L'objectiu de la present tesis fou estudiar si la incorporació d'ingredients fibrosos a la dieta de garrins recent deslletats, era una bona estratègia per minimitzar els desordres intestinals que normalment ocorren durant l'etapa post¬deslletament, i d'aquesta manera facilitar l'adaptació digestiva dels animals en les següents etapes de creixement. Per aconseguir aquest objectiu, es dissenyaren quatre proves (capítols 4 a 7) experimentals.En la Prova 1 (Molist et al., 2009a), primer de tot volíem confirmar uns resultats preliminars obtinguts en una prova anterior on s'havia observat un major creixement dels animals quan una font de fibra insoluble (segó de blat, WB) fou introduïda en una dieta de garrins post-deslletament. Al mateix temps, també volíem analitzar si aquest tipus de fibra insoluble era adequada per aquest període de creixement dels animals, o si per contra, era més interessant incorporar un tipus de fibra soluble (com la polpa de remolatxa, SBP). L'objectiu de l'estudi era explorar l'efecte d'incloure dos tipus diferents de fonts de fibra (WB, insoluble i SBP, soluble) sobre el creixement, les característiques físico-químiques de la digesta i l'activitat metabòlica i la composició de la microbiota intestinal. Els resultats mostraren que la fermentació intestinal fou baixa durant la primera setmana post-deslletament. L'addició de WB o WB i SBP en la dieta incrementaren la fermentació intestinal i la concentració d'àcid butíric en la digesta cecal juntament amb una reducció de la població d'enterobactèries en les femtes. La conclusió de l'estudi fou que el consum d'un tipus de fibra insoluble durant els primers dies després del deslletament (ja sigui WB o WB-SBP) modifica les característiques físico-químiques de la digesta i afecta la colonització microbiana a l'intestí gros. També especularem que els efectes observats amb la inclusió de WB podrien està relacionats amb: 1.- canvis en les característiques físico-químiques de la digesta, tals com una majora capacitat de retenció d'aigua (WRC) i una major fermentació de la digesta intestinal, 2.- un efecte físic relacionat amb la mida de partícula gran o 3.- una reducció del temps de trànsit de la digesta intestinal. En la Prova 2 (Molist et al., 2009b), es volia confirmar la reducció de la població d'enterobactèries promoguda pel WB, i la seva capacitat per reduir els desordres digestius front a una infecció experimental amb E. coli K88. A més a més, es volia clarificar si aquest efecte observat amb la introducció de WB en la dieta estava relacionat amb la seva mida de partícula. Els resultats obtinguts confirmaren que la inclusió de WB reduïa la població de E. coli en la digesta ileal, i encara més interessant, també reduïa l'adhesió del E. coli K88 a la mucosa ileal. Al mateix temps, el WB amb mida de partícula grollera reduí la diversitat de la microbiota intestinal en comparació amb el WB molturat. La tercera prova (Prova 3, Molist et al., 2010a) fou dissenyada per esbrinar si els efectes positius del WB sobre la microbiota intestinal es devien a un efecte del WB sobre el trànsit intestinal dels animals. La hipòtesi del treball fou que la incorporació de WB en la dieta podia estimular el trànsit intestinal i reduir la paràlisis de la digesta intestinal dels garrins, causada per l'anorèxia que pateixen els animals en el període post-deslletament. En aquest experiment, el WB fou comparat amb un fàrmac que s'utilitza en medicina humana per tractar la diarrea que al mateix temps redueix el trànsit intestinal (loperamida). Els resultats de nou mostraren els efectes del WB sobre les característiques físico-químiques de la digesta (increment de la WRC) i la promoció de la fermentació intestinal (incrementant la concentració d'àcid butíric i disminuint la concentració dels isoàcids en la digesta intestinal). De forma inesperada, la loperamida incrementà el consum d'aliment i el creixement dels animals. Suggerírem que aquest efecte estava relacionat amb l'efecte analgèsic i l'activitat opioide d'aquest fàrmac en el tracte intestinal. No poguérem confirmar si el WB reduí el temps de trànsit intestinal o el possible rol que juga la modificació del temps de trànsit intestinal sobre els canvis de la microbiota intestinal. En l'última prova (Prova 4, Molist et al., 2010b) la intenció era confirmar tots els resultats previs (reducció de la població d'enterobactèries i increment de la concentració d'àcid butíric) en un comparació entre la incorporació de WB amb la inclusió d'òxid de zinc (ZnO) en la dieta. El ZnO és un ingredient àmpliament utilitzat en les dietes post-deslletament pel seu efecte antimicrobià similar al que s'obtenia amb la incorporació d'antibiòtics promotors de creixement (AGP) en el pinso, i per tant oposat a l'efecte promogut per la incorporació de fibra en la dieta. A més a més, considerant els resultats observats sobre la reducció de l'adhesió del E. coli K88 a la mucosa ileal promogut per l'addició de WB, es volia clarificar si el WB també podia exercir un efecte físic i blocar l'adhesió del E. coli K88 a la mucosa. Els resultats foren una mica sorprenents perquè s'observà una interacció negativa entre el WB i el ZnO sobre la microbiota intestinal. Aquesta interacció negativa s'associà a la presència de fitats en la dieta. Aquests resultats posaren de relleu la recomanació d'incorporar enzims (fitases) en les dietes després del deslletament amb l'objectiu d'incrementar la biodisponibilitat del zinc de la dieta. També detectarem una alta habilitat de la fracció soluble extreta del WB d'unir-se al E. coli K88 in-vitro. Aquest resultat ens permet suggerir que part dels efectes positius sobre la microbiota intestinal observats amb la incorporació de WB en la dieta eren deguts entre altres factors, a la seva capacitat de blocar l'adhesió de E. coli patògens a la mucosa intestinal. Els resultats exposats en la present tesis, avalen l'estratègia d'incloure un nivell moderat de fibra (>60 g FND/kg per porcs entre 6 - 12 kg) en les dietes post-deslletament. Els resultats obtinguts mostren els efectes positius derivats de la inclusió d'una font de fibra insoluble, com WB, en la modificació de l'ambient intestinal i la instauració d'una microbiota saludable. Aquests efectes beneficiosos observats amb l'addicció de WB s'associaren a modificacions en les característiques físico-químiques de la digesta (increment de la WRC de la digesta) i amb la seva habilitat per blocar l'adhesió del E. coli a la mucosa ileal. Tot i així, el contingut en fitats d'aquest ingredient pot reduir la biodisponibilitat i l'eficàcia del ZnO en la dieta, fins i tot quan es subministra a dosis terapèutiques. És per aquest motiu que proposem considerar l'addició de fitases en dietes post-deslletament a base de cereals per: 1.- incrementar la biodisponibilitat de Zn, 2.- mantenir els efectes beneficiosos relacionat amb la inclusió de ZnO o WB en la dieta, o 3.- reduir la dosis de ZnO en la dieta. / The objective of this thesis was to study whether the incorporation of fibrous ingredients in the diet of piglets would minimize the intestinal disorders that usually occur during the early period after weaning and facilitate the adaptation of the digestive system of the animals in the subsequent growing periods. To achieve this goal, four trials (chapters 4 to 7) were designed. In Trial 1 (Molist et al., 2009a), we first wanted to confirm some preliminary positive results associated with a higher growth rate of the animals obtained when an insoluble fibre source (wheat bran, WB) was introduced in post-weaning diets. At the same time, we wanted to assess whether this type of fibre source was appropiate for this period, or whether it would be more advantageous to incorporate a soluble fibre source (such as the sugar beet pulp, SBP). The study aimed to explore the effects of including two fibre sources (WB, insoluble and SBP, soluble) on the performance, the physicochemical properties of digesta and the metabolic activity and composition of the intestinal microbiota. Results showed that intestinal fermentation was low during the first week after weaning. The addition of WB or WB plus SBP in the diet increased intestinal fermentation and the concentration of butyric acid in the caecum digesta, and reduced the enterobacteria population in faeces. It was concluded that consumption of an insoluble fibre source during the first days after weaning (either WB or WB-SBP) modifies the physicochemical properties of digesta and affects the microbial colonization in the hindgut. We also speculated that the effects observed with the inclusion of WB could be associated with: 1.- changes in the physicochemical properties of digesta, such as the higher water retention capacity (WRC) and fermentation promoted in digesta, 2.- a physical effect related to its larger particle size or 3.- a reduction in the transit time of digesta. In Trial 2 (Molist et al., 2009b), we wanted to confirm the referred reduction of the enterobacteria population promoted by WB, and its likely ability to reduce digestive disturbances after an experimental infection with E. coli K88. In addition, we wanted to clarify whether this effect of WB was related to its particle size. The results confirmed that WB inclusion reduced the E. coli population in the ileum digesta and, more interesting, also reduced the E. coli K88 attachment to the ileum mucosa. Coarse particle size reduced the microbial diversity compared to finely milled WB. The third trial (Trial 3, Molist et al., 2010a) was designed to elucidate whether the positive effects of WB on the intestinal microbiota could be due to an effect of WB on the intestinal transit of the animals. Our hypothesis was that incorporation of WB in the diet could stimulate the intestinal transit and so reduce the intestinal stasis of digesta in the piglets provoked by post-weaning anorexia. In this experiment, WB was compared with a drug used in human medicine to treat diarrhoea that slows the intestinal transit (loperamide). The results again showed the effects of WB on the physicochemical properties of digesta (increasing WRC) and the enhancement of gut fermentation (increasing butyric acid and lowering isoacid concentration associated to gut fermentation). Unexpectedly, loperamide increased the feed intake and animal growth. We suggested that this effect could be associated to its analgesic effect on and opioid activity in the intestinal tract. We were not able to confirm if WB reduced the intestinal transit time or the likely role of the modification of the intestinal transit time in the changes in intestinal microbiota. The last trial (Trial 4, Molist et al., 2010b) intended to confirm all the previous results (the reduction of enterobacteria population and increasing the butyrate concentration) in a comparison between the incorporation of WB with the inclusion of zinc oxide (ZnO) in the diet. ZnO is a widely used ingredient in post-weaning diets producing antimicrobial effects resembling those of the antibiotic growth promoters (AGP) and therefore opposed to the inclusion of fibre in the diet. In addition, and considering the previous observed effects on the E. coli K88 adhesion to the ileum mucosa, we wanted to clarify whether WB could have a physical role on the blockage of the adhesion of E. coli K88 to the mucosa. The results were quite surprising because a negative interaction between WB and ZnO was observed on the intestinal microbiota, which was associated to the presence of phytates in the diet. These results highlighted the recommendation of incorporating enzymes (phytases) in the post-weaning diets in order to increase the bioavailability of zinc. We also detected a high ability of soluble WB extract to bind E. coli K88 in-vitro, which suggests that part of the positive effects on the intestinal microbiota reported with the WB inclusion were due to its ability to block the adhesion of pathogenic E. coli to the intestinal mucosa. Results exposed in this thesis, support the strategy of including a moderate amount of fibre (>60 g NDF/kg for pigs between 6 - 12 kg) in the diets of early weaned pigs. Our results show the positive effects of including an insoluble source, such as WB on the modification of the intestinal environment and the instauration of a healthy microbiota. These beneficial effects of WB inclusion were associated to changes on the physicochemical properties of digesta (like an increasing WRC of the digesta) and with its ability to block E. coli attachment to the ileum mucosa. However, the presence of phytates in this ingredient may also reduce the availability and efficacy of ZnO in the diet, even when it is provided at therapeutic doses. We propose the consideration of the inclusion of phytase in the post-weaning cereal based diets in order to: 1.- increase Zn biovailability, 2.- maintain the beneficial effects related to ZnO or WB inclusion, or 3.- reduce the therapeutic doses of ZnO in the diet.

Doctor of Philosophy / Department of Grain Science and Industry / Yong Cheng Shi / Wheat bran is a by-product of the wheat flour milling industry. The number of food products containing wheat bran is on the rise because it is a well-recognized good source of dietary fiber. Currently, bran is a low-value commodity used mostly in animal feed, but it has the potential for more extensive applications. To understand the functional and nutritional properties of wheat bran and better use wheat bran in food, it is critical to understand the physical structure of wheat bran. For the first time, solid-state ¹³C cross-polarization magic-angle spinning nuclear magnetic resonance (¹³C CP/MAS NMR), X-ray diffraction (XRD), and small angle X-ray scattering (SAXS) were used to study the physical structure of wheat bran and its dissected layers. The XRD and Solid-State ¹³C CP/MAS NMR both confirmed the presence of crystalline cellulose in untreated bran, enzymatically treated bran, and dissected bran layers. Destarched and deproteinized wheat bran (DSDPB) was treated with a mixture of either 7 or 9% sodium hydroxide and 12% urea solvent and structure of the extracted polymers was investigated. Three and 6 cycle dissolution schemes, were examined involving the repeated cooling of the solvent bran mixture to -12.6 °C and then agitating it at 25 °C. When 7% NaOH/12% urea (6 cycle) was applied to DSDPB, 84.1% of the material was solubilized including 89.8% of the arabinoxylans (AX). This procedure recovered more wheat bran AX for characterization than any previous study using alkaline dissolution. Wheat bran was enzymatically and hydrothermally treated to maximize the soluble fraction. Unlike previous research, the starch and protein were kept and not removed before endoxylanase treatment. The retained protein and glucose polymers (starch, β-glucan, cellulose) could provide functional benefits in addition to the arabinoxylan and could make the process more economical. Wheat bran hydrolyzed with thermostable α-amylase, protease, and xylanase was the recommended treatment. The combined solubles had a viscosity of 23 cP (10% w/w solids) and ranged in estimated molecular weight from ~600 to 20,000. The percentage of untreated wheat bran AX that was solubilized was 50% and the percentage of AX in the solubles was 23%.

Doctor of Philosophy / Department of Grain Science and Industry / Yong-Cheng Shi / Wheat bran is high in dietary fiber. Resistant starch (RS) is considered a source of dietary fiber. Wheat bran and RS have different functional properties and may not have the same nutritional properties. This dissertation covers two areas of importance in cereal chemistry and human nutrition: wheat bran and RS. Wheat bran chemical and physical influence of nutritional components Wheat bran has become a hot topic due to positive nutritional correlations, and industrial /humanitarian needs for healthy ingredients. Evolving wheat bran into a demanded product would impact the industry in a positive way. The overall aim of this research was to understand chemical and structural composition, to provide avenues for wheat bran development as a healthy food ingredient. To achieve this goal, antioxidant properties in dry wheat milling fractions were examined, effects of wheat bran particle size on phytochemical extractability and properties were measured, and substrate fermentation was investigated. It was noted that mixed mill streams, such as mill feed, have antioxidant properties (0.78 mg FAE/g; 1.28 mg/g total antioxidant capacity; 75.21% DPPH inhibition; 278.97 [mu]mol FeSO[subscript]4/g) originating from the bran and germ fractions. Additionally, extraction of reduced particle size whole wheat bran increased measured values for several assays (185.96 [mu]g catechin/g; 36.6 [mu]g/g; 425 [mu]M TE), but did not increase volatile fatty acid production during in vitro rumen fermentation over unmilled bran. RS digestion, glycemic response and human fermentation In vitro action of enzymes on digestion of maize starches differing in amylose contents were studied. The objectives of this study were to investigate the exact role of [alpha]-amylase and amyloglucosidase in determining the digestibility of starch and to understand the mechanism of enzymatic actions on starch granules. Starch digestibility differed (30-60%) without combination of enzymes during in vitro assay. Further investigations utilized human glycemic response and fermentation with consumption of a type 3 RS without dietary fiber (AOAC method 991.43). Blood glucose response provided lower postprandial curves (glycemic index value of 21) and breath hydrogen curves displayed low incidences fermentation (40%) with consumption of the type 3 RS, due to the structure of starch and digestion by enzymatic action.

<p>Sporedni proizvodi dobijeni u procesu mlevenja žitarica, p&scaron;enične i ovsene mekinje, hidrotermički su tretirane u cilju dobijanja gelova, koji se, kao zamenjivači masti, mogu koristiti u formulacijama prehrambenih proizvoda. Optimizacija procesnih parametara (koncentracija mekinja, vreme homogenizacije i temperatura homogenizacije) proizvodnje gelova vr&scaron;ena je primenom postupka odzivne funkcije (RSM). Gelovi od p&scaron;eničnih i ovsenih mekinja, koji su pripremljeni po prethodno utvrđenim optimalnim parametrima (za p&scaron;enične mekinje: 22,0% koncentracija mekinja, vreme homogenizacije od 11,7 min i temperatura homogenizacije od 83,2&deg;C; za ovsene mekinje: 22,0% koncentracija mekinja, vreme homogenizacije od 10,0 min i temperatura homogenizacije od 95,0&deg;C), su, dalje, kao zamenjivači masti, bili inkorporirani u formulaciju keksa na različitim nivoima supstitucije masti (30%, 40% i 50%).<br />Fizičke, teksturne i senzorske karakteristike keksa sa zamenjivačima masti ispitane su u poređenju sa kontrolnim (punomasnim) keksom, te je nivo zamene od 30% izabran kao najpogodniji u smislu sniženja sadržaja masti, sa jedne strane, i ostvarenja željenih karakteristika, sa druge strane.<br />S obzirom da su proizvedeni zamenjivači masti na bazi mekinja nutritivno vredni i bogati funkcionalnim komponentama, ustanovljeno je da je dodatak ova dva funkcionalana zamenjivača masti na nivou od 30% doprineo pobolj&scaron;anju nutritivnih i funkcionalnih svojstava keksa u pogledu povećanog sadržaja prehrambenih vlakana i minerala, povoljnijeg odnosa PUFA/SFA, kao i porasta sadržaja antioksidativno delotvornih komponenti.</p> / <p>Wheat and oat brans, by-products of grain processing, were processed by hydrothermal treatments into the form of gels for partial replacement of fat in food products.<br />Response surface methodology (RSM) approach was applied to examine the effects and to optimize process parameters (bran concentration, homogenization time and homogenization temperature).<br />Wheat and oat bran gels prepared according to the previously determined optimal parameters (for wheat bran: 22.0% bran concentration, homogenization time of 11.7 min and homogenization temperature of 83.2 &deg;C; for oat bran: 22.0 % bran concentration, homogenization time of 10.0 min and homogenization temperature of 95.0 &deg;C) were further incorporated as fat substitutes into the cookie formulation at different levels of substitution (30%, 40% and 50%).<br />The physical, texture and sensory properties of cookies with fat replacers were examined in comparison with the control (full fat) cookies, and the fat replacement level of 30% was chosen as the most suitable in terms of reducing the fat, on the one hand, and achieving the desired mentioned characteristics, on the other.<br />Knowing that the produced fat replacers are nutritionally valuable and rich in functional components, it has been found that the addition of these two functional fat replacers at the level of 30% contributed to the improvement of the nutritional properties of cookies in terms of higher content of dietary fibers, minerals and more favourable ratio of PUFA/SFA, as well as higher content of antioxidant components.</p>

Owing to the increasing demand for alternative fuel additives, the Canadian ethanol industry has grown tremendously. In Western Canada, wheat has been the dominant feedstock for ethanol production because of steadily increasing domestic production and higher ethanol yields. Low protein and high starch wheat varieties have further increased the potential of grain-based ethanol production. As a consequence, the increased ethanol production has demonstrated an exponential increase in the availability of its co-products. Depending on the processes used, several co-products are produced, such as bran, condensed distillers solubles (CDS), and distillers dried grains with solubles (DDGS). Wheat bran is obtained as the co-product when debranning is incorporated in ethanol production. Debranning of wheat feedstock may be integrated into the ethanol production process to improve ethanol quality and yield. Debranning follows the principles of abrasion and friction. It improves the starch content of the feedstock and the fermentation efficiency of the ethanol plants. Several abrasive equipment that generate products having good quality and desirable ethanol yield are being used commercially. Among these, the Satake mill and the tangential abrasive dehulling device (TADD) are prominent, having high debranning efficiency, levels of sanitation, and improved production rates. In this thesis, the laboratory debranning process using these two equipment was optimized by varying the process variables in order to improve the ethanol production process. In the Satake mill, the sample size (30 and 200 g), rotational speed (1215, 1412, and 1515 rpm), grit size (30, 36, and 40), and retention time (30, 60, and 90 s) were varied. In the TADD mill, the sample size (30 and 200 g), grit size (30, 36, 50, and 80), and retention time (120, 180, 240, and 300 s) were varied while maintaining a constant rotational speed of 900 rpm. The experimental results indicated that in the Satake mill, 200 g sample size, 1515 rpm rotational speed, 30 grit size, and 60 s retention time provided optimal debranning and starch separation efficiency. For the TADD mill, 200 g sample size, 900 rpm rotational speed, 50 grit size, and 240 s retention time provided optimal results. Increased availability of ethanol co-products from the pretreatments and other processes brings forth the need for broadening the areas of application of these co-products. Among the various applications, the usage of the co-products as animal feed is predominant. Ethanol co-products have been traditionally incorporated as ingredients for animal feed. This thesis is aimed at combining the wheat bran and CDS in varying proportions (70:30, 80:20, and 90:10) and producing high quality animal feed pellets. Laboratory-scale pelleting was done at varying pelleting temperatures, 60, 75, and 90°C, to optimize the pelleting process. The results of laboratory-scale single pelleting indicated that 90:10 bran-CDS ratio and 90°C pelleting temperature produced pellets having good physical properties. Pilot-scale pelleting was done to verify the optimized variables, and to produce dimensionally stable and highly durable feed pellets. The results showed that 70:30 bran-CDS mixture produced pellets with high nutrient content and physical properties (760.88±2.04 kg/m3 bulk density and 97.79±0.76% durability). Similar to the single pelleting results, high pelleting temperatures (75°C) produced pellets with desirable physical properties. However, on cooling, the bulk density and durability change was the highest for 70:30 bran-CDS pellets, indicating an improvement in the physical characteristics. In conclusion, the bran and CDS, the two co-products of the ethanol industry, could be combined to produce feed pellets having good physical and nutritional properties.

The main objective of this study was to investigate the fibers and their effects and availability in ketchup (tomato fiber) and cake (wheat bran fiber) production. In order to this, rheological properties of ketchups with tomato fiber, and cake (100, 80, 60 g flour formulations) with wheat bran fiber in different concentrations were investigated. Tomato powder in ketchup and wheat bran in cake was used for comparison. The samples studied had pseudoplastic behavior having a definite yield stress with a good fit for the Herschel-Bulkley model. The viscosity and yield stress values increased as the percentage of fiber increased. Moreover the samples were found to be more elastic than viscous (G&rsquo / &gt / G&rsquo / &rsquo / ). Both G&rsquo / and G&rsquo / &rsquo / values increased with oscillatory frequency, percentage of fiber, and in cake samples decreased as the amount of flour decreased. Stability measurements of ketchups studied were done by using Lumisizer. The microstructure of tomato powder, wheat bran and fibers were investigated under SEM. It was seen that the fibers had branched, long and thin structure while the other two had lumy and thick structure. The pressure used, resulted in this structure with increased surface area and finally increased water holding capacity in fibers. Moreover, texture of cakes prepared was all investigated in terms of volume, outer surface, hardness, cohesiveness and gumminess. Finally it was found to be possible to produce healthier ketchups and cakes with fiber in a good quality by decreasing the other undesired ingredients.

Dietary fiber is a component in the structure of plants which is an important aspect of diet and nutrition. The demand of fiber has increased significantly, as consumers recognize its health benefits such as reduction of risk of colon cancer, cholesterol lowering affect, regulating blood glucose levels and low calorie intake. Therefore food manufacturers pay more attention to develop new products containing high fiber content. Of all the categories of food products, bakery products are the most common fiber-enriched products. In this research two different wheat bran fibers (coarse and fine fibers) that are produced by microfluidization method are utilized in one of the highly consumed bakery product &ldquo / cracker&rdquo / . In this thesis study coarse and fine wheat bran fibers were utilized in different amounts with replace to wheat bran (0,15, 25, 35, 45, 55, 65, 75 g). The effects of wheat bran fiber on crackers were determined by rheological measurements of dough samples and it was found that as the amount of wheat bran fiber increases / elasticity increases as well. Textural analysis were conducted for both dough and cracker samples and these analysis demonstrated that wheat bran fiber containing dough had higher hardness values than non/less containing ones. In addition to the above analysis, HPLC analyses were done for ferulic acid determination which is a significant nutritive compound in wheat bran. It was concluded that ferulic acid amount in fiber was much higher than wheat bran. This research demonstrated that more nutritive and much fiber containing crackers could be made by using wheat bran fiber instead of wheat bran.

A static in vitro digestion method was developed as a strategy to understand the effects of modelled digestion on the solubility of nutrients and selected bioactive compounds of autoclaved and untreated wheat bran. Brans from common soft, hard, and durum wheats were evaluated. Results indicated that the in vitro digestion protocol was suitable and effective. Effects of gastrointestinal simulation were considerably larger than gastric digestion alone. Digestibility of the brans ranged from 28.1 to 47.9%. Digestibility of bran minerals, starch and protein was substantial compared to lesser, but still significant, effects on fibre. Fibre solubility was significantly enhanced due to autoclaving. Total phenolic content, free radical scavenging and metal chelation activity were all substantially increased in soluble digests. Yields of these factors indicated that digestion of wheat bran releases ample levels of antioxidants that would be available for absorption in the small intestine to promote beneficial health effects.

A static in vitro digestion method was developed as a strategy to understand the effects of modelled digestion on the solubility of nutrients and selected bioactive compounds of autoclaved and untreated wheat bran. Brans from common soft, hard, and durum wheats were evaluated. Results indicated that the in vitro digestion protocol was suitable and effective. Effects of gastrointestinal simulation were considerably larger than gastric digestion alone. Digestibility of the brans ranged from 28.1 to 47.9%. Digestibility of bran minerals, starch and protein was substantial compared to lesser, but still significant, effects on fibre. Fibre solubility was significantly enhanced due to autoclaving. Total phenolic content, free radical scavenging and metal chelation activity were all substantially increased in soluble digests. Yields of these factors indicated that digestion of wheat bran releases ample levels of antioxidants that would be available for absorption in the small intestine to promote beneficial health effects.

O experimento foi conduzido com o objetivo de avaliar o desempenho corporal e reprodutivo de 120 novilhas de corte de um rebanho comercial Braford do desmame ao fim do período reprodutivo aos 14/15 meses de idade, quando submetidas a três sistemas alimentares: pastagem de aveia preta (Avena strigosa Schreb.) e azevém (Lolium multiflorum Lam.) (AV+AZ), pastagem de aveia e azevém mais 1% do peso corporal de farelo de trigo (FT), pastagem de aveia e azevém mais 1% de peso corporal de farelo de trigo e 200ml/cabeça/dia de glicerina bruta (FTG) e da prenhez das novilhas aos 14/15 meses de idade ao fim da prenhez quando primíparas aos 24/25 meses de idade, quando submetidas a dois sistemas alimentares: pastagem de azevém (Lolium multiflorum Lam.) por 22 dias pós-parto e mais 22 dias em pastagem natural (PSS), pastagem de azevém por 22 pós-parto recebendo 1% de peso corporal de farelo de trigo e por mais 22 dias em pastagem natural (PCS). O delineamento experimental foi o inteiramente ao acaso, com medidas repetidas no tempo. Sem limitações na oferta forrageira, as suplementações não afetaram a taxa de prenhez, mas determinaram maior concepção nos primeiros 21 dias da temporada Novilhas prenhes, independentes dos tratamentos, têm melhores características fenotípicas de conformação, precocidade, musculatura e tamanho já ao desmame, têm maiores ganhos de peso e condição corporal até o início e ao fim dos tratamentos alimentares e início da temporada reprodutiva, o que permite uma seleção prévia, à idades menores, das bezerras a serem postas em sistemas para prenhez aos 14/15 meses de idade. Rebanhos com prenhez estabilizada aos dois anos de idade necessitam de seleção para maior precocidade sexual e prenhez aos 14/15 meses de idade, não somente ter pesos e condições corporais. Novilhas prenhas aos 14/15 meses de idade têm bom desenvolvimento em pastagem de tifton 85 nos meses de outono com a oferta de 2.500kg de MS/ha. Primíparas suplementadas por 44 dias no pré-serviço têm significativo maior ganho de peso, maior prenhez, com menores intervalo parto-concepção e intervalo entre partos do que as não suplementadas, porém ainda cerca de trinta dias a mais do que o recomendado em sistemas de cria de maior produtividade e eficiência. / This study aimed to evaluate the body development and reproductive performance of 120 Braford heifers from a commercial beef herd from the weaning to first breeding at 14/15 months of age, when submitted to three different feeding systems: black oat (Avena strigosa Schreb.) and Italian ryegrass (Lolium multiflorum Lam.) pastures (AV+AZ), black oat and Italian ryegrass plus supplementation with wheat bran at 1% of the body weight (FT), and black oat and Italian ryegrass plus supplementation with wheat bran at 1% of the body weight plus 200 mL head-1 day-1 of crude glycerol (FTG). We also evaluated the reproductive performance of primiparous cows first bred with 14/15 months of age at their second calving, when submitted to two feeding systems prior to the second breeding season: Italian ryegrass pasture for 22 days postpartum following another 22 days in natural pasture (PSS), and Italian ryegrass pasture for 22 days postpartum receiving 1% of the body weight of wheat bran, following another 22 days in natural pasture (PCS). Treatments were arranged in a completely randomized design with repeated measures in time. Without limitations on herbage allowance from the pasture, supplementation did not affect the pregnancy rate, but increased conception on the first 21 days of the breeding season Heifers that conceived, regardless of the treatments, had better phenotypic characteristics of body conformation, precocity, musculature and frame size at weaning. These animals also had greater average daily gain and body condition at the beginning and at the end of the feeding treatments, and at the beginning of the breeding season. Those traits could be used as indicators for an early selection of heifers to be designated to breeding programs at 14/15 months of age. Herds with stabilized conception at two years of age require selection for greater sexual precocity and conception at 14/15 months of age, and not only have adequate body weight and condition at the time of breeding. Heifers that conceived at 14/15 months of age with forage allowance of 2,500 kg DM ha-1 present good development in tifton 85 pasture during the autumn months. Primiparous supplemented for 44 days prior to breeding had greater weight gain and conception, with shorter calving-to-conception interval and shorter interval between calving than those not supplemented, but still about thirty days longer than recommended to calving systems with higher productivity and reproductive efficiency.