Plants containing condensed tannins (CT) represent an alternative feed resource for ruminants. However, limited information regarding nutrient disappearance from these plants is available. Two experiments were conducted to evaluate phosphorus (P) and other nutrient disappearance from plants containing CT. In the first experiment, nutrient disappearance from three native Texas species (Acacia angustissima var. hirta, Desmodium paniculatum, Smilax bona-nox, and Medicago sativa as control) were evaluated using the mobile nylon bag technique. For the second experiment, ruminal degradation parameters, ruminal and post-ruminal disappearance of P and other nutrients from a browse containing CT (Quercus virginiana) were compared to species without CT (Cynodon dactylon cv. Tifton 85, and Medicago sativa). Results from the first experiment indicate that the proportion of nutrient that disappeared during rumen, pepsin/HCl, or intestinal incubation differed among plant species and nutrient evaluated (P<0.05) and did not appear to be directly related to relative CT concentrations. Dry matter (DM), inorganic matter (IM), and organic matter (OM) disappearance were greater (P

Single cell proteins such as that of edible filamentous fungal biomass are considered as a promising sustainable source of animal feed supplementation. Filamentous fungi can be cultivated on different organic substrates including volatile fatty acids (VFAs) such as acetic, propionic, and butyric acids. These VFAs can be generated through the famous waste valorisation approach of anaerobic digestion (AD) as intermediate metabolites. This project investigates a sustainable approach for the production of animal feed supplementation through cultivation of fungal biomass on waste derived VFAs along with the in vitro analysis of fungal biomass digestibility as ruminant feed. In this regard, optimum conditions for the production of Aspergillus oryzae biomass on different VFAs effluents derived from anaerobic digestion process of food waste plus chicken manure (FWCKM) and potato protein liquor (PPL) at different pH, nitrogen sources, and feed mixture was studied. Accordingly, analyses showed that PPL has the highest biomass yield with 0.4 (g biomass/g consumed VFAs) based on the volatile solids (VS) by adjusting pH to 6.2. Furthermore, the digestibility of the produced fungal biomass is analysed by using three different in vitro digestion methods including Tilley and Terry (TT) method, Gas Production Method (GPM), and Nylon Bag Method (NBM) and the results are compared with the conventional feed (silage and rapeseed meal). Results obtained from different digestibility methods illustrate that different A. oryzae fungal biomass had approximately 10-15 % higher dry matter digestibility fraction compared to silage and rapeseed meal (reference feeds). Hence, these results revealed that A. oryzae fungal biomass can grow on VFAs effluents and produce protein-rich fungal biomass while this biomass has better digestibility compared to conventional feeds and confirmed the initial hypothesis of the study.

La collaboration scientifique PICO a comme but de développer des détecteurs pour découvrir la matière sombre. Bien que le modèle standard de la physique des particules décrit bien la matière qui nous entoure, plusieurs phénomènes nous indiquent qu'il reste d'autres particules à ajouter à ce modèle. Les recherches montrent que la matière connue ne représente que 5% de toute la masse-énergie contenue dans l'Univers, ce qui laisse place à découvrir les 95% restants. Le groupe PICO se spécialise dans la détection de matière sombre en utilisant les chambres à bulles. Les chambres à bulles de PICO ont été très performantes au cours des dernière décennies, mais elles ont récemment atteint leur apogée. Ce mémoire a pour but d'évaluer une autre approche quant au design des détecteurs pour voir s'il y a de nouvelles technologies permettant de poursuivre l'utilisation des chambres à bulles. Cependant, des contraintes mécaniques, de radiopureté, financières et techniques s'appliquent sur les matériaux utilisés pour la construction de la chambre. Nous nous intéressons donc à voir si l'utilisation d'un sac en nylon pour remplacer la jarre en verre qui contient le fréon amènerait une approche novatrice à la jarre. Afin d'évaluer cette idée, la construction d'un modèle réduit de la chambre à bulles, nommé NBBC (\textit{Nylon Bac Bubble Chamber}), a été mis sur pied. Si le concept fonctionne réellement, ce détecteur justifierait la création d'un modèle plus gros que tout ce qui a été réalisé jusqu'à présent en termes de détection par chambre à bulles. Ce mémoire présente toutes les étapes nécessaire à la réalisation de la chambre test NBBC, en commençant par un bref historique des détecteurs déjà existants. Les principes du fonctionnement de la chambre sont ensuite exposés, suivis d'une description de tous les circuits électriques développés et de tous les codes écrits. Finalement, les tests effectués sont présentés et le dernier chapitre est dédié aux conclusions obtenues et aux conseils sur la poursuite du projet. / The PICO scientific collaboration seeks to discover dark matter. Although the standard model of particle physics describes well the matter we already know, several phenomena show that there are more particles to add to this model. These shows that «normal» matter makes up only 5% of all the mass-energy in the Universe, leaving the other 95% still to be found. The PICO group specializes in the use of bubble chambers to find this dark matter. PICO bubble chambers have been very efficient, but they have reached their peak in recent years. The purpose of this master thesis is to evaluate other technologies that can be used to construct larger bubble chambers. Mechanical, radiopurity, financial and technical constraints apply to the materials used for the construction of the chamber. We are therefore interested to see if the use of a nylon bag to replace the glass jar containing freon could bring an innovative perspective to this jar. To evaluate this idea, we have embarked to build a prototype chamber, called NBBC. If the concept actually works, this detector would justify the creation of a larger model than anything that has ever been done in terms of bubble chamber detection before. This MSc thesis presents all the steps for the NBBC test chamber construction, starting with a brief history of the existing detectors. The working principles of the chamber will then be explained, followed by a description of all the new design elements. Finally, the tests carried out are presented and the last chapter is dedicated to the conclusions obtained and the advice on the continuation of the project.