Apesar da evolução tecnológica, estudos sobre a estabilidade de nutrientes em alimentos preparados em Serviços de Alimentação têm recebido pouca atenção. No entanto, é cada vez maior o número de pessoas que fazem suas refeições nestes estabelecimentos. Uma vez que o conteúdo em vitaminas é um dos fatores mais importantes na determinação da qualidade dos alimentos processados, o objetivo deste estudo foi definir métodos de análise quantitativa para tiamina, riboflavina e ácido nicotínico por CLAE em carnes, para, então, avaliar a influência da preparação em Serviço de Alimentação sobre o conteúdo destas vitaminas em diferentes cortes de carnes bovina, suína e de frango. Objetivou-se também avaliar a estabilidade das vitaminas citadas após métodos de preparação tradicionais comparados com métodos de preparação em forno combinado (um dos equipamentos de cocção mais modernos utilizados em Serviço de Alimentação). As amostras de carnes foram grelhadas, fritas, assadas e refogadas ou cozidas sem imersão em água utilizando-se o forno combinado e também equipamentos industriais de modelo convencional. Os resultados obtidos mostraram que a tiamina foi a vitamina mais afetada pelos métodos de preparo em Serviço de Alimentação (47,2 a 84,7% de retenção em carne bovina; 49,6 a 79,8% de retenção em carne suína e 53,7 a 81,1% de retenção em carne de frango). Para riboflavina as porcentagens de retenção foram de 69,3% a 91,4% em carne bovina; 71,8% a 92,7% em carne suína e 60,1 a 92,3% em carne de frango. A estabilidade do ácido nicotínico foi, de um modo geral, maior em carne bovina (60,7 a 91,5% de retenção), intermediária em carne de frango (65,1 a 84,4% de retenção) e menor em carne suína (62, 8 a 77,0% de retenção). Para a grande maioria das preparações, o uso do forno combinado (em comparação com os equipamentos convencionais) preservou mais as três vitaminas, sugerindo que este equipamento é a melhor opção para preparação de carnes bovina, suína e de frango quando se deseja uma maior estabilidade destas vitaminas. Nos três tipos de carnes preparadas de formas semelhantes as perdas das vitaminas foram associadas às perdas de umidade e às condições de preparo das carnes / Despite the progress achieved, studies on nutrient retention in food service preparation have not received much attention. However, more and more people eat at these places. Since vitamin content is one of the most important factors in determining processed food quality, the objetive of this study was to define quantitative analysis methods for thiamin, riboflavin and nicotinic acid by high-performance liquid chromatography (HPLC) in meat in order to evaluate the influence of food service preparation on the content of these vitamins on different beef, pork and chicken cuts. Another objeticve was to evaluate these vitamins\' retention under conventional preparation methods, compared to combined oven, one of the most modern cooking methods used in food service. Samples of meat were charbroiled, fried, roasted and cooked without water in a combined oven and in conventional equipments. The results showed that thiamin was the vitamin most affected by the food service preparation methods (47.2 to 84,7% of retention in beef; 49.6 to 79.8% of retention in pork and 53.7 to 81.1% of retention in chicken). Riboflavin content retention was from 69.3 to 91.4% in beef; 71.8 to 92.7% in pork and 60.1 to 92.3% in chicken. Nicotinic acid retention was, in general, higher in beef (60.7 to 91.5%), medium in chicken (65.1 to 84.4%) and lower in pork (62.8 to 77.0%). For most preparations, the use of combined oven preserved the three vitamins better than the other conventional equipments. The results obtained indicate that, as far as food service is concerned, the combined oven is the best option for beef, pork and chicken preparation when a greater thiamin, riboflavin and nicotinic acid stability is desired. In the three types of meat prepared in a similar manner, vitamins losses were associated to moisture loss and to the conditions of meat preparation

Influenza, também conhecida como gripe, é uma doença infecciosa viral que acomete um grande número de indivíduos anualmente, sendo responsável por um elevado número de internações e óbitos. O agente etiológico é o Myxovirus influenzae, vírus envelopado, de RNA de fita simples e polaridade negativa. A vacinação é a forma mais eficaz de se prevenir a infecção pelo vírus, no entanto, a capacidade produtiva dessa vacina não é suficiente para a vacinação da totalidade da população mundial, principalmente em casos de pandemia. Esse projeto teve por objetivo desenvolver uma vacina influenza (fragmentada e inativada) adjuvada, visando aumentar a capacidade produtiva dessa vacina no Instituto Butantan, que hoje é estimada em aproximadamente 40 milhões de doses por campanha. A utilização de adjuvantes na formulação da vacina influenza é capaz de produzir a mesma resposta imunológica protetora contra esse vírus, utilizando uma quantidade menor dos antígenos vacinais, aumentando a capacidade de produção da vacina em até quatro vezes. Foram estudadas 23 formulações adjuvantes utilizando o esqualeno como referência (formulação similar ao MF59®, adjuvante desenvolvido pela Novartis), vitaminas lipossolúveis (vitaminas A, D e E), vitamina B2 (vitamina hidrossolúvel), MPLA (monofosforil lipídio A, produzido pelo Instituto Butantan como subproduto da vacina pertussis low) e gel de hidróxido de alumínio. Para tanto, foram avaliadas a resposta imune conferida a camundongos BALB/c após imunização com diferentes formulações de vacina influenza (fragmentada e inativada) adjuvada e a existência, ou não, de toxicidade induzida pelas formulações vacinais estudadas. As formulações vacinais mais promissoras farão parte das formulações candidatas para realizações de ensaios clínicos. Os animais foram imunizados por via intraperitoneal com as formulações vacinais e foram colhidas amostras de sangue para ensaios sorológicos (inibição de hemaglutinação e ELISA) e células esplênicas para avaliação celular (dosagem de citocinas por citometria de fluxo: IL-2, IL-4, IL-6, IL-10, IL-17 TNF-α e INF-γ). Além disso, em um dos experimentos avaliou-se a formação de memória imunológica contra influenza, parâmetro importante em se pensando em uma vacina. Os três primeiros experimentos foram uma triagem a partir da qual selecionaram-se as melhores formulações que foram testadas no último experimento. Nele foram avaliados além da indução de resposta imune a toxicidade e a memória imunológica. Todas as 23 formulações estudadas induziram resposta minimamente protetora nos animais, com exceção da formulação contendo apenas MPLA como adjuvante. As formulações que se mostraram mais promissoras continham além do gel de AI(OH)3 MPLA de B. pertussis ou vitamina B2. Isso sem considerar o tocoferol (vitamina E), que embora tenha apresentado bons resultados acabou preterido em decorrência de sua potencial relação com casos de narcolepsia descritos na literatura. O teste de memória foi capaz de demonstrar que essas formulações produzem resposta de memória imunológica duradoura. Assim, tem-se resultados promissores para novos estudos pré-clínicos e clínicos com a vacina influenza (fragmentada e inativada) sazonal (trivalente). / Influenza, also known as flu, is a viral infectious disease that infects a large number of people annually, being responsible by large morbidity and mortality rates. The etiologic agent is the Myxovirus influenzae, an enveloped virus with single-stranded RNA and negative polarity. Vaccination is the best way to prevent the virus infection; however, the production capacity of this vaccine is not sufficient to vaccinate the entire world population, especially in cases of pandemics. This project aimed to develop an adjuvanted influenza vaccine (split and inactivated), increasing the productive capacity of this vaccine in Instituto Butantan, which is estimated in approximately 40 million of doses by campaign. Influenza vaccines formulated with adjuvants can produce the same protective immunological response against the virus using less amount of antigen increasing the production capacity of this vaccine up to four times. Twenty-three adjuvants containing fat-soluble vitamins (vitamins A, D and E), vitamin B2 (water-soluble vitamin), MPLA (monophosphoryl lipid A, produced by Instituto Butantan as a byproduct of pertussis low vaccine production) and aluminum hydroxide gel were studied. An adjuvant similar to MF59® (Novartis adjuvant) containing squalene was used as control. The immune response elicited in BALB/c mice after immunization with the different formulations of the influenza vaccine and the existence or not of toxicity induced by the vaccines formulations were studied. The most promising formulation will be part of the candidate formulations of clinicai trials. The animais received the vaccine formulations intraperitoneally and at specific days blood samples were taken to serological tests (hemagglutination inhibition and ELISA). At the end, they were euthanized to collect the spleens and splenic cells were cultivated to evaluate cytokines by flow cytometry: IL-2, IL-4, IL-6, IL-10, IL-17 TNF-α and INF-γ. Furthermore, in one experiment the immunological memory against influenza was evaluated, an important parameter to vaccines. The most promising formulations contained besides to alum either B. pertussis MPLA or B2 vitamin. Tocopherol (vitamin E) presented good results too, however it has a potential relationship with reported cases of narcolepsy. The memory test was able to demonstrate that these formulations induced long lasting immune memory response. Thus, these are promising results for new pre-clinical and clinical trials with seasonal trivalent influenza vaccine (split and inactivated).

Dentre os diversos fatores responsáveis pela instabilidade química das vitaminas nos alimentos, a exposição à radiação luminosa é determinante, principalmente em alimentos contendo vitamina B2. O presente trabalho investigou a degradação fotossensibilizada das vitaminas do complexo B (ácido fólico, piridoxal, biotina e niacina) por flavinas. O piridoxal-5\'-fosfato (PLP) mostrou-se reativo frente aos estados singleto e tripleto excitado das flavinas com constante de desativação de 1,03 1011 L mol-1 s-1 para o estado singleto, valor este superior ao valor esperado para reações bimoleculares controladas por difusão em meio aquoso. Foi observada uma dependência significativa da constante de velocidade de desativação do estado singleto excitado com a temperatura, onde o aumento da temperatura proporciona um decréscimo da constante de velocidade sugerindo a existência de um complexo [FMN...PLP] no estado fundamental o qual foi confirmado por espectroscopia de fluorescência resolvida no tempo. O PLP mostrou-se reativo frente ao estado tripleto excitado da FMN com constante de velocidade de 3kq = 3,0 108 L mol-1 s-1 em meio de tampão fosfato pH 6,4 ou em meio de óxido de deutério a 25 °C. Não foi observada diferença significativa entre as constantes de desativação do estado tripleto excitado em meio aquoso e de óxido de deutério o que corrobora com um processo direto de transferência de elétrons do PLP para a 3FMN* ao invés de um processo de transferência de átomo de hidrogênio. As vitaminas (biotina e niacina) mostraram-se não reativas frente aos estados singleto e tripleto excitados da vitamina B2 o que pode ser atribuído aos altos potenciais de oxidação, Eo > 2 V vs. NHE, observados para estas vitaminas em meio aquoso. A voltametria cíclica do PLP apresentou um processo anódico e irreversível (E= 1,07 V vs. NHE), controlada cineticamente por transferência de elétrons heterogênea do PLP para o eletrodo. O rendimento quântico de fotodegradação do PLP em meio aquoso e aerado é 2,5 vezes superior ao encontrado para a reação em meio anaeróbico, o que sugere a participação do íon superóxido no processo global de degradação do PLP. O ácido fólico demonstrou-se igualmente reativo frente ao estado tripleto excitado das flavinas (3kq= 4,8 108 L·mol-1 s-1 e Φ = 0,26 (meio aerado) e Φ = 0,32 (meio anaeróbico)) e a sua complexação pela β-LG (Φ = 0,032 (meio aerado) e Φ = 0,055 (meio anaeróbico)) uma eficiente abordagem na proteção desta vitamina frente a fotodegradação sensibilizada por flavinas. / Among several factors responsible for the chemical instability of vitamins in food, exposure to light radiation is decisive, especially in supplemented or fortified food with vitamin B2. This study investigated the photosensitized degradation of B-vitamins (folic acid, pyridoxal, biotin and niacin) by flavins. The pyridoxal-5\'-phosphate (PLP) reacted with singlet and triplet excited states of flavins with rate constant for quenching of 1kq = 1,03 1011 L mol-1 s-1 for the singlet state, this value is higher than expected value of bimolecular reactions controlled by diffusion in an aqueous solvent. A significant dependence was observed for the rate constant for deactivation of singlet excited state with temperature, the increase of the temperature leads to a decrease of the rate constant suggesting the existence of a complex [FMN...PLP] in ground state confirmed by time resolved fluorescence spectroscopy. PLP reacted with FMN triplet excited state with rate constant 3kq = 2,96 108 L mol-1 s-1 in phosphate buffer pH 6,4 or deuterium oxide at 25 °C. There was no significant difference between the rate constant of deactivation of the triplet-excited of FMN in aqueous solution or deuterium oxide which confirms a direct process of electron transfer to PLP for 3FMN* rather than a process of transfer of hydrogen atom. Biotin and niacin unreacted with singlet and triplet excited states of vitamin B2 which can be attributed to high oxidation potentials, Eo > 2 V vs. NHE, observed for this vitamins in aqueous solution. The cyclic voltammetry of PLP had an irreversible anodic oxidation process (E = 1.07 V vs. NHE) kinetically controlled by heterogeneous electron transfer from PLP to the electrode. The quantum yield of photodegradation of PLP in aerobic condition is 2.5 times higher than that found for the reaction in anaerobic condition, which suggests the of participation of superoxide ion in the PLP global degradation process. Folic acid demonstrated reactive with triplet excited state of flavins (3kq= 4,8 108 L·mol-1 s-1 and Φ = 0,26 (aerobic condition) and Φ = 0,32 (anaerobic condition)) and the complexation with β-LG (Φ = 0,032 (aerobic condition) and Φ = 0,055 anaerobic condition)) an efficient approach in protecting the vitamin against photodegradation sensitized by flavins.

Thesis (Ph.D.) --University of Limpopo, 2012 / A series of experiments were carried out to evaluate the feeding values of forage sorghum (Sorghum sudanense), cowpea (Vigna ungiculata), lablab (Lablab purpureus) and mucuna (Mucuna pruriens) hays for Pedi goat production in Limpopo Province, South Africa. The first study determined nutrient composition and tannin contents of the forages. The experimental design was a completely randomised design with four treatments: forage sorghum, cowpea, lablab and mucuna hays. All the legume species had higher (P<0.05) protein contents than sorghum hay, ranging from 18 to 22 %. Within the legume species, cowpea hay had a higher (P<0.05) protein content than lablab and mucuna hays. Similarly, lablab hay had a higher (P<0.05) protein content than mucuna hay. Mucuna hay had a higher (P<0.05) concentration of both condensed tannins and hydrolysable tannins than cowpea, lablab and sorghum hays, while lablab hay had the highest (P<0.05) concentration of total polyphenols. The second study determined relative palatability indices of Pedi goats offered forage sorghum, cowpea, lablab and mucuna hays. Four male Pedi goats aged five months and weighing an average of 18 + 2 kg were used. The experimental design was a completely randomized design, with feeds (forage sorghum, cowpea, lablab and mucuna) as treatments and individual animals as replicates. Lablab and mucuna legumes had higher (P<0.05) intake and palatability indices than sorghum and cowpea hays. Palatability indices were positively and significantly (P<0.05) predicted from dry matter intakes of goats (r2 = 0.98). However, there were poor and non-significant (P>0.05) relationships between nutrient contents of the forages and their intake and palatability indices by goats. The third study determined diet intake, digestibility and live weight gain of seven months old Pedi goats fed a basal diet of forage sorghum supplemented with different amounts of cowpea, lablab or mucuna hays. The experimental design was a completely randomized design, with individual animals placed in digestibility crates as experimental units. This study was divided into a series of experiments due to lack of equipment to conduct the whole experiment in one session. A total of four experiments were conducted. Fifteen growing male Pedi goats were used in each experiment, with mean live weights of 15 + 4 kg, 18 + 2 kg, 17 + 3 kg and 20 + 4 kg for experiments 5.1, 5.2, 5.3 and 5.4, respectively. In each experiment, different goats were used. Experiments 5.1 to 5.3 involved cowpea, lablab and mucuna hays, respectively, while Experiment 5.4 compared the levels of supplementation for optimum intake from each of the first three experiments. Dry matter intakes of cowpea and lablab hay were optimised at 39 and 32 %, respectively, while that of mucuna hay increased with increasing levels of mucuna hay supplementation. Dry matter digestibilities of cowpea, lablab and mucuna hays increased with increasing levels of the respective forage supplementations. Cowpea and mucuna hay supplementations improved (P<0.05) final live weights and feed conversion ratios, while goats on lablab hay supplementation lost weight. At optimum intake, goats supplemented with mucuna hay had a better (P<0.05) feed conversion ratio than those supplemented with lablab and cowpea hays. The fourth study determined in vitro gas production of pure and mixtures of forage sorghum with cowpea, lablab and mucuna hays. Two experiments were conducted. In the first experiment (Experiment 6.1) the experimental design was a completely randomised design with four treatments (forage sorghum, cowpea, lablab and mucuna). The legume species of cowpea, lablab and mucuna hays produced more (P<0.05) gas than sorghum hay after 12 hours of incubation. Sorghum hay produced more (P<0.05) gas than cowpea, lablab and sorghum hays after 24, 48 and 72 hours of incubation. Sorghum hay dry matter intake by goats in the palatability trial was positively and significantly (P<0.05) predicted from gas production after 12 (r2 = 0.99), 24 (r2 = 0.97) and 48 (r2 = 0.93) hours of incubation. Cowpea hay, lablab hay and mucuna hay dry matter intakes by goats were poorly predicted from gas production after 12, 24, 48 and 72 hours of incubation. In the second experiment (Experiment 6.2), the experimental design was a completely randomised design with three treatments (mixtures at optimum intake): 1. FS61C39: A mixture of 61 % forage sorghum and 39 % cowpea, 2. FS68L32: A mixture of 68 % forage sorghum and 32 % lablab, 3. FS77M23: A mixture of 77 % forage sorghum and 23 % mucuna. There were no differences in gas production (P>0.05) across dietary mixtures after 12, 24, 48 and 72 hours of incubation. Dry matter intake by Pedi goats of sorghum hay mixed with cowpea at 39 % hay was positively and significantly (P<0.05) predicted from gas production of the mixtures after 24 hours (r2 = 1.0) of incubation. Dry matter intake from gas production from the same mixture was poorly predicted from gas production after 48 (r2 = 0.45) and 72 (r2 = 0.13) hours of incubation. Dry matter intake of sorghum hay by Pedi goats supplemented with lablab hay at 32 % was moderately predicted from gas production after 48 (r2 = 0.67) and 72 (r2 = 0.60) hours, but poorly predicted after 12 (r2 = 0.50), 24 (r2 = 0.53) hours of incubation. Dry matter intake of sorghum hay by Pedi goats supplemented with 23 % mucuna hay was positively predicted from gas production after 12 (r2 = 0.90) hours, but moderately predicted after 24 (r2 = 0.80), 48 (r2 = 0.72) and 72 (r2 = 0.83) hours of incubation. Dry matter digestibility of sorghum hay mixed with 23 % mucuna hay was positively and significantly (P<0.05) predicted from gas production after 24 (r2 = 1.0), 48 (r2 = 0.99) and 72 (r2 = 1.0) hours of incubation. Dry matter digestibility of sorghum hay mixed with 39 % cowpea hay was positively predicted from gas production after 48 (r2 = 0.95), moderately predicted after 24 and 72, and poorly predicted after 12 hours of incubation. Dry matter digestibility of sorghum hay mixed with 32 % lablab hay was positively predicted from gas production after 72 (r2 = 0.92) hours of incubation. The relationships between digestibility of the mixtures and gas production after 12, 24 and 48 hours of incubation were poor. The fifth study determined in sacco degradation of mixtures at optimum intake of forage sorghum mixed with cowpea, lablab or mucuna when incubated in goats. The ‘a’ values and dry matter losses in cowpea and lablab hays were higher (P < 0.05) than those of mucuna hay. Dry matter intake of sorghum hay mixed with lablab hay at 32 % was positively and strongly predicted from in sacco degradation after 12 (r2 = 0.90), 24 (r2 = 0.94), 48 (r2 = 0.96) and 72 (r2 = 0.97) hours of incubation. Dry matter intake of sorghum hay mixed with 39 % cowpea hay was poorly predicted from in sacco degradation after 12 (r2 = 0.25), 24 (r2 = 0.20), 48 (r2 = 0.11) and 72 (r2 = 0.08) hours of incubation. Dry matter intake of sorghum hay mixed with 23 % mucuna hay was positively and moderately predicted from in sacco degradation after 12 (r2 = 0.68) hours and 24 (r2 = 0.55) hours, but poorly predicted after 48 (r2 = 0.40) and 72 (r2 = 0.20) hours of incubation. vii It was concluded that cowpea, lablab and mucuna hays had higher protein contents and palatability indices than forage sorghum and therefore, have the potential of being utilised as protein supplements for goats on low quality roughages. Legume supplementation, in general, improved diet intake, digestibility, feed conversion ratio and live weight of goats, except for lablab hay supplementation. It was also noted that diet intake, digestibility and final live weights of the goats were optimised at different levels of forage supplementation. This may indicate that supplementation levels for optimum productivity will depend on the particular parameter in question. In vitro gas production and in sacco degradation techniques have the potential of predicting intake, digestibility and palatability indices of goats fed sorghum hay supplemented with cowpea, lablab or mucuna hays.

Recent epidemiological evidence suggests that many chronic health disorders in the developed world are associated with endogenous toxins formed from the Western diet. The Western diet, which encompasses calorie dense foods, processed foods and increased quantities of red meat, can cause intracellular oxidative stress through increased formation of reactive oxygen species(ROS) and reactive carbonyl species (RCS). A number of micronutrients have been investigated for their protective capacity in in vitro and in vivo models of oxidative stress. This thesis investigated the cytotoxic targets of Fenton-mediated ROS and RCS and the subsequent protective mechanisms of vitamins B1 (thiamin) or B6 (pyridoxal, pyridoxamine or pyridoxine) in an isolated rat hepatocyte model. The approach was to use an “accelerated cytotoxicity mechanism screening” technique (ACMS) to develop an in vitro cell system that mimicked in vivo tissue cytotoxicity. Using this technique, we investigated the protective mechanisms of vitamins B1 and/or B6 against the cytotoxic effects of two endogenous toxins associated with the Western diet: 1) RCS, as exemplified by glyoxal, a glucose/fructose autoxidation product and 2) biological ROS induced by exogenous iron. Firstly, we developed an understanding of the sequence of events contributing to glyoxal-induced oxidative stress, with a focus on protein carbonylation. Next, we determined the mechanisms by which carbonyl scavenging drugs (vitamin B6 included) protected against the intracellular targets of glyoxal-induced toxicity. Our results suggested that the agents used were cytoprotective by multiple mechanisms and glyoxal trapping was only observed when the agents were administered at concentrations equal to glyoxal. We also evaluated the protective capacity of vitamins B1 and B6 against iron-catalyzed cytotoxicity and found that hepatocytes could be rescued from protein and DNA damage when vitamins B1 or B6 were added up to one hour after treatment with iron. The vitamins also varied in their primary mechanisms of protection. Our improved understanding of Western diet-derived endogenous toxins enabled us to identify and prioritize the specific inhibitory mechanisms of vitamins B1 or B6. The ability to delay, inhibit or reverse toxicity using multi-functional B1 or B6 vitamins could prove useful as therapy to minimize oxidative stress in diet-induced chronic conditions.

This thesis described the results of two studies that measured the concentrations of serum micronutrients in western Canadian beef cows at key production points, and examined associations between reproductive outcomes and micronutrient concentrations. The first study reported the serum copper and molybdenum concentrations at pregnancy testing time in cows from 66 cow-calf herds that were enrolled in a study of factors affecting productivity in 205 herds from western Canada. A relatively small proportion of cows had serum copper and molybdenum concentrations outside of adequate levels (16.2% of cows had below adequate serum copper, < 0.60 ppm; 12% of cows had high serum molybdenum, > 0.10 ppm). There were no associations between copper and molybdenum concentrations measured at the end of the grazing season and reproductive outcomes measured in these cows, with the exception that cows with the lowest serum copper concentrations at pregnancy testing were more likely to be pregnant than cows with higher copper concentrations. The practice of comparing serum copper and molybdenum concentrations between pregnant and non-pregnant animals in the fall as a tool in investigating poor pregnancy rates was not supported by this study. In the second study, serum micronutrient concentrations of beef cows (n = 791) in southern Saskatchewan were measured before placement onto summer grazing and breeding pastures and again at the end of the grazing season. Pre-breeding serum copper concentrations were less than adequate (< 0.60 ppm) in 75% of cows. High concentrations of serum molybdenum (d 0.10 ppm) were present in 19% of cows at pre-breeding. Cows < 10 years of age with lower pre-breeding serum copper concentrations were at increased odds of nonpregnancy. The greatest effect on pregnancy rates was observed for pre-breeding serum copper concentrations < 0.4 ppm. Season of measurement influenced the concentrations of serum micronutrients in these cows. Copper and vitamins A and E were higher in the fall, and molybdenum and selenium concentrations were lower in the fall. These studies described serum micronutrient concentrations from healthy cows in western Canada at two production points, pre-breeding placement onto grazing pastures and pregnancy testing when cows are removed from grazing pasture. Identifying increased odds of nonpregnancy in cows with below adequate serum copper at pre-breeding emphasizes the importance of ensuring adequate copper concentrations in breeding females during this critical production phase.

Recent epidemiological evidence suggests that many chronic health disorders in the developed world are associated with endogenous toxins formed from the Western diet. The Western diet, which encompasses calorie dense foods, processed foods and increased quantities of red meat, can cause intracellular oxidative stress through increased formation of reactive oxygen species(ROS) and reactive carbonyl species (RCS). A number of micronutrients have been investigated for their protective capacity in in vitro and in vivo models of oxidative stress. This thesis investigated the cytotoxic targets of Fenton-mediated ROS and RCS and the subsequent protective mechanisms of vitamins B1 (thiamin) or B6 (pyridoxal, pyridoxamine or pyridoxine) in an isolated rat hepatocyte model. The approach was to use an “accelerated cytotoxicity mechanism screening” technique (ACMS) to develop an in vitro cell system that mimicked in vivo tissue cytotoxicity. Using this technique, we investigated the protective mechanisms of vitamins B1 and/or B6 against the cytotoxic effects of two endogenous toxins associated with the Western diet: 1) RCS, as exemplified by glyoxal, a glucose/fructose autoxidation product and 2) biological ROS induced by exogenous iron. Firstly, we developed an understanding of the sequence of events contributing to glyoxal-induced oxidative stress, with a focus on protein carbonylation. Next, we determined the mechanisms by which carbonyl scavenging drugs (vitamin B6 included) protected against the intracellular targets of glyoxal-induced toxicity. Our results suggested that the agents used were cytoprotective by multiple mechanisms and glyoxal trapping was only observed when the agents were administered at concentrations equal to glyoxal. We also evaluated the protective capacity of vitamins B1 and B6 against iron-catalyzed cytotoxicity and found that hepatocytes could be rescued from protein and DNA damage when vitamins B1 or B6 were added up to one hour after treatment with iron. The vitamins also varied in their primary mechanisms of protection. Our improved understanding of Western diet-derived endogenous toxins enabled us to identify and prioritize the specific inhibitory mechanisms of vitamins B1 or B6. The ability to delay, inhibit or reverse toxicity using multi-functional B1 or B6 vitamins could prove useful as therapy to minimize oxidative stress in diet-induced chronic conditions.

Gangrenous dermatitis (GD) has become a major health problem among broiler flocks in the United States, resulting in high mortality, carcass condemnations, and trimmed parts. There are large economic losses due to GD. Clostridium septicum, Clostridium perfringens type A, and Staphylococcus aureus are the etiologic agents associated with GD. Gangrenous dermatitis has been associated with birds that have a compromised immune system. It is known that the gastrointestinal (GI) tract plays a crucial role in animal health and performance. The development of a healthy normal microflora in the GI tract benefits the host by improved resistance to pathogens. Our hypothesis is the application of commercial disinfectants, probiotics, vitamins, acidifiers, and windrowing technologies will reduce Clostridium levels in poultry operations. The objective of the first study was to administer probiotics to commercial broilers on three farms periodically throughout the grow-out cycle to conclude if bird health and performance was improved. The objective of the second study was to use commercial disinfectants, vitamins, acidifiers, and windrowing technologies on three farms in multiple houses and determine their effects on broiler production parameters. During grow-out, standard production practices were followed in all experiments and standard production parameters were measured. On all three farms in this study, the probiotic-treated houses had no mortality due to GD and an increase (P </= 0.05) in body weight gain was observed unlike their respective control houses. These experiments indicate that the application of probiotic in this field trial significantly altered the onset of GD by providing the birds with normal GI flora that contributed to their overall health during a commercial field study. When evaluating the different products and field technologies to control GD, our laboratory observed that treatment houses that were windrowed and received added vitamins did break with GD. Houses that were treated with peroxymonosulfates and monoglyceride, peroxymonosulfates, or glutaraldehyde litter disinfectants; acidifiers or vitamins had higher gross and net pounds weight gain at processing than their respective control houses. In conclusion, the significance of this work was to determine if products and technologies can be used by growers in commercial broiler houses to eliminate disease.

Many of the factors that shape contaminant accumulation profiles in marine mammals also strongly influence fat soluble vitamin accumulation. Vitamin A and E are essential fat soluble nutrients for numerous biological processes, including reproduction, growth, endocrine and immune function. Contaminants, such as polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs), can alter vitamin dynamics; as such these vitamins have been proposed as sensitive biomarkers of contaminant exposure in wildlife. In light of these considerations, the present thesis was aimed at better understanding the factors that influence the accumulation of lipophilic contaminants and vitamins in western Arctic beluga whales, and to determine if there was an interaction between the two. Maternal offloading to neonates during gestation reduced overall contaminant (PCBs and PBDEs) and vitamin (A and E) concentrations in reproductively active female whales. The PCB and PBDE congener pattern in mothers changed during gestation as a result of preferential transfer of light-low Log KOW congeners to the fetus. Overall, female beluga whales transferred approximately 11% of their PCB and PBDE blubber burden to their fetus. In terms of vitamins transfer, lower concentrations of tocopherols, retinol and retinyl esters were found in reproductively active females relative to males and reproductively inactive females. Metabolism was also found to be an important factor for contaminant and vitamin accumulation in beluga tissues. In a principal components analysis, PCBs clustered into metabolically-derived structure-activity groups, which separated along the first principal component according to its metabolic potential (metabolizable vs. recalcitrant). Contaminant-related up-regulation of metabolizing enzymes, including cytochrome P450, likely explained changes in the concentration and pattern of PCB and PBDE congeners, as well as hepatic, plasma, and blubber vitamin A and E. Since vitamins and lipophilic contaminants accumulated in beluga whales in the same way in relation to most biological processes, including sex, reproduction, size, condition, and feeding ecology, it was important to control and reduce the number of these confounding factors before claiming any tissue vitamin change was indeed the result of chemical exposure. In doing so, it was found that vitamin A and E homeostasis was influenced by PCBs in beluga whales, resulting in reduced hepatic storage and increased plasma and blubber concentrations. Overall, these results suggest that liver, plasma, and inner blubber vitamin A and E concentrations can be sensitive biomarkers of contaminant exposure only if major confounding effects are taken into consideration. The implications of altered vitamin dynamics on the health of beluga whales is unknown at this time; however, as Arctic marine mammals face continued stress related to climate change, increased human disturbance and emergence of infectious diseases, this study can serve as essential baseline data that can be used to monitor the health status of western Arctic beluga whales. / Graduate / 0383 / 0329 / 0768 / jpdesforges@gmail.com

Graduation date: 1943