<p>Aktuelni problem industrije proizvodnje hrane za ribe jeste smanjena dostupnost i visoka<br />cena ribljeg bra&scaron;na, tradicionalnog izvora proteina u hrani za ribe, koja je direktna posledica rasta sektora akvakulture i visoke potražnje za ovim kvalitetnim proteinskim hranivom. Delimična ili potpuna zamena ribljeg bra&scaron;na visokoproteinskim sirovinama biljnog porekla u recepturama za ishranu riba, uz iznalaženje novih alternativnih visokoproteinskih sirovina pristup je kojim se prevazilazi ovaj problem i koji ima potencijal da obezbedi održivost celokupne industrije hrane za ribe u budućnosti. U okviru ove disertacije predloženo je novo, relativno jednostavno i jeftino tehnolo&scaron;ko re&scaron;enje za suvo frakcionisanje suncokretove sačme, čijom bi se primenom dobile njene visokoproteinske frakcije kao potencijalne proteinske sirovine biljnog porekla za zamenu ribljeg bra&scaron;na u hrani za ribe. Shodno tome, istraživanja ove disertacije urađena su u dve odvojene faze, gde je prva, faza vazdu&scaron;ne klasifikacije, imala za cilj ispitivanje mogućnosti primene kombinacije postupaka usitnjavanja suncokretove sačme mlinom čekidarom i vazdu&scaron;ne klasifikacije ovako usitnjene sačme primenom vazdu&scaron;nog gravitacionog kaskadnog, cik-cak, klasifikatora u cilju dobijanja frakcija povedanog sadržaj proteina u odnosu na polaznu sačmu. Nezavisni parametri usitnjavanja i klasifikacije bili su prečnik otvora sita (POS) čekidara (3, 2 i 1 mm), protok<br />klasifikacionog vazduha (5, 8,7 i 12,5 m³/h) i jačina oscilacije vibro dozatora (JOVD)<br />klasifikatora (30, 60 i 90% maksimuma). Zavisne promenljive bile su sadržaj proteina u<br />dobijenim frakcijama i njihov prinos. Primenjen je 3x3x3 potpuni faktorijalni eksperimentalni dizajn prema metodi odzivne povr&scaron;ine. U cilju dobijanja frakcije sa &scaron;to<br />većim sadržajem proteina, u &scaron;to većem prinosu, kombinacija postupaka usitnjavanja i<br />vazdu&scaron;ne klasifikacije je optimizovana primenom regresione analize, analize glavnih<br />komponenata (PCA analiza), analize varijanse, kao i računske dinamike fluida (CFD analiza), kojom je dobijeni kompjuterski model vazdu&scaron;ne klasifikacije suncokretove sačme poređen sa eksperimentalno dobijenim rezultatima. Cik-cak vazdu&scaron;ni klasifikator uspe&scaron;no je primenjen za razdvajanje usitnjene suncokretove sačme na grubu i finu frakciju. Pri povećanju protoka vazduha smanjivao se prinos grube a istovremeno povećavao prinos fine frakcije. Grube frakcije suncokretove sačme dobijene pri protocima vazduha od 8,7 i 12,5 m³/h imale su za 0,5 &minus; 41,4% relativno veći sadržaj proteina u poređenju sa polaznom sačmom. Smanjenje POS i povećanje protoka vazduha uticalo je na povećanje, dok je povećanje JOVD, uticalo na smanjenje sadržaja proteina grube frakcije. Najveći sadržaj proteina (50,90%SM) imala je gruba frakcija suncokretove sačme dobijena pri sledećim parametrima: POS &minus; 1 mm; protok vazduha &minus; 12,5 m³/h; JOVD &minus; 30%. Na sadržaj proteina grube frakcije i odnos prinosa frakcija značajan uticaj (p &lt; 0,05) imali su POS čekidara i protok vazduha, dok je CFD model pokazao zadovoljavajuće poklapanje sa eksperimentalnim rezultatima. Cilj druge faze disertacije, faze ekstrudiranja, bio je najpre ispitivanje uticaja dodatka polazne suncokretove sačme (oko 37% proteina na SM) i njene dve visokoproteinske frakcije (oko 43% i 49% proteina na SM), dobijenih na osnovu odabranih parametara usitnjavanja i vazdu&scaron;ne klasifikacije, na postupak ekstrudiranja i fizički kvalitet ekstrudirane hrane za ribe. Maksimalno 20% ribljeg bra&scaron;na bilo je zamenjeno polaznom sunockretovom sačmom i njenim odabranim visokoproteinskim frakcijama, a njihov udeo u recepturi za ishranu pastrmke menjan je na osnovu dizajna sme&scaron;e. Za ekstrudiranje eksperimentalnih sme&scaron;a i dobijanje hrane u obliku granula kori&scaron;ćen je dvopužni ekstruder. Ulazni parametri ekstrudiranja bili su konstatni, osim sastava sme&scaron;e, a<br />praćeni su izlazni parametri ekstrudiranja: temperatura u cevi ekstrudera, temperatura<br />matrice, pritisak na matrici, specifična potro&scaron;nja energije (SME) i obrtni moment<br />elektromotora ekstrudera. Proizvedenim uzorcima ispitani su pokazatelji fizičkog kvaliteta: stepen ekspanzije, nasipna masa, tvrdoća, stepen otiranja, kapacitet upijanja ulja, nivo otpu&scaron;tanja ulja iz zauljenih granula, stabilnost u vodi i mikrostruktura granula. Prisutvo suncokretove sačme vi&scaron;eg sadržaja proteina i manjeg sadržaja celuloze u sme&scaron;i uticalo je na formiranje vi&scaron;e temperature matrice ekstrudera, kao i na smanjenje SME i obrtnog momenta. Povećanje sadržaja proteina suncokretove sačme doprinelo je stvaranju kompaktnije strukture granule, povećanju tvrdoće, otpornosti otiranju i stabilnosti granula u vodi, smanjenju nivoa otpu&scaron;tanja ulja, te je tako pozitivno uticalo na fizičke karakteristike granula. Visokoproteinska frakcija suncokretove sačme sa 49% proteina na SM doprinela je optimalnim fzičkim karakteristikama ekstrudirane hrane za pastrmku. Karakterizacija ove frakcije kao potencijalne nove sirovine u industriji hrane za ribe bio je krajnji cilj ispitivanja ove disertacije. U tu svrhu navedena frakcija suncokretove sačme poređena je u novom eksperimentu ekstrudiranja i ispitivanja fizičkog kvaliteta hrane za pastrmku sa ribljim bra&scaron;nom, kao i sojinim bra&scaron;nom, koje je najče&scaron;će kori&scaron;ćen izvor biljnih proteina u hrani za ribe. Kori&scaron;ćena je nova receptura sme&scaron;e ali ista postavka eksperimenta kao u prvom delu faze ekstrudiranja. Rezultati su pokazali da je prisustvo visokoproteinske suncokretove sačme sa oko 49% proteina (SM) doprinelo smanjenju temperature matrice, ali i povedanju SME i obrtnog momenta, a time i poroznosti granula &scaron;to je imalo pozitivan uticaj na kapacitet upijanja ulja granula, stabilnost granula i otpu&scaron;tanje nutrijenata u vodi, kao i negativan uticaj na stepen otiranja i nasipnu masu granula. Zamena 13,4% ribljeg bra&scaron;na u recepturi ovom viskoproteinskom frakcijom suncokretove sačme za rezultat je imala granule zadovoljavajućeg fizičkog kvaliteta. Granule najboljeg fizičkog kvaliteta dobijene su<br />kombinacijom visokoproteinske frakcije suncokretove sačme sa sojinim bra&scaron;nom, te se<br />moglo zaključiti da se funkcionalne karakteristike ove dve sirovine odlično dopunjuju, i da visokoproteinska frakcija suncokretove sačme, sa stanovi&scaron;ta tehnolo&scaron;kog kvaliteta hrane za ribu, predstavlja dobru alternativu ribljem bra&scaron;nu.</p> / <p>High price and finite availability of fish meal (FM), due to high expansion of aquaculture<br />sector in recent decades, are main concerns for modern day aquafeed industry. Partially or completely substation of fish meal in fish feed with protein sources of plant origin, together with finding novel alternative protein sources, is commonly used approach that enables sustainability of aquafeed industry in decades to come. New, relatively simple and low-cost procedure for dry fractionation of sunflower meal (SFM) was proposed within this thesis, with aim for producing high protein SFM fractions as a potential plant source alternative for FM in fish feed. Thus, thesis&rsquo;s researches were done in two phases, where the aim of the first phase, air classification phase, was to investigate the possibility of applying combination of grinding by hammer mill and air classification of ground SFM using gravitational, cascade air classifier (zigzag), in order to obtain protein enriched fractions. Independent variables of grinding and air classification were sieve openings diameter (SOD) of hammer mill (3, 2 and 1 mm), air flow (5, 8.7 and 12.5 m3/h) and bowl feeder oscillation rate (BFOR) of air classifier (30, 60 and 90% of the maximum). Depended responses were protein content and yield of obtained fractions. The experimental data were obtained using 3 x 3 x 3 full factorial experimental design according to response surface methodology (RSM). For the optimization of grinding and air classification, in order to obtain fraction with highest possible protein content and in high yield, regression analysis, principal component analysis (PCA), analysis of variance (ANOVA) and computational fluid dynamics (CFD) approach were employed. Zigzag air classifier was successfully used for fractionation of ground SFM into coarse and fine fraction. Yield of coarse fractions was decreasing, while fine fractions yield was increasing with the increase of the air flow. Coarse fractions of SFM obtained at 8.7 and 12.5 m3/h were 0.5 &minus; 41.4% relatively enriched in protein content compared to the starting SFM. Decrease of SOD and increase of air flow resulted in coarse fraction protein content increase, while increasing BFOR decreased coarse fraction protein<br />content. The coarse SFM fraction with highest protein content was obtained for the SFM<br />ground by 1 mm SOD, air flow of 12.5 m3/h, with BFOR set at 30%. Protein content of<br />coarse fraction and ratio of fractions yields were significantly affected (p &lt; 0.05) by SOD of hammer mill and air flow. CFD model coincide with the experimental results of air<br />classification. The first aim of second phase, extrusion phase, was to investigate influence of starting SFM (37% of protein at DM) and its two high protein fractions (43% and 49% of protein at DM), obtained by grinding and air classification, on extrusion process and physical quality of extruded fish feed. Maximum 20% of FM was substituted with SFM and its high protein fractions in trout feed recipe, and their share was changed according to the<br />mixture design. Twin screw extruder was used for the production of trout feed samples.<br />Primarily extrusion parameters were constant, except dry mixture composition, and<br />secondary extrusion factors were observed: extruder barrel&rsquo;s temperatures, temperature<br />and pressure at the die, specific mechanical energy (SME) and motor load as torque.<br />Selected physical properties of extruded trout feed samples were determined: radial<br />expansion, bulk density, hardness, durability, oil absorption capacity, oil leakage, water<br />stability and microstructure of feed. SFM higher in protein and lower in fiber influenced<br />higher die temperature and lower SME and torque during extrusion process. Increase in<br />protein content of SFM resulted in more compact structure of pellets, increased hardness, durability and water stability, decreased oil leakage and thus positively influenced on physical properties of feed. High protein SFM fraction with around 49% of protein (DM) contributed to the optimal physical properties of experimental feed and characterization of this SFM fraction, as a potential new raw material in fish feed industry, was definite aim of this thesis. Towards that, new set of experiments was conducted, where high protein SFM fraction was compared with FM and soybean flour (SBF) by extruding new samples of trout feed and investigating their physical quality. Results of second extrusion experiment showed that presence of high protein SFM fraction (49% of protein DM) in dry mixture decreased die temperature, while increased SME and torque, and with that also increased porosity of pellets, oil absorption capacity and water stability but decreased bulk density and durability. Substitution of 13.4% FM by high protein SFM fraction resulted in pellets with satisfactory physical quality. The highest quality pellets were obtained in combination of high protein SFM and SBF, which lead to the conclusion that functional characteristics of high protein SFM fraction and SBF are complementary, and that novel SFM, from the point of technical quality, presents good FM alternative.</p>

A novel method was developed to design and fabricate nozzles capable of producing low-divergence fluid jets. Nozzle apertures were elliptical, and jets exhibited elliptical cross-sections with divergence varying predictably between 0 and 13°. Nozzle aperture aspect ratios varied from 1.00 to 2.45, area was equivalent to that of a 6mm diameter circle. An elliptical jet was developed with 0.4° and 0.9° divergence in the major and minor axes, respectively. Performance of this elliptical nozzle was compared to that of a circular nozzle via profiled creep-feed grinding trials. Results indicate the circular nozzle performs similarly to the horizontal ellipse; the vertical ellipse frequently caused wheel breakdown. Optimized cutting parameters: wheel speed 23m/s, cut depth 1.78mm, feed rate 200mm/min, jet pressure 3.21MPa or greater. Experiments were performed on a Blohm Planomat 408 CNC grinding machine using CimTech 310 cutting fluid. Nozzle experiments used a Brix concentration of 6.1%, grinding experiments used 3.1%.

<p>U savremenom uzgoju živine i svinja sme&scaron;e se retko koriste u pra&scaron;kastom obliku<br />već se uglavnom peletiraju nakon ume&scaron;avanja pojedinačnih sastojaka. Pri<br />peletiranju dolazi do naru&scaron;avanja granulacije sme&scaron;e, odnosno do gotovo<br />potpunog eliminisanja krupnih čestica, kao i do nastajanja velike količine najsitnijih čestica. U okviru istraživanja u ovoj doktorskoj disertaciji ispitivan je uticaj promene odabranih parametara mlevenja i peletiranja na granulaciju čestica od kojih su pelete sačinjene. Cilj je bio da se utvrdi kombinacija parametara koja doprinosi povećanju sadržaja krupnih čestica, &scaron;to je značajno u ishrani živine, odnosno da se utvrdi kombinacija parametara koja će u &scaron;to većoj meri uvećati sadržaj čestica srednje veličine i umanjiti udeo najsitnijih čestica, &scaron;to je značajno u ishrani svinja. Pri tome je određivan i kvalitet peleta, koji ne sme biti značajnije naru&scaron;en, kao i potro&scaron;nja energije pelet prese za koju je poželjno da je &scaron;to niža.<br />Nezavisni parametri peletiranja bili su granulacija kukuruznog mliva, rastojanje (zazor) između valjaka i matrice pelet prese, debljina matrice pelet prese i sadržaj vode materijala koji se vodi na peletiranje. Istraživanje je podeljeno u dve faze, gde je u prvoj za usitnjavanje primenjen mlin čekićar, a u drugoj mlin sa valjcima. Na oba uređaja prizvedene su po tri granulacije mliva, pri čemu se granulacija ukrupnjava od najsitnijeg mliva dobijenog na mlinu čekićaru do najkrupnijeg mliva dobijenog na mlinu sa valjcima. U prvoj fazi tri granulacije mliva dobijene na mlinu čekićaru su peletirane u kombinaciji sa tri zazora valjci-matrica (0,30; 1,15 i 2,00 mm) i tri sadržaja vode materijala (14,5%, 16,0% i 17,5%), a u drugoj fazi tri granulacije mliva dobijene na mlinu sa valjcima peletirane su u kombinaciji sa tri debljine matrice (24, 30 i 36 mm) i tri sadržaja vode materijala (14,5%, 16,0% i 17,5%). Dakle, u obe faze su varirana tri parametra na tri nivoa pri čemu je primenjen Box-Behnken eksperimentalni dizajn. Zavisno promenljive karakteristike (odzivi) bili su temperatura matrice pelet prese, specifična potro&scaron;nja energije pelet prese, udeo pra&scaron;ine u peletama, stepen želatinizacije skroba, tvrdoća, stepen otiranja i nasipna masa peleta, kao i granulacija materijala nakon peletiranja. Za svaki od pomenutih odziva definisan je polinom (model) drugog reda. Dobijeni modeli upotrebljeni su za optimizaciju procesa peletiranja sa ciljem da se postigne željena granulacija peletiranog materijala, uz &scaron;to bolji kvalitet peleta i uz &scaron;to manju potro&scaron;nju energije.<br />U istraživanju je utvrđeno da mliva sa približno istom vredno&scaron;ću geometrijskog srednjeg prečnika, dobijena na mlinu čekićaru i mlinu sa valjcima, imaju značajno različitu raspodelu veličine čestica. Na mlinu čekićaru dobija se &scaron;ira raspodela, sa većim sadržajem najkrupnijih i najsitnijih čestica, u poređenju sa mlinom<br />sa valjcima. Za proizvodnju mliva približno istog geometrijskog srednjeg prečnika, a pogotovo mliva sa relativno sličnom raspodelom veličine čestica,<br />potro&scaron;nja energije kod mlina sa valjcima značajno je manja u poređenju sa mlinom<br />čekićarom. &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Potvrđeno je da peletiranje uzrokuje veliki intenzitet usitnjavanja čestica bez obzira na primenjene parametre. Međutim, određene kombinacije parametara mogu doprineti značajnijem očuvanju krupnih čestica. Parametar peletiranja koji najvi&scaron;e doprinosi<br />povećanju udela krupnih čestica u peletama je granulacija mliva koje se upućuje na<br />peletiranje. &Scaron;to je krupnija granulacija, udeo krupnih čestica u peletama će biti veći.<br />Rezultati optimizacije procesa peletiranja u prvoj fazi ukazuju da je u pogledu proizvodnje peletirane hrane za živinu, kada je poželjno očuvanje određene količine krupnih čestica, potrebno primeniti krupno mlevenje na mlinu čekićaru, uz<br />pode&scaron;avanje zazora između valjaka i matrice od 2 mm i uz sadržaj vode materijala od 17,5%. U drugoj fazi optimizacijom je utvrđeno da je potrebno koristiti debljinu matrice od 30 mm, najkrupniju granulaciju mliva na mlinu sa valjcima i vlagu od 17,5%. Pri proizvodnji peletirane hrane za živnu povoljnije je koristiti mlin čekićar, s obzirom da je utvrđeno da su čestice mliva dobijenog na čekićaru otpornije na usitnjavanje tokom peletiranja od čestica dobijenih na mlinu sa valjcima &scaron;to omogućuje očuvanje većeg broja krupnih čestica tokom peletiranja. Povećanje &scaron;irine zazora valjci-matrica nije poželjno prilikom peletiranja hrane za svinje jer se povećava intenzitet usitnjavanja čestica, a time i udeo najsitnije frakcije čestica. Sličano je i sa povećanjem debljine matrice. U prvoj fazi istraživanja, rezultati optimizacije pokazuju da je u cilju povećanja udela frakcija čestica srednje veličine (630 &ndash; 1600 &mu;m), kao i smanjenja sadržaja najsitnijih čestica (&lt; 125 &mu;m), potrebno primeniti najsitnije mlevenje na mlinu čekićaru, najveći sadržaj vode materijala (17,5%), dok zazor između valjaka i matrice treba podestiti da bude ne&scaron;to veći od 0,30 mm. I u drugoj fazi istraživanja optimizacija je ukazala da je najveći udeo čestica srednje veličine (630 &ndash;<br />1600 &mu;m), kao i najmanji udeo čestica &lt; 125 &mu;m, ostvaren pri peletiranju najsitnijeg<br />mliva dobijenog na mlinu sa valjcima. Pri tome sadržaj vode je potrebno podesiti na<br />17,5%, dok debljina matrice treba biti oko 28 mm.<br />Pri predloženim optimalnim parametrima peletiranja ostvaren je zadovoljavajući<br />kvalitet peleta, a potro&scaron;nja energije pelet prese bila je na prihvatljivom nivou.</p> / <p>In modern poultry and swine breeding, animal feed is rarely used in powder form but mainly pelleted after mixing of different ingredients. During pelleting process, granulation of the feed is compromised, i.e. coarse particles are<br />almost completely destroyed and the content of fine particles is strongly<br />increased. This doctoral thesis investigated the impact of changes in selected grinding and pelleting parameters on granulation of particles after pelleting. The goal was to achieve the quantity of coarse particles in pellets to be as high as possible, which is important in poultry nutrition. Another goal was to determine the combination of parameters that will increase, as much as possible, the content of particles medium in size and reduce the share of the smallest particles, which is important in swine nutrition. At the same time quality of the pellets must not be significantly degraded and energy consumption of pellet press should be as low as possible.<br />Independent pelleting parameters were corn granulation after grinding, the distance (gap) between the rollers and the die of pellet presses (roller-die gap), the thickness<br />of the pellet press die (die thickness) and the water content of pelleted material. The study was divided in two stages. In the first stage the corn was ground using a hammer mill and in the second stage, roller mill was used. Three different granulations were produced on both mills. Coarseness of the ground material increased from the finest material produced using the hammer mill to the coarsest material obtained at the roller mill. In the first stage, three different granulations produced at the hammer mill were pelleted in combination with three different roller-die gaps (0.30, 1.15 and 2.00 mm) and three different water contents of material (14.5%, 16.0% and 17.5%). In the second stage three different granulations produced at the roller mill were pelleted in combination with three different die thicknesses (24, 30 and 36 mm) and three different water content of material (14.5%, 16.0% and 17.5%). Thus, three parameters were varied at three levels in both stages and experiments were designed according to Box-Behnken design. Depended variables (responses) were: temperature of the pellet press die, specific energy consumption of pellet press, dust content in pellets, degree of starch gelatinization,&nbsp; particle size of the material after pelleting. For each of the responses, a second order polynomial model was defined and used for optimization of the pelleting process. It was determined that particle size distribution of material with similar geometric mean diameter, obtained with hammer mill and roller mill, is significantly different from each other. Hammer mill produced higher quantity of the coarsest and the finest particles comparing to roller mill. Energy consumption of roller mill for grinding to similar particle size distribution or similar geometric mean diameter is lower compared to hammer mill. Even though it was determined that secondary grinding of particles during pelleting is inevitable, certain combinations of pelleting parameters may contribute to significant preservation of large particles and to reduction of quantity of small particles. Results of optimization in the first stage indicated that for the production of pelleted poultry feed, when certain amount of coarse particles should be preserved, it is necessary to apply coarse grinding on hammer mill, with the roller-die gap of 2 mm and with material water content of 17.5%. In the second stage it was determined that it is necessary to use die with thickness of 30 mm, coarsest granulation at the roller mill and material water content of 17.5%. In the production of pelleted poultry feed it is better to use a hammer mill since it was found that the particles obtained on hammer mill are more resistant to secondary grinding than the particles obtained with the roller mill. Roller-die gap increase is not desirable during pelleting of swine feed because it increases secondary grinding, and thus the proportion of the smallest particles. Similar effect has an increase of the die thickness. In the first stage of the study, the results of the optimization showed that the largest quantity of medium-sized particles (630 &ndash; 1600 &mu;m), and the lowest quantity of the smallest particles (&lt; 125 &mu;m), were achieved with the finest grinding on the hammer mill. At the same time water content of 17.5% should be applied, while the roller-die gap should be close to 0.30 mm. In the second stage of the study, the largest quantity of medium-sized particles, and the lowest quantity of the smallest<br />particles, was achieved with the finest grinding on the roller mill. According to the optimization results, the water content should be set to 17.5%, while die thickness should approx. 28 mm. With the proposed optimal parameters, satisfactory pellet quality was achieved, and energy consumption of the pellet<br />presses was at an acceptable level.</p>

In mehrfaktoriellen 2 x 2 x 4 Untersuchungen im Zeitraum vom 7. - 28. Lebenstag und in Bilanzversuchen vom 15. - 20. Lebenstag mit männlichen Broilerküken (Cobb 500) wurden die Effekte der Versuchsfaktoren Zerkleinerung (Hammermühle vs. Walzenstuhl), thermische Behandlung (Konditionierung bei 70°C vs. Konditionierung/Expandierung 100°C) und Zusätze von Zink-Bacitracin bzw. Roxazym G2 (ohne Zusatz, mit Zink-Bacitracin 50 mg, mit Roxayzm G2 150 ppm und deren Zusatzkombination A+E) sowie die Interaktionen untersucht. Als Kriterien dienten die Parameter Futterverzehr, Lebendmassezunahme, Futteraufwand, Nährstoffansatz und -verwertung, ileale Verdaulichkeit von ausgewählten Aminosäuren, Proteinverwertung/Proteinqualität und Umsetzbarkeit der Energie. Die Versuchstiere erhielten ab dem 7. Lebenstag die entsprechenden Versuchsmischungen. Der Gehalt an XP und MEn aller Versuchsmischungen war einheitlich (XP 21,7% und MEn 12,3 MJ/kg Futter). Die Lysinversorgung wurde auf 90 % unter der optimalen Bedarfsdeckung in allen Futtermischungen limitiert. Die Auswirkungen der Versuchsfaktoren lassen sich wie folgt zusammenfassen: - Zerkleinerung : Die Zerkleinerungstechnologie mit dem Walzenstuhl übte einen signifikanten Einfluss auf den Futterverzehr (-3,5 %) und Futteraufwand (-2,8 %) gegenüber der Zerkleinerung mit der Hammermühle aus. Die Nährstoffverwertung (XP und Energie) zeigten durch Walzenstuhl-Zerkleinerung tendenzielle Verbesserungen. Die ileale Lysinverdaulichkeit blieb unverändert, die ileale Verdaulichkeit von Threonin und Met+Cys wurde signifikant erhöht. Die Walzenstuhl-Zerkleinerung führte zu einer besseren Futterstruktur und zu einer höheren Nährstoffdichte in den Pellets. Das wird deutlich durch die höhere N-Aufnahme bzw. N-Bilanz sowie durch gesteigerte N-Verwertungsparameter und einen erhöhten Gehalt an N-korrigierter umsetzbarer Energie (MEn). - Thermische Behandlung : Durch erhöhte Hitzeapplikation mit dem Expander konnten in der vorliegenden Arbeit hinsichtlich der Leistungsparameter, Nährstoffansatz und -verwertung keine Unterschiede gegenüber der Konditionierung festgestellt werden. Die Expandierung führte zu einer signifikant erhöhten ilealen Lysinverdaulichkeit, die durch die gemessene Lysinwirksamkeit im Bilanzversuch jedoch nicht widergespiegelt wurde. Auch signifikant niedrigere N-Bilanz und physiologische Proteinnutzwerte (PNu) sowie die tendenzielle Verringerung der N-Verdaulichkeit und des Gehaltes an umsetzbarer Energie deuten auf eine negative Wirkung der intensiveren thermischen Behandlung durch Expandieren hin. Hierzu sind weitere klärende Untersuchungen notwendig. - Futterzusätze: Durch die alleinige Supplementierung mit dem Antibiotikum Zink-Bacitracin oder NSP-spaltenden Enzym Roxazym G2 bzw. deren Kombination reagierten Mastleistung und Futterverwertung signifikant positiv. Während der Effekt der Enzymzulagen bei Nährstoffverwertung und ilealer Verdaulichkeit ausgewählter Aminosäure signifikant höher gegenüber der unsupplementierten Gruppe war, blieb ein Effekt von Zink-Bacitracin hinsichtlich dieser Parameter aus. Der Effekt der Zusatzkombination war bei Mastleistung, Nährstoffansatz und -verwertung und bei der ilealen Verdaulichkeit der ausgewählten Aminosäuren gegenüber der Kontrolle oder dem alleinigen Zusatz signifikant höher. Das deutet auf einen synergistischen Effekt der gleichzeitigen Applikation der beiden Additive hin. Die N-Verwertung einschließlich des Gehalts an N-korrigierter scheinbar umsetzbarer Energie lag nach alleiniger Applikation von Zink-Bacitracin unerwartet signifikant niedriger gegenüber den anderen Zusätzen bzw. tendenziell gegenüber der Kontrolle. Die Gehalte an scheinbar umsetzbarer Energie (AMEn) waren deutlich durch den Enzymzusatz allein oder in Kombination mit Zink-Bacitracin erhöht. -Interaktionen: Die Abhängigkeit der Versuchsfaktoren voneinander im Mastversuch war nicht stark ausgeprägt. Die Zerkleinerung in Verbindung mit anschließender thermischer Behandlung führte zur Beeinflussung der Futterverzehrsdaten. Danach verbesserten die Verfahrenskombinationen Hammermühle x Konditionierung oder Walzenstuhl x Expandierung bedingt durch einen erhöhten Futterverzehr die Lebendmassezunahme und den Nährstoffansatz signifikant. Hinsichtlich der ilealen Aminosäurenverdaulichkeit zeigten die Futterzusätze eine Abhängigkeit von der Behandlung bzw. Zerkleinerung und Behandlung. Die Enzymzulage allein oder in Kombination mit Zink-Bacitracin zeigte stärkere Effektivität in Verbindung mit der thermischen Behandlung durch Expandieren.