Fontes alternativas de alimentos vem sendo estudadas em substituição à farinha de peixe na aquicultura, podendo acarretar diferença na incorporação de carbono e nitrogênio decorrentes da disponibilidade e do valor nutricional da fonte. Três experimentos tiveram o objetivo de quantificar a participação das diferentes fontes protéicas nos tecidos de juvenis e pós-larvas através da composição isotópica de C e N e sua influência no crescimento. Além disso, a digestibilidade aparente das dietas contendo mistura de plantas C3 e C4 foi estudada usando o 13C nas fezes como traçador. As dietas consistiram de quatro ingredientes protéicos. Farelo de soja FS, farelo de coco FC, farinha de vísceras de aves FVA e farinha de peixe FP que compuseram cinco combinações diferentes: FS100; FS60FC40; FS60FVA40; FS60FP40; FS19F10FP10FVA11. No primeiro experimento duzentos juvenis de tilápia com peso médio de 3,4 ± 0,20 g foram distribuídos em 20 gaiolas flutuantes e após serem alimentados com as dietas experimentais, foram coletados amostras aos 0, 22, 44, 66 e 88 dias para estimar a contribuição de C e N das dietas no tecido. Foi observada diferença significativa (P<0,05) entre peso final (PF), ganho em peso (GP), conversão alimentar (CA), rendimento de filé (RFL), taxa de eficiência protéica (TEP) e fator de condição (FC). No entanto, não observou diferença entre o consumo alimentar (CO), peso do filé (PF) e índice de perfil (IPERF). Para o experimento dois, trezentas pós-larvas de 20 dias com peso médio inicial de 0,07 ± 0,020 g, foram distribuídas aleatoriamente, perfazendo cada unidade experimental com quinze animais. Foram realizadas coletas aos 0, 6, 12, 18, 24 e 30 dias para C e N. Neste experimento foi demonstrada diferença significativa (P<0,05) entre as variáveis PF, GP, CO, CA e TEP. Para o comprimento total e padrão; IPERF e FC n(Pão foi observado diferença (P>0,05). Juvenis e pós-larvas atingiram o equilíbrio isotópico de 13C e 15N com suas respectivas dietas, permitindo assim que estes sejam usados para estimar a quantificação de nitrogênio e carbono, com excessão para a dieta FS60FC40. Em ambos os experimentos, houve aumento percentual de ganho de peso em juvenis e pós-larvas, sendo observada maior porcentagem de nitrogênio no músculo e carcaça total pelas dietas com farinha de peixe FS60FP40 e farinha de vísceras de aves FS60FVA40. Posteriormente, para o experimento de digestibilidade, 2500 juvenis com peso médio de 5,0 ± 1,0 g foram utilizados para determinação do coeficiente de digestibilidade aparente CDA,% de componentes de origem C3 e C4 contidos nas dietas experimentais. Os valores de CDA apresentaram valores inferiores para os componentes de origem C3 em relação aos de origem C4. A avaliação dos isótopos estáveis do C e do N nas dietas permitiu estimatimar a contribuição entre as diferentes fontes, o que sugeriu que a ingestão de nutrientes está relacionados com a qualidade da dieta. Verificou-se que fontes de proteína, quando combinadas, podem apresentar resultados superiores do que quando usada sozinha na composição. / Alternative sources of food have been studied in substitution for fishmeal in aquaculture, and it may result in a difference in incorporation of carbon and nitrogen, depending on the nutritional value and availability of the source. Two experiments were designed to quantify the participation of different protein sources in the muscle tissue in juvenile and post larvae through isotopic composition and its influence on growth and body composition. In addition, the apparent digestibility of feedingstuffs containing mixture of C3 and C4 plants has been studied using 13C as tracer. The experiments were conducted in a random design with five treatments and four repetitions. Diets consisted of by four sources of protein ingredients. soybean meal SBM, coconut meal CM, poultry product meal PPM, meal and fish meal FM, composed five different combinations of diets: SBM100 SBM60CM40 SBM60PPM40 SBM60FM40 SBM19CM10FM10PPM11. In the first experiment, it used 200 juveniles with an average weight of 3.4 ± 0.20 g, distributed in 20 vinyl cages. Fish collections were held after being fed the experimental diets for 0, 22, 28, 38, 44, 66 and 88 days. In this assay, it was observed significant difference (P<0.05) for final weight, weight gain, feed conversion, fillet yield, protein efficiency ratio and condition factorHowever, there was no difference between food consumption, weight and content of the fillet profile. For the experiment two, 300 post-larvae, 20 days old and with average weight starting at 0.07 ± 0.020g, were randomly distributed in the five treatments, making each experimental unit with twenty animals. Six fish collections were held at 0, 6, 12, 18, 24 and 30 days. This assay also showed significant difference (P<0.05) for final weight, weight gain, food intake, feed conversion and protein efficiency ratio. It was observed that juvenile and post larvae did reach the isotopic equilibrium of 13C and 15N with their own diets, thus allowing it to be used for estimating the quantification of nitrogen and carbon incorporated into fish tissue, with exception for the SBM60CM40 diet. The higher percentage of nitrogen in the muscle and carcass were obtained by total diets with fish meal SBM60FM40 and poultry product meal SBM60PPM40To test the digestibility of the diets, 2,500 juvenile with average weight 5.0 ± 1.0 g were used for determination of apparent digestibility coefficient ADC, % of source components C3 and C4 contained in the experimental diets. The values of CDA constituents of experimental diets of fingerling showed lower values for source components C3 in respect of C4 origin. The evaluation of stable isotopes of carbon and nitrogen contained in protein ingredients permitted the estimation of contributions among the different sources, which suggests that the intakes of nutrients are related to the higher quality of the diet. It was noted that protein sources when combined can present superior results when used alone in the composition. The contribution of different protein sources in feed of Nile Tilapia, through the natural variation of stable isotopes of carbon and nitrogen, proved promising.

<p>Задатак ове докторске дисертације је био да се испита могућност и ефекти примене мешавине етарских уља тимијана (Thymus vulgaris), оригана (Origanum vulgare) и рузмарина (Rosmarinus officinalis), као природног промотера раста, у узгоју бројлерских пилића на производне карактеристике, биохемијске параметре крви, хисто-морфолошке параметре јетре и цревних ресица, сварљивост хранљивих материја, квалитет трупа и меса пилића, као и на економичност саме производње.<br />У циљу реализације постављених задатака изведен је биолошки оглед у којем су коришћени бројлерски пилићи линијског хибрида Ross 308. Биолошки оглед је изведен на укупно 840 једнодневних бројлерских пилића, подељених у три огледна третмана, два експериментална и један контролни. Као природни промотер раста коришћена је мешавина етарских уља тимијана, оригана и рузмарина у концентрацијама од 0,05 и 0,10%.<br />Током огледног периода континуирано су праћене производне карактеристике бројлерских пилића, а на основу анализе добијених резултата закључено је да испитивана мешавина етарских уља тимијана, оригана и рузмарина може веома успешно да се користити у исхрани бројлерских пилића као природни промотер раста. Позитиван утицај овог додатка је најпре исказан кроз пораст прираста бројлерских пилића (4,29-4,61%), као и на конверзију хране код јединки (7,69-8,28%). Посматрано по периодима исхране, најекономичнија производња бројлерских пилића у стартер периоду исхране постигнута применом 0,05% мешавине етарских уља тимијана, оригана и рузмарина у исхрани бројлерских пилића, док се у гровер периоду исхране ефикаснијом показала доза од 0,10%. Најекономичнија производња бројлерских пилића током целокупног периода това остварена је применом 0,05% мешавине етарских уља тимијана, оригана и рузмарина у исхрани, будући да је у овом третману постигнута најмања вредност цене прираста пилића (71,41 din/kg) највећа вредност индекса економске ефикасности, као и најмања вредност индекса цена производње. Анализом резултата добијених испитивањем активности панкреасних ензима у крвеном серуму и панкреасу бројлерских пилића, установљено је да додата мешавина етарских уља утиче позитивно на активност поменутих ензима у панкреасу, при чему је установљена и значајна позитивна корелација између активности протеазе у панкреасу и крвном серуму бројлерских пилића (r =+0,858; p&lt;0,05). Када је реч о специфичном титру антитела у крвном серуму бројлерских пилића утврђено је да је примена мешавине етарских уља тимијана, оригана и рузмарина у исхрани бројлерских пилића у концентрацији од 0,10% допринела благом порасту концентрације IgА антитела у крви што потенцијално представља индикатор јачања имунолошког система, док је статистички значајан (p&lt;0,05) утицај уочен и на секрецију IgG антитела у крвном серуму бројлерских пилића у оба експериментална третмана. Додата мешавина етарских уља није испољила ефекте на одабране показатеље липидног статуса крви бројлерских пилића, међутим утицала је на значајно побољшање сварљивости сирових протеина, сирове масти, сировог пепела, калцијума и фосфора код бројлерских пилића, чиме је повећана искористљивост основних хранљивих материја, а самим тим су побољшане и производне карактеристике. Утврђене појединачне вредности свих испитаних фактора квалитета трупа закланих пилића указују на позитивне ефекте које су фитобиотици испољили у организму бројлерских пилића. Такође, применом наведене мешавине етарских уља у исхрани бројлерских пилића добијено је пилеће месо побољшаних нутритивних, технолошких и сензорских својстава. С обзиром на значај масних киселина у исхрани људи, од велике важности је позитиван учинак који је додата мешавина етарских уља тимијана, оригана и рузмарина испољила на маснокиселински састав меса бројлерских пилића. Смањен је садржај засићених масних киселина, уз истовремено повећање садржаја полинезасићених масних киселина, чиме је постигнут препоручен однос n-6 / n-3 масних киселина у месу пилића.<br />На основу добијених резултата може се закључити да се избалансираном храном за бројлерске пилиће, са оптималним саставом и садржајем природних промотера раста могу добити пилићи побољшаних производних карактеристика, који се одликују ефикасном сварљивошћу хранљивих материја, те имају добре рандмане и више меса на трупу. Додатно, добијено месо je побошљаног нутритивног, технолошког и сензорског квалитета, обогаћено n-3 масним киселинама и одликује се оптималним односом n-6/n-3 масних киселина. Када се на све то додају и позитивни економски параметри производње онда се са сигурношћу може тврдити да је употреба мешавине етарских уља тимијана, оригана и рузмарина у исхрани бројлерских пилића потпуно оправдана.</p> / <p>Zadatak ove doktorske disertacije je bio da se ispita mogućnost i efekti primene mešavine etarskih ulja timijana (Thymus vulgaris), origana (Origanum vulgare) i ruzmarina (Rosmarinus officinalis), kao prirodnog promotera rasta, u uzgoju brojlerskih pilića na proizvodne karakteristike, biohemijske parametre krvi, histo-morfološke parametre jetre i crevnih resica, svarljivost hranljivih materija, kvalitet trupa i mesa pilića, kao i na ekonomičnost same proizvodnje.<br />U cilju realizacije postavljenih zadataka izveden je biološki ogled u kojem su korišćeni brojlerski pilići linijskog hibrida Ross 308. Biološki ogled je izveden na ukupno 840 jednodnevnih brojlerskih pilića, podeljenih u tri ogledna tretmana, dva eksperimentalna i jedan kontrolni. Kao prirodni promoter rasta korišćena je mešavina etarskih ulja timijana, origana i ruzmarina u koncentracijama od 0,05 i 0,10%.<br />Tokom oglednog perioda kontinuirano su praćene proizvodne karakteristike brojlerskih pilića, a na osnovu analize dobijenih rezultata zaključeno je da ispitivana mešavina etarskih ulja timijana, origana i ruzmarina može veoma uspešno da se koristiti u ishrani brojlerskih pilića kao prirodni promoter rasta. Pozitivan uticaj ovog dodatka je najpre iskazan kroz porast prirasta brojlerskih pilića (4,29-4,61%), kao i na konverziju hrane kod jedinki (7,69-8,28%). Posmatrano po periodima ishrane, najekonomičnija proizvodnja brojlerskih pilića u starter periodu ishrane postignuta primenom 0,05% mešavine etarskih ulja timijana, origana i ruzmarina u ishrani brojlerskih pilića, dok se u grover periodu ishrane efikasnijom pokazala doza od 0,10%. Najekonomičnija proizvodnja brojlerskih pilića tokom celokupnog perioda tova ostvarena je primenom 0,05% mešavine etarskih ulja timijana, origana i ruzmarina u ishrani, budući da je u ovom tretmanu postignuta najmanja vrednost cene prirasta pilića (71,41 din/kg) najveća vrednost indeksa ekonomske efikasnosti, kao i najmanja vrednost indeksa cena proizvodnje. Analizom rezultata dobijenih ispitivanjem aktivnosti pankreasnih enzima u krvenom serumu i pankreasu brojlerskih pilića, ustanovljeno je da dodata mešavina etarskih ulja utiče pozitivno na aktivnost pomenutih enzima u pankreasu, pri čemu je ustanovljena i značajna pozitivna korelacija između aktivnosti proteaze u pankreasu i krvnom serumu brojlerskih pilića (r =+0,858; p&lt;0,05). Kada je reč o specifičnom titru antitela u krvnom serumu brojlerskih pilića utvrđeno je da je primena mešavine etarskih ulja timijana, origana i ruzmarina u ishrani brojlerskih pilića u koncentraciji od 0,10% doprinela blagom porastu koncentracije IgA antitela u krvi što potencijalno predstavlja indikator jačanja imunološkog sistema, dok je statistički značajan (p&lt;0,05) uticaj uočen i na sekreciju IgG antitela u krvnom serumu brojlerskih pilića u oba eksperimentalna tretmana. Dodata mešavina etarskih ulja nije ispoljila efekte na odabrane pokazatelje lipidnog statusa krvi brojlerskih pilića, međutim uticala je na značajno poboljšanje svarljivosti sirovih proteina, sirove masti, sirovog pepela, kalcijuma i fosfora kod brojlerskih pilića, čime je povećana iskoristljivost osnovnih hranljivih materija, a samim tim su poboljšane i proizvodne karakteristike. Utvrđene pojedinačne vrednosti svih ispitanih faktora kvaliteta trupa zaklanih pilića ukazuju na pozitivne efekte koje su fitobiotici ispoljili u organizmu brojlerskih pilića. Takođe, primenom navedene mešavine etarskih ulja u ishrani brojlerskih pilića dobijeno je pileće meso poboljšanih nutritivnih, tehnoloških i senzorskih svojstava. S obzirom na značaj masnih kiselina u ishrani ljudi, od velike važnosti je pozitivan učinak koji je dodata mešavina etarskih ulja timijana, origana i ruzmarina ispoljila na masnokiselinski sastav mesa brojlerskih pilića. Smanjen je sadržaj zasićenih masnih kiselina, uz istovremeno povećanje sadržaja polinezasićenih masnih kiselina, čime je postignut preporučen odnos n-6 / n-3 masnih kiselina u mesu pilića.<br />Na osnovu dobijenih rezultata može se zaključiti da se izbalansiranom hranom za brojlerske piliće, sa optimalnim sastavom i sadržajem prirodnih promotera rasta mogu dobiti pilići poboljšanih proizvodnih karakteristika, koji se odlikuju efikasnom svarljivošću hranljivih materija, te imaju dobre randmane i više mesa na trupu. Dodatno, dobijeno meso je pobošljanog nutritivnog, tehnološkog i senzorskog kvaliteta, obogaćeno n-3 masnim kiselinama i odlikuje se optimalnim odnosom n-6/n-3 masnih kiselina. Kada se na sve to dodaju i pozitivni ekonomski parametri proizvodnje onda se sa sigurnošću može tvrditi da je upotreba mešavine etarskih ulja timijana, origana i ruzmarina u ishrani brojlerskih pilića potpuno opravdana.</p> / <p>The main objective of this research was to investigate the possibility and effects of dietary essential oils mixtures of thyme (Thymus vulgaris), oregano (Origanum vulgare) and rosemary (Rosmarinus officinalis), as a natural growth promoter, in broiler chicken nutrition on productive performances, blood biochemical parameters, morphological parameters of liver and villus, ileal nutrient digestibility, carcass characteristics and broiler meat quality, as well on the economic efficiency coasts of broiler chicken production. In order to realize the tasks set, biological trial was carried out on which Ross 308 strain broiler chickens. A totall of 840 one-day-old broiler chickens were equally distributed into three dietary treatments, two experimental and one control. As a natural growth promoter dietary thyme, oregano and rosemary essential oils mixture in concentrations 0.05 i 0.10% was used.<br />During the experimental period, the production characteristics of broiler chickens were continuously monitored. Based on the analysis of the obtained results, it was concluded that the dietary thyme, oregano and rosemary essential oils mixture can be used very successfully in the nutrition of broiler chickens as a natural growth promoter. The positive effect of this supplement was first expressed through the increase in broiler chickens body weight gain (4.29-4.61%), as well through the feed conversion ratio (7.69-8.28%). Observed by the nutrition periods, the most economical production of broiler chickens in the starter period was achieved using 0.05% of the dietary thyme, oregano and rosemary essential oils mixture, while in a grover period a 0.10% dose proved to be more effective. The most economical production of broiler chickens during the entire fattening period was achieved using 0.05% of the dietary thyme, oregano and rosemary essential oils mixture in nutrition, since in this treatment the lowest value of body weight gain price (71.41 din/kg) was achieved, as well as the highest value of the economic efficiency index, and the smallest value of the price index. Regarding the activity of pancreatic enzymes in blood serum and pancreas of broiler chickens, it was found that the added mixture of essential oils had positive influence on the enzymes activity in pancreas, with a significant positive correlation between the protease activity in the pancreas and the blood serum of broiler chickens (r=+0.858; p&lt;0.05). When it comes to the specific antibody titer in the blood serum of broiler chickens, it has been found that the use of a dietary thyme, oregano and rosemary essential oils mixture in broiler chickens nutrition at a concentration of 0.10% contributed to a mild increase in the IgA antibody concentration in the blood, which potentially represents an indicator of the strengthening of the broiler chickens immune system, while statistically significant (p&lt;0.05) influence was observed on the IgG antibodies secretion in blood serum of broiler chickens in both experimental treatments. The added mixture of essential oils did not influence lipid profile status of broiler chickens blood, however, had positive effect on the digestibility of raw proteins, raw fats, raw ash, calcium and phosphorus in broiler chickens, which increased the utilization of basic nutrients, and therefore production characteristics of broiler chickens were improved. Improved carcass characteristics in experimental treatments indicate positive effects that phytobiotic exhibited in broiler chickens. Moreover, using the mixture of essential oils, nutritional, technological and sensory properties of chicken meat has been improved. Considering the importance of fatty acids in human nutrition, the positive effect of dietary thyme, oregano and rosemary essential oils mixture on the fatty acid composition of broiler chicken meat has a great significance. The saturated fatty acids content was reduced, while the polyunsaturated fatty acids content was increased, thus achieving the recommended ratio of n-6/n-3 fatty acids in chicken meat.<br />Based on the obtained results, it can be concluded that with well-balanced feed, which contains optimal composition and content of natural growth promoters, can produce broiler chickens with improved production characteristics, which are characterized by an effective nutrients digestibility, and have good carcass yield and more meat. In addition, the obtained meat will have improved nutritive, technological and sensory quality, enriched with n-3 fatty acids and with optimal ratio of n-6/n-3 fatty acids. When all of this is added to the positive economic parameters of production then it can be safely claimed that the use of a dietary thyme, oregano and rosemary essential oils mixture in broiler chickens nutirition is completely justified.</p>

This thesis explores the complex relationship between food protein structure and digestibility. Food proteins are important nutrients that play a central role in controlling the textural properties of many foods. Processing of food proteins may alter the protein aggregate structure and digestibility. The degree of protein aggregation during food processing depends on the denaturing conditions and the presence of other food components. Sugars and lipids may contribute to protein glycation and protein cross-linking via the Maillard reaction. Furthermore, amino acid residues of food proteins may be chemically modified during processing, thereby influencing both the structure and the nutritional value of proteins. An in vitro digestibility assay was used to investigate the relationship between protein aggregate structure and protein digestibility. Raw and boiled egg whites were exposed to a wide range of conditions: pH 2 - 12, in the presence and absence of 200 mM NaCl. It was found that pH and NaCl treatment prior to in vitro digestion resulted in significantly different protein ultrastructures, but did not markedly influence protein digestibility under the tested conditions. Raw egg white was less digestible than boiled egg white under all test conditions. The inclusion of Maillard reaction partners caused protein cross-linking concurrent with a decrease in digestibility. The digestibility decreased with the reactivity of the Maillard reaction partner and with increasing heating time. Proteomic analysis, using tandem mass spectrometry, of raw and heated egg white showed an increase in hydrothermally induced amino acid modifications. In the presence of glucose and methylglyoxal, a Maillard reaction specific increase in arginine modification to hydroimidazolone was observed with increasing heating times. The observed modifications are likely to contribute to a change in the nutritional quality of egg white. Aggregation kinetics of the major egg white protein, ovalbumin, were studied by dynamic light scattering, small angle X-ray scattering, and transmission electron microscopy. Shape determination was only possible for ordered aggregates, but not for disordered aggregates. Prior to heating, ovalbumin molecules in the presence of water and glucose repelled each other in concentrated solution. The presence of NaCl shielded electrostatic repulsion, leading to early onset dimerisation and disordered aggregation upon heating. Methylglyoxal treated ovalbumin formed more ordered aggregates. The scattering of these structures was able to be fitted to cylindrical shape models showing an increase of cylinder length with time while the cylinder diameter remained near constant over 24 hours of heating. In addition, food protein derived amyloid fibril aggregates were characterised. Amyloid fibrils are a common ordered protein fold that has been linked to neurodegenerative diseases. In the recent literature, amyloid fibrils have been proposed as new functional macromolecules in proteinaceous foods because of their desirable textural properties. Food fibrils formed from whey, egg white, soy bean and kidney bean protein were tested to establish whether they are protease resistant or display toxicity to human Caco-2 cells (a model intestinal cell line). The food fibrils were compared to insulin amyloid fibrils, a well characterised amyloid system. It was shown that the food fibrils displayed some resistance towards in vitro hydrolysis and were not found to be toxic. This work contributes to the understanding of food protein aggregation and digestibility under relevant conditions. It highlights the relationship of aggregate structure and digestibility and the particular role of the Maillard reaction. Moreover, evidence is provided that food protein derived amyloid fibrils may be safe ingredients in consumables. These findings may contribute to optimising industrial food processes and creating safe new food products.

No description available.

The effect of inclusion rate of pea meal (PM), pea protein concentrate (PPC), soybean meal (SBM), soy protein concentrate (SPC), canola meal (CM) and canola protein concentrate (CPC) in salmonid diets was determined through six corresponding meta-analyses of all data available in the literature for these six feed ingredients, which was followed by weighted regression analysis. Increasing dietary inclusion levels of SBM, SPC, CM and CPC reduced specific growth rate (SGR). Regression analysis determined all of these relationships to be linear declines in SGR (P < 0.05). Inclusion levels of PM or PPC did not influence salmonid SGR (P > 0.05). These results showed that the influence plant proteins have on salmonid SGR is dependent on ingredient type and inclusion level. PM, PPC, SBM, SPC, CM an aqueous-extracted CPC and a high phytate CPC (PCPC) were analyzed for chemical nutrient (proximate, amino acid and phosphorus analysis) and antinutrient composition and total tract digestibility (two separate digestibility trials) in rainbow trout (Oncorhynchus mykiss). The digestibility of proximate chemical components and amino acids were significantly higher for the soy products than the pea products. These digestibilities were also significantly higher in protein concentrates than in plant meals. Dry matter and gross energy digestibility was higher in CPC than in CM (P < 0.05). Phosphorus digestibility was higher in CPC-fed fish than in CM-fed fish (P < 0.05), which is likely due to the fact that CPC did not contain phytic acid. Six consecutive growth studies (one trial per test ingredient) were conducted over a 361-day period to determine the effects of feeding increasing inclusion rates of PM, PPC, SBM, SPC, CM and CPC on the growth performance of rainbow trout. Diets were formulated based on the digestible nutrient content of all ingredients as determined in the previously conducted digestibility trials, to contain 0, 75, 150, 225 or 300 g/kg of each test ingredient. All diets were nutritionally equal and contained 17.6 MJ/kg digestible energy, 386.2 g/kg digestible crude protein and were balanced for digestible essential amino acids to meet or exceed the requirements of rainbow trout. Linear and quadratic analysis was conducted on the experimental data. There were no significant regressions resulting from feeding PM, SPC or CPC at 0-300 g/kg for average daily feed intake (ADFI), specific growth rate (SGR), feed conversion ratio (FCR) or protein efficiency ratio (PER). A positive relationship was associated between PPC inclusion and ADFI (P < 0.05). There was a significantly negative quadratic equation associated with the inclusion level of SBM on SGR and FCR and significantly negative linear and quadratic equations for PER. There were significantly negative linear relationships between the inclusion rate of CM and the SGR, FCR and PER of rainbow trout (P < 0.05). Growth trial results suggest at inclusion levels up to 300 g/kg, PM, PPC, SPC and CPC are feasible plant-based fish meal replacements with predictable growth effects, provided the nutritional constraints set in this experiment are followed. The results of these growth experiments were further analyzed using structural equation modeling to determine the relationship between ANF in the six ingredients and ADFI and SGR, which were transformed (tSGR and tADFI, respectively) to enable comparisons between experiments. All possible models between ingredient ANF (starch, phytic acid, glucosinolates, tannins, isoflavones, total NSP, soluble NSP, insoluble NSP and saponins) and ADFI and SGR were calculated. The model with the highest likelihood, as determined by the Akaike Information Criteria0, contained 29 parameters and six degrees of freedom. tADFI positively influenced tSGR. Glucosinolates, saponins, and phytates had a significantly negative impact on tADFI, whereas tannins had a significantly positive impact. The presence of saponins in the diet resulted in a decrease in tSGR. This structural equation model had significant correlations between all ANF, with the exception of phytates and saponins. Future applications of this work will be to develop a nutritional model for optimal inclusion of plant-based feed ingredients in rainbow trout diets, based on their ANF content, which may improve the accuracy of diet formulation and growth prediction.

There has been increased interest in utilizing switchgrass (Panicum virgatum) as biomass. There are several challenges to developing this industry, and these have led to the potential use of switchgrass as hay for feeding beef cattle in Kentucky. The effect of increasing maturity on crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF) and nutritive values of switchgrass hay has been well documented, but few in vivo intake and digestibility trials have been conducted to assess this effect on animal performance when feeding beef cattle. Two in vivo intake and digestibility trials were conducted in 2011 in which Angus x Hereford beef steers (200-265 kg) were fed Alamo and Cave-in-Rock switchgrass harvested as late vegetative, boot, and early flowering hay. The objectives of these trials was to evaluate the effect of increasing maturity on apparent dry matter intake (DMI), digestible dry matter intake (DDMI), and dry matter digestibility (DMD); and to discuss potential challenges that producers might face if incorporating switchgrass hay into their forage program for feeding beef cattle. Observed decreases in nutritive value, DMI, DDMI, and DMD indicate that producers should harvest Alamo and Cave-in-Rock switchgrass before it reaches the boot stage of maturity.

Aquaculture represents a sustainable alternative to natural fisheries for provision of high quality, animal protein. Crustaceans make a significant contribution to global aquaculture production, of which decapods are the most economically important group. Among freshwater crayfish, the genus Cherax includes several species that have emerged as important culture species. A suite of favourable biological attributes, including fast growth and an omnivorous feeding habit, have contributed to establishment of successful culture of Cherax quadricarinatus (redclaw) in many countries. Aspects of redclaw production, however, remain relatively undeveloped, in particular feed formulation. To better understand the digestive processes and nutritional requirements of redclaw, this study examined the relationship between diet composition and digestive enzyme activity, growth performance and diet digestibility coefficients. The extent to which redclaw can efficiently utilise complex polysaccharides, such as cellulose, has been speculated on by authors who reported endogenous cellulase activity in this species. I evaluated the use of insoluble α-cellulose by redclaw, demonstrated that high dietary levels (30%) can significantly reduce the specific activity of selected digestive enzymes (amylase and cellulase), while also lowering apparent digestibility coefficients. Inclusion of α-cellulose above 12% also significantly reduced survival rate, specific growth rate and feeding efficiency in this organism which corresponds with low tolerance for insoluble fibre by other decapods. Even though redclaw possess endogenous cellulases, they appear to have only a limited capacity to utilise insoluble fibre in their diets. Further, I assessed the impact of different nutrient profiles on digestive enzyme activity, growth and tail muscle composition in redclaw. Purified diets containing varying levels of dietary protein significantly affected activity of digestive enzymes (protease, amylase and cellulase) and the composition of the tail muscle tissue. Redclaw have a relatively low protein requirement, which was reflected here, as little significant difference was observed in growth rates and the feed conversion ratio was only significantly affected by the lowest protein diet. Manipulation of the non-protein energy component in purified diets (protein to lipid ratio) had no effect on growth performance indices in redclaw. Digestive enzyme activity (protease) was however, strongly influenced by both the amount of protein and lipid in the diet and a significant correlation was observed between protease activity and growth performance indices. The findings here, provide preliminary data for consideration of digestive enzymes such as proteases as potential growth indicators for freshwater crayfish. These enzymes are already recognised as reliable biological indicators for comparison of digestive efficiency and potential growth rate in fish. The relationship between diet composition and digestive enzyme expression observed here, stress the need for further empirical evaluation of specific ingredients in artificial diets for redclaw. A range of single cell, plant and animal-based, agricultural products were assessed for their potential use in diets formulated for redclaw. Analysis of dietary supplements revealed that apparent digestibility of crude protein was generally higher for diets containing plant-based ingredients. A similar outcome was observed for digestibility coefficients of test ingredients. Ingredient type also had a significant effect on digestive enzyme activity. Importantly, a significant correlation was observed for enzyme activity and apparent digestibility coefficients. It appears that redclaw have the capacity to utilise nutrients from a broad range of dietary ingredients successfully including animal, single cell and in particular, plant matter in their diet. Taken together, the results presented here demonstrate that digestive enzyme activities in redclaw are significantly influenced by diet composition. I show clearly that the ability of redclaw to utilise various nutrients (measured as digestibility coefficients) is highly correlated with digestive enzyme activity. Finally, protease activity demonstrated a potential for use as an indicator of redclaw growth performance. The data presented here will contribute to development of better and cheaper feed formulations for use in redclaw aquaculture and have broader applications to freshwater crustacean culture. In particular, the potential for use of plant-based ingredients in aqua-feeds for redclaw will contribute to a more economically and environmentally sustainable redclaw culture.

The nutritional value of faba beans (Vicia faba), Australian sweet lupins (Lupinus angustifolius), white lupins (Lupinus albus) and peas (Pisum sativum) grown in New Zealand for broilers were evaluated in terms of their nutritional characteristics, protein quality (protein efficiency ratio), apparent metabolisable energy, apparent ileal digestibility coefficient of amino acids and the effects on bird performance. The effects of dehulling and extrusion cooking on the nutritive value of legumes were also investigated. The first experiment discussed in Chapter 3 evaluated the effect of cultivars on the nutrient profile and protein quality of chickpeas (Cicer arietinum), Australian sweet lupins, peas and soybeans (Glycine max). With the exception of white lupins, cultivars had no effect on the proximate and fibre composition of grain legumes. Starch was the primary carbohydrate component of chickpeas and peas, whilst non-starch polysaccharides were the major carbohydrates in lupins. The legume proteins were deficient in lysine, methionine, cystine and threonine. No differences were found in protein quality between cultivars of the different grain legume species. The lowest weight gain and protein efficiency ratio, in addition to the highest relative pancreatic weight and mortality rate was found in raw soybeans, suggesting that soybeans contained high a concentration of anti-nutritional factors, such as protease inhibitors. Birds fed chickpeas, lupins and peas had a low mortality rate and relative pancreatic weight, confirming that the level of anti-nutrients in these legume seeds was low. The apparent metabolisable energy and apparent ileal digestibility coefficient of amino acids of faba beans, Australian sweet lupins, white lupins and peas were determined in the second experiment (Chapter 4). Cultivar effect on the apparent metabolisable energy values was observed only for faba beans and white lupins. Faba beans, white lupins and peas had comparable apparent metabolisable energy values, but these values were higher than those of Australian sweet lupins, and lower than that of soybean meal. No cultivar differences were found in the apparent ileal digestibility coefficient of amino acids of grain legumes. The apparent ileal digestibility coefficient of amino acids of both lupin species was found to be comparable to that of soybean meal. The effects of feeding diets containing 200 g/kg faba beans, lupins or peas on the performance, digestive tract development and litter quality of broilers were investigated in the third and fourth trials. In the cage trial (Chapter 5), the results showed that the weight gain of birds fed diets containing grain legumes was similar to that of control diet. Feed intake and feed per gain of birds fed diets containing the majority of grain legume cultivars did not differ from those fed the maize-soy diet. Birds fed diets containing faba beans had more dry and friable excreta compared to other treatment diets. The performance of birds fed diets containing 200 g/kg grain legumes during the 35 d grow-out period, in the floor pen trial (Chapter 6), confirmed the results of the cage trial. In this trial, weight gain and feed per gain of birds fed diets without meat meal were superior to those with meat meal. In cage trials, the modification of some segments of digestive tract development was probably due to the dietary NSP. Whilst in floor pen trial, digestive tract development was not influenced by the inclusion of grain legumes. The effect of methodology of determination (direct vs. difference method) on the apparent ileal digestibility coefficient of amino acids of wheat, maize, Australian sweet lupins, peas and soybean meal for broilers was evaluated in the fifth study (Chapter 7). The influence of methodology on apparent ileal digestibility coefficient of amino acids was found to vary amongst the feed ingredients. In general, the apparent ileal digestibility coefficient of amino acids of test ingredients determined by the difference method was higher than those determined by the direct method, suggesting that the use of the direct method may underestimate the apparent ileal digestibility coefficient of amino acids in low and medium protein ingredients. Data reported in Chapter 8 shows that dehulling increased the apparent metabolisable energy values of faba beans and Australian sweet lupins, but it had no beneficial effect on peas. The increase of apparent metabolisable energy values may be attributed to the decrease in non-starch polysaccharides of these legume seeds after dehulling. The removal of hulls increased the amino acid concentrations, but it had no effect on the apparent ileal digestibility coefficient of most amino acids. These results suggest that dehulling of grain legumes would be nutritionally beneficial and, likely to be economical in view of the improved amino acid concentrations and energy values. The final experiment (Chapter 9) demonstrated that extrusion of peas markedly influenced the content of crude protein, non-starch polysaccharides, starch, and trypsin inhibitors. The soluble non-starch polysaccharides and trypsin inhibitor contents of the majority of extruded pea samples were higher than those of raw peas, but insoluble and total non-starch polysaccharides decreased with extrusion. Extrusion had no effect on the apparent ileal protein digestibility and the apparent metabolisable energy of peas, but it increased ileal starch digestibility.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2007. / Härtill 4 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2006. / Härtill 4 uppsatser.