Concerns about beef production are growing among consumers, questioning the use of antibiotics, hormones, and metaphylactic treatments, as well as its environmental footprint. Therefore, beef production systems need to be more efficient to increase productivity while using less resources to become sustainable and reduce environmental impact. There is a need to develop and apply non-pharmaceutical alternatives to improve health, feed efficiency and performance of beef cattle. We investigated four different targeted strategies to enhance performance of beef cattle: 1) The effect of an injectable multi-mineral complex supplementation for grazing beef cows on overall mineral status, fertility, and subsequent offspring performance. Two doses of the trace mineral injection increased in pregnancy rate after artificial insemination, with a greater impact on cows with poor body condition score; 2) Inclusion of a yeast-derived product combining live yeast (probiotics) and cell wall components (prebiotics), on performance and physiological responses of beef steers during backgrounding and finishing phases. Including a yeast-derived product into a finishing diet containing monensin did not improve performance, physiological responses, and carcass quality of feedlot cattle. Nonetheless, inclusion of the yeast derived product as a substitute of monensin during the backgrounding and finishing phases decreased feed intake without affecting growth, with an overall improvement in feed efficiency; 3) Use of phytotherapy (condensed tannins) to reduce protozoa parasites load and prevent coccidiosis in peripartum beef heifers and their newborn calves. Daily supplementation of condensed tannins reduced coccidia load in heifers and newborn calves, although this reduction was transient; and 4) following the smart farming approach, validate the use of an automated scale system for grazing or feedlot beef cattle, which was able to accurately measures body weight in grazing and feedlot systems for growing and mature beef cattle while reducing cattle handling, without disrupting feeding behavior, decreasing the probability of animal lesions, accidents and optimizing labor. / Doctor of Philosophy / Diet diversification is a response of a growing economy, growing population, and urbanization, which increases the demand of meat products, especially beef, in substitution of staple foods. However, concerns around beef production and its impact on the environment are becoming more relevant for consumers. The need to produce more with less resources requires a sustainable intensification process. Specifically, beef cattle production systems are less efficient when compared to poultry or swine in terms of time and amount of feed required. Beef production systems need to focus on environmental and socially conscious strategies to satisfy the demand, increase animal health, productivity, and profitability. One approach is based on nutritional strategies and applied technologies to enhance productivity, efficiency, welfare, and health. In this dissertation we present three different strategies to improve efficiency of beef production systems: 1) using injectable trace minerals supplementation to ensure adequate mineral nutrition in grazing cows, improving their pregnancy rate to artificial insemination, particularly when cows are in poor body condition; 2) use of yeast as natural additives to successfully substitute antibiotics as growth promotants in feedlot diets with an improvement in feed efficiency; 3) use of secondary plant compounds, such as tannins, to substitute prophylactic antibiotic utilization for coccidiosis in cows and newborn calves. We demonstrate three successful strategies that can improve health, feed efficiency and reproductive performance of beef cattle, all of which are important to achieve greater productivity and profitability in beef production systems.

In the pulp production industry one potential problem is the production of gas from microbial activity in the storage tank. If left unchecked such gas production can in extreme cases lead to an explosion. To prevent any such event the current method of maintaining microbial activity in pulp plants is to use hazardous biocides. Such biocides can be expensive and dangerous to handle – therefore a safer and cheaper alternative would be preferred. This study aims to examine and evaluate two potential alternatives: Tannins extracted from trees with natural antibacterial properties and introduction of Lactobacillus plantarum to see if a more manageable bacteria can out-compete the bacteria already in the pulp. The results were measured by observing gas production in different trials where pulp from a nearby plant was mixed with different concentrations of tannins or Lactobacillus. The results showed that this strand of Lactobacillus plantarum had no effect on gas volume production while the pulp mixed with tannins did have some effect by lowering the amount of gas volume produced. However, the experiments with tannins and pulp showed no clear dose-response relationship which most likely is caused by varying quality and handling of the pulp used in the experiments. In summary this study shows that tannins can have an effect on the volume of gas produced by recycled paper pulp by lowering it – although not completely inhibiting it.

No description available.

The overall objective of this investigation was to develop a chemical method for treating spent vegetable tannin liquor. Vegetable tannin wastes are plagued by a multitude of undesirable characteristics, principal of which is a color problem. Historically, chemical coagulation processes have been successful in reducing color associated with industrial wastes. The coagulants tested were aluminum sulfate and polyelectrolytes. In addition, the pH and the time interval between aluminum ion and polyelegtrolyte addition were studied. Considerable difficulty was encountered in obtaining a waste product of uniform characteristics over an extended period. This problem was solved by storing a large quantity of waste of typical properties at temperatures near zero degrees centigrade. / Ph. D.

Captive gray squirrels were fed acorns or diets containing commercial tannins to determine the effects of tannins on digestion and detoxification (glucuronidation) activity. In the Acorn experiment, Northern red oak acorns (Quercus rubra), white oak acorns (Q. alba), or rat chow were fed to squirrels. Levels of phenols, condensed tannins, and hydrolyzable tannins were higher in red oak acorns than white oak acorns and were likely responsible for the lower dry matter intake, lower apparent protein digestibility, lower digestible protein and energy intakes, and higher glucuronidation activity observed in squirrels fed red oak acorns. Although apparent protein digestibility and digestible protein intakes were reduced on a white oak acorn diet, this diet did not continuously suppress dry matter intake or stimulate glucuronidation. It appears that gray squirrels may not be able to subsist on red oak acorns alone, but may require other foods to dilute tannin intake and provide additional nutrients. In the Tannin experiment, squirrels were fed rat chow containing no tannins, 4% or 8% tannic acid (hydrolyzable tannin), or 3% or 6% quebracho (condensed tannin). Apparent protein and energy digestibilities of tannic acid-containing diets were lower than the control. These reductions were likely due to the formation of strong complexes between protein and high molecular weight gallotannins. These complexes may have simultaneously protected these gallotannins from hydrolysis and allowed tannic acid to reduce digestive efficiency. Apparent protein and energy digestibilities of quebracho-containing diets were reduced, indicating protein complexing by these nonhydrolyzable tannins. Consistent with the hypothesis that hydrolyzable tannins are more likely to be broken down and absorbed internally than condensed tannins, only the 8% tannic acid diet tended to increase glucuronide excretion. / Master of Science

Les déchets issus de l’industrie vinicole française sont traditionnellement traités et valorisés en distilleries. Ce travail porte sur l’étude de la valorisation à échelle industrielle d’un des résidus ultimes des distilleries : le marc de raisin épuisé. Les marcs issus de différents bassins de productions français ont été caractérisés chimiquement, principalement par leur taux de tannins condensés et de sucres. Les conditions d’extraction des tannins condensés ont été optimisées en laboratoire puis le procédé a été transféré à l’échelle industrielle. Plusieurs extractions ont été menées dans trois distilleries partenaires et l’analyse chimique (en termes de polyphénols, de tannins condensés, de sucres et de matières inorganiques) des différentes fractions isolées a été réalisée. Des extraits industriels ont permis la fabrication du premier panneau de particules dont l’adhésif est constitué à 80 % de tannins de marcs de raisins et renforcé à l’aide d’une résine synthétique satisfaisant à la norme européenne de cohésion interne. Ces extraits industriels ont également partiellement substitué une résine phénol-formaldéhyde pour la production de panneaux de particules. Différents post-traitements ont été réalisés sur les extraits de marcs afin d’en augmenter la réactivité chimique vis-à-vis d’agents de réticulation. Une filtration à un seuil de coupure de 1 µm a entrainé une légère amélioration des performances adhésives, alors qu’une hydrolyse acide de l’extrait les a dégradées. Un procédé d’ultrafiltration des extraits à 5 kDa ou 1 kDa a permis d’obtenir des extraits beaucoup plus réactifs et ouvre des perspectives pour la production d’adhésifs biosourcés pour le bois / Wastes from the French wine industry are traditionally treated and upgraded in distilleries. This work deals with the study of an industrial-scale valorization of a final waste from distilleries: the spent grape pomace. Pomace from different French production areas were chemically characterized, in terms of condensed tannins and polysaccharides. An extraction process of condensed tannins has been optimized in laboratory and was then transferred to an industrial scale. Several extractions were carried out in three partner distilleries and chemical analysis (in terms of polyphenols, condensed tannins, sugars and inorganics) of the different isolated fractions were performed. Industrial extracts were used for the elaboration of the first particleboard whose adhesive constituted by 80% of grape pomace tannins and strengthened with a synthetic resin to satisfy the European standard for internal bond. These industrial extracts were also used to partially substitute a phenol-formaldehyde resin for the production of particleboards. Different post-treatments were performed on the pomace extracts in order to increase their chemical reactivity toward cross linking agents. Filtration with a cut-off of 1 µm led to a slight improvement in adhesive performances, whereas acid hydrolysis of the extract have degraded it. An ultrafiltration process of the extracts at 5 kDa or at 1 kDa enabled to get much more reactive extracts and opened up prospects for the production of bio-based adhesives for wood

La mutation de nos activités industrielles vers le développement durable est l’un des plus gros enjeux humains du 21ème siècle. L’utilisation de la biomasse dans divers domaines tels que l’énergie, la construction et les matériaux est une réponse face à la raréfaction des ressources fossiles et face aux risques écologiques. Les objectifs de cette thèse sont de créer de nouveaux matériaux les plus bio-sourcés possibles et d’optimiser les propriétés de ces matériaux en vue d’une éventuelle utilisation industrielle. Les travaux présentés ici traitent de la fabrication de matériaux composites à renforts de fibres naturelles, ayant pour matrice des résines bio-sourcées. Les ressources végétales principalement étudiées ici sont les tannins, utilisés pour la réalisation de : - Composites à matrice tannin – hexamine - Composites à matrice tannin – résorcine – aldéhyde Les tannins végétaux ont également été étudiés pour la conception de bio-plastiques tannin – alcool furfurylique pouvant être appliqués à la fabrication de composites. Les panneaux composites ont été réalisés en laboratoire et analysés mécaniquement en se basant sur des méthodes normatives européennes. Les résines ont également été caractérisées à l’aide de diverses techniques telles que l’analyse thermomécanique (TMA) ou la spectroscopie de masse MALDI-ToF. Au final, ces travaux ont permis de réaliser des matériaux composites hautement bio-sourcés, aux propriétés homogènes et reproductibles satisfaisant en outre les exigences d’emploi de plusieurs normes européennes / Changing our industrial activities towards sustainable development is one of the major human concerns of the 21th century. The use of biomass in various areas like energy, construction and materials is an answer to the future scarcity of fossil resources and to the ecological risks. The objectives of this thesis are to create new materials with the highest bio-based content possible and then to optimize these materials properties for a potential industrial use. The work presented here is about the fabrication of composite materials reinforced with natural fibers, using bio-based resins as a matrix. The main vegetable resources studied here are tannins, used to make: - Tannin – hexamine matrix composites - Tannin – resorcinol – aldehyde matrix composites Vegetable tannins were also studied to prepare tannin – furfuryl alcohol bio-plastics that may be used in the composites fabrication. The composites boards were made in laboratory and mechanically analyzed based on European norms methods. Resins were also characterized using various techniques such as thermomechanical analysis (TMA) or MALDI-ToF mass spectrometry. The end results of this work is the fabrication of highly bio-based composite materials, with homogenous and repeatable properties that furthermore satisfy several European norms requirements.

Les animaux sont constamment soumis à des variations de leur environnement auxquelles ils doivent s’adapter. Au sein des systèmes d’élevage qui reposent sur la stimulation de processus naturels réduisant les intrants requis pour la production, et dans une perspective agro-écologique, l’autonomie et les capacités d’adaptation des animaux apparaissent particulièrement importantes. Au pâturage, les petits ruminants sont confrontés au parasitisme par les nématodes gastro-intestinaux, qui représente une menace majeure notamment du fait du développement de résistance aux traitements anthelminthiques chimiques, et une alternative à ces traitements est l’utilisation de fourrages bioactifs contenant des composés secondaires tels que les tannins condensés. Dans ce contexte, nous avons exploré les capacités d’automédication des ovins et des caprins via l’utilisation d’aliments riches en tannins lorsque ceux-ci sont confrontés au parasitisme gastro-intestinal, en proposant plusieurs scénarios pour lesquels nous avons fait varier la complexité de l'environnement alimentaire et la charge parasitaire.Ainsi, nous avons dans un premier temps évalué les capacités des moutons à apprendre les bénéfices associés à l’ingestion d’un fourrage riche en tannins, le sainfoin, à l’aide d’une période de conditionnement, et à adapter leur sélection alimentaire suivant un changement de statut parasitaire. Dans un second temps, nous avons examiné les différences entre chèvres et moutons dans leur propension à sélectionner du sainfoin lorsque ceux-ci sont parasités, en supposant que les chèvres montreraient de meilleures capacités d’automédication. Enfin, dans une troisième expérimentation, nous nous sommes intéressés aux priorités qu’accordaient les ovins dans leur sélection alimentaire aux nutriments (énergie, protéines) et aux tannins selon leur statut parasitaire.Nos expérimentations s’accordent sur l’absence d’automédication curative. En effet, nous n’avons observé ni de sélection plus importante de l’aliment riche en tannins par les animaux parasités par rapport à ceux non parasités, ni d’augmentation de la sélection après infection. Comme nous nous y attendions, les chèvres ont montré une propension plus importante à consommer l’aliment riche en tannins que les moutons, mais n’ont néanmoins pas manifesté de meilleures capacités d’automédication. Enfin, les agneaux n’ont pas priorisé l’apport en composés bioactifs par rapport aux nutriments, mais ont considérablement augmenté leur apport en énergie après infestation. Il apparait que les niveaux de tannins que nous avons volontairement choisis modérés pour les aliments expérimentaux ont induit des bénéfices nutritionnels ayant potentiellement surpassé les effets anthelminthiques, qui étaient eux-mêmes modérés, et expliquant ainsi que les animaux parasités et les animaux sains ont sélectionné les tannins de façon similaire. Par ailleurs, des difficultés d’apprentissage peuvent également expliquer cette sélection, comme en témoigne la claire inversion de préférences pour l’aliment riche en tannins observée après que les animaux ont appris à associer l’aliment riche en tannins à ses conséquences post-ingestives, après la période de conditionnement. En ce qui concerne la flexibilité de la sélection alimentaire, les préférences alimentaires sont restées inchangées après déparasitage, probablement du fait de l’absence d’effets antinutritionnels des tannins, et du statut sécuritaire accordé aux aliments riches en tannins.Nous pensons que l’évaluation des capacités d’automédication des ruminants mérite des travaux complémentaires, notamment en explorant d’autres modèles que celui du parasitisme gastro-intestinal et des fourrages bioactifs. L’analyse de l’étiologie du comportement d’automédication, en s’intéressant à l’influence du modèle social par exemple, apparait également importante afin de favoriser un tel comportement au sein de pratiques d’élevage adaptées. / Animals are constantly facing variations in their environment to which they have to adapt. In breeding systems that rely on the stimulation of natural processes to reduce the inputs needed for production, under an agroecology perspective, animal's autonomy and adaptive abilities are particularly important. In grazing systems of small ruminants, parasitism by gastrointestinal nematodes is a major threat notably due to worms' resistance to chemical anthelminthic, and one alternative is the use of bioactive forages containing secondary compounds such as condensed tannins. Within this context, we explored the abilities of sheep and goats to self-medicate through the selection of tannin-rich feeds while facing gastrointestinal parasitism, by proposing different scenarios in which we varied the complexity of the feeding environment.We assessed the abilities of sheep to learn about the benefits of the tannin-rich sainfoin, by carrying out a conditioning period, and to adapt their diet selection according to changes in parasitic load. Secondly, we evaluated the differences between sheep and goats in their willingness to select sainfoin when parasitized, assuming that goats would show greater self-medication abilities. Thirdly, we studied the interactions between nutrients and medicines on diet selection by analyzing the way sheep selected proteins, energy and condensed tannins depending on their parasitic status.Our experiments did not support evidence for curative self-medication as we did not observe a greater selection of the tannin-rich feeds in parasitized than non-parasitized animals, nor an increase in selection following infection. As expected, kids were more willing than lambs to consume the tannin-rich feed, but they did not show greater abilities to self-medicate. Lastly, lambs did not prioritize medicine over nutrients, but greatly increased their energy intake following infection. It appears that the levels of tannins we voluntarily chose moderate for the experimental feeds, induced nutritional benefits that may have outweighed the anthelminthic ones, which were moderate, making both parasitized and non-parasitized animals select tannins in a similar way. Furthermore, learning impairment may be involved as well, as indicated by the striking reversal of preferences for the tannin-rich feed we observed once animals were helped to associate the tannin-rich feed with its consequences via conditioning. Regarding diet selection flexibility, feed preferences remained unchanged after deworming, likely because of the absence of anti-nutritional effects of tannins, and the safe status attributed the tannin-rich feeds.We think that the investigation of self-medication abilities in ruminants deserves further work, notably by exploring other models than gastrointestinal parasitism and bioactive forages. The analysis of the etiology of self-medication, by investigating the influence of the social model for example, appears also important in order to favour such behaviour by adapted farming practices.

No description available.

Les polyphénols et les phénols sont des molécules organiques largement présentes dans le règne végétal et souvent évaluées pour leur potentiel pharmacologique. Ces travaux de thèse concernent la synthèse totale de gallotannins, une classe importante de polyphénols, et l’hémisynthèse de la norbergénine, un C-arylglucoside naturel. Les gallotannins font partie des tannins hydrolysables dont la biosynthèse conduit à des structures chimiques caractérisées par la présence, sur un cœur glucopyranose, de plusieurs unités galloyle liées les unes aux autres par des liaisons méta-depside. Aucune synthèse chimique de ces composés n’ayant été décrite à ce jour, nous avons réalisé la synthèse totale de gallotannins naturels et de leurs anomères non naturels porteurs de motifs di- ou tri-galloyle depside. Ces travaux ont également permis d’étudier l’équilibre méta-para de ces motifs en solution. Quant à l’hémisynthèse de la norbergénine, elle a été réalisée avec succès en une seule étape à partir de la bergénine, un C-arylglucoside commercial, par réaction de O-déméthylation oxydante au SIBX (version stabilisée commerciale du iodane_λ5 IBX). Cette réaction chimiosélective a également été appliquée à des 2-méthoxyphénols et a notamment permis l’obtention de l’hydroxytyrosol à partir de l’alcool homovanillique. / Polyphenols and phenols are organic molecules widely found in the plant kingdom and very often evaluated for their pharmacological potential. This thesis work describes the total synthesis of gallotannins, an important class of polyphenols, and the hemisynthesis of norbergenin, a natural C-arylglucoside. The gallotannins belong to the hydrolysable tannins whose biosynthesis leads to chemical structures characterized by the presence, on a glucopyranose core, of several galloyl units linked ones to the others by meta-depside bonds. No chemical synthesis of these compounds have been reported to date, so we completed the total synthesis of several naturally occurring meta-depsidic gallotannins and their non natural anomers that contain di- or tri-galloyl motifs. This work also allowed the study of the meta-para equilibrium of these motifs in solution. For the norbergenin hemisynthesis, it was successfully achieved in a one step reaction from bergenin, a commercial C-arylglucoside, by a SIBX-mediated oxidative O-demethylation (SIBX = commercially available stabilized version of the λ5 _iodane IBX). This chemoselective reaction was also applied to 2-methoxyphenols and notably allowed the hemisynthesis of hydroxytyrosol from homovanillyl alcohol.