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SOYBEAN MEAL AND FULL FAT SOYBEAN IN ANIMAL FEED

Application in animal feed

It is critical to establish the market demand for soybean meal derived from variousprocesses before investing in capital to process soybeans. Furthermore, the economicviability of manufacturing various types of soybean meal compared to high proteindehulled solvent extracted soybean meal (preferred source for poultry and pigs) shouldbe considered.

Soybeans need to be subjected to some form of heat treatment or their nutritive value isvery low. Raw full fat soybeans may adversely influence animal health if fed as a resultof containing biological compounds with an anti-nutritive action.

Soybean processors around the world produce several types of soybean products, themajority of which is soybean meal after oil extraction. The degree of oil extracted andthe level of hulls removed from the beans, result in the different chemical andnutritional composition of the meals.

Soybeans contain 33 to 40% protein and 16 to 20% oil versus 42 to 48% protein and0.8 to 6% oil in soybean meal. Full fat soya retains the nutrient content of the soybeanconcentrated marginally by the reduced moisture content in full fat soya whencompared to soybeans. The usage of full fat soy is therefore dependent on the relevantprices of soybean meal and supplemental fats.

Table 1 Chemical composition of several types of soybean meals and full fat soya

Soybean Meal TypeDry Matter

%Crude

Protein %Ether Extract

%Crude Fibre

%

Expeller* 90 43 4.0 6

Solvent extracted** 90 44 1.0 7

Dehulled solventextracted***

90 48 1.0 3

Full Fat**** 90 36 18 6

*Expeller: In this method, soybeans are initially cleaned, cracked, and dried. The dried soybeans are then transported to temperingdevices and heated uniformly. From the tempering bins, the soybeans are fed into expeller presses. A central revolving shaft createspressure within the press, causing the extraction of oil from the ground soybeans. The oilcake product may still contain 6-8% oil.

**Solvent extracted: In this method, soybeans are first cracked, then heated to approximately 60 degrees Celsius for about 10 minutes.After the cracked beans are heated, they proceed through a series of grinding rollers where they are flaked. The flakes are allowed tocool to about 45 degrees Celsius and are then conveyed to the extraction equipment where the oil is removed by the solvent (hexane) inone of several countercurrent extraction systems.The extracted flakes then proceed to dryers where the solvent is volatilized. From the dryer, the flakes are conveyed to a toaster and,finally, are cooled and ground. At that time, the meal is typically 45% protein.

***Dehulled solvent extracted: In this method, soybeans are first cracked and de-hulled, before solvent extraction.

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****Full fat: In this method, soybeans are fed into an extruder barrel, where a central revolving shaft forces the beans through theextruder. This technique creates sufficient heat through friction to destroy the trypsin-inhibiting enzymes. No oil is removed from thesoybeans during extrusion. Rather, beans are processed into meal through pressure and heat of friction.

Soybean meal is the primary source of protein and amino acids for poultry and pig dietsglobally primarily as a result of amino acid digestibility of soybean meal being higherthan most oilseed meals. The low fibre content of dehulled soybean meal is also criticalin poultry and pig feeds. High levels of soybean meal of higher fibre level (6%) increaseswater consumption and nitrogen content of the litter, which may result in reducedperformance. Low fibre soybean meals are preferred for poultry rations. The higher thequality of the soybean meal the higher the inclusion level that is possible in feed.

The competitive advantage of soybean meal derived from a superior amino acid profileand digestibility is of much less importance in ruminant diets, consequently othersources of protein such as cottonseed meal are often used in place of soybean meal dueto their lower price. Recently imposed restrictions on the use of animal products inruminant feeds has significantly increased the use of soybean products such as soybeanmeal and whole heat treated soybeans in dairy and beef feeds. Soybean meal is anexcellent source of protein for dairy and beef cattle but is limited by its high costrelative to other sources of protein.

The use of soybean meal in pet foods has increased, as research has yielded somemethods of dealing with limitations as a result of indigestible carbohydrates.

Considering the ideal amino acid profile for pigs, it is obvious that soybean meal cancontribute significantly to pig diets. Removal of some trypsin inhibitors improves pigfeeds significantly when compared to feeding raw soybeans.

Soya fibre can be well utilised by pigs as an energy source. Soybean meal can be wellutilised by all groups of pigs and all pig diets can be produced with soybean meal as theprimary protein supplement.

Processing

Processing conditions have a major effect on the nutritional value of soybeans. Soybeanmeals are an excellent source of protein, while full fat soy provides an excellent sourceof energy as seen in Table 2.

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Table 2 Average true metabolizable energy (TME) content of soybean meals and full fatsoybeans (dry matter)

Soybean type TME (MJ/kg)

Expeller de-hulled 13.54

Solvent extracted de-hulled 14.07

Full fat soya 17.27

Processing methods of soybeans to produce full fat have a profound effect on the energyvalue of the product that is produced, as seen in Table 3, and the amino acid digestibilityas reflected in Table 4.

Table 3 Influence of treatment on the apparent metabolizable energy (AME) offull fat soybeans for chicks

Procedure AME (MJ/kg)

Extrusion 17.9

Dry 17.4

Wet 17.3

Micronized 15.5

Roasting 15.8

Raw Soybeans 13.5

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Table 4 Effect of processing method on the nutritional value of full fat soybean (ffs)

FFS processingmethod

TME:GE* (%)Digestibility (%)

methionineDigestibility(%) cystine

Digestibility(%) lysine

Dry heat (1) 61.8 71.6 68.6 78.0

Steam heat 71.3 87.8 78.9 86.3

Extrusion 75.0 92.6 86.0 92.2

Dry heat (2) 72.4 - - -

(1) Over-processed ; (2) Well processed *Ratio of Total metabolizable energy to Gross energy

The use of laboratory tests can be utilised to control the quality of soybean processing.

Practical application of soybean meal and full fat soya

In South Africa the majority of soybean meal is used in poultry and pig feeds whilelimited quantities are utilised in ruminant, pet foods and other feeds. High protein andlow fibre soybean meal is the source of choice, while full fat soya when correctly pricedcan fulfil a role as a protein and energy source. Expeller soybean meal and low proteinsoybean meal have limited application in the industry due to constraints in the numberof types of soybean products that can be used in a feed manufacturing facility (limitedholding bins), as well as their price relative to nutrient contribution. High fibre soybeanmeals such as expeller meal have limited inclusion levels.

The majority of large to medium size feed mills have established their own full fatprocessing capacity or contracted full fat processing with established manufacturersresulting in a limited market for independent full fat producers.

Conclusion

The majority of soybean meal required is for poultry and pig feeds where low fibre andhigh protein is critical. This meal can only be produced in large sophisticated solventextraction crushing facilities that require significant capital (currently estimated R100million, dependant on size). Given the high oil extraction % and large contribution ofincome from oil sold for human consumption solvent extracted soybean mealproduction is the most efficient.

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Full fat soya has limited application for niche markets and is ideal for companies andfarms producing animal feed in an integrated process.

Expeller soybean meal currently has very limited utilization by the formal feed industryand should be considered mainly for on farm usage or the smaller informal feed market.The economic returns of this product given the lower extraction of high value oil andlack of premium received for higher energy content is significantly lower than solventextracted soybean meal.

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GEBRUIK VAN SOJABOONMEEL EN VOLVETSOJABONE VIRDIEREVOER

Toepassing vir dierevoer

Dit is van kritieke belang om die vraag in die mark te bepaal vir sojaboonmeel watverkry word volgens onderskeie prosesse, voordat kapitaal belê word om sojabone teverwerk. Verder moet die ekonomiese lewensvatbaarheid van die vervaardiging vanverskillende soorte sojaboonmeel, vergeleke met hoëproteïen-ontdopte vloeistof-ekstraksiesojaboonmeel (voorkeurbron vir pluimvee en varke) oorweeg word.

Die voedingswaarde van sojabone word nadelig beïnvloed, indien dit nie een of andertipe hittebehandeling ondergaan nie. Rou volvetsojabone kan nadelig wees vir diere segesondheid as dit gebruik word vir voer, omdat dit biologiese samestellings metteenvoedingswerking bevat.

Oral ter wêreld produseer sojaboonprosesseerders verskillende soortesojaboonprodukte, maar meestal sojaboonmeel, nadat olie onttrek is uit die sojabone.Die hoeveelheid olie wat onttrek word en die hoeveelheid doppe wat verwyder word,lei tot verskillende chemiese en voedingkundige samestellings van die meel.

Sojabone bevat 33% tot 40% proteïen en 16% tot 20% olie, vergeleke metsojaboonmeel, wat 42% tot 48% proteïen en 0.8% tot 6% olie kan bevat, afhangendevan die hoeveelheid olie en doppe wat verwyder is. Volvetsoja behou dievoedingkundige inhoud van die sojabone, behalwe dat dit marginaal meergekonsentreerd is, as gevolg van die laer voginhoud. Die gebruik van volvetsoja hangdus af van die relatiewe pryse van sojaboonmeel en aanvullende vette.

Tabel 1 Chemiese samestelling van verskillende soorte sojaboonmeel en volvetsoja

Soort sojaboonmeelDroë materiaal

%Ru-proteïen

%Eter-ekstrak

%Ru-vesel

%

Gepersde (expeller) * 90 43 4.0 6

Vloeistof-ekstraksie ** 90 44 1.0 7

Ontdopping en vloeistof-ekstraksie ***

90 48 1.0 3

Volvet **** 90 36 18 6

* Gepersde (expeller): Volgens hierdie metode word die sojabone skoongemaak, gekraak en gedroog. Die gedroogde sojabone word dan egalig verhit,waarna die bone onder hoë druk meganies uitgepers word, in ‘n sentrale draaiskag. Die oliekoek kan nog 6-8% olie bevat.

**Vloeistof-ekstraksie (solvent extraction): Volgens hierdie metode word die sojabone gekraak, waarna dit verhit word tot nagenoeg 60 grade Celcius virongeveer 10 minute. Hierna word die sojabone gevoer deur ‘n reeks maalrollers, waar die bone gevlok word. Die vlokkies word afgekoel tot nagenoeg 45grade Celcius, en word dan gevoer na ekstraksietoerusting, waar die olie onttrek word deur vloeistof (heksaan) in een van verskeieteenstroomekstraksiestelsels. Die vlokkies word hierna na droërs gevoer, waar heksaanverdamping plaasvind, waarna die vlokkies gerooster word. Diéoliekoek bevat tipies 45% proteïen.

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***Ontdopping met vloeistof-ekstraksie: In hierdie geval word sojabone gekraak en ontdop en word die olie deur vloeistofekstraksie verwyder. Ontdoptesojabone verseker oliekoek met ‘n laer veselinhoud en ‘n hoër proteïeninhoud.

****Volvet: Volgens hierdie metode word sojabone in ‘n ekstruheerderbuis (extruder) gevoer, waar ‘n sentrale draaiskag die bone deur dieekstruheerderbuis forseer. Die wrywingsproses skep voldoende hitte om tripsien-inhiberende ensieme te vernietig. Geen olie word onttrek in die proses nie.Die bone word dus geprosesseer deur druk en hitte, veroorsaak deur wrywing.

Sojaboonmeel is ‘n belangrike proteïen- en aminosuurbron in pluimvee- envarkrantsoene, hoofsaaklik weens die hoë verteerbaarheid van aminosure insojaboonmeel teenoor ander oliesaadmeel. Die lae veselinhoud van ontdoptesojaboonmeel is ook van groot belang vir pluimvee- en varkvoere. Hoë vlakke vansojaboonmeel met ‘n hoër veselvlak (6%) veroorsaak verhoogde waterinname enstikstofinhoud van die werpsel, wat swakker prestasie tot gevolg mag hê. Laevesel-sojaboonmeel word verkies in pluimveerantsoene. Hoe hoër die gehalte van diesojaboonmeel, hoe hoër die moontlike insluitingsvlak vir voer.

Die mededingende voordeel van sojaboonmeel wat verkry word van ’n bogemiddeldeaminosuurprofiel en verteerbaarheid, is van minder belang vir herkouerdiëte engevolglik word ander bronne van proteïen soos katoensaadmeel dikwels gebruik inplaas van sojaboonmeel, omdat dit goedkoper is. Beperkings wat onlangs ingestel is opdie gebruik van produkte van dierlike oorsprong in voer vir herkouers, het die gebruikvan sojaboonprodukte, soos sojaboonmeel en hittebehandelde sojabone vir melk- envleisbeesvoer aansienlik laat toeneem. Sojaboonmeel is ’n uitstekende bron vanproteïen vir melk- en vleisbeeste, maar word beperk weens die hoë koste daarvan,vergeleke met ander bronne van proteïen.

Die gebruik van sojaboonmeel in troeteldierkos het toegeneem, omdat navorsing geleihet tot sekere metodes wat voorsiening maak vir beperkings weens onverteerbarekoolhidrate.

Wanneer die ideale aminosuurprofiel vir varke oorweeg word, is dit duidelik datsojaboonmeel ‘n aansienlike bydrae kan maak in varkrantsoene. Hittebehandeldesojabone, waar sekere tripsien-inhibeerders verwyder word deur hitte, is ‘n beter bronvan proteïene as rou sojabone in varkrantsoene.

Sojavesel kan goed benut word as bron van energie in varkvoer. Sojaboonmeel kan viralle groepe varke gebruik word, en alle varkrantsoene kan geproduseer word metsojaboonmeel as primêre proteïenbron.

Sojaboonmeel is ’n uitstekende bron van proteïen vir melk- en vleisbeeste, maar wordbeperk deur die hoë koste daarvan, vergeleke met ander proteïenbronne.

Prosessering

Prosessering het ’n groot invloed op die voedingswaarde van sojabone. Sojaboonmeel is’n uitstekende bron van proteïen, terwyl volvetsoja ook ’n uitstekende bron van energieis, soos geïllustreer deur Tabel 2.

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Tabel 2 Gemiddelde ware metaboliseerbare energie-inhoud (WME) van sojaboonmeelen volvetsojabone (droë materiaal)

Soort sojaboon WME (MJ/kg)

Gepersde (expeller) - ontdop 13.54

Vloeistof-ekstraksie 14.07

Volvetsoja 17.27

Prosesseringsmetodes van sojabone om volvetsojaboonmeel te produseer, het ’n baiegroot invloed op die energiewaarde van die produk, soos gesien kan word in Tabel 3 endie aminosuurverteerbaarheid, soos gesien kan word in Tabel 4.

Tabel 3 Invloed van behandeling op die klaarblyklike metaboliseerbare energie-inhoud(KME) van volvetsojabone vir pluimvee

Prosedure KME (MJ/kg)

Ekstraheerder (extrusion) 17.9

Droog 17.4

Nat 17.3

Mikroniseer 15.5

Rooster 15.8

Rou sojabone 13.5

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Tabel 4 Invloed van verwerkingsmetode op die voedingswaarde van volvetsojabone (VVS)

VVS-verwerkings-metode WME:BE (%)

Verteerbaar-heid: (%)

metionien

Verteerbaar-heid: (%)

sistien

Verteerbaar-heid: (%)

lisien

Droë hitte (1) 61.8 71.6 68.6 78.0

Stoomhitte 71.3 87.8 78.9 86.3

Ekstraksie 75.0 92.6 86.0 92.2

Droë hitte (2) 72.4 - - -

(1) Oorverhit; (2) Korrek verhit *Ware metaboliseerbare energie tot Bruto-energie

Laboratoriumtoetse kan gebruik word om die kwaliteit van sojaboonverwerking tebepaal.

Praktiese toepassing van sojaboonmeel en volvetsoja

In Suid-Afrika word die meeste sojaboonmeel gebruik vir pluimvee- en varkvoere,terwyl beperkte hoeveelhede benut word vir herkouervoer, troeteldierkos en anderdierevoer. Hoëproteïen- en laevesel-sojaboonmeel is die voorkeurbron, terwylvolvetsoja teen die regte prys ’n rol kan speel as bron van proteïen en energie.Gepersde sojaboonmeel en laeproteïen-sojaboonmeel het beperkte toepassings in diebedryf, weens beperkings ten opsigte van die aantal sojaboonprodukte wat gebruik kanword by ’n voervervaardigingsfasiliteit (beperkte bergingsfasiliteite), asook die prysvergeleke met voedingswaarde. Hoëvesel-sojaboonmeel soos meganies-gepersde meelhet beperkte insluitingsmoontlikhede in pluimvee- en varkrantsoene.

Die meeste groot tot gemiddelde voermeulens het die vermoë om volvetsoja self teprosesseer, of kontrakteer volvetverwerking met gevestigde vervaardigers, wat lei tot’n beperkte mark vir onafhanklike volvetprodusente.

Gevolgtrekking

Die meeste sojaboonmeel word deur varke en pluimvee gebruik, waar lae vesel- en hoëproteïën-inhoud van kritieke belang is. Die meel kan egter slegs geproduseer word waargebruik gemaak word van moderne ekstraksie- en persfasiliteite, wat aansienlikekapitaal verg (tans nagenoeg R100 miljoen, afhangend van die grootte van die aanleg).Gegewe die hoë olie-ekstraksiepersentasie en die groot bydrae van inkomste uit olie

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wat verkoop word vir menslike verbruik, is vloeistof-ekstraksie die mees doeltreffendeprosesseringmetode.

Volvetsoja het beperkte toepassings vir die nismark en is ideaal vir maatskappye enplase wat dierevoer in ’n geïntegreerde proses produseer.

Meganies-gepersde sojaboonmeel het tans baie beperkte benuttingsmoontlikhede in dieformele dierevoerbedryf en behoort hoofsaaklik oorweeg te word vir plaasgebruik, ofbinne die kleiner informele dierevoermark. Die ekonomiese opbrengs op die produk,gegewe die laer ekstraksie van olie teen hoë waarde en gebrek aan premies wat ontvangword vir hoër energie-inhoud, is aansienlik laer as vir vloeistof-ekstraksiesojaboonmeel.