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1
Stebbens, Helen Rose. „The digestion and utilisation of food fibre by growing pigs“. Thesis, University of Edinburgh, 1988. http://hdl.handle.net/1842/27458.
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A series of investigations were undertaken to provide information for compounders to consider when including fibrous foods in diets for growing pigs. The work involved measurements of nutrient digestibilities, growth trials and calorimetric studies. The digestibility of the neutral detergent fibre (NDF) fraction of a food was dependent on a number of factors including the source of fibre, the adaptation period and liveweight of the pig, and the protein and lipid contents of the diet. The level of addition of food fibre was not important in determining the digestibility of the NDF component of a fibre source, whereas an inverse relationship was found between the digestibility of nitrogen and energy, and the level of added food fibre. It was concluded that increasing the level of addition of food fibre is more important in determining the depressive effect on the digestibility of non-fibre components than its own. Rapid growth was achieved when young, weaned and growing pigs were given diets containing wheatfeed and sugar-beet pulp. A substantial part of the energy supplied was in the form of VFA produced by the fermentation of non-starch polysaccharides in the wheatfeed and sugar-beet pulp. A growth trial with diets containing sugar-beet pulp and maize revealed that fermented energy from beet pulp was used with an efficiency of 0.72 that of the energy of maize. The apparently digested energy arising from the fermentation of non-starch polysaccharides, therefore, does not correspond directly in terms of potential use to the animal with that obtained by the enzymic digestion of maize starch. A net energy value for sugar-beet pulp was also calculated. This work has shown that wheatfeed and sugar-beet pulp may be useful as dietary ingredients for growing pigs. However, growth rates may be slightly depressed due to a lower efficiency of utilisation of apparently digested energy from the fibrous fraction of the diet. This could lead to on farm problems associated with a decreased throughput eg overstocking. However, the use of a corrected digestible energy value and ileal digestibilities of amino acids for a fibrous food, when formulating rations, could lead to an improvement in the prediction in performance. As well as the nutritional aspects of feeding fibrous foods, there are also a number of non-nutritional factors which will influence the use of fibrous materials and these are discussed in the light of their practical implications for the feeding of fibrous foods to pigs.
2
Key, Fiona Brigit. „Digestion and large intestinal fermentation of breads and haricot beans (Phaseolus vulgaris)“. Thesis, University of Newcastle Upon Tyne, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.308980.
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3
Useni, Bilungi Alain. „Effect of exogenous fibrolytic enzymes on fibre and protein digestion in ruminant animals“. Thesis, Stellenbosch : University of Stellenbosch, 2011. http://hdl.handle.net/10019.1/6744.
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Thesis (MScAgric (Animal Sciences))--University of Stellenbosch, 2011.Includes bibliography.
ENGLISH ABSTRACT: Forages are the main feed components in ruminant production systems for the reason that they are often the major source of energy available to the animal. However, only 10 to 35% of energy intake is available as net energy because the digestion of plant cell walls is not complete. This can significantly affect livestock performance and profits in production systems that use forages as a major source of nutrients of the diet. As a result of low and variable nutritive values of forage feedstuffs, attempts to improve ruminal fibre degradability have been an ongoing research topic. The use of exogenous fibrolytic enzymes (EFE) has been proposed as means to improve forage digestibility. Positive results with regard to rumen forage digestibility and other animal production traits have consequently been obtained due to increased rumen microbial activity following EFE addition in ruminant diets. Two EFE (Abo 374 and EFE 2) and one commercial yeast preparation were firstly identified and selected for their potential to improve the cumulative gas production (GP) at 24 hours of a range of feed substrates using the in vitro GP system as a screening step to identify the superior EFE products. The different feed substrates were lucerne hay, wheat straw, wheat straw treated with urea and a commercial concentrate diet. An in vitro experiment was undertaken on these four different substrates in order to evaluate the two EFE and the yeast preparation. This was to identify the most promising EFE capable of producing a significant effect on feed digestibility using organic matter digestibility (in vitro true digestibility) and fermentation characteristics (in vitro GP system). Results from the in vitro evaluation showed that EFE significantly enhanced in vitro DM degradability and GP profiles (P < 0.05). Abo 374 enzyme showed potential to increase in vitro microbial protein synthesis (MPS) of GP residues of the concentrate diet. In addition, no correlation was found between the in vitro MPS and the 48 hours cumulative GP of all the tested substrates (P < 0.05; R2 < 0.30). Treatments were found to increase in vitro MPS, feed degradability and the cumulative GP of different quality forages and the concentrate diet, with Abo 374 being the best treatment (P < 0.05). However in vitro responses of EFE were variable depending on the energy concentration and chemical composition of different substrates. Variation in MPS was mostly due to the low recovery of purine derivates with the purine laboratory analysis. On the basis of these results, Abo 374 was selected and consequently further tested in another in vitro and in situ trial using a mixed substrate of lucerne hay and wheat straw. Abo 374 significantly improved the cumulative GP, in vitro DM and NDF disappearance of the mixed substrate (P < 0.05). In addition, no correlation was found between the in vitro MPS and the cumulative GP at 48 hours (P = 0.68; R2 < 0.25). The in situ disappearance of feed nutrients (DM, NDF and CP) with Abo 374 was similar to the control. The lack of significance of disappearance was probably due to the small number of sheep used in the study and the relatively high coefficient of variation associated with measuring ruminal digestion. Abo 374 significantly increased the in situ MPS (P = 0.0088) of the mixed substrate of lucerne hay and wheat straw. Evidence of the increased MPS and both in vitro and in situ disappearance of DM and NDF resulted from the Abo 374 activity during either the pre-treatment or the digestion process. The addition of Abo 374 to the mixed substrate of lucerne hay and wheat straw appeared to have been beneficial for microbial colonization of feed particles as a result of the increased rumen activity. It could be speculated that the primary microbial colonization was thus initiated, leading to the release of digestion products that attract in return additional bacteria to the site of digestion. This EFE may be efficient to produce some beneficial depolymerisations of the surface structure of the plant material and the hydrolytic capacity of the rumen to improve microbial attachment and the feed digestibility thereafter. Therefore, the mechanism of action by which Abo 374 improved the feed digestion can be attributed to the increased microbial attachment, stimulation of the rumen microbial population and synergistic effects with hydrolases of ruminal micro-organisms. With regard to these findings, the addition of EFE in ruminant systems can improve the ruminal digestion of DM, NDF and CP to subsequently enhance the supply of the metabolizable protein to the small intestine. Key words: crude protein (CP), exogenous fibrolytic enzymes (EFE), dry matter (DM), gas production (GP), neutral detergent fibre (NDF), microbial protein synthesis (MPS).
AFRIKAANSE OPSOMMING: Ruvoere is die hoof-voerkomponent in herkouer produksiesisteme aangesien dit dikwels die vernaamstebron van energie aan herkouer is. Slegs 10 tot 35% van die energie-inname is beskikbaar as netto-enrgie, omdat die vertering van selwande onvolledig is. Dit kan die prestasie en profyt in produksiesisteme drasties beïnvloed waar ruvoere as ’n hoofbron van nutriënte in die dieet gebruik word. Aangesien die nutriëntwaarde van ruvoere laag is en baie varieer, is navorsing vir verbeterde ruminale veselvertering steeds ’n voorgesette onderwerp. Dit is voorgestel dat eksogeniese fibrolitese ensieme (EFE) gebruik kan word vir verbeterde ruvoervertering. Positiewe resultate in ruminale ruvoerverterig en ander diereproduksie-eienskappe, is verkry as gevolg van toenemende rumen mikrobiese aktiwiteit na EFE aanvulling in herkouerdiëte. Twee EFE’s (Abo 374 en EFE 2) en `n gisproduk is geïdentifiseer en geselekteer vir hul potensiaal om die kumulatiewe gasproduksie (GP) na 24 uur met ’n reeks voersubstrate te verbeter met die gebruik van die in vitro GP sisteem as seleksiemetode om die superieure EFE produkte te identifiseer. Die verskillende ruvoersubstrate was lusernhooi, koringstrooi, ureumbehandelde koringstrooi en ’n kommersiële konsentraatdieet. ’n In vitro eksperiment was onderneem om die vier verskillende substrate te gebruik om die twee EFE’s en gisproduk te evalueer. Hierdeur sou die belowendste EFE’s identifiseer kon word wat ’n betekenisvolle effek op ruvoervertering het. Die vertering van ruvoer sal bepaal word deur organiese materiaal vertering (in vitro ware vertering), asook fermentasie-eienskappe (in vitro GP sisteem). Resultate van die in vitro evaluering het getoon dat EFE’s in vitro DM degradering en GP profiele verbeter. Dit blyk dat die Abo 374 ensiem ’n potensiële toemame in in vitro mikrobiese proteïensintese (MPS), soos bepaal deur die GP oorblyfsels van konsentraat diëte, tot gevolg gehad het. Daar was geen korrelasie tussen die in vitro GP en MPS van al die proefsubstrate nie. Dit blyk dat die behandelings ’n toename in in vitro GP, MPS en ruvoerdegradeerbaarheid van lae kwaliteit ruvoer- en konsentraatdiëte gehad het, waar Abo 374 die beste behandeling was. Die in vitro reaksies van die EFE’s was egter wisselend, afhangende van die energiekonsentrasie en die chemiese samestelling van die verskillende substrate. Variasie van MPS was meestal as gevolg van die lae herwinning van purienderivate tydens die purienanalise. Op grond van dié resultate, is Abo 374 geselekteer om verdere toetse in ander in vitro en in situ proewe te doen. Die substraat wat gebruik is, was ’n 1:1 mengsel van lusernhooi en koringstrooi. Abo 374 het die kumulatiewe RP, in vitro DM en NBV verdwyning van die gemengde substraat verbeter. Boonop is geen korrelasie tussen die MPS en in vitro GP gevind nie. In situ verdwyning van DM, NBV en RP was hoër vir Abo 374, maar nie betekenisvol nie. Die gebrek aan betekenisvolle verdwynings mag die gevolg wees van die klein hoeveelheid skape wat in die proef gebruik is, asook die relatiewe hoë koëffisient van variasie wat gepaard gaan met die bepaling van ruminale vertering. Abo 374 het die in situ MPS betekenisvol verhoog. Verhoogde MPS en in vitro en in situ verdwyning van DM en NBV is waargeneemwaarskynlik as gevolg van die aktiwiteit van Abo 374 gedurende die voorafbehandeling óf die verterings proses. Die byvoeging van Abo 374 tot die gemengde substraat van lusernhooi en koringstrooi blyk om voordelig te wees vir mikrobiese kolonisering van voerpartikels as gevolg van ’n toename in rumenaktiwiteit. Die primêre mikrobiese kolonisering het waaarskynlik gelei tot die vrystelling van verteringsprodukte wat addisionele bakterieë na die plek van vertering lok. Die EFE mag geskik wees vir voordelige depolimerisasie op die oppervlakstruktuur van die plantmateriaal, asook verbeterde hidrolitiese kapasiteit van die rumen om sodoende mikrobiese aanhegting, asook ruvoervertering te verbeter. Dus, Abo 374 se meganisme van aksie wat verbeterde ruvoervertering tot gevolg het, kan toegeskryf word aan `n verhoogde mikrobiese aanhegting, stimulering van die rumen mikrobiese populasie en die sinergistiese effek met hidrolases van rumen mikroörganismes. Ten opsigte van die bevindings, kan die byvoeging van EFE in herkouersisteme ruminale vertering van DM, NBV en RP verbeter, wat dan daaropvolgend die dunderm met meer metaboliseerbare proteïn sal voorsien. Sleutelwoorde: eksogene fibrolitiese ensieme (EFE), droëmaterial (DM), ruproteïen (RP), neutraal bestande vesel (NBV), mikrobiese proteïensintese (MPS), gasproduksie (GP).
4
Anelich, Claudia Bruna. „Association between grinding energy and in-vitro neutral detergent fibre digestion kinetics in forages“. Diss., University of Pretoria, 2017. http://hdl.handle.net/2263/63233.
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Through the measurement of grinding energy, the possibility exists to predict forage fragility as
related to the chemical composition of forages. It is also possible to predict a potential relationship
between forage fragility and 240 hour in vitro neutral detergent fibre digestibility (uNDF240). These
results could lead to improved predictions of particle size reduction, animal chewing activity and energy
usage during the process of chewing.
Physically effective fibre (peNDF) is a key component of many nutritional models used to predict
the effect of forage particle size on cow chewing response. Chewing activity is a response which reflects
the chemical and physical properties of feeds, including intrinsic fragility. Forage fragility, or the ease of
particle size reduction during chewing, has been said to be similar among different sources of NDF, when
attempting to estimate peNDF. However, different NDF sources with similar particle sizes can elicit ariable chewing responses and this variation has serious implications for nutritional models which use
peNDF values. This variation has led to numerous inaccuracies in the system; therefore factors affecting
peNDF particularly forage fragility, need to be better understood as forage fragility may be closely linked
to NDF digestibility. Therefore, in this study, a possible association between forage fragility and short
term or long term in vitro NDF digestibility (ivNDFd) was investigated.
In order to investigate the possibility of predicting an association between forage fragility and in
vitro NDF digestion, a total of 35 forage samples from three forage species were collected from 25
different locations. Forage species included commonly used fibre sources in ruminant nutrition in South
Africa, namely Medicago sativa, Maize silage and Eragrostis curvula.
The forage samples were analysed for numerous chemical components, as well as 6-, 12-, 18-, 24-,
36-, 48-, 72-, 96-, 120-, 240-h ivNDFd and rate of NDF digestion (kd). The 240-h ivNDFd was used to
estimate indigestible NDF (iNDF). Particle size distributions were measured for all forage samples. Dried
samples were pre-cut with a knife mill fitted with a 2 cm screen, after which particle size distributions
were determined for each sample using a Retsch sieve shaker. For the measurement of grinding energy,
10 g duplicates of the 2 cm milled samples were milled with an ultra-centrifugal mill, fitted with a 1 mm
screen. During the grinding process, energy usage of the specific mill was measured using a data logger
with corresponding computer software and energy transducer. Energy measurements were reported as J/g
sample on dry matter (DM) basis. The 1 mm samples were then used for determining particle size
distribution again, in order to analyse change in particle distribution for each forage sample.
The results of this study showed, according to the final models, that initial particle size (IPS), final
particle size (FPS), cellulose and undigested NDF at 6 hours digestion (uNDF6) explain most of the
variation in forage fragility. All of these variables can be associated with a decrease in forage fragility,
due to an increase in energy usage during grinding with an increase in any of the aforementioned
components. Upon adding species as a variable that could influence forage fragility, it could be seen that
an interaction between M. sativa and FPS can be associated with a decrease in forage fragility, whereas an
interaction between maize silage and FPS can be associated with an increase in forage fragility, due to a
decrease in energy usage during grinding with an increase in this interaction. From the simple
associations and correlations, it was evident that kd can be associated with increased forage fragility, as
there was a decrease in energy usage during grinding with an increase in this parameter. Further correlations and/or linear associations indicate that NDF, acid detergent fibre (ADF), uNDF18, uNDF24,
uNDF36 and uNDF48 can possibly be associated with a decrease in forage fragility, due to an increase in
energy usage during grinding with an increase in any one of these variables. It would be expected that
acid detergent lignin (ADL) is also associated with decreased forage fragility; however, this can only be
assumed as the results for the effect of lignin on forage fragility are non-significant in this study.
The use of grinding energy has the potential to be a practical and useful measure to predict forage
fragility. However, the relative contribution of physical factors such as original particle size, particle
shape, surface area, morphology and a multitude of chemical factors toward the fragility of forages is
difficult to predict. Additional research is needed on the prediction of forage fragility and the possible
relationship between forage fragility and NDF digestion and which factors influence this concept, before
it can be incorporated as a meaningful and accurate input into nutritional models such as the National
Research Council (NRC) and the Cornell Net Carbohydrate and Protein System (CNCPS).Dissertation (MSc)--University of Pretoria, 2017.
Animal and Wildlife Sciences
MSc (Agric)
Unrestricted
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Colombatto, Dario. „Use of enzymes to improve fibre utilisation in ruminants : a biochemical and in vitro rumen degradation assessment“. Thesis, University of Reading, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.340076.
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Rallis, Ilias. „Intelligent chromatic fibre optic sensors and monitoring systems for enhancing useful by-products from anaerobic digestion“. Thesis, University of Liverpool, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.417968.
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Chikunya, Sifelani. „Microbial protein synthesis and fibre digestion in the rumen in relation to the form of supplementary nitrogen“. Thesis, University of Cambridge, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.624398.
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Dickner-Ouellet, Laurie. „Optimisation de l'usage des coproduits dans l'alimentation des porcs en croissance : impact du type de fibre et de la xylanase sur la digestion des nutriments“. Master's thesis, Université Laval, 2018. http://hdl.handle.net/20.500.11794/29576.
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L’augmentation du coût des ingrédients de base des aliments pour porcs a permis à certains ingrédients alternatifs de se tailler une place sur les marchés nord-américains de l’alimentation animale. En effet, leur utilisation judicieuse en production porcine peut représenter un atout économique important. Toutefois, l’usage d’ingrédients alternatifs est limité dans les aliments pour porcs, notamment à cause leur effet parfois négatif sur la qualité de la carcasse ainsi que de leur teneur élevée en fibres alimentaires, peu valorisées par les monogastriques. Ce projet avait comme objectif de mieux comprendre l’impact de l’usage des ingrédients alternatifs disponibles dans l’Est du Canada afin de diminuer les coûts d’alimentation, sans modifier les performances de croissance chez le porc. Plus précisément, le projet visait à évaluer l’impact de différents types de fibres (solubles et insolubles) et de la supplémentation en xylanase, une enzyme exogène, sur la digestibilité iléale apparente des composants nutritionnels ainsi que sur les performances de croissance et la composition corporelle chez le porc en croissance-finition. Pour ce faire, deux expérimentations ont été réalisées. La première était un essai de digestibilité réalisé à l’aide de porcs canulés chez lesquels la digestibilité iléale apparente a été mesurée pour différents aliments variant en leur teneur et leur type de fibres, et selon l’addition ou non de xylanase. La seconde expérimentation consistait en un essai de croissance chez le porc en finition afin de mesurer ces mêmes traitements sur les performances de croissance, la composition corporelle et la qualité du gras. Les résultats obtenus montrent que les niveaux élevés de fibres alimentaires utilisés n’ont pas eu d’effets majeurs sur la digestibilité iléale apparente des nutriments et de l’énergie, sur la composition corporelle et sur les performances de croissance des animaux. De plus, l’ajout de xylanase dans les aliments a eu peu d’effets sur les critères mesurés
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Selvin, David. „Regulation of Myoplasmic Ca2+ During Fatigue in KATP Channel Deficient FDB Muscle Fibres“. Thèse, Université d'Ottawa / University of Ottawa, 2013. http://hdl.handle.net/10393/26174.
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It is known that muscles that lack KATP channel activity generate much greater unstimulated [Ca2+]i and force than normal muscles during fatigue. The increase in unstimulated force in KATP channel deficient muscles is abolished by a partial inhibition of L-type Ca2+ channels, suggesting that it is due to a Ca2+ influx through L-type Ca2+ channels and a subsequent increased myoplasmic Ca2+. However, there is also evidence that the increase in resting force is abolished by NAC, a ROS scavenger. The objective of this study was to reconcile these observations by studying the hypothesis that “the increase in resting [Ca2+]i during fatigue in KATP channel deficient muscles starts with an excess Ca2+ influx through L-type Ca2+ channels, followed by an excess ROS production that causes a further increase in resting [Ca2+]i”. To test the hypothesis, single FDB fibres were fatigued with one tetanic contraction/sec for 180 sec. KATP channel deficient fibres were obtained i) by exposing wild type muscle fibers to glibenclamide, a KATP channel blocker and ii) by using fibres from Kir6.2-/- mice, which are null mice for the Kir6.2 gene that encodes for the protein forming the channel pore. Verapamil, a L-type Ca2+ channel blocker, applied at 1 μM, significantly reduced resting [Ca2+]i during fatigue in glibenclamide-exposed wild type fibres. NAC (1 mM) also reduced resting [Ca2+]i in glibenclamide-exposed muscles. The results suggest that the increase in resting [Ca2+]i during fatigue in KATP channel deficient FDB fibres is due to an influx through L-type Ca2+ channels, and an excess ROS production.
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Wilfart, Aurélie. „Digestion et transit digestif chez le porc en croissance : influence de la composition de l’aliment“. Rennes, Agrocampus, 2007. http://www.theses.fr/2007NSARB178.
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La mise a point de modèles de digestion nécessite de caractériser le transit et la digestibilité des nutriments dans les différents segments digestifs ces paramètres dépendent de l’animal et de la composition de l’aliment. Le premier objectif du travail de thèse était d’évaluer les conséquences d’une modification de la composition de l’aliment sur la digestibilité des nutriments et le transit dans les segments digestifs. Le deuxième était de quantifier les cinétiques d’hydrolyses des matières premières dans ces mêmes organes. Le temps de séjour moyen des digesta était de 1 heure dans l’estomac, 4 heures dans l’intestin grêle et 38 heures dans le gros intestin. L’augmentation de la teneur en fibres dans l’aliment réduit le temps de transit dans l’intestin grêle etle gros intestin diminue la digestibilité fécale des nutriments. Les cinétiques d’hydrolyse ont révélé que l’amidon était essentiellement hydrolysé dans l’intestin grêle et que l’hydrolyse dépendant de la matière premièreTo develop mechanistic models of digestion, digesta transit and nutrient digestibility have to be quantified in different segments of the gastrointestinal tract. The processes are affected by the animal and feed composition. The objectives of the thesis were to quantify the consequences of a modification inf feed composition on nutrient digestibility and on passage kinetics in the gut, and quantifying the kinetics of hydrolysis (solubilisation) of main dietary constituents. The mean retention time averaged 1, 4 and 38 h in the stomach, small intestine, and large intestine respectively. Increasing the insoluble fibre content in the diet decreased the mean retention time in the small intestine and the large intestine and decreases faecal digestibility of nutrients. Kinetics of hydrolysis indicated that starch was essentially hydrolyzed in the large intestine. The extent and rate of hydrolysis depended on the raw material
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Borel, Patrick. „Effets du son et du germe de ble sur l'activite in vitro de la lipase pancreatique, et sur la digestion et le metabolisme des lipides chez le rat“. Aix-Marseille 2, 1987. http://www.theses.fr/1987AIX22078.
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Bournazel, Marion. „Effet des coproduits riches en fibres alimentaires sur l'utilisation disgestive et métabolique des minéraux chez le porc et le poulet“. Thesis, Tours, 2017. http://www.theses.fr/2017TOUR4047.
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L’optimisation de l’utilisation de phosphore reste un enjeu majeur pour assurer la durabilité de nos filières avicoles et porcines. Aujourd’hui, l’utilisation de coproduits, relativement riches en fibres alimentaires, est grandissante. Or, les fibres alimentaires sont reconnues pour moduler les processus de digestion et la digestibilité des nutriments. Ce travail de thèse a permis de progresser sur les mécanismes digestifs engendrés par l’apport de coproduits riches en fibres alimentaires et leurs effets sur la digestion des minéraux, en lien avec la phytase microbienne, spécifiquement chez le porc et le poulet. Leurs conséquences métaboliques en terme de balance minérale et d’équilibre acidobasique ont également été mises en évidence Les connaissances acquises vont contribuer à l’amélioration de l’apport en minéraux, notamment de phosphore et de calcium, dans des formules diversifiées chez le porc et le poulet. A terme, ceci permettra de mieux adapter nos systèmes d’alimentations au regard des enjeux de durabilitéThe optimisation of the use of phosphorus remains a major challenge to ensure the sustainability of poultry and pig industry. Today, the use of co-product, relatively rich in dietary fibre, is increasing. However, dietary fibre is known to modulate digestion processes and digestibility of nutrients. This work contributed to progress on the digestive mechanisms generated by the intake of dietary fibre from coproducts and their effects on the digestion of minerals, in relation with microbial phytase, specifically in pigs and chickens. Their metabolic consequences in terms of mineral and acid-base balance have also been demonstrated. The knowledge gained will contribute to the improvement of the intake of minerals, in particular phosphorus and calcium, in diversified formulas in pigs and the chicken. Finally, this will allow us to better adapt our feeding systems to the challenges of sustainability
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Souza, Nedilse Helena de. „Efeitos de níveis crescentes de fibra em detergente neutro na dieta sobre a fermentação e digestão ruminal em bubalinos e bovinos“. Universidade de São Paulo, 1999. http://www.teses.usp.br/teses/disponiveis/74/74131/tde-25062002-203038/.
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Quatro bubalinos e quatro bovinos adultos com fístulas ruminais foram utilizados com o objetivo de se estudar os efeitos de diferentes níveis de fibra em detergente neutro na dieta sobre as características de fermentação e digestão ruminal. Foram avaliadas os seguintes parâmetros: degradabilidades da matéria seca, proteína bruta, fibra em detergente neutro do feno de Coast-cross e do farelo de trigo; matéria seca e, proteína bruta do milho em grãos moídos e do farelo de soja; digestibilidade com marcador (Cr2O3); concentração de amônia, produção de ácidos graxos voláteis (acético, propiônico e butírico) e pH do líquido ruminal. Os animais foram delineados em dois Quadrados Latinos (4x4) com arranjo fatorial 4x2 sendo quatro níveis crescentes de FDN na MS (54, 60, 66 e 72%) e duas espécies (bubalinos e bovinos). Cada subperíodo compreendeu 29 dias, sendo 13 de adaptação. Observou-se um efeito significativo (P<0,01) da espécie sobre o pH ruminal, onde os bubalinos apresentaram valor médio (6,78) mais elevado que os bovinos (6,58). Houve efeito da interação tempo x espécie, na concentração de amônia do líquido ruminal somente após 2 horas da alimentação da manhã, onde os bubalinos obtiveram média de 31,76 mg% e os bovinos de 27,74 mg%. Os bubalinos mostraram valores de concentração média de ácidos graxos voláteis, ácido acético e ácido butírico (69,94 mM, 51,31 mM e 6,12 mM) menor (P<0,05) que a dos bovinos (77,96 mM, 56,72 mM e 8,01 mM). Não houve diferença significativa (P>0,05) na concentração de ácido propiônico e na relação acético:propiônico, não sofrendo influência de nenhum dos parâmetros principais analisados. Os bubalinos apresentaram maior desaparecimento ruminal da MS e FDN do feno de Coast-cross e da MS e PB do farelo de soja do que os bovinos, na maioria dos tempos de incubação. O desaparecimento ruminal da PB do feno de Coast-cross foi maior para os bubalinos somente nas últimas horas de incubação. Por outro lado, o desaparecimento ruminal da FDN do farelo de trigo foi mais elevado para os bovinos, somente nas primeiras horas. Para o coeficiente de digestibilidade da MS, houve interação de espécies com níveis de FDN. O coeficiente de digestibilidade da FDN foi influenciada pelos níveis de FDN e para o coeficiente de digestibilidade da PB, não foram notados efeitos de espécies ou níveis de FDN.Four buffaloes and four cattle rumen fistulated, were used to study the effects of different levels of neutral detergent fiber in the diet on the rumen fermentation and digestion. In situ degradability assay was make of dry matter (DM), crude protein (CP), neutral detergent fiber (NDF) of the Coast-Cross hay (Cynodon dactylon) and the concentrate mixture; digestibility with marker (Cr2O3); ammonia concentration, production of volatile fatty acids (acetic, propionic and butyric) and pH in the ruminal liquid. The animals were designed in two Latin Square experiment (4x4). Treatments were applied in factorial 4 x 2 with four rations with increasing levels of NDF (54, 60, 66 and 72%) and two animal species (buffaloes and cattle). Twenty-nine days subperiods were used, the first thirteen for diet's adaptation. A significant effect was observed (P<0,01) in the species on the ruminal pH, with average of 6.78 in buffaloes and of 6.58 in cattle. There was effect of the interaction time x species, in the rumen ammonia concentration only at 2 hours after feeding with buffaloes having mean of 31.76 mg% and cattle 27.74 mg%. Buffaloes had lower (P<0,05) concentration of volatile fatty acids, acid acetic and acid butyric (69.94 mM, 51.31 mM and 6.12 mM) than cattle (77.96 mM, 56.72 mM and 8.01 mM). There was no significant difference (P>0,05) acid propionic concentration and acetic:propionic relation. The buffaloes showed higher ruminal disappearance of DM and NDF of the Coast-cross hay and DM and CP of the soybean meal than the cattle, in most of the times of incubation. The ruminal disappearance of CP of Coast-cross hay went higher for the buffaloes only in the last hours of incubation. On the other hand, the ruminal disappearance of NDF of wheat bran went higher for the cattle only in the first hours. There was interaction of species with levels of NDF for digestibility coefficient of the DM. The digestibility coefficient of NDF was only influenced by the levels of NDF. The digestibility coefficient of CP wasn't noticed effects of species or levels of NDF.
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Mohamed, Ahmed ben. „Impact des fibres alimentaires et des acides gras à chaîne courte sur le dialogue tube digestif, foie et tissus périphériques, dans le cadre d'une surnutrition“. Thesis, Université Clermont Auvergne (2017-2020), 2018. http://www.theses.fr/2018CLFAS026.
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Une des causes de l’augmentation de la prévalence de l’obésité et des maladies chroniques au niveau mondial (notamment dans les pays occidentaux) est la consommation de régimes hypercaloriques. A l’inverse la consommation d’un régime riche en fibres alimentaires est favorable à une bonne santé. Or la consommation de fibres alimentaires dans les pays occidentaux (20 g/j en France) est inférieure aux recommandations alimentaires préconisées par les organismes de santé (30 g/j). Un des moyens possibles d’augmenter l’ingestion des fibres est la mise à disposition d’aliments enrichis en fibres, et en particulier de fibres capables d’impacter favorablement sur la santé métabolique (les fibres fermentescibles). L’objectif de ma thèse a donc été de déterminer si, chez des mini-porcs en situation de surnutrition, une supplémentation en un mélange de fibres fermentescibles inclues dans un aliment de consommation courante (le pain) était capable de limiter l’apparition des désordres métaboliques associés au développement de l’obésité. Quatorze mini-porcs femelles ont été nourries 2 mois avec un régime en surnutrition enrichi en saccharose (10% p/p) et huile de palme (10% p/p) supplémenté ou non avec un mélange de fibres (25 g/j, pectine, inuline et amidons résistants) inclues dans un pain (250 g/j). Les animaux ont été cathétérisés au niveau intestinal et hépatique pour mesurer les flux nets splanchniques de nutriments durant l’adaptation aux régimes expérimentaux. Des fèces ont été prélevés pour analyser le microbiote et son activité. A l’euthanasie des animaux (après 56 jours de traitement nutritionnel), des tissus (jéjunum, caecum, foie, muscle, tissu adipeux) ont été prélevés pour un phénotypage métabolique (histologie, transcrits de gènes, protéomique).Nous avons mis en évidence que la supplémentation en fibres fermentescibles, après 2 mois de surnutrition, permettait de limiter la prise de poids corporelle, l’accumulation de gouttelettes lipidiques dans le foie et stimulait l’activité oxydative des tissus périphériques (comme le muscle). La moindre accumulation de gouttelettes lipidiques dans le foie est associée à une réduction de l’entrée des lipides (Fabp1) et une baisse probable de la lipogenèse (Srebp-1c). Ce mécanisme, confirmé par l’analyse des flux de nutriments, a induit une augmentation de la biodisponibilité en nutriments énergétiques vers les tissus périphériques. Les nutriments en excès sont pris en charge par le muscle via une augmentation de l’activité oxydative (↑ ARNm Pgc1α, Pparα, Nrf2, Acox, Ucp2, sdha, Cpt1-m). Ces modulations de dialogue foie- muscle avec la supplémentation en fibres pourrait passer par GLP1 et/ou GLP2 synthétisés par les cellules L de l’intestin (↑ ARNm de GCG jéjunum) et par une stimulation de la signalisation par les acides gras à chaine courte (AGCC) dans le caecum (↑ ARNm GPR41) mais probablement pas par une action directe des AGCC sur les tissus périphériques. Ces résultats montrent donc une amélioration du profil métabolique des mini-porcs en surnutrition lors de la supplémentation en fibres alimentaires fermentescibles via une réorganisation de l’utilisation des nutriments entre le foie et les tissus périphériques et une adaptation de leurs activités métaboliques. La quantité de fibres et de pain supplémentées dans notre étude, raisonnable, permet d’envisager une étude chez l’homme pour valider ces concepts et la stratégie nutritionnelleHypercaloric diets are one of the causes of the increased obesity prevalence worldwide (and particularly in western countries). Conversely, dietary fibers consumption is associated with a better health status. Yet, dietary fibers consumption in western countries (20 g/d in France) is below the values of dietary fiber intake recommended by health care organizations (30 g/d). One of the ways to increase fiber intake in populations is to supply fiber-enriched foodstuffs, and particularly food products enriched with fibers capable to improve metabolic health (i.e. fermentable fibers). The aim of this thesis was to determine if, in overfed minipigs, dietary fermentable fibers supplementation included in a regularly consumed food (i.e. bread), was capable to limit the obesity-linked metabolic disorders induced by overfeeding. Fourteen female minipigs were overfed for 2 months with a diet supplemented with sucrose (10% w/w) and palm oil (10% w/w) associated with a supplementation (or not) of fibers (25 g/d, pectin, inulin & resistant starch) included in a specially designed bread (250 g/d ingested). Animals were multicatheterized at the gut and hepatic levels for net splanchnic nutrients fluxes measurements over the experimental period. Feces were also sampled for microbiota composition and activity analysis. Animals were euthanized after 56 days of nutritional treatment and tissues sampled (caecum, jujunum, liver, muscle, adipose) for metabolic phenotyping (histology, qRT-PCR, proteomics).We have shown that fermentable fibers supplementation, in a situation of overnutrition for 56 days, was capable to limit body weight gain and lipids droplets accumulation in the liver. We also observed a stimulation of the oxidative capacity in peripheral tissues (particularly the muscle). The decreased lipids droplets accumulation within the liver was due to a decreased entry of lipids (Fabp1) and a probable decreased lipogenesis (Srebp-1c). This mechanism, confirmed by the analysis of net nutrients fluxes, induced an increased bioavailability of energy nutrients to peripheral tissues. This excess of nutrients was handled by the muscle that increased its oxidative capacity (↑ mRNA Pgc1α, Pparα, Nrf2, Acox, Ucp2, sdha, Cpt1-m). This altered liver-muscle cross talk could be regulated by an increased release of GLP1 and / or GLP2 by intestinal L cells (↑ mRNA jejunum GCG) and stimulation of short chain fatty acids receptor (SCFA) GPR41 in caecum (↑ mRNA). A direct action of SCFA directly on peripheral tissues is highly improbable. As a conclusion, fermentable fibers supplementation, even during overfeeding, was beneficial for metabolic health via an impact on tissues cross talk and metabolic activities regulations. The next step would be to test a similar nutritional strategy in human being
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Allman, Andrea Lauren. „Fiber digestion in the juvenile blue crab, (Callinectes sapidus) rathbun“. College Park, Md.: University of Maryland, 2006. http://hdl.handle.net/1903/3358.
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Thesis (M.S.) -- University of Maryland, College Park, 2006.Thesis research directed by: Marine, Estuarine, Environmental Sciences Graduate Program. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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Gomes, Jacinta Diva Ferrugem [UNESP]. „Efeitos do incremento da fibra em detergente neutro, sobre parâmetros de desempenho, de digestibilidade dos componentes dietéticos e da morfologia intestinal de marrãs“. Universidade Estadual Paulista (UNESP), 1996. http://hdl.handle.net/11449/104148.
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Previous issue date: 1996-02-08Bitstream added on 2014-06-13T19:26:25Z : No. of bitstreams: 1
gomes_jdf_dr_botfmvz.pdf: 534381 bytes, checksum: ae99b49a5e8b0ffe9bc4f1a31533cea1 (MD5)Embora os suínos apresentem limitada capacidade em degradar material fibroso, é possível utilizar fontes fibrosas na ração de determinadas categorias animais, como por exemplo suínas em fases pré-púbere e púbere, devido à necessidade de moderado ganho de peso neste período. Por ocasião do primeiro cio útil (terceiro cio fisiológico), as fêmeas devem apresentar valores mínimos de 110 kg de peso corporal e 1,8-2,0 cm de espessura de toucinho. O objetivo desta pesquisa foi o de determinar os efeitos causados pelo emprego de 0; 6,6; 13,2 e 19,8% de fibra em detergente neutro (FDN), na ração basal de fêmeas suínas em fase pré-púbere e púbere (marrãs). As concentrações de FDN na ração, foram obtidas através da inclusão de 0, 10, 20 e 30 % de feno de coast cross (Cynodon dactylon), respectivamente. Foram utilizadas 20 marrãs puras e mestiças, das raças Landrace e Large White, com peso e idade médias iniciais de 52,85 kg e 110 dias, em um experimento em blocos casualizados, com cinco repetições/tratamento. Em relação às características de desempenho animal, o incremento de FDN na ração de marrãs, promoveu respostas lineares (P<0,01) no ganho diário de peso (0,675; 0,607; 0,525; 0,483 g/d); no peso corporal por ocasião do primeiro cio útil (118,0; 114,0; 102,2; 98,2 kg); na conversão alimentar (3,6; 4,0; 4,7; 5,3); e resposta quadrática (P<0,05) na espessura de toucinho (3,28; 3,34; 2,82; 1,74 cm). No referente à idade de ocorrência do primeiro cio útil, não houve registro de efeito significativo (P>0,10) sobre esta característica, a qual apresentou valor médio de 203 dias. A digestibilidade dos componentes dietéticos foi influenciada pela presença de fibra dietética na ração das marrãs. A adição de FDN promoveu resposta linear (P<0,01) na digestibilidade da matéria seca...
Although swines show limited capability in degrading fiber, it is possible utilization of feeds in the diet of some animal categories such as gilts. These animals need to gain moderate weight during this period that precede breeding and by the time females exhibit their third physiological heat, they have to weight a minimum of 110 kg and have at least 1.8-2.0 cm of subcutaneous fat. The objective of this research was to assess the effects caused by utilization of 0; 6.6; 13.2 and 19.8 % of neutral detergent fiber (NDF) in the basal diet of gilts. These concentrations of NDF were obtained through inclusion of 0; 10; 20 and 30 % of coast-cross hay (Cynodon dactylon), respectively. This trial was conducted with 20 pure and crossbred Landraceand Large White females with average weight of 52.8 kg and 110 days old. The experimental design employed was a completely randomized block design with five repetitions per treatment. Increasing concentration of NDF in the diet of gilts led to linear response (P<0.01) on the daily weight gain (0.675; 0.607; 0.525; 0.483 g/d); on the body weight by the onset of the third physiological heat (118.0; 114.0; 102.2; 98.2 kg); on the feed efficiency (3.6; 4.0; 4.7; 5.3); and quadratic response (P<0.05) on the subcutaneous fat thickness (3.28; 3.34; 2.82; 1.74 cm). However, no significance was found (P>0.10) on the third physiological heat onset age which average 203 days. Nutrient digestibility was also affected by addition of hay to the basal diet. Dry matter digestibility had linear response... (Complete abstract click electronic access below)
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Yang, Tzu-Hsuan. „Effects of diet on phosphorus digestion in dairy cattle“. Thesis, Virginia Tech, 2006. http://hdl.handle.net/10919/34581.
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Two studies were conducted to evaluate the effects of diet on phosphorus (P) digestion in dairy cattle. The objective of the first study was to evaluate the effects of forage and non-fiber carbohydrate (NFC) content on total P (TP) and inositol phosphates-P (IPs-P) digestion. Samples of feed, duodenal digesta and feces from a previously conducted study were analyzed for TP and IPs-P. In this study, eight lactating Holstein cows were fed diets containing either 60 or 35% forage and either 30 or 40% NFC in a 2 × 2 factorial with replicated 4 × 4 Latin square design. Dietary TP content (% DM) was 0.35, 0.36, 0.36, 0.36 and dietary IPs-P content (%DM) was 0.08, 0.13, 0.06, 0.11 for diets with forage: NFC ratio 35:30, 35:40, 60:30, and 60:40, respectively. Increasing dietary forage content decreased IPs-P and TP intake, fecal TP excretion, and total tract IPs-P digestibility (72.4 vs. 61.4%). Fecal IPs-P excretion tended to decrease as increasing forage content. Duodenal IPs-P and TP flow and apparent TP digestibility were unaffected by forage content. Increasing dietary NFC content increased IPs-P and TP intake, duodenal IPs-P flow, fecal IPs-P excretion, total tract IPs-P digestibility (61.4 vs. 72.4%), and apparent TP digestibility (32.8 vs. 41.6%). Dietary forage and NFC content affected IPs-P and TP digestion. The second study was to evaluate the effects of increasing dietary beet pulp (BP) content to replace high moisture corn (HMC) on ruminal and post-ruminal digestion of TP and IPs-P. Eight lactating Holstein cows were fed diets containing 0, 6.1, 12.1 or 24.3% BP in a replicated 4 × 4 Latin square design. Samples of rumen contents, duodenal digesta, and feces from this previously conducted study were analyzed for TP and IPs-P content. Linear and quadratic effects of BP content were analyzed using Proc Mixed of SAS. Dietary TP and IPs-P content were reduced linearly with increasing BP (0.59, 0.58, 0.57, 0.56% TP and 0.15, 0.14, 0.13, 0.11% IPs-P). Intake, ruminal content, and rumen pool size of TP decreased with increasing BP content. Digestion of TP and duodenal flow and fecal excretion of IPs-P and TP were not affected. With increasing dietary BP content, IPs-P intake was reduced, ruminal IPs-P pool size was reduced, and rumen turnover time (h) of IPs-P was increased. Apparent ruminal IPs-P digestibility (36.5, 31.8, 24.6, 13.6 %) and apparent total tract IPs-P digestibility (85.3, 82.7, 82.1, 79.1%) decreased linearly with increasing BP. Fecal excretion of IPs-P averaged 5.2 g/d. Replacing HMC with BP reduced digestion of IPs-P. The majority of IPs-P disappearance occurred post-ruminally. In conclusion, dietary BP, forage, and NFC content affected IPs-P digestion in dairy cows.Master of Science
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Vienney, Martine. „Etude d'un procede de retention de biomasse pour le fonctionnement de reacteurs biologiques a l'alimentation continue : son application au traitement anaerobie des effluents industriels“. Poitiers, 1988. http://www.theses.fr/1988POIT2339.
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Piwonka, Edward Joseph. „Associative effects of non-structural carbohydrates on fiber digestion by Ruminal microorganisms /“. The Ohio State University, 1994. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487859879940817.
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Lima, Ana Cristina Silva de. „AvaliaÃÃo da bioacessibilidade de cobre, ferro, zinco e atividade antioxidante total de suco integral e fibra de caju“. Universidade Federal do CearÃ, 2013. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=10796.
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CoordenaÃÃo de AperfeiÃoamento de NÃvel SuperiorO caju possui componentes que lhe conferem o tÃtulo de alimento funcional, sendo assim considerado, por se subentender que este atende as necessidades nutricionais e possui funÃÃo agregada à saÃde pela riqueza em fibras, minerais, vitaminas, compostos fenÃlicos e aÃÃo antioxidante. Em termos de nutriÃÃo nÃo à suficiente determinar apenas o conteÃdo total de nutrientes de determinado alimento, mas tambÃm conhecer a bioacessibilidade, ou seja, a quantidade absorvida e utilizada pelo organismo. Nesse contexto o objetivo desse trabalho foi determinar a bioacessibilidade dos minerais cobre, ferro e zinco, Ãcido ascÃrbico, compostos fenÃlicos e atividade antioxidante total, em suco integral e em subproduto do pseudofruto de caju, uma vez que uma melhor compreensÃo da contribuiÃÃo nutricional desses elementos no organismo se faz necessÃria. Considerando a escassez de estudos sobre os percentuais bioacessÃveis de nutrientes em suco de caju, seus produtos e subprodutos, neste estudo, o suco integral e a fibra de caju foram submetidos a um processo de digestÃo gastrointestinal simulada in vitro onde estes foram analisados antes e apÃs essa digestÃo e tiveram seu conteÃdo de cobre, ferro e zinco, componentes bioativos (Ãcido ascÃrbico, compostos fenÃlicos totais e atividade antioxidante total pelo mÃtodo ABTS) avaliados. Como resultado, para o suco integral de caju, os percentuais bioacessÃveis do conteÃdo dos minerais cobre e ferro se apresentaram >10%, para o zinco este teor foi <5%, enquanto que para a fibra de caju, os percentuais bioacessÃveis para estes minerais foram menores que 5% para os trÃs minerais analisados. Para a porcentagem bioacessÃvel de Ãcido ascÃrbico, compostos fenÃlicos totais e atividade antioxidante total do suco integral os percentuais de bioacessibilidade ficaram sempre >25%, enquanto que para a fibra, os teores bioacessiveis ficaram em torno de 15%, sugerindo que o suco integral se apresenta como fonte mais relevante de antioxidantes naturais bioacessÃveis, podendo sua ingestÃo diÃria, teoricamente, contribuir na proteÃÃo contra diversas doenÃas, com base no que se refere ao seu potencia antioxidante.
Cashew has components that confer the title of functional food, and therefore considered, by itself imply that meets the nutritional needs and health aggregate function has the richness in fiber, minerals, vitamins, phenolic compounds and antioxidant action. In terms of nutrition is not sufficient only to determine the total content of nutrients in a food, but also know the bioaccessibility i.e. the amount absorbed and utilized by the body. In this context, the objective of this study was to determine the bioaccessibility minerals copper, iron and zinc, ascorbic acid, phenolics and total antioxidant activity in whole cashew juice and cashew byproduct of the pseudofruit, since a better understanding of the nutritional contribution of these elements the body is necessary. Given the scarcity of studies on the percentage of nutrients in bioavailability cashew juice, their products and by products, this study, the whole cashew apple juice and cashew byproduct of the pseudofruit underwent a simulated gastrointestinal digestion process in vitro where they were analyzed before and digestion and after that had their content of copper, iron and zinc, bioactive compounds (ascorbic acid, total phenolics and total antioxidant activity by TEAC method) assessed. As a result, for the whole cashew apple juice, percentages bioavailability the mineral content of copper, iron showed> 10% for zinc this level was <5% where as for the product, the percentages for these minerals were bioavailability in about <5%. For bioavailability percentage of ascorbic acid, total phenolics and total antioxidant activity from whole cashew apple juice bioaccessibilityâs percentages were always> 25%, while for the byproduct bioavailability levels were around 15%. May be suggested that the whole cashew apple juice presents as most relevant source of natural antioxidants bioavailability, your daily intake can lead to positive health outcomes.
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Gomes, Jacinta Diva Ferrugem. „Efeitos do incremento da fibra em detergente neutro, sobre parâmetros de desempenho, de digestibilidade dos componentes dietéticos e da morfologia intestinal de marrãs /“. Botucatu : [s.n.], 1996. http://hdl.handle.net/11449/104148.
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Orientador: Aleksandrs SpersBanca: Dirlei Antonio Berto
Banca: Rodolfo Nascimento Kronka
Banca: Romualdo Shigueo Fukushima
Resumo: Embora os suínos apresentem limitada capacidade em degradar material fibroso, é possível utilizar fontes fibrosas na ração de determinadas categorias animais, como por exemplo suínas em fases pré-púbere e púbere, devido à necessidade de moderado ganho de peso neste período. Por ocasião do primeiro cio útil (terceiro cio fisiológico), as fêmeas devem apresentar valores mínimos de 110 kg de peso corporal e 1,8-2,0 cm de espessura de toucinho. O objetivo desta pesquisa foi o de determinar os efeitos causados pelo emprego de 0; 6,6; 13,2 e 19,8% de fibra em detergente neutro (FDN), na ração basal de fêmeas suínas em fase pré-púbere e púbere (marrãs). As concentrações de FDN na ração, foram obtidas através da inclusão de 0, 10, 20 e 30 % de feno de "coast cross" (Cynodon dactylon), respectivamente. Foram utilizadas 20 marrãs puras e mestiças, das raças Landrace e Large White, com peso e idade médias iniciais de 52,85 kg e 110 dias, em um experimento em blocos casualizados, com cinco repetições/tratamento. Em relação às características de desempenho animal, o incremento de FDN na ração de marrãs, promoveu respostas lineares (P<0,01) no ganho diário de peso (0,675; 0,607; 0,525; 0,483 g/d); no peso corporal por ocasião do primeiro cio útil (118,0; 114,0; 102,2; 98,2 kg); na conversão alimentar (3,6; 4,0; 4,7; 5,3); e resposta quadrática (P<0,05) na espessura de toucinho (3,28; 3,34; 2,82; 1,74 cm). No referente à idade de ocorrência do primeiro cio útil, não houve registro de efeito significativo (P>0,10) sobre esta característica, a qual apresentou valor médio de 203 dias. A digestibilidade dos componentes dietéticos foi influenciada pela presença de fibra dietética na ração das marrãs. A adição de FDN promoveu resposta linear (P<0,01) na digestibilidade da matéria seca... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Although swines show limited capability in degrading fiber, it is possible utilization of feeds in the diet of some animal categories such as gilts. These animals need to gain moderate weight during this period that precede breeding and by the time females exhibit their third physiological heat, they have to weight a minimum of 110 kg and have at least 1.8-2.0 cm of subcutaneous fat. The objective of this research was to assess the effects caused by utilization of 0; 6.6; 13.2 and 19.8 % of neutral detergent fiber (NDF) in the basal diet of gilts. These concentrations of NDF were obtained through inclusion of 0; 10; 20 and 30 % of coast-cross hay (Cynodon dactylon), respectively. This trial was conducted with 20 pure and crossbred Landraceand Large White females with average weight of 52.8 kg and 110 days old. The experimental design employed was a completely randomized block design with five repetitions per treatment. Increasing concentration of NDF in the diet of gilts led to linear response (P<0.01) on the daily weight gain (0.675; 0.607; 0.525; 0.483 g/d); on the body weight by the onset of the third physiological heat (118.0; 114.0; 102.2; 98.2 kg); on the feed efficiency (3.6; 4.0; 4.7; 5.3); and quadratic response (P<0.05) on the subcutaneous fat thickness (3.28; 3.34; 2.82; 1.74 cm). However, no significance was found (P>0.10) on the third physiological heat onset age which average 203 days. Nutrient digestibility was also affected by addition of hay to the basal diet. Dry matter digestibility had linear response... (Complete abstract click electronic access below)
Doutor
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Goulart, Rodrigo Silva. „Avaliação da fibra fisicamente efetiva em rações para bovinos de corte“. Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/11/11139/tde-11022011-154913/.
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Objetivou-se com este trabalho avaliar o efeito de fontes e teor de fibra no consumo voluntário, no comportamento ingestivo, na efetividade de fontes de fibra, na cinética digestiva e alguns aspectos do metabolismo ruminal de bovinos de corte. Foram utilizados seis bovinos machos castrados da raça Nelore contendo cânula no saco dorsal do rúmen, alojados em gaiolas metabólicas, em delineamento do tipo quadrado latino 6x6, contendo 19 dias de período experimental cada. Seis rações foram formuladas com diferentes teores e fontes de fibra: CN (controle negativo com 10% da fração FDN de silagem de milho); CP (controle positivo com 20% da fração FDN de silagem de milho); e quatro rações contendo 10% da fração FDN de silagem de milho e 10% da fração FDN de cada uma das seguintes fontes: bagaço in natura de cana-de-açúcar (BAG), cana-de-açúcar (CAN), casca de soja (CSOJ) e torta de algodão desengordurada (TALG). Comparado ao tratamento CP, observou-se CMS semelhante (P>0,05) entre os tratamentos CAN, CSOJ e TALG (9,20, 8,60, 8,83 e 9,52 kg.dia-1, respectivamente). Contudo, tratamento BAG promoveu depressão no CMS (6,97 kg.dia-1). Ração contendo menor teor de fibra (CN) apresentou resultado intermediário quanto ao CMS. Para estimar o fator de efetividade física (fef) ou fator de efetividade (fe) foram utilizados os métodos de bioensaio preconizado por Armentano e Pereira (1997). Além disso, foram utilizados métodos laboratoriais recomendados por Mertens (1997) e Lammers; Buckmaster; Heinrichs (1996) para estimar o fef de fontes de fibra (fef1,18 ou fef>8,0 mm, respectivamente). Ao calcular o fef das fontes de fibra utilizando métodos laboratoriais, foi possível evidenciar grande divergência entre estes e os valores calculados pelos métodos de bioensaio. Medidas de efetividade física calculadas por meio de métodos laboratoriais (fef1,18 ou fef>8,0 mm) apresentaram baixa ou nenhuma correlação (P>0,05) com tempo de ruminação, tempo de mastigação, pH ruminal e mat ruminal. Por outro lado, ao avaliar os fef calculados conforme Armentano e Pereira (1997), coeficientes de correlação adequados foram observados (P<0,05) quando relacionados com tempo de ruminação, tempo de mastigação e mat ruminal. Equações de regressão envolvendo cálculos de efetividade física utilizando métodos laboratoriais e bioensaio foram sugeridas para que se pudesse oferecer aplicabilidade em condições de campo. Os valores médios de pH ruminal foram influenciados pelo nível e fonte de fibra. A concentração total de ácidos graxos de cadeia curta (AGCC) foi significativamente alterada (P<0,05) em função dos diferentes tratamentos. Rações contendo fontes e teores de fibra não alteraram o tempo médio de digestão da MS e da fração FDN (P>0,05), como também, não provocaram alteração (P>0,05) nas frações A e U referente à MS avaliadas pelo ensaio de degradabilidade in situ. Teor e fontes de fibra alteraram (P<0,05) a taxa de passagem do pool de partículas escapáveis no rúmen retículo (ke), o TMRRp e o TMRTp. Não houve diferença (P>0,05) na taxa assintótica de líquidos (L, h-1), no tempo de trânsito da fase líquida (TTL, h), como também, no TMRRL e TMRTL entre os tratamentos avaliados (média de 0,11 h-1, 8,73, 20,6 e 29,6 horas respectivamente).This study aimed to evaluate the effect of different sources of fiber on voluntary intake, ingestive behavior, on effectiveness fiber sources, on digestive kinetics and some aspects of the rumen metabolism in beef cattle. Six ruminally canulated Nellore steers, housed in tie-stall barns, were used in a 6 x 6 Latin square design with 19 days of experimental periods each. Each experimental period consisted of 10 days of adaptation to the experimental diet and 9 days of data collection. Six diets were formulated with different contents and sources of fiber: NC (negative control - with 10% of the NDF fraction from corn silage), PC (positive control - with 20% of the NDF fraction from corn silage) and four diets containing 10% of NDF fraction from corn silage and 10% of the NDF fraction from each the following sources: sugarcane (SC), sugarcane bagasse (SCB), soybean hulls (SH) and high oil cottonseed meal (HOCM). In comparison to the PC treatment, it was observed similar dry matter intake (DMI) (P>0.05) between the treatments SC, SH e HOCM (9.20, 8.60, 8.83 and 9.52 kg.day-1, respectively). However the SCB treatment decreased DMI (6.97 kg.day-1). The diet containing lower fiber level (NC) presented an intermediate result in relation to DMI. To estimate physical effectiveness factor (pef) or effectiveness factor (fe), bioassay methods recommended by Armentano and Pereira (1997) were used. Also, laboratory methods recommended by Mertens (1997) and Lammers; Buckmaster, Heinrichs (1996) to estimate the effectiveness factor of physical fiber sources (fef1,18 or pef>8.0mm, respectively) were used. There was a large discrepancy between physical effectiveness factor of fiber sources when calculated by laboratory or bioassay methods. Measurements of physical effectiveness calculated by laboratory methods (fef1.18 or fef>8.0mm) showed low or no correlation (P> 0.05) with rumination time, chewing time, rumen pH and ruminal mat. On the other hand, when pef was calculated according to Armentano and Pereira (1997), appropriate correlation coefficients were observed (P <0.05) between pef and rumination time, chewing time and ruminal mat. Regression equations involving calculations of physical effectiveness using laboratorial methods and bioassays have been proposed to provide applicability in field conditions. The mean ruminal pH levels were influenced by the content and source of fiber. The concentration of total short-chain fat acids (SCFA) were significantly altered (P<0.05) according to the different treatments. Diets containing different sources and contents of fiber did not change the average time of digestion from the DM and NDF fraction (P>0.05), also they did not cause changes (P>0.05) in the A and U fractions of the DM evaluated by the in situ degradability study. Content and fiber sources changed (P<0.05) the ke, the TMRRp and the TMRTp. No difference was observed (P>0.05) on asymptotic rate of fluid (L, h- 1), along the transit time of the fluid phase (TTL, h) and TMRRL and TMRTL between different treatments (average of 0.11 h-1, 8.73, 20.6 and 29.6 hours, respectively).
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Yapi, Yapo Magloire. „Physiologie digestive de l'aulacode (Thryonomys swinderianus) en croissance et impact des teneurs en fibres et céréales de la ration sur la santé et les performances zootechniques“. Thesis, Toulouse, INPT, 2013. http://www.theses.fr/2013INPT0019/document.
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L’aulacode (Thryonomys swinderianus) est un rongeur herbivore récemment domestiqué en Afrique pour la production de viande. Quelques études antérieures ont portés sur l’alimentation de cet animal, dans le but d’améliorer la productivité des élevages. A ce jour, nos connaissances sur la digestion et les besoins nutritionnels de cet animal sont encore très parcellaires. Le premier objectif de notre étude était d’améliorer nos connaissances sur la physiologie digestive de l’aulacode en croissance, en particulier en relation avec les apports de fibres alimentaires, avec pour finalité de proposer des recommandations nutritionnelles en fibres pour optimiser la croissance et la santé digestive de cet animal. Notre second objectif était d’analyser les effets d’une diminution du ratio protéines digestibles / énergie digestible parallèlement à une hausse des apports d’amidon, sur la digestion et les performances. La finalité était d’analyser les possibilités de formuler un aliment complet moins onéreux pour les éleveurs et qui respecte les besoins de l’aulacode en croissance. Notre étude a permis de savoir que le caecum est le compartiment digestif le plus important du jeune aulacode entre 1 et 3 mois d’âge, avec plus de 40% du contenu digestif total. L’activité microbienne caecale (100 mM d’acides gras volatils totaux (AGVt) par gramme de contenu frais) est élevée, et similaire à celle des ruminants ou d’autres herbivores monogastriques. Le profil fermentaire est caractérisé par une prédominance de l’acétate (75 % des AGVt) et un ratio propionate / butyrate supérieur à 1. Le pyroséquençage 454 de l’ADN16S bactérien a permis de caractériser le microbiote caecal. Au sevrage, nous observons une prédominance du phylum des Bacteroidetes, avec 51 % d’abondance relative, alors que le phylum des Firmicutes devient majoritaire (50%) à 3 mois d’âge. Le microbiote caecal est caractérisé par la présence de genres souvent identifiés dans d’autres écosystèmes digestifs d’herbivores, tels que : RC9 (2 à 8%), Parabacteroides (1 à 8%), Prevotella (3 à 6%) et Xylanibacter (1%), Erysipelotrichaceae Turicibacter (1 à 7%), Lachnospiraceae Incertae_Sedis (4 à 5%), Ruminococcaceae Incertae_Sedis (1 à 2%) et Ruminococcus (1 à 3%). D’autres genres, absents chez des espèces voisines comme le lapin et le cobaye, semblent plus spécifiques de l’aulacode, tels que Termite_Treponema_cluster (1.7 à 2.2%) et Treponema (7 à 13%), du phylum des Spirochaetes. L’analyse des performances zootechniques indique qu’un taux de fibres compris entre 17 et 21 % d’ADF représenterait un bon compromis entre santé digestive et croissance de l’aulacode après son sevrage. Descendre au dessous de 6 g de protéines digestibles par MJ d’énergie digestible, via une hausse importante des apports d’amidon et une baisse importante du taux de protéines brutes (en dessous de 11 %) et de fibres, est préjudiciable à la croissance des animauxThe cane rat or grasscutter (Thryonomys swinderianus) is a rodent herbivore recently domesticated in Africa for meat production. Some previous studies focused on the feeding of this animal, in order to improve the productivity of farms. To date, our knowledge of digestion and nutritional requirements of this animal are still very scarce. Our first objective was to improve our knowledge of digestive physiology of the young grasscutter, particularly in relation to dietary fibre supply, in order to improve the recommendations for dietary fibre content of diets to optimize growth and digestive health. Our second objective was to analyze the effects of a decreased digestible protein / digestible energy ratio, along with an increased intake of starch, on digestion and performances. The final aim was to analyze the possibilities to formulate a complete feed, cheaper for farmers and that meets the requirements of the young grasscutter. Our study found that the caecum is the most important digestive compartment of the young grasscutter between 1 and 3 months of age, with more than 40% of the total gut contents. The caecal microbial activity (100 mM of total volatile fatty acids (VFA) per gram of fresh content) is high and similar to that of ruminants or other herbivorous monogastric animals. The fermentation profile is characterized by a predominance of acetate (75% of total VFA) and a propionate / butyrate ratio greater than 1. A pyrosequencing of bacterial 16S-DNA was used to characterize the caecal microbiota. At weaning (one month), we observe a predominance of the Bacteroidetes phylum, with 51% of relative abundance, whereas the Firmicutes phylum becomes predominant (50%) at 3 months of age. Caecal microbiota is characterized by the presence of genera often identified in other digestive ecosystems of herbivores, such as: RC9 (2-8%), Parabacteroides (1-8%), Prevotella (3.6%) and Xylanibacter (1%), Erysipelotrichaceae Turicibacter (1-7%), Lachnospiraceae Incertae_Sedis (4-5%), Ruminococcaceae Incertae_Sedis (1-2%) and Ruminococcus (1-3%). Other genera, absent in related species such as rabbits and guinea pigs, seemed more specific of the grasscutter, such as Termite_Treponema_cluster (1.7-2.2%) and Treponema (7-13%) of the Spirochaetes phylum. The analysis of growth performances indicated that a dietary fibre content between 17% and 21% of ADF represents a good compromise between digestive health and growth of the grasscutter after weaning. Decreasing below 6g of digestible protein / MJ of digestible energy, via a high increase in starch intake and a significant decline in crude protein content (below 11%) and fibre, is detrimental to the growth of animals
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Wrangbert, Marcus. „Counteracting Ammonia Inhibition in Anaerobic Digestion using Wood Residues : Evaluating Ammonium Adsorption Capacity of Fibres from Pulp and Paper Mills“. Thesis, Linköpings universitet, Tema Miljöförändring, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-177891.
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One of the main interests in commercial methane production is to maximize the gas yield, and it is thus appealing to use material with relative high methane potential. However, such material often results in process instability whereas ammonia inhibition is common. Removal of ammonia through adsorption is a fairly unexplored method in the field of biogas production, and could prove to be cost-effective.The adsorption capacity of pulp fibres from the paper making industry were investigated through batch adsorption experiments. Additionally, the fibres effect on small scale batch digesters in terms of methane production and cellulase activity was explored. Overall, the adsorption capacity of the pulp fibres was low, whereas Kraft hardwood had the highest adsorption capacity in both an aqueous ammonium solution and digester fluid at 11±3 and 60±20 mg g-1, respectively. The initial total ammonium nitrogen concentration had the highest effect on the adsorption capacity with a positive correlation. The pulp fibres seemingly had no effect on the ammonia inhibited anaerobic digestion systems. However, the cellulase activity was higher after day 5 in the anaerobic digestion systems with a high ammonia concentration.In essence, the overall results showed that the adsorption of the fibres was relatively low and most likely not suitable as a material to prevent ammonia inhibition in an AD.
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Wang, Pan. „Transcriptomic and metatranscriptomic approaches to characterizing genes coding for fiber digestion within the rumen ecosystem“. Thesis, Lethbridge, Alta. : University of Lethbridge, Dept. of Biological Sciences, 2013. http://hdl.handle.net/10133/3459.
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The rumen microbiome constitutes a unique genetic resource of plant fiber degrading microbial enzymes that could be used for agricultural and industrial purposes. Anaeromyces mucronatus is a poorly characterized anaerobic lignocellulolytic fungus in the rumen. This thesis aimed at better understanding A. mucronatus YE505 and the particle associated rumen microbiota based on transcriptomic and metatranscriptomic approaches. High quality RNA was isolated from the fiber-associated rumen sample based on an improved RNA extraction method. A transcriptomic study was performed to investigate the expression of the fiber degrading system of A. mucronatus YE505, and the functional diversity of the fiber-associated eukaryotes from the rumen of muskoxen (Ovibos moschatus) was explored by a metatranscriptomic study. Much carbohydrate degradation related protein modules were detected. This study established effective approaches to characterizing the functional contents of rumen eukaryotic microbiome as well as rumen fungi, and identified several candidate genes that merit further investigation.xiv leaves : ill. (some col.) ; 29 cm
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Lavoie, Judith. „Étude du comportement rhéologique en digestion in vitro de systèmes modèles laitiers enrichis en fibres“. Master's thesis, Université Laval, 2013. http://hdl.handle.net/20.500.11794/25170.
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Ce projet visait à mesurer l’effet de l’enrichissement en polysaccharides d’une matrice laitière sur son comportement rhéologique en digestion in vitro. Le comportement rhéologique de solutions de protéines laitières (3,9%), de gomme xanthane (0,7%), de gomme de caroube (0,7%) et de leurs mélanges, acidifiés par HCl sous agitation, a été suivi durant une digestion in vitro. Le comportement de solutions de poudre de lait écrémé (3,5 et 4% de protéines) enrichies des mêmes polysaccharides (0,7%) et fermentées a aussi été suivi en digestion in vitro. Le mode d’acidification affectait le comportement rhéologique des solutions contenant des protéines. La viscosité des solutions a diminué en cours de digestion, à l’exception des solutions contenant protéines et gomme xanthane dont la viscosité augmentait de l’étape gastrique à l’étape intestinale. L’ajout de polysaccharides à une matrice laitière permettrait donc de moduler sa viscosité lors de la digestion et pourrait ainsi procurer des bénéfices physiologiques.This project aims to measure the effect of enrichment in polysaccharides of a dairy matrix on its rheological behaviour when subjected to in vitro digestion. The rheological behaviour of solutions containing milk protein (3,9%), xanthan gum (0,7%), carob gum (0,7%) and their binary or ternary mixtures, acidified by HCl with stirring, was followed during in vitro digestion. The rheological behavior of solutions of skimmed milk powder (3,5% and 4% of protein) enriched or not with same polysaccharides (0,7%) and fermented has also been followed during in vitro digestion. The mode of acidification affected the rheological behavior of solutions containing proteins. The viscosity of the acidified and fermented solutions decreased throughout digestion, except for the protein solutions containing xanthan gum for which viscosity increased at the transition from gastric to intestinal stage. Integration of polysaccharides to a dairy matrix would, therefore, modulate its viscosity during digestion and could provide physiological benefits.
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Holtshausen, Lucia. „Effect of nonfiber carbohydrates on product yield and fiber digestion in fermentations with mixed ruminal microbes“. [Gainesville, Fla.] : University of Florida, 2004. http://purl.fcla.edu/fcla/etd/UFE0008120.
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Migwi, Perminus K. „Improving the nutritive value of low quality roughage for ruminants by ensiling with citrus pulp and poultry litter“. Title page, contents and summary only, 1997. http://web4.library.adelaide.edu.au/theses/09AS/09asm636.pdf.
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Bibliography: leaves 107-130. This study evaluates quality of fermentation of the silage and also its nutritive value to ruminants on the basis of "in vitro" and "in sacco" digestability. Animal response to the silage is also evaluated in an "in vivo" digestability and nitrogen balance trial with Australian Merino sheep. The objective of this thesis is to investigate the opportunities for utilising citrus pulp and poultry litter to improve the nutritive value of wheat straw.
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Comtet-Marre, Sophie. „Evolution structurale et fonctionnelle des communautés microbiennes digestives sous l'influence de facteurs biotiques et abiotiques. Développement d'une biopuce ADN ciblant les gènes impliqués dans la dégradation des glucides complexes alimentaires“. Thesis, Clermont-Ferrand 2, 2014. http://www.theses.fr/2014CLF22467/document.
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La dégradation des fibres alimentaires est une fonction essentielle des écosystèmes digestifs microbiens. Chez le ruminant, elle est assurée par des bactéries, champignons et protozoaires capables de produire de nombreuses enzymes nécessaires à l’hydrolyse des polysaccharides de paroi végétale. Parmi les facteurs susceptibles d’influencer l’efficacité de dégradation des fibres, qui est une composante importante de la productivité et de la santé animales, des additifs tels que des levures probiotiques apparaissent comme un levier intéressant. Afin d’approfondir les connaissances sur les facteurs de modulation de l’activité fibrolytique, une biopuce ADN fonctionnelle, outil moléculaire haut-débit, ciblant les gènes codant les enzymes clés de la dégradation de la cellulose et des xylanes dans les écosystèmes digestifs a été développée. Aussi, une méthode efficace dédiée à des échantillons ruminaux pour la soustraction des ARNr à partir des ARN totaux a été mise au point afin d’accroitre la sensibilité de l’outil. La biopuce fonctionnelle a été validée sur échantillons de complexité croissante et démontre d’excellents caractères de spécificité et de sensibilité tout en étant exploratoire et quantitative. Des régulations différentielles de l’arsenal des gènes de la fibrolyse de la bactérie du rumen Fibrobacter succinogenes ont pu être montrées. De même, les résultats sur échantillons de rumen suggèrent un rôle des microorganismes eucaryotes dans la fibrolyse pouvant être plus important qu’initialement envisagé. Cette approche métatranscriptomique dirigée pourra in fine continuer d’être appliquée dans l’étude de l’impact de facteurs biotiques et abiotiques sur la fonction fibrolytique microbienne chez les animaux d’élevageDietary fibre degradation is an essential function of microbial digestive ecosystems. In ruminants, this function is ensured by bacteria, fungi and protozoa, producing a large array of enzymes able to degrade plant cell wall polysaccharides. Among factors likely to influence the efficiency of fibre degradation, which is an important component in animal productivity and health, dietary additives such as probiotic yeasts appear as an interesting tool. To provide more insight on factors modulating fibrolytic activity, we designed a functional DNA microarray targeting genes coding for key enzymes involved in cellulose and xylan degradation by digestive microbiota. Also, an efficient method dedicated to rumen samples for removing microorganisms’ rRNA from total RNA samples was developed to increase the sensitivity of the tool. The DNA microarray was validated using targets of increasing complexity and demonstrated sensitivity and specificity as well as explorative and quantitative potential. Differential expression of genes involved in fibrolysis was evidenced in the rumen bacterium Fibrobacter succinogenes. Moreover, results on rumen samples suggest a more important role of eucaryotes in fibre degradation than previously thought. This targeted metatranscriptomic approach will be further applied to the study of the impact of biotic and abiotic factors on the microbial mechanisms of fibre degradation in livestock
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Elrgaiye, Ali Saad Ab. „Semi-quantitative Risk Assessment of an anaerobic digestion process“. Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016.
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Biogas is the most emerging industrial sector for energy production from renewable sources at National and European levels, and growing government funds favor the development of its market. From a process safety standpoint, Seveso Directive (Directive 2012/18/EU of the European Parliament and of the Council), but Biogas plants are complicated enough to require both their specific technology and an accurate risk assessment for design purposes. The number of accidents involving biogas plants has been too many to be ignored. Biogas plants are often operated wrongly, deficient in technological details and incorrectly scaled-up. Moreover, all these mistakes are repeated over and over again. Therefore, there is the pressing need for an assessment of the reliability of these plants in order to operate them safely. For this reason, a quantitative risk assessment was carried out to on a biogas production plant.
Starting from event trees conventional for process industry (EU- Project ARAMIS), to the critical events, and ending with selecting the specific reference accident scenarios.
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Russouw, Tracy Karen Joe. „Molecular characterisation of the fibre-digesting bacteria isolated from the ostrich (Struthio Camelus var. Domesticus) hindgut“. Master's thesis, University of Cape Town, 2000. http://hdl.handle.net/11427/9740.
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Includes bibliographical references.Eleven bacterial strains that have been isolated from the ostrich hindgut, have successfully been identified with the aid of PCR amplification of the 16S rDNA genes and sequence analysis using the BLASTN search of the GenBank database. The nucleotide sequences were determined either through direct sequencing of the PCR products or after cloning the products into the plasmid vector pBluescript (SK). The results obtained from the 16S rDNA sequence homologies strongly suggests that the newly identified bacteria should be assigned to three major bacterial genera, namely, Ruminococcus, Buryrivibrio and Bacteroides. Four highly cellulolytic strains were identified as ruminococci while two weakly cellulolytic strains, showed highest homology to members of the genus Butyrivibrio. Another weakly cellulolytic strain showed closest identity to the sulfur reducing bacterial genus Desulfovibrio. Four non-cellulolytic strains showed highest homology to the genus Bacteroides.
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Denis, Claire. „Caractérisation biochimique de l'algue Grateloupia turuturu, évaluation de ses potentialités de valorisation via un procédé de digestion enzymatique et la purification partielle d'un pigment d'intérêt (R-phycoétythrine)“. Nantes, 2009. http://www.theses.fr/2009NANT2022.
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Grateloupia turuturu Yamada est une macroalgue rouge originaire du Japon qui prolifère sur les côtes bretonnes depuis une vingtaine d’années. L’étude de la composition biochimique et de ses variations saisonnières est réalisée afin d’évaluer les voies de valorisations potentielles de cette espèce. La meilleure période de collecte de cette algue pour une utilisation en alimentation humaine (ex : légumes de mer) se situe entre février et juin. La voie de valorisation biotechnologique explorée est la production R-phycoérythrine. Deux méthodes sont testées pour extraire ce pigment : l’hydrolyse enzymatique des thalles par des polysaccharidases et le cryobroyage. Les meilleurs résultats sont obtenus avec le cryobroyage, l’hydrolyse enzymatique étant mieux adaptée à l’extraction des oligosaccharides qu’à celle de la R-phycoérythrine. L’étude comparée des techniques de purification de la R-phycoérythrine (la précipitation au sulfate d’ammonium, le système biphasique aqueux, l’ultrafiltration) montre que la précipitation à 80% de saturation au sulfate d’ammonium et l’ultrafiltration sur membrane en polyéther sulfone de seuil de coupure 30 kDa sont les deux procédés qui donnent les meilleurs résultats. Par ailleurs, les extraits hydrosolubles et liposolubles de G. turuturu testés ne présentent pas d’activités cytotoxiques à l’encontre de cellules cancéreuses ni de neurotoxicité significative sur larves de diptères, mais présentent une activité élicitrice des mécanismes de défense des cellules de vignes. Ces résultats confortent les potentialités de valorisation de cette algue en alimentation humaine comme légume de mer ou produit alimentaire intermédiaire (PAI)Grateloupia turuturu Yamada, a red macroalgae native of Japan, is proliferating on the Brittany coast since twenty years. Study of the chemical composition and its seasonal variations is carried out to determine the potential valorization of G. Turuturu. The best period to collect the seaweed for food use is between February and June. The biotechnological way of valorization is the R-phycoerythrin production. Two methods of extraction are tested: enzymatic hydrolysis of the thallus with polysaccharidases and the grinding in liquid nitrogen. The grinding in liquid nitrogen gives the best results, the enzymatic hydrolysis is an useful approach for the solubilization of oligosaccharides. The comparative analysis of purification methods of R-phycoerythrin (ammonium sulfate precipitation, separation in aqueous two-phase systems, ultrafiltration process) shows that the best results are obtained with the precipitation procedure (80% ammonium sulfate) and ultrafiltration process with polyethersulfone membrane with molecular weight cut-off equal to 30kDa. Moreover, both water- and liposoluble extracts of G. turuturu do not show cytotoxic activities against to cancerous cell lines, no significant neurotoxicity on larva of Diptera but induces elicit defense responses in grapevine. These results confirm the potential valorization of this algae in human nutrition such as sea vegetables or ingredients
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GOURGUE-JEANNOT, CLAUDINE. „Effets de fibres alimentaires issues de fruits tropicaux sur la digestion de l'amidon et le metabolisme des lipides“. Nantes, 1993. http://www.theses.fr/1993NANT2060.
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L'objectif de ce travail consistait a: 1) approfondir l'un des mecanismes d'action des fibres sur le metabolisme glucidique, en determinant le mode d'intervention de pectines differemment chargees sur la digestion enzymatique de l'amidon; 2) obtenir a partir de sous-produits de fruits tropicaux de nouvelles sources de fibres alimentaires et optimiser par voie technologique leurs proprietes hypoglycemiantes; 3) verifier au cours d'une experimentation in vivo l'influence des fibres selectionnees sur les metabolismes glucidique et lipidique, en comparant leurs effets a ceux d'une fibre visqueuse (la gomme de guar) et d'une fibre insoluble (la cellulose). Dans un premier temps, nous avons mis en evidence que, en presence de 3 fibres, de meme viscosite mais de teneurs en groupements ionisables differentes, incorporees a un aliment mixte au taux de 6%, la reduction de l'activite de l'-amylase pancreatique dependait essentiellement de la viscosite du milieu. Puis, nous avons montre qu'un traitement de cuisson-extrusion applique a des fibres d'oranges et de citrons entrainait un accroissement de la fraction fibres solubles ainsi que de la viscosite apparente d'un extrait aqueux de fibres. Toutefois, des tests predictifs in vitro n'ont pas fait ressortir une amelioration des proprietes hypoglycemiantes des fibres traitees. Nous avons ensuite montre que les sous-produits de mangues constituaient une source de fibres se caracterisant, apres purification ethanolique, par une composition equilibree en acides uroniques, hemicelluloses et cellulose et par une fraction de fibres solubles representant la moitie des fibres totales. Cependant, leurs proprietes hypoglycemiantes, suggerees par des tests predictifs, n'ont pas ete confirmees par une etude realisee chez le rat. Ces fibres contribuaient neanmoins a retarder l'apparition du pic insulinique postprandial. Les variations de taux des triglycerides et du cholesterol total plasmatiques induites par les fibres de mangues et la gomme de guar etaient comparables, alors que la concentration en hdl-cholesterol etait significativement reduite avec les fibres de mangues riches en pectines. Les parametres lipidiques hepatiques etaient principalement affectes par la gomme de guar. Ce travail fait ressortir que les proprietes hypoglycemiantes des fibres sont davantage liees a leur viscosite qu'a leur composition ou a la presence de groupes ionisables. Par ailleurs, le traitement de cuisson-extrusion n'a pas ameliore, dans nos essais, les effets de fibres peu visqueuses
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Castells, Domingo Llorenç. „Effect of different fiber sources on the digestive function and development of calves“. Doctoral thesis, Universitat Autònoma de Barcelona, 2013. http://hdl.handle.net/10803/117315.
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Per analitzar l'efecte de la inclusió de fonts de fibra en la dieta dels vedells abans del deslletament sobre el rendiment productiu, comportament, i el desenvolupament i funció del tracte gastrointestinal es van realitzar cinc estudis. En el primer dels estudi es va realitzar una sèrie de proves per tal de trobar les fonts de fibra que poguessin afavorir el creixement i desenvolupament dels vedells. Com a resultat d'aquest estudi, es va trobar que els vedells que rebien un farratge de gramínies, milloraven els paràmetres productius. Cal destacar la palla d'ordi, el fenc de civada i l'ensitjat de triticale. Contràriament, el fenc d'alfals no va millorar els paràmetres productius. De la mateixa manera, en un segon estudi, l'oferta de fonts fibroses no farratgeres tampoc va millorar el creixement i la ingestió de concentrat. Veien la disparitat de resultats entre gramínies i lleguminoses, es va triar el fenc picat de civada i el d'alfals per tal d'intentar dilucidar els mecanismes que poden explicar els diferents resultats. En aquest tercer experiment es va observar que els vedells alimentats amb farratge a la dieta presentaven un pH ruminal més elevat i una menor concentració d’àcids grassos volàtils que els vedells que no rebien farratge. A més, en els vedells alimentats amb fenc de civada es va poder observar un increment en el ritme de pas del marcador en el rumen, un menor temps de retenció del marcador en el tracte gastrointestinal i una major expressió de proteïnes transportadores d'àcids grassos volàtils del rumen en comparació amb els vedells sense farratge a la dieta. Aquests resultats ens informen sobre com el fenc de civada estimula el consum de pinso, i conseqüentment el creixement d’aquests animals. Per altra banda, l'ús de concentrats texturitzats s'ha postulat com una alternativa a l'ús de farratge en vedells lactants per tal d'estimular el correcte desenvolupament funcional del rumen. En els resultats obtinguts en el quart estudi, s'ha vist que l'ús de concentrats texturitzats sense farratge no millora els paràmetres productius i comporta un clar descens del pH ruminal. Finalment, es va estudiar l'ús de fenc de civada abans del deslletament en vedelles de reposició. Les vedelles alimentades amb fenc de civada van créixer més i van tenir una major ingestió de concentrat abans de deslletar. Al deslletament, totes les vedelles van rebre fenc de civada, i les diferències en els paràmetres productius van desaparèixer. Tot i el major pes al deslletament de les vedelles alimentades amb fenc de civada, als 10 mesos d'edat no hi havia diferències de pes entre tractaments, i tampoc es van trobar diferències en els paràmetres reproductius a la primera inseminació.Five studies were conducted to evaluate the effects of the inclusion of different fiber sources on performance parameters, behavior, and the digestive function and the development of pre- and postweaned calves. First of all, a series of experiments were done to assess the fiber sources that better improve performance of young calves fed following a conventional milk feeding program. Performance improvements were generally observed when forage from chopped grasses were offered to young calves. Chopped oat hay, barley straw, and triticale silage were the best grass forage sources that improve calves performance. Conversely, alfalfa hay did not improve calves performance. Similarly, offering non-forage fiber sources in the diet of young calves did not successfully improve animal performance and concentrate intake. Due to the different results between grasses and legumes forages, alfalfa and oat hay were chosen to find out the mechanisms involved in the different results observed. In a third experiment, calves supplemented with forage in the diet showed an increase on ruminal pH and a decrease on rumen volatile fatty acids concentration compared with animals without forage in the diet. Moreover, oat hay fed animals showed an increase on ruminal marker passage rate, a decrease on marker's retention time in the gastrointestinal tract, and a greater expression of volatile fatty acids transporters. All these parameters explained how oat hay stimulate concentrate intake, and consequently performance results of young calves. Recently, offering texturized concentrate feed to preweaned calves has been suggested as other strategy to stimulate rumen development, concentrate intake and performance of preweaned calves. In the forth study presented herein, it was showed that calves fed only a texturized concentrate feed did not improve performance compared with calves fed texturized and pelleted concentrate feed with straw, and decreased ruminal pH, predisposing those animals to suffer ruminal acidosis. Finally, offering oat hay to young female calves during the preweaning period was studied. Calves with access to oat hay during the preweaning period had greater body weight gain and concentrate feed intake, as previously observed. After weaning, all heifers received forage in the diet, and differences on performance between oat hay-fed and non-forage fed calves disappeared. Despite the improvement on body weight at weaning of forage-fed calves, there were no differences on body weight at 10 months of age, and on age at first artificial insemination, age at fertile artificial insemination, and times bred.
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Taghipoor, Masoomeh. „MODÉLISATION DU TRANSPORT, DE LA DÉGRADATION ET DE L'ABSORPTION DES ALIMENTS DANS L'INTESTIN GRÊLE“. Phd thesis, Université François Rabelais - Tours, 2012. http://tel.archives-ouvertes.fr/tel-00762216.
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L'objectif de ce travail est de présenter un modèle générique de la digestion dans l'intestin grêle. Dans la première partie de ce travail, un modèle mécaniste basé sur les équations différentielles ordinaires est utilisé pour présenter la digestion : les équations décrivent l'évolution de la position et de la composition du bolus provenant de l'estomac. Chaque bolus est représenté par un cylindre. Ce modèle prend en compte simultanément les différents aspects de la digestion à savoir le transport du bolus dans la lumière intestinale, la dégradation des aliments par des enzymes, et l'absorption des nutriments. Dans la deuxième partie de cette étude, nous utilisons les méthodes d'homogénéisation mathématique pour justifier le modèle de la digestion développé dans la première partie. Nous montrons que ce modèle peut être considéré comme une version macroscopique des modèles plus réalistes, qui contiennent des phénomènes biologiques à des échelles inférieures de l'intestin grêle : (i) les ondes péristaltiques à haute fréquence (échelle du temps microscopique) et leurs effets sur la vitesse du bolus, (ii) la présence des villosités intestinales (échelle microscopique de l'espace) et leur influence sur la digestion. Enfin, dans la troisième partie de ce travail, nous étudions l'influence du changement de la structure de bolus sur la digestion en intégrant les fibres alimentaires dans sa composition. Les deux principales caractéristiques des fibres alimentaires qui interagissent avec la fonction de l'intestin grêle, à savoir, la viscosité et la capacité de rétention d'eau ont été modélisées. Ce modèle nous a permis de considérer, en particulier, la relation entre l'évolution de la matière sèche et de l'eau au sein du bolus. Bien que ce modèle est générique et contient un grand nombre de paramètres, à notre connaissance, il est parmi les premiers modèles dynamiques qualitatives de l'influence des fibres sur la digestion intestinale.
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Barcena-Gama, Jose Ricardo. „Effect of roughage source on ruminal kinetics of digestion and passage of individual feed components in mixed diets for steers“. Diss., The University of Arizona, 1989. http://hdl.handle.net/10150/184834.
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Total tract digestion coefficients for dry matter (DM) and neutral detergent fiber (NDF), passage rates for grain and roughage components of diets and liquid turnover were measured for 65 and 90% concentrate diets in separate 4 x 4 Latin square experiments using intact growing steers. Kinetics of in situ digestion for DM and NDF in diet ingredients, rumen pH, volume and DM distribution were determined in mature, rumen cannulated steers. Rates of passage and digestion were combined to calculate apparent extent of ruminal digestion (AERD) for diet ingredients. Diets were based on steam flaked milo. The control roughage was chopped alfalfa hay (AH). In 65% concentrate diets, chopped wheat straw (WS), bermudagrass straw (BS) or cottonseed hulls (CSH) replaced 50% of the AH. In 90% concentrate diets, all of the AH was replaced by WS, BS or CSH. Total tract starch digestion was not influenced by source of roughage at either concentrate level. In 65% concentrate diets, total tract digestion of DM and NDF was not adversely affected by substitution of WS for 50% of the AH. Digestion of these fractions was lower (P<.05) for BS and CSH diets, but the severity of depression was greatest (P<.05) for the CSH diet. Reduced digestibility of the CSH diet was attributed to lower digestibility of CSH in comparison with AH. Although WS and BS were also less digestible than AH, their inclusion in the diet improved (P<.05) AERD of DM and NDF from milo and AH. Improved AERD for NDF appeared to be related to the raft-forming properties of WS and BS, and their ability to maintain rumen pH in a more desirable range for NDF digestion. In 90% concentrate diets, effects of roughage source on utilization of milo were minimal. Total tract digestion of DM and NDF was lower (P<.05) for WS, BS and CSH diets than for the AH diet, because of dilution of the more digestible AH by these roughages. Wheat straw had a tendency to moderate ruminal pH and consequently might be more useful in high concentrate diets than roughages such as CSH and BS.
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AUFFRET, AGNES. „Caracteristiques des fibres de betterave et fermentation digestive in vitro : influence des traitements technologiques“. Nantes, 1993. http://www.theses.fr/1993NANT2022.
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La fermentation colique des fibres alimentaires par la microflore de ce compartiment permet d'expliquer une grande partie des effets benefiques des fibres. Notre but a consiste a identifier les caracteristiques chimiques, physico-chimiques et physiques des fibres conditionnant leur fermentation colique. Les outils utilises ont ete: 1) des traitements chimiques et(ou) physiques destines a modifier les caracteristiques des fibres, 2) un systeme in vitro simple simulant la fermentation colique humaine. Le substrat selectionne, les fibres de betterave, constituait un modele classique de fibres alimentaires. Les traitements chimiques eliminent des quantites variees de pectines, d'arabinases, d'arabinogalactanes, de galactanes, de radicaux methyles et acetyles et entrainent tous une augmentation de la fermentescibilite. Il n'y a pas de relation entre la nature des composants extraits et la fermentescibilite. L'elimination des composes parietaux provoque une augmentation de la capacite de retention d'eau des fibres (cre). Nos resultats montrent que ces modifications de la cre proviennent d'une augmentation de la porosite du substrat a la suite de l'extraction. Nous avons confirme la relation entre cre et porosite en modifiant la structure physique des fibres par sechages. Les sechages provoqueraient des phenomenes de retraction des fibres (collapse) se traduisant par une diminution de la capacite de retention d'eau, du volume total de pores et de la fermentescibilite. Pour l'ensemble des fibres, la cre et la porosite apparaissent liees (r=0,9; n=11). Il existe egalement une relation reliant les volumes de pores, accessibles aux bacteries et aux enzymes, a la fermentescibilite des fibres (r=0,8; n=6). De facon originale, l'ensemble de ces resultats met en lumiere l'importance de l'etat physique des fibres et notamment de la porosite pour comprendre leur fermentation dans le colon humain
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MOORE, JEANNETTE AILEEN. „RATE OF PASSAGE, RATE OF DIGESTION, AND RUMEN ENVIRONMENTAL CHANGES AS INFLUENCED BY ROUGHAGE SOURCE IN 65 AND 90% CONCENTRATE DIETS FOR STEERS“. Diss., The University of Arizona, 1987. http://hdl.handle.net/10150/184246.
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Diets were based on steam-flaked milo and contained chopped alfalfa hay in the control diet. At the 65% concentrate level, cottonseed hulls or chopped wheat straw replaced half the alfalfa hay. At the 90% concentrate level, roughage sources were chopped alfalfa hay, cottonseed hulls, or wheat straw. Six growing steers and three mature, rumen-cannulated steers per concentrate level were used in separate Latin square experiments. Total tract digestion coefficients, particulate passage rates, liquid turnover rates, and rumination time were measured in the intact steers. In situ digestion, rumen pH, and rumen dry matter distribution were evaluated in the cannulated steers. Competition between rates of passage and digestion were used to calculate apparent extent of ruminal digestion (AED). At the 65% concentrate level, total tract digestion coefficients for the wheat straw vs alfalfa hay diet were not different, apparently due to increased milo and alfalfa hay neutral detergent fiber (NDF) digestion in the wheat straw diet. Milo and alfalfa hay AED for NDF were higher (P<.10). Dietary AED for DM, NDF, and cell solubles were highest (P<.05) for the alfalfa hay diet. Differences between diets were minimal, indicating roughage source in 90% concentrate diets does not substantially influence milo digestion or passage as it does in 65% concentrate diets.
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Cara, Louis. „Effets des produits céréaliers riches en fibres sur la digestion des lipides et le métabolisme des lipoprotéines plasmatiques chez le rat et chez l'homme“. Aix-Marseille 3, 1991. http://www.theses.fr/1991AIX30014.
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Cette these a contribue tout d'abord a confirmer in vitro le pouvoir inhibiteur du germe de ble vis-a-vis de l'hydrolyse des lipides par la lipase pancreatique. Ensuite, il s'est agit d'evaluer chez le rat la dose minimale efficace de germe de ble necessaire pour l'obtention des effets metaboliques benefiques au niveau des lipides plasmatiques, lipoproteiques et hepatiques. Enfin, nous avons demontre chez l'homme sain les effets benefiques de certaines fractions cerealieres riches en fibres sur le metabolisme des lipides et des lipoproteines en periode postprandiale et montre les effets favorables du germe de ble sur ces parametres a court terme (un mois) et a long terme (trois mois et demi) chez des sujets moderement hypercholesterolemiques. Les traitements thermiques et technologiques du ble et du germe de ble ont par ailleurs entraine une diminution plus ou moins marquee de ces effets. En consequence des resultats experimentaux obtenus, on peut recommander l'augmentation de la consommation des produits cerealiers riches en fibres
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CLOUTOUR, FRANCOISE. „Caracteristiques des fibres alimentaires : influence sur leur fermentation in vitro par la flore digestive de l'homme“. Nantes, 1995. http://www.theses.fr/1995NANT2010.
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Notre objectif etait de mieux comprendre le comportement fermentaire des fibres en regard de leurs caracteristiques structurales et physiques. Nous avons donc selectionne des fibres modeles, fibres de pois et de pomme dont les proprietes fermentaires semblaient dependre essentiellement de la cristallinite pour les coques de pois et de la porosite pour les fibres de pomme. Les moyens utilises ont ete 1) des traitements chimiques et/ou physiques destines a modifier ces caracteristiques 2) un systeme in vitro simulant la fermentation colique humaine. La cristallinite (indice et allomorphisme) de la cellulose des fibres de pois semblait le parametre cle dans l'explication de leur comportement fermentaire. En effet, le traitement a la soude concentree transformait la cellulose native de type 1 en type 2 et augmentait le volume poreux, notamment celui accessible aux bacteries. Toutefois, la cellulose n'etait pas plus degradee que celle du substrat natif. De plus, la fermentation de la cellulose etait accrue par un broyage prealable des fibres de pois. Le broyage mis en uvre induisait, outre une augmentation de la surface specifique, une diminution de la cristallinite. A taille de particules identique, la cellulose dans des fibres de pois pretraitees par voie enzymatique etait moins degradee que celle presente dans les fibres broyees. Ces deux produits se differenciaient par leur taux de cristallinite. Dans le cas de fibres comportant de la cellulose peu cristalline, nous avons montre que la macroporosite intervenait dans la vitesse de degradation de cette derniere. Toutefois, la prise en compte de ce facteur n'etait pas suffisante pour rendre compte des differences observees dans la fermentescibilite des differents produits issus de differents sechages. D'autres parametres d'ordre structural, (reagencement des constituants au sein de la paroi) seraient susceptibles d'intervenir
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Jordan, Katherine Van. „Effect of sodium caseinate on hindgut fermentation and fiber digestion in the equine and Effect of Megasphaera elsdenii on broiler chick performance“. Thesis, Kansas State University, 2017. http://hdl.handle.net/2097/38250.
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Master of ScienceDepartment of Animal Sciences and Industry
James M. Lattimer
Eight cecally cannulated horses were used in a replicated, 4 x 4 Latin square design conducted in 4, 14-d periods to determine effects of sodium caseinate on equine hindgut fermentation and fiber digestion. Horses were maintained on an ad libitum diet of Smooth Bromegrass hay and treatments consisted of cecal infusions of water (CON), 0.125 g sodium caseinate/kg BW (LOW), 0.25 g sodium caseinate/kg BW (MED), and 0.50 g sodium caseinate/kg BW (HI). Cecal NH3 concentrations increased (P < 0.01) as casein increased. Horses on the CON and MED treatments had greater cecal pH (P < 0.01) than horses on the LOW and HI treatments; however, there was no effect of treatment of fecal pH. Dry matter, OM, NDF, and ADF digestibility were unaffected by treatment (P > 0.10). There were no differences in dry matter intake (DMI), regardless of treatment. There was no treatment effect on cecal acetate, propionate, butyrate, total VFA concentration or acetate:propionate (A:P) ratio. Inter-horse variability and a small sample size may contribute to the lack of statistical differences amongst treatments. Results from this study may imply that medium quality, roughage based protein supplies an adequate level of nitrogen to the microflora of the hindgut. A performance study was conducted to evaluate the effect of strain and method of administration of Megasphaera elsdenii on growth performance in broiler chickens. In Experiment 1, pens were randomly assigned to 1 of 6 treatments: 0.2 mL oral gavage containing 1.97 x 10⁹ CFU/mL of M. elsdenii strain NCIMB 41125 (Lactipro, MS-Biotec, Wamego, KS; O-L), 0.2 mL of fresh culture containing 0 CFU/mL of M. elsdenii strain KS 249 (O-KS; Attempts to grow this strain were unsuccessful), 0.2 mL of a fresh culture containing 1.06 x 10⁹ CFU/mL of M. elsdenii strain B52-2083 (O-B52), aerosolized mist at rate of 15 mL per pen containing 1.97 x109 CFU/mL of M. elsdenii strain NCIMB 41125 (~1.88 mL/bird; MS-Biotec, Wamego, KS; OM), topdressing (mixture of diet and freeze dried M. elsdenii strain NCIMB 41125; TD) containing 1.18 x 10⁷ CFU/g of M. elsdenii strain NCIMB 41125 at a rate of a quarter teaspoon per bird, or negative control that had no contact with the probiotic product. Broilers across all treatment groups showed similar ADFI (P = 0.82), ADG (P = 0.89), gain:feed (P = 0.93), and mortality rates (P = 0.54). In Experiment 2, chicks were assigned to 1 of 2 treatments consisting of lyophilized M. elsdenii strain NCIMB 41125 in the form of a topdressing (TD) or a negative control that had no contact with the probiotic product (C). Average daily gain (P = 0.02) and gain:feed (P = 0.04) were both greater in birds receiving the TD when compared to the C birds. Feed intake (P = 0.70) and mortality rates (P = 0.31) were not different between treatments. Administration of lyophilized M. elsdenii strain NCIMB 41125 may be an effective means to improve growth rate and feed efficiency of broiler chicks.
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Hart, Ashley Yeong. „Effects of resistant starch and soluble fiber on the bioaccessibility of dietary carotenoids from spinach and carrot using simulated in vitro digestion“. The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1332442523.
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Silva, Flavio Lopes da [UNESP]. „Emprego de fibra de cana-de-açúcar na alimentação de cães“. Universidade Estadual Paulista (UNESP), 2013. http://hdl.handle.net/11449/89185.
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silva_fl_me_jabo.pdf: 435848 bytes, checksum: de9018bb62cc16d528ef39f84fb30691 (MD5)Proveniente do refinamento do bagaço de cana, a fibra de cana torna-se ingrediente potencial para cães. Nesta pesquisa avaliaram-se os aspectos nutricionais e funcionais da fibra de cana-de-açúcar (FC) em quatro alimentos extrusados para cães: Controle (CO) sem adição de fibra; adição 10% de FC (FC-10); adição de 20% de FC (FC-20); adição de 10% de CEL (CEL-10). O experimento foi organizado em dois blocos de 12 cães, totalizando 6 cães por tratamento. Em cada bloco, nos dias 1-10 foram determinados os coeficientes de digestibilidade aparente e energia metabolizável das rações. Nos dias 11, 12 e 13 foram avaliados o pH, ácido lático e amônia das fezes. Nos dias 15, 16 e 17, foram avaliadas as respostas pós-prandiais de glicose, insulina, colesterol e triglicerídeos. A saciedade foi verificada no 20º dia, pela oferta de um alimento desafio. E nos dias 24, 25 e 26, foi avaliado o tempo de retenção do alimento no TGI. Os dados foram submetidos à análise de variância pelo procedimento GLM do SAS. Em inclusões de até 20% e dietas com 3,2Kcal EM/g, a fibra insolúvel não limitou o consumo de matéria seca e energia metabolizável, não induzindo perda de peso nos cães. Verificou-se redução linear no CDA da MS, MO, FDT, EB e EM, assim como redução quadrática no EEHA. O tempo de retenção intestinal apresentou redução linear. A quantidade de fezes produzida teve aumento linear entre os tratamentos, no entanto, não se obteve diferença significativa entre os escores fecais, ensaio de saciedade, tempo de retenção e resultados pós-prandiais de glicose, insulina, triglicerídeo e colesterol entre os tratamentos. Portanto, os dados obtidos validam o uso do bagaço de cana-de-açúcar como fonte alternativa de fibra insolúvel na alimentação de cães
From the refining of sugarcane bagasse, sugarcane becomes a potential ingredient for dogs. The research evaluated the nutritional and functional sugarcane fiber (FC) in four extruded dog food: Control (CO) without added fiber; addition 10% of FC (FC-10), adding 20% FC (FC-20); addition of 10% CEL (CEL-10). The experiment was divided into two blocks of 12 dogs, totaling 6 dogs per treatment. In each block, on days 1-10 were determined the apparent digestibility coefficients and metabolizable energy of diets. On days 11, 12 and 13 were evaluated for pH, lactic acid and ammonia from feces. On days 15, 16 and 17, were evaluated postprandial glucose, insulin, cholesterol and triglycerides. Satiety was assessed on day 20, by offering a food challenge. And on days 24, 25 and 26, was measured the retention time. Data were evaluated by analysis of variance by the GLM procedure of SAS. Until inclusions of 20% and diets with 3,2Kcal EM/g, insoluble fiber did not limit the dry matter and metabolizable energy intake, as well as did not induce weight loss in dogs. There was a linear reduction in ADC of DM, OM, TDF, CE and ME as well as quadratic reduction in fat. The intestinal retention time presented linear reduction. The quantity of stools produced was increased linearly among treatments, however, there was no significant difference among the scores fecal, test satiety and postprandial glucose, insulin, triglycerides and cholesterol results among treatments. Therefore, the data validate the use of sugarcane bagasse as an alternative source of insoluble fiber in the feed dogs
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Silva, Flavio Lopes da. „Emprego de fibra de cana-de-açúcar na alimentação de cães /“. Jaboticabal, 2013. http://hdl.handle.net/11449/89185.
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Orientador: Áulus Cavalieri CarciofiBanca: Ananda Portella Félix
Banca: Ricardo Souza Vasconcellos
Resumo: Proveniente do refinamento do bagaço de cana, a fibra de cana torna-se ingrediente potencial para cães. Nesta pesquisa avaliaram-se os aspectos nutricionais e funcionais da fibra de cana-de-açúcar (FC) em quatro alimentos extrusados para cães: Controle (CO) sem adição de fibra; adição 10% de FC (FC-10); adição de 20% de FC (FC-20); adição de 10% de CEL (CEL-10). O experimento foi organizado em dois blocos de 12 cães, totalizando 6 cães por tratamento. Em cada bloco, nos dias 1-10 foram determinados os coeficientes de digestibilidade aparente e energia metabolizável das rações. Nos dias 11, 12 e 13 foram avaliados o pH, ácido lático e amônia das fezes. Nos dias 15, 16 e 17, foram avaliadas as respostas pós-prandiais de glicose, insulina, colesterol e triglicerídeos. A saciedade foi verificada no 20º dia, pela oferta de um alimento desafio. E nos dias 24, 25 e 26, foi avaliado o tempo de retenção do alimento no TGI. Os dados foram submetidos à análise de variância pelo procedimento GLM do SAS. Em inclusões de até 20% e dietas com 3,2Kcal EM/g, a fibra insolúvel não limitou o consumo de matéria seca e energia metabolizável, não induzindo perda de peso nos cães. Verificou-se redução linear no CDA da MS, MO, FDT, EB e EM, assim como redução quadrática no EEHA. O tempo de retenção intestinal apresentou redução linear. A quantidade de fezes produzida teve aumento linear entre os tratamentos, no entanto, não se obteve diferença significativa entre os escores fecais, ensaio de saciedade, tempo de retenção e resultados pós-prandiais de glicose, insulina, triglicerídeo e colesterol entre os tratamentos. Portanto, os dados obtidos validam o uso do bagaço de cana-de-açúcar como fonte alternativa de fibra insolúvel na alimentação de cães
Abstract: From the refining of sugarcane bagasse, sugarcane becomes a potential ingredient for dogs. The research evaluated the nutritional and functional sugarcane fiber (FC) in four extruded dog food: Control (CO) without added fiber; addition 10% of FC (FC-10), adding 20% FC (FC-20); addition of 10% CEL (CEL-10). The experiment was divided into two blocks of 12 dogs, totaling 6 dogs per treatment. In each block, on days 1-10 were determined the apparent digestibility coefficients and metabolizable energy of diets. On days 11, 12 and 13 were evaluated for pH, lactic acid and ammonia from feces. On days 15, 16 and 17, were evaluated postprandial glucose, insulin, cholesterol and triglycerides. Satiety was assessed on day 20, by offering a food challenge. And on days 24, 25 and 26, was measured the retention time. Data were evaluated by analysis of variance by the GLM procedure of SAS. Until inclusions of 20% and diets with 3,2Kcal EM/g, insoluble fiber did not limit the dry matter and metabolizable energy intake, as well as did not induce weight loss in dogs. There was a linear reduction in ADC of DM, OM, TDF, CE and ME as well as quadratic reduction in fat. The intestinal retention time presented linear reduction. The quantity of stools produced was increased linearly among treatments, however, there was no significant difference among the scores fecal, test satiety and postprandial glucose, insulin, triglycerides and cholesterol results among treatments. Therefore, the data validate the use of sugarcane bagasse as an alternative source of insoluble fiber in the feed dogs
Mestre
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Paredes, García Julio Alejandro. „Efecto del nivel de fibra detergente neutra sobre el consumo en alpacas (Vicugna pacos)“. Bachelor's thesis, Universidad Nacional Mayor de San Marcos, 2013. https://hdl.handle.net/20.500.12672/14185.
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Publicación a texto completo no autorizada por el autorEvalúa el consumo de materia seca (CMS) y de fibra detergente neutra (CFDN) en función a los niveles de Fibra Detergente Neutro (FDN) en la dieta en alpaca; estima el consumo potencial de FDN a fin de predecir el CMS y de esta manera mejorar sus sistemas de crianza. Se utilizó el diseño experimental Cuadrado Latino 4x4. Los tratamientos fueron a base de heno de avena en diferentes proporciones de tallos y hojas y procesado por una picadora de 2 cm y separado por un tamiz de 0.4 cm. Los tratamientos fueron: Tratamiento 1 (T1, 58.24% de FDN), hojas de heno (todo lo que pase por el tamiz de 0.4 cm.); Tratamiento 2 (T2, 61.38% de FDN), 50% de heno entero y 50% de hojas de heno; Tratamiento 3 (T3, 66.31% de FDN), heno de entero; Tratamiento 4 (T4, 70.22% de FDN), tallos de heno (todo lo que no pase por el tamiz de 0.4 cm). Las alpacas fueron de la raza huacaya, machos de 3 años de edad, con peso promedio de 48.6 ± 1.3kg. El alimento fue suministrado ad libitum dos veces al día, a las 08:00 y 16:00 h, Los resultados fueron analizados mediante análisis de varianza. La comparación de medias se realizó mediante la prueba de Duncan. La fuente de variabilidad debida a tratamientos fue descompuesta en un contraste lineal y en una falta de ajuste, las funciones de respuesta en consumo de MS y FDN sobre porcentaje de FDN fueron obtenidas mediante análisis de regresión. Los análisis se realizaron con ayuda del paquete estadístico SAS/STAT® 9.2 con un nivel de significación de 0.05. Los resultados muestran que el incremento del nivel de FDN en la dieta causa disminución del CMS (p<0.05) y no afecta el CFDN (p>0.05). El consumo máximo de FDN fue de a 0.97% PV y de 25.6 g/kg 0.75 , CFDN promedio fue de 0.92 ± 0.06% PV y 24.22 ±1.62 g/kg 0.75.
Tesis
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Faria, Elisa de Sousa. „Avaliação de níveis de fibra na dieta de novilhas leiteiras de diferentes grupos zootécnicos“. Universidade Federal de Viçosa, 2000. http://www.locus.ufv.br/handle/123456789/10986.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
No presente trabalho foi avaliado o desempenho de novilhas leiteiras de três grupos zootécnicos (7/8HZ, 15/16HZ, HPC), quando submetidas a dietas, em mistura completa, com dois níveis diferentes de fibra (30 e 60%FDN), mantidas em regime de estabulação, utilizando-se como volumoso o capim-elefante (Pennisetum purpureum, Schum., cv. Mineirão) picado. Foram determinados o consumo, o ganho de peso, a taxa de passagem do volumoso, o comportamento ingestivo e as respostas fisiológicas desses animais frente às condições do ambiente. O experimento foi montado segundo um esquema fatorial 3x2 (grupo zootécnico x nível de fibra), no delineamento em blocos casualizados, com três repetições. Os dados de ambiente foram analisados em parcelas subdivididas no tempo. Já a cinética digestiva foi determinada num ensaio ao final do período experimental, em um delineamento inteiramente casualizado com três repetições. Foram observados consumos médios de MS, FDN e FDA de 10,13; 2,69; e 1,45 kg/dia e 2,70; 0,71; e 0,38%PV, respectivamente, para a dieta com baixa fibra contra 10,68; 6,17; e 2,92 kg/dia e 2,90; 1,67; e 0,79%PV para a dieta com alta fibra, e ganhos de peso obtidos de 1,28 e 0,92 kg/dia, respectivamente. O tempo de retenção no rúmen-retículo (TRRR) foi 13,8% menor e o tempo de retenção no ceco-cólon (TRCC), 13,9% maior para a dieta com 30% de FDN que para a dieta com 60% de FDN. Houve, ainda, aumento dos tempos gastos com alimentação, ruminação e mastigação total, enquanto a taxa de ingestão e a taxa de ruminação da MS decresceram com o aumento do nível de fibra da dieta. Os animais submetidos à dieta com alta fibra, embora tenham aumentado o consumo de matéria seca e atingido ganhos de peso superiores aos esperados, não chegaram ao ganho máximo de peso obtido pelos animais submetidos à dieta com baixa fibra. Quanto aos grupos zootécnicos, o consumo de MS foi maior para os animais 15/16HZ e HPC, 2,80 e 2,94 %PV, respectivamente, que para os animais 7/8HZ, 2,65%PV. Os consumos de FDN, FDA e PB (%PV) diferiram entre os grupos zootécnicos 7/8HZ e HPC. O tempo de retenção no rúmen- retículo foi 14,75% maior para os animais 7/8HZ que para os animais HPC, e o tempo de retenção no ceco-cólon foi 28,2% menor para os animais 7/8HZ. As novilhas HPC despenderam maiores tempos alimentando e mastigando que as novilhas 7/8HZ. Este grupo apresentou, ainda, valores absolutos de freqüência respiratória superiores às novilhas 7/8 em todos os tratamentos.
This work aimed to evaluate the performance of dairy heifers from three genetic groups (7/8HZ, 15/16HZ, HPC), fed diets, in a complete mixture, with two different fiber levels (30 and 60%NDF), and confined, using chopped elephant grass (Pennisetum purpureum, Schum., cv. Mineirão) as roughage. The intake, weight gain, roughages passage rate, ingestive behavior and physiological answers of these animals were determined under different environmental conditions. The experiment was conducted according to a 3x2 factorial scheme (genetic group x fiber level), in a completely randomized design, with three replicates. The environment data were analyzed according to split plot in time. The digestive kinetic was determined in a trial at the end of the experiment period, in a completely randomized design with three replicates. Average intakes of DM, NDF and ADF of 10.13, 2.69, and 1.45 kg/day and 2.70, 0.71 and 0.38%LW, respectively, were observed for the diet with low fiber content versus 10,68; 6,17; and 2.92 kg/day and 2.90, 1.67, and 0.79%LW for the diet with high fiber content and weight gains of 1.28 and 0.92 kg/day, respectively were obtained. The retention time in the rumen-reticulum (TRRR) was 13.8% lowerand the retention time in the cecum-colon (TRCC) was 13.9% higher for the diet with 30% NDF in relation to the diet with 60% NDF. It was also verified that the times spent with feeding, ruminations and total chewing increased, while the ingestive rate and DM rumination rate decreased as dietary fiber level increased. The animals fed diet with high fiber content, although showed high dry matter intake and reached weight gains higher than the expected, did not obtain maximum weight gain of the animals fed low fiber based diet. Concerning to the genetic groups, the DM intake was higher for the 15/16HZ and HPC animals, 2.80 and 2.94 %LW, respectively, than for the 7/8HZ animals, 2.65%LW. The NDF, ADF and CP (%LW) intakes differed between 7/8HZ and HPC. The retention time in the rumen-reticulum was 14.75% higher for the 7/8HZ than for HPC, and the retention time in the cecum-colon was 28.2% lower for 7/8HZ. HPC heifers dispended longer feeding and chewing times in relation to 7/8HZ heifers. This group also showed than 7/8 heifers in all treatments. higher absolute values of breathing frequency
Dissertação importada do Alexandria
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Marcé, Clavillé Marta. „Estrategias adhesivas de los postes de fibra de vidrio“. Doctoral thesis, Universitat Internacional de Catalunya, 2015. http://hdl.handle.net/10803/321361.
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La restauración de los dientes endodonciados ha sido un tema ampliamente estudiado en la literatura científica. A principios de los años 2000, época en que empezaban a despuntar los materiales adhesivos a base de resina, con buenos resultados clínicos, no había aún un consenso definido a la hora de restaurar los dientes endodonciados
La aparición de nuevos diseños anatómicos, materiales de los postes intrarradiculares y los sistemas adhesivos actuales, han hecho que los protocolos de restauración de los dientes endodonciados, se hayan modificado, para ser más conservadores y sólo aquellos dientes con poca estructura dental remanente requerirán de un poste intrarradicular para ser restaurados satisfactoriamente.
Se ha observado que la restauración de los dientes endodonciados mediante postes intrarradiculares presenta un grado de supervivencia de entre el 80 al 95% de los casos entre los 5 y 10 años, según el artículo revisado. La literatura reporta varias causas de fracaso de estas restauraciones, siendo las principales, de causa restaurativa y la pérdida de retención del poste de fibra.
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Canora, Alice. „Studio del potenziale prebiotico degli alimenti con un modello intestinale in vitro e analisi multi-omiche“. Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021. http://amslaurea.unibo.it/22359/.
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In questo lavoro ci siamo concentrati sullo studio di un pane arricchito col 4% (p/p) di sansa sgrassata di oliva (DOP) prodotto nell’ambito del progetto europeo H2020 EcoProlive.
La sansa di oliva sgrassata è un sottoprodotto derivante dalla produzione dell’olio di oliva ed è caratterizzata da un elevato contenuto di polifenoli, risulta interessante valutarne il potenziale prebiotico e l’impatto sul microbiota del colon umano. Per questo, i prodotti studiati sono stati sottoposti a digestione gastro duodenale e successivamente a fermentazione colonica distale nel modello intestinale in vitro MICODE (Multi-Unit In vitro Colon Model). Il campionamento è stato effettuato prima, durante e dopo 24 ore di fermentazione, al fine di eseguire analisi metabolomiche tramite SPME GCMS, sequenziamento genomico 16S attraverso MiSeq e quantificazione assoluta delle principali specie batteriche tramite qPCR.
Dai risultati di questo studio è possibile affermare che il prototipo di pane Eco 4% possiede un potenziale prebiotico più debole rispetto ai frutto-oligosaccaridi dell’inulina, ma più forte del suo pane di controllo privo di polifenoli aggiunti.
Durante il periodo di fermentazione Eco4% non ha influenzato l’eubiosi e non ha indotto la disbiosi. Inoltre sono stati registrati l’aumento dell’abbondanza di specie probiotiche o benefiche, come Lactobacillales e Bifidobacteriaceae e la diminuzione di specie opportunistiche o patogene.
Grazie all’analisi del volatiloma è stata riscontrata la produzione di composti bioattivi come gli acidi grassi a corta e media catena. Composti dannosi come gli acidi grassi a catena ramificata ed indolo e scatolo, invece, sono stati ridotti.
Questi risultati sono supportati da un approccio statistico multivariato in grado di combinare dati di genomica e di metabolomica microbica, in una vetrina multi-omica, a dimostrazione della visibile relazione causa-effetto generata da una certa fibra che possiede un potenziale prebiotico.
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Jacquier, Vincent. „Approches génomiques des interactions entre l’implantation du microbiote digestif chez le lapereau et la maturation du système immunitaire“. Thesis, Toulouse, INPT, 2014. http://www.theses.fr/2014INPT0131/document.
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La santé digestive du lapin est difficile à maîtriser en élevage, notamment en période de sevrage où des troubles digestifs sont fréquents et peuvent entraîner des pertes importantes. Bien que l’utilisation d’antibiotiques diminue, afin d’éviter l’apparition de problèmes de résistance, des solutions alternatives doivent être trouvées. Nos principaux objectifs étaient : i) d’étudier l’influence de l’incorporation de fibres rapidement fermtentescibles (FRF) dans un aliment distribué précocement dès 15 jours d’âge, en comparaison d’un aliment avec antibiotiques (tiamuline et apramycine) utilisés pour lutter contre l’entéropathie épizootique du lapin ; ii) de déployer des méthodologies en génomique ciblant l’espèce lapin (amélioration et réannotation d’un microarray) et son microbiote digestif (pipeline d’analyse du gène de l’ARNr 16S), pour du phénotypage moléculaire. L’originalité de notre travail réside ainsi dans l’acquisition de données par trois approches complémentaires : phénotypique, transcriptomique, et métagénomique. Au niveau phénotypique, la stimulation de l’activité fermentaire par les FRF est vérifiée avec une hausse de la concentration caecale en AGV (+20%) et une plus forte acidité du biotope caecal. De plus, les FRF tendent à réduire la mortalité en post-sevrage et améliorent l’efficacité alimentaire. Au niveau transcriptomique, nous avons tout d’abord apporté de nouvelles connaissances sur l’immunité du lapin adulte avec la stimulation in vitro de cellules mononuclées du sang périphérique par du LPS et de la PMA-ionomycine. Cette étude confirme l’importance du lapin comme animal modèle pour la recherche biomédicale. Chez le jeune lapin, la nouvelle version du microarray nous a permis de montrer que les fonctions biologiques sont plus rapidement mises en place avec les FRF qu’avec un aliment standard, et que les antibiotiques nivellent l’expression génique. De plus, les FRF contribueraient à limiter l’inflammation intestinale. Au niveau métagénomique et en ciblant l’ARNr 16S, nous montrons qu’une augmentation de l’activité microbienne caecale n’est pas associée à une modification majeure de la composition du microbiote, à l’exception de la stabilisation de l’abondance des Campylobacteraceae, qui limiterait l’inflammation digestive. Nos travaux, encore préliminaires, n’ont pas permis d’identifier des corrélations significatives entre l’expression génique dans le sang et/ou l’iléon, et les profils taxonomiques (OTUs) majoritaires du microbiote digestif. L’ensemble de nos résultats suggère d’une part que les FRF peuvent être proposées comme une nouvelle stratégie nutritionnelle péri-sevrage, avec une amélioration de l’efficacité alimentaire et une protection accrue de la santé digestive, et d’autre part que des approches génomiques sont prometteuses pour qualifier finement les phénotypes d’intérêt chez le lapinDigestive health of rabbits is difficult to manage in breeding systems, especially around weaning where digestive problems are very common and can result in significant losses. The use of antibiotics decreases in order to avoid the emergence of problems with antibiotic resistance, but alternatives must be found. The objectives of this work were: i) to study effects of the incorporation of rapidly fermentable fiber (FRF) in diets fed to rabbits from 15 days of age, and compared to a feed with antibiotics (tiamulin and apramycin), used to fight against epizootic rabbit enteropathy; ii) to deploy genomics methodologies targeting the rabbit species (improvement and re-annotation of a microarray) and the digestive microbiota (pipeline analysis of 16S rRNA gene), for molecular phenotyping. An innovative approach was used in this work through the combination of three complementary approaches: phenotypic, transcriptomic, and metagenomic. At the phenotypic level, the stimulation of the fermentation activity by FRF is verified with higher cecal VFA concentrations (+ 20%) and higher cecal acidity. Moreover, the FRF tend to reduce mortality post-weaning and improve feed efficiency. At the transcriptomic level, we obtained new data on the immunity of the adult rabbit with in vitro stimulation of peripheral blood mononuclear cells with LPS and PMA-ionomycin. This study confirms the importance of the rabbit as an animal model for biomedical research. In young rabbits, the new version of the microarray allowed us to show that biological functions are more quickly implemented with FRF than a standard diet, and that antibiotics level out the gene expression. In addition, FRF help to limit intestinal inflammation. At the metagenomic level, the targeting of the 16S rRNA, we showed that an increase in cecal microbiota activity is not associated with major changes of microbiota composition, with the exception of the stabilization of the relative abundance of Campylobacteraceae, which limits gastrointestinal inflammation. Our preliminary results did not identify significant correlations between gene expression in blood and/or ileum, and principal taxonomic profiles of the digestive microbiota. Our results suggest that FRF can be proposed as a new nutrition strategy peri-weaning, with improved feed efficiency and increased protection of digestive health, and secondly that genomic approaches are promising to describe more precisely phenotypes of interest in rabbits
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BENAOUDA, MOHAMMED 893158, und MOHAMMED BENAOUDA. „Efecto de la calidad de la dieta y el nivel de la fibra en la cinética de digestión y la producción de metano en bovino lechero“. Tesis de doctorado, Universidad Autónoma del Estado de México, 2018. http://hdl.handle.net/20.500.11799/79746.
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La presente investigación fue realizada en la Facultad de Medicina Veterinaria y Zootecnia, de la Universidad Autónoma del Estado de México y trata el tema de la producción de metano entérico y su relación con la calidad de la dieta, específicamente el impacto del contenido y la calidad de la fibra sobre la emisión de metano. La primera parte de este documento se enfoca en dar a conocer el panorama general de los avances realizados en la región de América Latina tanto en determinación de los factores de emisión del gas metano como en el desarrollo de estrategias de mitigación. A escala mundial, la región latino americana contribuye con el 14% de las emisiones de metano, siendo Brasil y México los mayores contribuyentes. Los trabajos de estrategias de mitigación se han enfocado en el uso de plantas taníferas y aceites esenciales. A partir de los trabajos encontrados en la primera parte, se construyó una base de datos que fue utilizada para estudiar la variabilidad de la producción de metano por el ganado bovino en la región latinoamericana que varía entre 50 y 400 g/animal/día con un promedio de alrededor de 200 g. La base de datos compilada fue utilizada para desarrollar después ecuaciones de predicción de la emisión de metano. Se obtuvo una buena predicción de dicha emisión usando variables de consumo (consumo de materia seca y consumo de energía bruta), no obstante, la predicción mejora significativamente, al incluir en la ecuación la digestibilidad y el contenido en fibra. Al final, se estudió, experimentalmente, el efecto de la fibra y su digestibilidad sobre la emisión de metano por el ganado lechero. Para ello, se evaluaron cuatro dietas con niveles crecientes de fibra. A pesar de que el aumento de fibra no afecto el consumo ni la producción diaria de metano, el rendimiento de metano (l/kgMSI) disminuyó linealmente conforme incrementa el contenido de fibra en la dieta. De esta manera, se concluyó que América Latina, incluyendo México, ha empezado recientemente la labor de cuantificar el impacto medio ambiental de sus sistemas ganaderos en términos de contaminación con el gas metano, a pesar de que en esta zona existe un gran rebaño bovino. El consumo de alimento es el factor más importante para estimar la emisión de metano, sin embargo, la calidad de la fibra aportada por los forrajes es un factor clave para entender el comportamiento de la emisión de metano por el ganado bovino en México.UNIVERSIDAD AUTONOMA DEL ESTADO DE MEXICO, SECRETARIA DE RELACIONES EXTERIORES MEXICO