September | October 2012

Gustor Aqua and Ecobiol Aqua: enhancing digestion in a different manner

The International magazine for the aquaculture feed industry

International Aquafeed is published five 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

The digestive system of fish andshrimp is sensitive and responsiveto a number of stressing factorsthatfrequentlyoccurandarecause

of disease and poor performance. In ordertolessenthenegativeimpactsofthoseandachieve sustainable, safe, and cost-efficientaquaculture production, nutritionists mustfocus not only on nutritional specificationsbut also on promoting digestive health. Insuch task, probiotics and organic acid saltshavearousedasnaturalsolutionsthatresultinimprovedhealthstatus,nutrientutilization,andconsequentlyperformance.

Inbothindustrialisedanddevelopingcoun-tries,nutritionplaysacritical role in thesus-taineddevelopmentofaquaculture,thuspar-ticularemphasisisbeingplacedonnutritionalstrategiesandtheireffectonhealth,perform-ance, and environmental integrity. While afirst nutritional approach is the increasinglyaccessible information on nutrient require-ments as well as on the more effective useof alternative and available ingredients, asecond approach is supplementation withnaturalgrowthpromoters(NGPs).NGPsnotonly providebenefits in termsof health andperformance but also do not bear any risk

regarding bacterial resistance or undesiredresiduesintheedibleproduct.

Itismoreandmorecommonbynutrition-ists to includeNGPs asorganic acid saltsorprobioticsintheaquafeedformula.Intheaimof optimising health and growth, both arecharacterized by the resultant enhancementofnutrientutilization,whichisinturnachievedbydifferentmechanismsofaction.

Gustor Aqua- an organic acid saltGustor Aqua contains sodium butyrate,

which has been proposed as candidatereplacement for antibiotics. Although theconsistency of the effects on performanceachievedbyantibiotics isdifficult toemulate,sodiumbutyrateprovidesantimicrobialactiv-itybesidesotherkeybenefitsthatgobeyondof those provided by antibiotics, such asenhanced development of intestinal epithe-liumand intestinalbarrier integrityaswell asanti-inflammatoryproperties.

Once in the gastrointestinal tract, sodiumbutyrate dissociates into butyric, which isstrongly lipophilic and capable to diffuseacross themembraneof gramnegativebac-teria (Gálfi and Bokori 1990), leading to adisruptionofthemetabolicprocessesandtheconsequent bacterial death. The subsequentreductioninthebutyricacidintolerantmicro-organismscontributestoadiminishedriskofsubclinical infectionsandnutrientdemandbythe gut-associated immune system, resultinginenhancedhealthstatus, lessnutrientcom-petition,andconsequentlybetterefficiencyintermsofnutrientutilisation.

Thestimulatoryeffectofbutyrateonintes-tinalepitheliumdevelopmenthasbeendem-onstratedinbothin vivo andin vitroconditions,

Gustor Aqua and Ecobiol Aqua: enhancing digestion in a different manner

by Waldo G. Nuez-Ortín (DVM, MSc) and Jorge Zarate Domínguez (Eng), Norel S.A, Spain

table 1: effect of dietary supplementation of GUStor aqua on performance parameters of catfish (P. hypohthalmus)

Initial weight (g) Weight gain (g) SGr (% day) FCr Per

Control 6.90a 37.56a 3.34a 1.65a 1.34a

GUStor aqua 6.75a 50.68b 4.32b 1.32b 1.81b

Gustor Aqua dosed at 0.5 kg/ton feed

Means with different superscripts in the same column are significantly different (P<0.05) SGR: Specific growth rate / FCR: Feed conversion ratio / PER: Protein efficiency ratio

table 2: effect of dietary supplementation of GUStor aqua (protected) on digestibility and performance parameters of shrimp (P. monodon)

DMd (%) CPd (%) ed (%) Weigh gain (g) Survival (%) FCr

Control 64.90a 85.20a 78.10a 13.67 90 3.43GUStor aqua 72.46a 89.11b 83.26b 4.01 93 3.29

Gustor Aqua dosed at 1 kg/ton feed

Means with different superscripts in the same column are significantly different (P<0.05)

DMd: Dry matter digestibility / CPd: Crude protein digestibility / Ed: energy digestibility / FCR: Feed conversion ratio

Coefficients of digestibility were determined by the use of chromic oxide as an inert marker

14 | InternatIOnal AquAFeed | September-October 2012

FEATURE

September-October 2012 | InternatIOnal AquAFeed | 15

elucidating greater epithelial cell proliferationwith the administration of sodium butyratewhen compared to other salts as sodiumacetate and sodium propionate (Sakata andTamata1978a,1979;Sakata1987).

In a study conducted in broilers, dietarysupplementation of 0.05% sodium butyrate(92%) significantly increased the length(+35.5%) and width (+ 55.7%) ofvilli at 21 and 42days, respectively(Mallo et al. 2011). As a result ofimprovedvillidevelopment,absorp-tive surface area is enlarged, lead-ing to better feed utilisation andenhanced animal health status andperformance.

Gustor Aqua has also gainedinterest due to increasing use ofplant-based diets. Several investiga-tions have reported soya-inducedenteritis in salmonids (Baeverfjordand Krogdahl 1996; Knudsen et al.2008; Krogdahl et al. 2003) andcommon carp (Urán et al. 2008).This observation has led special-ists to not include more than 5-15 percentof soya in salmon diets in order to prevententeritis.

Whencopingwiththissituation,sodiumbutyrate arises as a tool to prevent thedevelopmentofsoya-inducedenteritisandallow for a more convenient formulation

ofcommercialfeed.Thissolutionisattrib-uted to the anti-inflammatory propertiesofsodiumbutyrate,whosemodeofactionis by modification of transcription factors(NF-kB) that control the expression ofinflammatory response genes (Hamer et al.2008,LeGallet al.2009).Theresult isahealthy absorptive surface areaensuring

optimal absorption of important nutrientsaswater,mineralsorfattyacids.

In a experiment conducted with catfish(Pangasius hypohthalmus), a dietwas supple-mentedwith0.5KgGustorAqua/tonoffeedand fed twice daily during 56 days. Results(Table 1) showed significant improvements

in weight gain (+35%), specific growth rate(SGR) (+30%), feed conversion ratio (FCR)(-16%) and protein efficiency ratio (PER)(+35%) relative to the non-supplementeddiet. In a second experiment with shrimp(Penaeus monodon),adietwassupplementedwith1kgofGustorAqua/tonoffeedandfedduringtwomonths.AsshowninTable2,the

supplementationofsodiumbutyratesignificantly enhanceddigestibilityofdry matter (DMd) (+12%), crudeprotein (CPd) (+5%) and energy(Ed) (+7%), leading to numericalimprovements in weight gain, sur-vivalandFCR. Inbothexperiments,the observed positive results canbe attributed to the abovemen-tioned modes of action describedforsodiumbutyrate.

Ecobiol Aqua- a probioticEcobiolAquacontains sporesof

Bacillus amyloliquefaciens.Thissporu-latedformgatherstheessentialandfavourablepropertiesforapotential

probiont listedby several authors (Farzanfar,2006; Gómez and Balcazar, 2008; Merrifieldet al. 2010; Vine et al. 2006).Among them;viability under normal storage conditions,acceptable survival under processing condi-tions, being non-pathogenic and resistant tobile salts and low pH, fast growth at host

Figure 1. Biomass of L. vannamei after Ecobiol Aqua supplementation

14 | InternatIOnal AquAFeed | September-October 2012 September-October 2012 | InternatIOnal AquAFeed | 15

FEATURE

AQUAGEST®

Digestibility enhancers

AQUABITE®

Attractants and palatability enhancers

APEX® AQUA Bio-active herbal extract

AQUASTIM®

Immune-modulators

SANACORE®

Natural growth promoters

NUTRI-BIND AQUA Low inclusion binders

RESOLVING THE BOTTLENECKS IN AQUAFEED through innovation and expertise

smart aqua additives for sustainable and cost-effi cient aquafeed

www.nutriad.com

NAD0031_AD_Aqua_190x132_W2.indd 1 17-02-12 09:59

rearing temperature, antagonistic propertiesagainst key pathogens, and capacity to pro-duceextracellularenzymesthatimprovefeedutilisation.

It is the combination of different modesof action what leads to host benefit whenEcobiol aqua is supplemented. B. amylolique-faciens is capable to secrete lactic acid andbarnase.Whiletheformerwillreducepatho-genic bacteria andwill be usedby beneficialbacteria such as Lactobacillus as substrate togrow,thelaterisapotentbacteriocine.Asaresult,theantimicrobialpropertiesofEcobiolAquahavebeendemonstratedagainstpatho-

gensaffectingbothcoldandwarmwateraquaticspeciessuchasAeromonas hydrophi-la, Aeromonas salmonicida,Yersinia ruckeri and Vibrio parahameolyticus (Nuez-Ortín2011).Thisinhibitoryactivity promotes optimalgut flora balance, which inturn results in less nutri-ent competition, enhanceddiseaseresistance,healthierabsorptive surface area,and consequently betternutrientutilization.

It is also known thatprobiotic bacteria canrelease extracel lularenzymes that help in thedigestion process. Thisabilitywas investigated ina recent study, in whicha total of 96 shrimp(Litopenaeus vannamei)with an average weightof 0.85 g were placed in12 aquariums and fed tosatietywith twodifferenttreatments (6 replicates/treatment); 1) unalteredcommercial shrimp feed(35% CP), and 2) com-mercialshrimpcontainingEcobiol Aqua at 2 kg/ton feed. Final biomass

was calculated as the sum of the indi-vidual weights of animals allocated ineachtreatment.AsshowninFigure1,thedifference in final biomass was numeri-cally higher until day 40, however, thisdifference became significant after day50. As the experiment was conductedin controlled conditions with absence ofpathogens, the most likely explanationforthisimprovementcanbefoundintheextracellular enzyme secretion capacityof the vegetative form of Bacillus amy-loliquefaciens. In order to investigate onthis assumption, a total of 6 shrimp per

treatment with an average weight of 6 gwere selected and fasted for 12 hours.Hepatopancreas were excised and theactivity of lipase, protease, and amylase

was analysed according to Hernández(1993), Versaw and Coupett (1989) andVega-Villsante et al. (1999), respectively.Results(Figure2)showedincreasedenzy-maticactivityinhepatopancreasafterfeedintake, suggesting enhanced digestibilityand consequently better final biomass.Secretionofamylases,cellulasesandxyla-nases has also been reported forBacillus amyloliquefaciens(Cortyl,2010).

ConclusionNutritionists must pay special focus

not only to nutritional specifications butalso to maximise nutrient utilisation. It istherefore that supplementationwithNGPssuchasorganicacid saltsorprobioticshasarousedasanaturalalternativetodevelopasuccessfulnutritionalprogram.Bydifferentmodes of action, supplementation of bothGustorAquaandEcobiolAquawill leadtothe enhanced gut efficiency to digest feed.Factorssuchastargetedspecies,methodol-ogy for use, or processing conditions, willdetermine the inclusion of one or theother,ortheircombination,intheaquafeedformula. ■

References

Availableuponrequest

Figure 2. Lipase (a), protease (b), and amylase (c) activity in hepatopancreas of L. vannamei

"Nutritionists must pay special

focus not only to nutritional

specifications but also to

maximise nutrient utilisation"

16 | InternatIOnal AquAFeed | September-October 2012

FEATURE

Extruder OEE for the Production of Fish FeedExtruder OEE for the Production of Fish Feed

AMANDUS KAHL GmbH & Co. KG, Dieselstrasse 5-9, D-21465 Reinbek / Hamburg, Phone: +49 40 727 71 0, Fax: +49 40 727 71 100

info@amandus-kahl-group.de, www.akahl.de

16 | InternatIOnal AquAFeed | September-October 2012

www.aquafeed.co.uk

LINKS

• Seethefullissue• VisittheInternationalAquafeedwebsite

• ContacttheInternationalAquafeedTeam

• SubscribetoInternationalAquafeed

Volume 15 I s sue 5 2 012

the international magazine for the aquaculture feed industry

The use of algae in fish feeds as alternatives to fishmeal

Gustor Aqua and Ecobiol Aqua:– enhancing digestion in a different manner

Fishmeal & fish oil– and its role in sustainable

aquaculture

Options and challenges of alternative protein and energy

resources for aquafeed

EXPERT TOPIC– Shrimp

Thisdigitalre-printispartoftheSeptember|October2012editionofInternationalAquafeedmagazine.Contentfromthemagazineisavailabletoviewfree-of-charge,bothasafullonlinemagazineonourwebsite,andasanarchiveofindividualfeaturesonthedocstocwebsite.Pleaseclickheretoviewourotherpublicationsonwww.docstoc.com.

Topurchaseapapercopyofthemagazine,ortosubscribetothepapereditionpleasecontactourCirculationandSubscriptionsManageronthelinkabove.

INFORMATIONFORADVERTISERS-CLICKHERE