. In the first case, the yeastbiomass is harvested and then dried withtherecycledenergy usedto heatthe vegetalmaterial.ThemajorityofethanolyeastcomesfromBrazil.

Production prices and selling prices arevery low, however the quality, such as theproteincontentisveryinconsistent.Thesup-plydependsontheactivityofthebioethanol

plantsandcanalsobeinconsistent.Anotherconcernisthesanitarysafetyoftheseprod-ucts.Antibioticsaresometimesaddedtotheprocessinordertopreventbacteriacompet-ingwith the yeast for nutrients andavoidingyield decrease. It is therefore possible thatsome antibiotic residues and possibly othertoxinsmightbeleft inthefinaldriedproduct.

AutolysedyeastInactiveDriedYeastInactive and Autolysed yeast come from

primary grown cultures or Brewers yeast.They are major products within the foodindustryasflavourenhancersandinpetfood

asfeedattractants.Theyareusedinaquacul-turefeedsasasourceofproteinandnitrogen.Brewers yeast, and itsethanol equivalent,ismostlyfavouredasitischeaperthanbakersyeast.Theyarealsoeasiersuppliedasyeastsuppliers prefer to sell the more controlledandtailoredBakersyeastonfoodmarkets.

Inactive yeast is a yeast that has beendeactivatedbyhightemperaturedrying(oftenspray drying). The cells come as a wholeandthecellwallisnotrupturedmakingtheaccess to intracellular material (amino acids,

vitamins) difficult. A way to access thesematerials is to partially hydrolyse the yeastcellwalltoletthecellularcontentbepartiallyreleasedfromthecell.Thiscanbefacilitatedby activating the internal autolytic enzymesof the live yeast (autolysis), adding external

enzymes (notably pro-teolysis) or playing onthe osmotic pressureto rupture the cell wall(plasmolysis). Differentgrades of autolysedyeast can be obtaineddepending on the levelofautolysis(frompartialtototal).Thefinalprod-

uctisamixtureofcel-lular content and yeastcell wall. Furthermorethe autolysis processdegrades protein andforms peptides (dipep-tides to tetra peptides)

andoligonucleicacidswhicharereadilydigest-iblebytheanimal.Againheredependingontheoriginalyeastmaterialused,autolysedandinactiveyeastqualitycanbeverydifferent.

Live Yeast as probioticsLiveyeasthelpsregulatethegutmicrobio-

ta.Itseffectshavebeenshown,first inhumanwhere it can reduce diarrhoea, especiallywithchildren.SpecificstrainshavethenbeendevelopedandproducedindustriallysuchasS.cerevisiae boulardii orS. cerevisiae Sc47(Actisaf)fortheanimalnutritionmarket.Itisacommonpracticenowtosupplementfeedsto increase milk production in dairy cowsor help pigletssurvival.

L ive yeastare charac-ter ized bythe ir liv ingcells count,expressed bycolonyformingunit (cfu pergram),typicallyten bil lionscfu/g. Dosagesare made inthe feeds as

dilutionstogetanefficientcfucountpergoffeed,a1000folddilutiongivinga10e107pergoffeedforexample.Viabilityoftheyeastismandatory for its effect and cfus should becheckedbeforeandafterpelletingusingplatecounts.

Despitetheincreasinguseofyeastasa probiotic in terrestrial animals, thereareonlyafewnumbersofworksstudyingits effect in fish as a gut functions stabi-

liser. The major reason is that live yeastdoes not resist the severe conditions ofthe manufacturing processes of aquafeeds(high temperatures, steam, long condi-tion ing times, see Aguirre -Guzzman et al2002). The studies are then diff icult to

transfer from lab condit ions to farm usingcommercialfeeds.

Alltheworkpublishedso far was madewith yeast either top dressed on feeds orincorporated in pressed (uncooked) feeds.NeverthelesssomedirecteffectstothegutmaturationhavebeenfoundinseabasswithaspeciesextractedfromtherainbowtroutgutDebaryomyceshansenii(seetheworksfromTovar-RamirezandalsothereviewsbyChiet

al2006andGatesoupe2007).Marineyeastsand yeasts isolated from fish seem a verylogicalchoicetouseinspeciesofaquacultureinterest.However,suchmaterialisoftendif-ficulttogrowunderindustrialconditionsanddidnotleadtothedevelopmentofanactualproductyet.TheproductsonthemarketarethereforeoftenfromS.cerevisiaeorigin.Ithastobenotedthatuptonow,noyeastprod-uctshavebeenregisteredinEUasaprobioticinaquaculture.

As an example of S. cerevisiae effects,

(LaraFloresetal2003,2010)Table2showssomeworksdoneintilapiafryfedfor3weekswith feeds supplemented with Actisaf (alsoknwnas Biosaf)at1 kg/Tintwodiets(40%and27%proteins)andat2crowdedcondi-tions(1fryperLor1 fryper2L).

AlltheyeasttreatmentsalsoincreasedthealkalinePhosphataseactivity,andwecanseeabetterimprovementoffeedconversionratio(FCR)andsurvivalunderstressfulconditions

(lowproteinpercentageandcrowdedcondi-tions).Thereisalsoabetterproteinefficiencyratio (PER) and digestive enzyme activitywhenActisafisused.

Live yeast canbe used directly on farm,where it has been showed (empirically) toimprove water quality in shrimp and fishponds.Itiseitherusedaloneormixedwithbacteria. Farms producing mash feed onsite

alsoaddyeastinordertodegradecellulolyticmaterialtoensureabetterdigestion.

Yeast Culture or fermented yeast.Yeast culture is a particular product in

whichyeastisallowedtoferment.Yeastbio-


FEATURE

Figure 4: Cumulative mortality after immersion

with L. anguiilrum (blue line is control, orange line

is Pronady at 0.5g/kg. n=3, Pronady significantly

decreases mortality at 120h. P


19/56

mass, substrate and fermented extracellularmetabolitesarethendried.

Yeast Extracts.Yeast extracts (YE) come from the

fur ther hydro lysi s and pur if icat ion ofautolysed yeast. Insoluble yeast cell wallsare separated from the cel lular contentby centr ifugat ion. YE are very soluble ,r ich in peptides (up to 65%-70% of theproduct), free amino-acids like glutamicacidandvitamins.Theyalsocontainahighlevelofnucleicacidwhichcanbefurtherpurified to increase the level of tasty 5nucleotides.Theyareusedinaquaculture

in functional feeds, and hatcheries, as asourceof nucleotidescomplementing thedenovosynthesisofcellsinmultiplicationandhelpingboostimmunityandanti-stressmechanisms.

Autolysed yeastand inactive yeastarecommonly mistakenly sold on the labelyeastextractinaquaculture.Agoodwayto dif ferent iate them is to look at thecarbohydrate levels. Autolysed yeast hasaround20-22%(mostlyfromtheremainingYCW)whereasYEcontainonlythreetosixpercentofcarbohydrates.

ThesmallpeptidesandfreeaminoacidsinYEcanalsoproveapotentattractantfor

aquafeedinshrimp.InatrialperformedinThailand with white shrimp L. vannamei.FeedcontainingYEat2kg/Toffeedwaspresentedinfeedingtraysatthecornerofhapasandtheremainingfeedwascounted

afteronehour.Wecanseeafasterfeed-ing when YE are included. (Tacon andSuyawanish2011).

Yeast Cell wallsYeast Cel l Wal ls (YCW) represent

the shell of the yeast cel l and are roughly40-50 percent of the mass of the cell .YCW are composed mainly of f ibrouspolysaccharidesglucanswithbeta1,3and


FEATURE

Figure 5: Yeast rich in organic selenium manufacturing process

MADE IN HOLLAND

AL30O

Almex b.v., Verlengde Ooyerhoekseweg 29, 7207 BJ Zutphen, The Netherlands, tel. +31 (0)575 572666, e-mail [email protected], www.almex.nl

High capacity extruders and expanders.

AD System


20/56

beta1,6links,(50%and8%respectively),mannansundertheformofMannoproteins(40%) and chit in (2%) (see Lippke andOvalle1998).Furtherpurificationcanleadto the product ion of either pur ified beta-glucans (50% and up) and mannoprotein(often used in wine making for clarifica-tion). The presence of these compoundsoftenleadstothemislabellingofYCWasMOSorBeta-glucans.

These two carbohydrate types are veryinterestingfortheaquaculturemarket,beta-glucansaredirectstimulatorsoftheimmunesystemsinshrimpandfish,uponthestimula-tion of specific blood cells (granulocytes ormacrophages).Mannansareinvolvedinthebinding to pathogenic bacteria (especiallythose with pili having mannose receptors)and eliminate them from the intestine. Itisalsosuspectedthatthemannanesactasprebioticspromotingthegrowthofbeneficialbacteria.

YCWhavebeenshowntobeeffectiveto improve the resistance to bacterial chal-lengesinnumerousaquaculturespecies.Betaglucanshavetobeusecarefullyinaquacul-ture as some experiments report negativeeffects in fish when used for prolongedperiodsathigh concentrations..Thiscan beavoided by careful choosing the source ofYCWandusingthemeitherathighconcen-

tration (2 kg/T) only for a short period, oralowconcentrationcontinuously(0.5g/Kg).

Anexampleofsea-bassjuvenilesfedwithPronady(aYCWoftheLesaffregroup)at0.5 g/kg of feed for8 weeks can be seeninFigure4,showingasignificantprotectionagainst L. Anguillarum without any growthdifferencewiththecontrol.Howeveramini-mal amount ofYCWseemsneededto beingestedbeforechallengeinordertoprovide

anefficientimmunostimulationandsotheremightbeagapperiodwhentheproductisnotefficient.(datafromDr.MorganeHenry,HellenicCenterformarineResearch,2011)

YCWproducts,dependingonthequalityof the autolysed yeast separation, containalsosignificant percentages of proteinsandlipids.Itshouldbenotedthatthelowerthelevelofproteins,thehigheroflevelofcarbo-hydrates,andthenthebetterimmunostimu-lationfromtheYCWis.VariousqualityofYCWareontheanimalproductionmarket

andmajordifferencescanbefoundbetweenproductsdependingonthestrain,thesub-strateusedtoproducetheyeast,andeventthedryingprocess.

Mannans represent as most 25-27 per-centofYCWingoodqualityYCWfrompri-marygrownyeastsbutcanbefoundaslowas 9 percent in crude preparation comingfromindustryby-products.Glucansorpoly-glucosecan rangefrom 18To 40percent.

YCW Prote inlevel remainsthe most con-venient indica-tor of qual ity,the best prod-uctsbeingthosehaving lowern it rogen con-tent. The vari-ability betweenbatchescanalsobe very h igh.Texture shouldbecheckedfirst.

Good YCWoften have asmooth, finetex ture , lowgranulometryandalightbeigecolour.Thereisalsothetenden-cy to believethat all YCWare the sameand that dif-

ferentiation ofproducts mustbedonetothehighest level ofglucans (some-times measured

as both alpha and beta forms)or mannans.NotalltheYCWareequal.Efficiencyshouldbe checked as a prerequisite to use, orchange,YCW.

At LFA we have conducted a surveyof four YCW (2 bakery and 2 breweryyeasts)producedin4ofourownfactoriesinthesameL.Anguillarumchallengeinseabass supplemented at 0.5 g/kg of feed for8 weeks. Only2 responded significantly (1

bakery,1brewery),theremaining2hadevennegative results at 4 weeks (lower survivalthancontrol).ThisresultshowsfirstthatnotallisunderstoodinthewaytheseproductsworkandthatoneparticularYCWcannotbereplacedbyanother.

Selenium YeastYeastcanbeinducedtobeasourceof

organicselenium,mainlyundertheformofseleniomethionine, which is then stored inproteins.Duringthegrowthofbakersyeast,

selenium is added to the medium and isreplacingsulphurinmethionine.Theexcessof selenium is then eliminated by carefulwashingsteps(seeFigure5)toensurethatthe selenium left is 97-99 percent organic .Seleniumyeastshouldbethencheckedforthe highest percentage of selenomethio-nineand theconsistency between batches.Seleniomethionineis themain carbon-asso-ciatedformofseleniumintheanimalsbodyand then allow making organic seleniumwhich are readily available when oxidative

stressreactionsoccur.Themainapplicationwouldbeinaquacul-tureasf ishmeali samainsupplyofseleniumandthedevelopmentofdietswithlessfishmealwillrequirecompensationofseleniumin aquafeed formulae. Such an applicationcouldbeusefulinpreventingtheoxidationof poly unsaturated fatty acids (PUFA) infishflesh.Chromiumyeastisseldomusedinaquaculturediets.

Conclusion Yeast products are getting more fre-

quently used in aquaculture. Some appli-cat ions are promis ing as the use as analternativesourceofproteinsorasasanitaryandwelfareenhancer.Howevermanyprod-ucts ranging from crude ethanol yeast by-productstomorepurifiedbeta-glucansareavailableonthemarket.Thereforepotentialusers must accurately select them in func-tion of their targeted application. It is alsoas important toselect a reliablesource of

the products toensure aconsistency of thesupply.

More InforMatIon:

Website: www.lesaffre.com


FEATURE

Upcoming

Eventsfor2

013

Making Sense of Science

February 21 - 25, 2013

Nashville, Tennessee

USAFor all info contact us on

www.was.com

[email protected]

The international triennial

conference & exposition of

World Aquaculture Society

August 9 - 12, 2013

Trondheim, Norway

Organised by European Aquaculture

Society

For all info contact us on

www.easonline.org

Asia Pacic Aquaculture

December 10-13th,

2013

Ho Chi Minh City, Vietnam

Aquaculture Europe

World Aquaculture

For all info contact us on

www.was.com

[email protected]


21/56

March 13 - 15, 2013 BITEC Bangkok, Thailand

Register now forFREE entrance

www.aquatic-asia.net

Eager to meet up with dedicated Aquaculture exhibitors?

Want to boost your Aquaculture business?

Check out this new event, in co-location with VIV Asia 2013

Aquatic Asia 2013: Find your suppliers of innovative

products and services in the Fish, Molluscs,

Crustaceans and Algae business.


22/56

Nowadaysweoftenhearstartling

news such as, seven billionth

babybornorworldpopulation

mayreach 9.2 billionby2050

(world news, msnbc.com). Hunger is the

worldsnumberonehealthrisk,itkillsmore

people thanAIDS every year, one in seven

peopleintheworldwillgotobedhungry

tonight.

To overcome these issues, farmers mustproduce70percentmorefoodby2050tofeedthepopulation.Buttheimpendingcrisisisthattheearthmayrunoutoffoodby2050.2.4billion extrapeople,no moreland,howwillwefeedtheworldin2050?

Atthesametimewealsohearinthenewsthatglobal fishconsumptionhashitarecordhigh. We have seen the commercial fishingtrendisdecliningwhereasaquaculturefarmingisgrowingrapidlyallovertheworld.

Is this supply enough to feed the future

population? May be not, but fish demandisgrowingeverydayallovertheworld.Tomaintainbaselineconsumptionineverycoun-try,159milliontonsoffish isneededto feedthe world population in 2030. This demandisdriven bypopulation and income growth.Ifacountrysaquacultureproductionfollowsthe recent trend, the expected aquaculturegrowthratewillneedafourpercentincreaseannually.Tofeedagrowingworldpopulation,the required aquaculture growth rate is 5.6percentannually.

Some of the main challenges to achievethese goals are proper and large-scale feedproduction systems for micro aquatic feed.Recently extruder manufacturers came upwithnewtechnologieswhichcansolvesomeof the aquaculture issues related to large

andcommercial-scalefeed,whichisthekeyforgrowthofaquacultureindustry.Thefun-damental components of extrusion systemshave consisted of the following items for anumberofyears:

1)Feeddeliverysystem2)Preconditioning3)Extruder4)Dieandknifeassemblies

Althoughexistingextrusionsystemswereabletoproduceawiderangeofgoodqualityaquaticfeeds(bothfloatingandsinking),smalldiameterpelletsizesweredifficulttoproduceat reasonable or cost-effective throughputs.Recent innovations in the basic hardwarecomponentspermitsmallerdiameterfeedsatattractiveproductionthroughputs.

Feed delivery systemHoppers or bins are an integral part of

a feeding device and are used to hold thedryingredientsabovethefeeders.Thefeed

delivery system must be able to uniformlyfeedbothadryand/orliquidingredientorablendofingredients.

Generally,whentheaddedfatcontentofarawformulationexceeds12percent,thepor-tionof fatabove the12 percentlevel shouldbe introduced into the extrusion system ina separate ingredient stream. The dry feedportionisdeliveredtotheextrusionsystemthroughaspecialisedmeteringdevicecapableof providing uniform flow at any desiredextrusionrate.

Dryingredientsareusuallyfreeflowing,andthereareanumberofcapablefeedingdevices which vary in their relative costand complexity. However, gravimetric orloss-in-weightsystemsarenecessaryforthestable,precisemeteringofdryfeedforthe

productionofmicro-aquaticfeeds.Therawrecipe is very finely ground or pulverizedanddoesnotpossessgoodflowproperties.The feed system must be able to handlethese fine ly ground formulations and avoidbridging and non-uniform metering of thefeed.

Automated feed delivery systems withPLCcontrolarethenorm.Slurrytanksand

liquidfeedingdevices(pumps)areutilizedtoaccomplishuniformmeteringofliquidingre-dients. The slurry tanks are often jacketedforheatingorcookingandareequippedwithagitators as required. Positive displacementmetering pumps deliver metered liquids atconstantratesbyvaryinglengthofstrokeorspeedof rotation.Slurries orliquids canbepremixedwithdryingredientsbutareprefer-ablyinjectedintopreconditioningdevicesorthe extruder barrel. The nutrient profile oflarvalfeedsiscriticalandtheprecisemeteringensurescorrectformulations.

PreconditioningThe dry portion of the feed and the

liquidportionareseparatelyintroducedintoa preconditioning device where they arecontinuouslymixed,heated,andmoisturisedbytheinjectionofhotwaterand/orsteam.Theintensemixingofwaterandsteamaddedtothe dryfeed andthe abilityto extendtheretention time during the preconditioningphaseallowsthemoistureleveltobemain-tainedatanoptimum.

Thisabilitytomaintainoptimummoisturedistributionnotonlyinitiatespropercookingbut alsois reportedas asignificantfactorinthe reduction of extruder barrel wear andextruder shaft power per ton of productprocessed.Thehighermixingintensityofnew

Extrusion technology for theproduction of micro-aquatic

feeds and shrimp feeds

by Mian N. Riaz, Ph.D, Head of Extrusion Technology Program,Food Protein R&D Center, Texas A&M University, USA

Image courtesy of Wenger

Manufacturing, USA


FEATURE


23/56

preconditioner designs improves hydrationandcooking,helpingtocapturethesteamin

the raw material. Excess steam can escapethe preconditioner and create fugitive dustwhichcreateshousekeepingconcernsintheplantenvironments.

Bettercookingwithnewprecondition-ers gives lower product viscosities which

improves extrudate flow through smalldie orifices. The result is smaller pelletsandmoreuniformpelletsize.Thehighermixing intensities in new preconditionerdesigns is the result of unique beaterdesigns and more beater contacts perretentiontime.

ExtrusionExtrudersaregenerallyclassifiedaseitherbeingasingleortwin-screwdesign.Inbothdesigns,theimpactoffinalproductcharacteristicsareaffectedbyscrewandbarrelprofile,screwspeed,process-ingconditions(temperature, moisture,etc.), rawmaterialcharacteristics,anddie/knifeselection.

Thefeedingzoneoftheextruderisthatareawherethelow-densitydiscreteparticlesof raw material are transported into theextruderbarrel inlet. This low-density, oftenpreconditioned, material is then transportedintotheinterioroftheextrusionprocessing

chamber. The flow channel of the screw istypically not filled in this zone due to theair entrapped in the incoming material. Theincomingmaterialiscompressedslightlyinthiszonewiththeairbeingexpelled.

Water, an excellent plasticizer, is typicallyinjected into the barrel in the feeding zoneto facilitate textural development, viscositydevelopment,andtoenhanceconductiveheattransfer. The kneading zone of the cookingextruder continues the compression startedinthefeedingzone,andtheflowchannelsof

theextruderscrewhaveahigherdegreeoffill.Asthedegreeofscrewfillincreasesandpressure begins to develop in the extruderbarrel, leakage flow (flow over the outsidediameterofthescrewinadirectiontowardthe extruder inlet) and pressure flow both

increase. The mechanismof sheardoes notbegintoplayadominantroleuntilthescrewflow channel is full. This full flow channelconditionbeginsinthekneadingzone.

The flow channel fil ls, first, with loosegranular material which is compressed andworked by shear as it passes through thekneading zone. It is in the kneading zone

wherethediscreteparticlesofmaterialbegintoagglomeratebecauseof theirtemperatureincrease resulting from conduction, directsteam injection, and viscous energy dissipa-tion.Here,thediscreteparticlesbegintoformamoreintegralflowingdoughmass.

At the dischargeend of the knead-ingzone,theextru-date most typicallyreaches its maxi-mum compaction.The shear in thisareaoftheextruderbarrel is moderateand the extrudatetemperature beginsto increase. Thefinal cooking zoneis that area whereamorphousizing and

texturis ing occur.Temperature andpressure typical lyincrease most rap-idly in this regionas shear rates arehighest because ofthe extruder screwconfiguration andmaximum compres-sion of the extru-date. The pressure,

temperature, andresultingfluidviscos-ityaresuchthattheextrudatewill expelfrom the extruderdie to form the

desired final product texture, density, color,andfunctionalproperties.

Twin-screw systems are preferred forextrusion of aquatic feeds smaller than 2mmdiameterduetotheirpositivetransportandself-wipingcharacteristicswhichpreventssignificant product build-up in the extruderbarrelwhichcouldlaterdislodgeandplugthe

smalldieorifices.TheCTXsystemisaco-rotatingsystemthatincludesataperedscrewdiameterwhichde-aeratestheextrudateandmakesiteasiertocreatehighdensityfeedsforgoodsinkingcharacteristicswithouttheneedforventedbarrels,pressurizeddensitycontrol

Image courtesy of Wenger Manufacturing, USA


FEATURE


24/56

devices,ordoubleextrusion.ByaddingaBPV(BackPressureValve)aftertheextruder,thenecessary restriction is provided to expand

theproductif floatingpelletsaredesired.

Die assembliesThedieisthemostcriticalpartofthe

complete system as it determines prod-uct shape and size, but also determinesthroughputs and buoyancy properties of

the fina l aquatic feed. As pellet diametersbecame smaller , the die created morerestrictionanddrasticallyreducedthrough-puts.

One die assembly design that allowedan increasein throughputs byincreasing die

openareais the OTD (ObliqueTubeDie).Thisdieactuallyincreaseddieopenarea(thenumber of orifices) by two to three timeswhichmaintainedhighthroughputsevenforsmalldiameterproductsduetolargerdieholepopulations.Thetubescreatedlongerreten-

tion times for improved cooking. Pressuredropinthetubescreatedadenserproductsothatmicro-aquaticfeedscouldbecookedthoroughly but still maintain high densitiesfor sinking characteristics. The process wasstill a short time/high temperature process,

which mini-mised nutrientdestruction.Floating prod-ucts are pos-sible by simplydecreasing dieopenarea.

Processguidelines

Processguidelinesrequiredfordieholes smallerthan 1.2 mmdiameter:1) Recipe tocontain ade-quate starchlevelsforbind-ing (at least

25%starchforfloatingfeeds).

2) Maximum particle size of the recipemustbesmallerthanonethirdthedieholesizes.

3) A spring-loaded knife blade isrecommended.

4) All massflow inputs must be free ofmaterial that is large enough to blockorpartiallyblockthedieopeningsandthis includes the steam, water, fat, andotherliquidinputs.Thewaterandsteam

linesgoingtotheextrudersystemneedto be fitted with screen filters having30mesh(0.6mm)openingsandtheseshould be adequate if maintained. Thefatline (and fat source) also needs tobefilteredtoremovedebrislargerthan

30mesh(0.6mm).Allstrainersor filters must beeasy to cleanortheywillgetremovedintheheatofarunwhereliquidflowsare interrupted due to pluggedfilters. It may be necessary tohaveadualfiltersetupforfish

solubles and fat lines. With thisinstallation,ifonefilterispluggedyoucanclosethevalvestotheprimary filter for cleaning andopen the valves for the secondforcontinuedoperation.

5)Thedryfeedmustpassthroughavibrat-ing sifter after the grinder and beforetheextruderlivebin.Thissiftermustbesizedtoremoveparticlesthesamesizeor larger than the die openings. Highfishmealdietsplugvibratingsifterscreens

veryeasilyandtheindustryoftenemploysrotarysifterstoavoidthisbottleneck.6) Pneumatic conveying is required from

the extruder die to the dryer inlet forseveralreasons:

a) For product containment around the

die/knifearea.Thesmalldiameterfeedsresults in spillage in this area and willcausesanitationproblems.

b) For product separation. Floating feedshave a tendency to stick togetherwhen wet on belt or HVH conveyorsand pneumatic conveying enhancesseparation.

c) For separation of tails from pellets.Pneumatic systems scrub the product

and remove tails for later separationduringsifting.

7) Fluid bed dryers are recommendedfor products under 1.2 mm diameterin size although horizontal dryers withpolyesterscreenscanworkwithsomeproducts.

8) Final product sifting after dryer andbeforecoating.Thissiftingoperationiscriticalforthreereasons:

a) To remove overs ( large tai ls anddoubles)forregrind.

b) To remove fines for regrind. Thisprevents a mess during coating stepwhere the fines are also coated andcausebuildup.

c)Toseparategoodpelletsintoseveraldifferent diameters depending on theclient criteria for size. The expecta-tions from the industry will be fortight specs on pellet size and this caneasily be controlled at this point bysifting product and producing severaldifferent sizes at the same time andsetting the standard for the industry.Theprimary-sizedproductcanbesentonthroughthesystemforcoatingandintofinalproductbins.Thesecondarysizescaneitherbereworkedorsavedseparatelyintotebagsforcoatingandbagginglater.

9)Productionprocedures.Thissmalldiam-eterproduct requires a dedicatedline,strictstartupandshutdownproceduresto avoid die plugging, and thoroughcleanup techniques. The extruder andcoater areas should be considered as

wet areas for cleaning. The coatermayneedtobecleanedbetweeneachdifferent pel let size to avoid crosscontamination.

By following these guidelines and usingnewlyinnovativeextruderpartsmicro-aquaticfloating feed can be produced on a largescale basis. This micro-aquatic floating feedwillbethefoundationtostartfishfarmingoncommercialscaletofulfillthefishdemandintheworld.

More InforMatIon:


"This micro-aquatic floating

feed will be the foundation

to start fish farming on

commercial scale to fulfill the

fish demand in the world"


FEATURE

ImagecourtesyofWengerManufacturing,

USA


25/56Nvmb-Dcmb 2012 | INterNatIoNal AquAFeed | 23

FEATURE

AQUAGEST

Digestibility enhancers

AQUABITE

Attractants and palatabilityenhancers

APEXAQUA

Bio-active herbal extract

AQUASTIM

Immune-modulators

SANACORE

Natural growth promoters

NUTRI-BIND AQUA

Low inclusion binders

RESOLVING THE BOTTLENECKSIN AQUAFEEDthrough innovation and expertise

smart aqua additivesfor sustainable and cost-efficient aquafeed

www.nutriad.com

www.evonik.com/feed-additives | [email protected]

Your challenge is our passion.MetAMINO The superior methionine source for your aquafeed.


26/5624 | INterNatIoNal AquAFeed | Nvmb-Dcmb 2012

TheVelellaResearchProject,whichranfromsummer2011toFebruary2012,raisedfishthroughto

harvestsizeforthefirsttimeinUSFederalwaters.Kampachi(atropicalyellowtail)wereraisedina

singleunanchored,submersiblenetpentetheredtoamannedsailingvessel,inwaterupto12,000feet

deep.Thefinalharvestcompletedthegrow-outcycleofsashimi-gradekampachifishfromthedrifterpen

thathasbeenridingeddiesintheopenocean,threeto75milesoffshoreoftheBigIslandofHawaii.

Thisfinalharvestfarsurpassedourexpectations,saysNeilAnthonySims,Co-CEOofKampachiFarms.

Thefishthrivedintheresearchnetpenfarfromshore,withphenomenalgrowthratesandsuperbfish

healthandwithoutanynegativeimpactonwaterquality,theoceanfloor,wildfishormarinemammals.

Thekampachiwerefedasustainablecommercialdietthatreplacedasignificantamountoffishmealandfish

oilwithsoyandotheralternativeagriculturalproteins.Noantibiotics,hormonesorpesticideswereused

throughouttheseven-monthtrial.

Thekampachireachedanaverageof5.6lbsinsixmonths,resultinginafirstharvestafullthree

monthsaheadofscheduleandafinalFCRof1.6:1.

Simssaysthatfishhealthwassuperbthroughoutthetrial,withanoverallmortalityrateoftwopercent

comparedwithastandardaquaculturemortalityrateof15percent.Sampletestingshowedthat

thekampachihadafatcontentof33percent,makingthisanextraordinarilyhealthyfishforhuman

consumption,highinheart-healthyOmega-3swithnodiscerniblemercuryorothercontaminants.

Itmakesperfectsensetoraisefishintheocean,wheretheybelong,saysSims.Thiswasahealthy,low-stressenvironmentforthefish,andwethinkthatthisallowedthemtochanneltheirenergyintogrowingfaster.

ThemajorityofthesupportforthetrialcamefromtheIllinoisSoybeanAssociation,whichprovided

fundingfromtheIllinoisSoyCheckoffProgram.Theprojectgarneredadditionalsupportfromawidevarietyhoto courtesy of Rick Decker

TheVelellaResearchProjectPHotoSHoot


27/56Nvmb-Dcmb 2012 | INterNatIoNal AquAFeed | 25

ofstakeholders,includingNationalScienceFoundation,InternationalCopperAssociation,

Lockheed-Martin,OceanFarmsTechnologiesandNOAA.

ThesuccessoftheVelellaresearchdemonstratesthatwecangrowfishintheopenoceanwith

nonegativeimpactonpristineoceanecosystems,saysSims.Wemustnowapplyourselvesto

responsiblyscaleupthisindustry,tomeetthegrowingglobaldemandforhigh-qualityseafood.

Thenextphaseoftheresearchwilltestasingle-pointmooringsixmilesoffshoreinwater6,000

feetdeep,wherethepencanmovefreelyincurrentsandstillbewithineasyrangeofshorefor

supplydeliveryandtelecommunicationssupportforremotecommandandcontrol.Thisnext

iterationoftheresearchwilltestanunmannedVelellaonasinglepointmooringsixmilesoffshore.

Photos above text: Courtesy of Bryce Groark - Photos around text: Courtesy of Jeff Milisen


28/56

Selenium yeast is commonly used

in aquaculture to improve animalperformance and meat quality.

Samplesofdifferentselenisedyeast

products were sourced in the EU and

USA.QAdepartmentsofTrouwNutrition

Internat ional and Selko

Feed Additives performed

a laboratory analysis on

these. Outcomes revealed

remarkable d if ferences

between product samples

on most effective and

active compound, namelyselenomethionine(SeMet).

Selenium is one of theessential trace elements inaquaculture.Itcanbeaddedto aquafeed in two forms;as inorganic selenite or asorganic selenium yeast. Eachform has different metabolicroutesandeffects.

Organicselenium-selenisedyeast-isregardedasamore

effectivewayofsupplementingselenium.Withmorefrequentusage of selenised yeast andincreasingamountofsuppliers,benchmarking on quali tybecomes relevant. Selenisedyeast mainly consists ofselenomethionine (SeMet),which can be convertedinto selenocysteine (SeCys)by natural turnover frommethionine into cysteine.

SeMet is regarded by animalsas normal methionine andabsorbed and processedfol lowing the methioninepathway. The SeMet willbe stored as methionine in

proteinsandsubsequently,tissuessuchasfillet

ororgans will be enriched with the selenium.Thisseleniumiseasilyavailablewhenrequiredfor the synthesis of selenoproteins (Figure 1).Thissavesvaluabletimeandensuresafastandeffectivereactionincaseofstressoradisease.

Benchmark

Several samples of selenised yeast weresourced from the market and analysedfor the most relevant selenium species atthe University of Pau, CNRS, France. Thisresearch lab is known as professional and

repeatable for organic seleniumspeciesdetermination.

Thevalueofselenisedyeastwas determined by the levelsoftotalselenium,SeMet,SeCysandinorganic selenium. A totalof 11 samples from different

batches of a number of pro-ducerswereexamined.Sampleswere randomly numbered andsent to the lab for analysesby HPLC ICP-MS. Results areshowninTable1.Mostinterest-ing is the variation in levels ofSeMet.Somesamplescontainedonly half the level of SeMetcompared to other samples(range from 24.8% to 69.7%).SeCys levels are, as expected,marginally present at all equal

levels. Unexpectedly, Sample 6containedarelativehighlevelofinorganicselenium(13.3%).

Need ofselenomethionine

Yeastisenrichedwithseleni-umthroughgrowingitinamedi-um with a controlled amountof selenium and a shortage ofsulphur. If the yeast grows, itmustsynthesisemethioninewith

selenium incorporated; SeMet.ThehighertheSeMetlevels,themorebeneficialtheyeastwillbeas an organic selenium sourceforaquaspecies.

It is widely accepted in

Why check selenomethioninelevels in selenium yeast?

by Wilbert Litjens, Technical manager Optimin & Betaine and Paul Perucchietti, Product manager Optimin, Selko Feed Additives,The Netherlands

table 1:

Sample otalSelenium SeMet SeCys InorganicSelenium

ppmppm as

Se% of

total Seppm as

Se% of

total Se% of total

Se

1 3000 2090 69.7 140 4.6 < 2%

2 2260 1460 64.6 100 4.4 < 2%

3 2250 1110 49.1 70 3.3 < 2%

4 1910 920 48.3 190 9.7 < 2%

5 1890 1160 61.2 670 3.5 < 2%

6 1990 490 24.8 < 10 - 13.3%

7 2217 1069 48.2 51 2.3 < 2%8 2377 1278 53.8 87 3.7 < 2%

9 2191 1092 49.8 59 2.7 < 2%

10 2027 854 42.1 49 2.4 < 2%

11 2239 1275 57.0 81 3.6 < 2%


FEATURE


29/56

scientific literature that SeMet is the mosteffective and active compound in selenisedyeastbringingbeneficialeffectstoorganism.ThepercentageofSeMetoftotalSeisthebestindicatorforthevalueandbioavailabilityoftheseleniumoutoftheyeast.

Theanalysisofthemainorganicseleniummetabolites (SeCys and SeMet) in relationto the total selenium level gives a strongevaluationonthesuccessoftheenrichmentprocess during production. Most selenisedyeastproductscontain97-99percentorganicseleniumoftotalselenium.

ThedominantorganicseleniumformisSeMet,whichcanbeaccurately(

november december international aquafeed full edition

Documents