Orientador: Antonio Celso Pezzato / Banca: Dirlei Antonio Berto / Banca: Manoel Garcia Neto / Resumo: O presente estudo objetivou avaliar os efeitos da suplementação de diferentes níveis de metionina digestível nas dietas de frangos de corte de 1 a 21 dias de idade, sobre o desempenho animal e o rendimento de carcaça, pelo do método tradicional de dose-resposta, e utilizar a técnica de isótopos estáveis através do turnover tecidual para certificar este procedimento de exigência nutricional. Foram realizados dois ensaios em delineamento inteiramente casualizado, com sete tratamentos que consistiram de níveis de metionina digestível para as fases pré-inicial e inicial, respectivamente: 70% (0,320 e 0,307), 80% (0,360 e 0,331), 90% (0,410 e 0,380), 100% (0,450 e 0,417), 110% (0,500 e 0,460), 120% (0,540 e 0,510) e 130% (0,591 e 0,540) de metionina digestível correspondentes às exigências preconizadas por Rostagno et al. (2011). No ensaio I foram utilizados 875 pintos de corte de um dia de idade alojados em 35 unidades experimentais e avaliou-se o desempenho e o rendimento de carcaça. No ensaio II foram alojados 567 pintos de corte de um dia de idade e avaliou-se o turnover do 13C no músculo peitoral e fígado. Todos os animais foram submetidos à dieta a base de arroz e farelo de soja do primeiro aos 21 dias de idade. No ensaio I foi verificado melhora no desempenho de 1 a 7 dias de idade nos tratamentos 100% e 120% para peso corporal e ganho de peso e de 1 a 21 dias de idade nos tratamentos 100%, 110%, 120% para ganho de peso e peso corporal. Observou-se melhora na conversão alimentar com os tratamentos 100%, 110%, 120% e 130%. Os tratamentos 100% e 120% apresentaram melhora no rendimento de peito, o 110% para gordura abdominal e o 120% para o peso do fígado aos 21 dias de idade. No ensaio II foi verificado diminuição da meia-vida e aumento da taxa metabólica para o músculo peitoral no tratamento 130% e para o fígado no tratamento 80%. Pode-se observar que os tratamentos 100%, 11 ... / Abstract: The present study aimed to evaluate the effects of different levels of digestible methionine in broiler diets on performance, carcass yield through the traditional method of dose-response, and use the stable isotopic of tissue turnover to certificate this procedure of nutritional requirement. Two trials were conducted in a completely randomized design with seven treatments that consisted in levels of digestible methionine to pre-starter and initial phase, respectively: 70% (0,320 e 0,307), 80% (0,360 e 0,331), 90% (0,410 e 0,380), 100% (0,450 e 0,417), 110% (0,500 e 0,460), 120% (0,540 e 0,510) e 130% (0,591 e 0,540) of digestible methionine corresponding to the requirements recommended by Rostagno et al. (2011). In the first trial, 875 one day old chicks were housed in 35 pens to evaluate the performance and carcass yield. In the second trial, 567 one day old chicks were housed to determinate the turnover of carbon-13 in the pectoral muscle and liver. All birds were fed a diet based on rice and soybean meal (predominantly C3) for the first 21 days of life. In the first trial was verified improved performance at 7 days old on treatments 100% and 120% for body weight and weight gain and at 21 days old on treatments 100%, 110% and 120% for body weight and weight gain. It was noted improving on feed conversion with treatments 100%, 110%, 120% and 130%. The treatments 100% and 120% showed improvement on breast yield, the 110% to fat abdominal and the 120% for liver weight at 21 days old. In the second trial was verified reduction of half-life and increase of metabolic rate to the breast muscle on treatment 130% and for liver on treatment 80%. It could be noted that treatments 100%, 110% and 120% improvement the animal performance / Mestre

Contamination of methylmercury (MeHg) in aquatic products has been a wide spread health concern. The objective of this study is to determine total mercury (THg) and MeHg concentrations in different species of aquatic products from major offshore farms in China, and to assess health impacts from consumption. Results showed that the concentrations of THg and MeHg ranged 5.6–328.4 ng/g (wet weight) and 4.3–303.6 ng/g (wet weight) in aquatic products, respectively, and were very variable among species and origin sources. Target hazard quotient (THQ) suggested that MeHg exposure via consumption posed high health risks to children aged 2–7 and higher income families. Residents above the age of 13 and with low income have relatively lower health risk of MeHg exposure. Health impacts on heart attacks and newborns’ IQ from MeHg exposure were evaluated using dose-response relationships. Results showed that mother’s consumption of aquatic products (at 6 ounce per day) may cause a loss of 0.38 IQ points for newborns. For non-pregnant, consumption of aquatic products may cause an increase rate of mortality and morbidity of heart attacks at 10.59 and 78.45 per 100,000 persons, respectively. The negative health impact of consuming seawater fish was higher than freshwater fish.

Xylitol, classified as a natural sugar substitute, has for about 35 years been known as an agent that may act against caries. The mechanism of action; how it inhibits mutans streptococci (MS) and the clinical dose-response relationship are not however fully investigated. The general aim of the investigations was to evaluate the effect of xylitol on oral ecology in children and adolescents. A series of experimental and controlled clinical trials were performed in which samples of saliva and plaque was collected and analysed with respect to xylitol content, pH, microbial composition and lactic acid production. In paper I, significantly reduced proportions of xylitol-sensitive MS in saliva were demonstrated after 18 weeks of regular use of two dose regimens of xylitol-containing tablets (1.7g and 3.4g xylitol/day) but the acidogenicity in dental plaque was not affected. In paper II, the effect on interdental plaque-pH of two different single dose intakes (2.0g and 6.0g) of xylitol was evaluated. The higher xylitol dose counteracted the pH-drop significantly (p<0.05) when the chewing was followed by a sucrose rinse while the lower dose did not differ from the control. In paper III, the xylitol concentrations in saliva after use of different common xylitol-containing products (0.1g-1.3g) were investigated. Statistically significant elevations of salivary xylitol levels were demonstrated for all products during the first 8-16 min when compared with baseline (p<0.05) but the individual variation was considerable. In samples of supragingival dental plaque, a high dose rinse (6.0g) increased the xylitol concentrations for a longer period (>30 min) than a low dose rinse (2.0g). In paper IV, it was demonstrated that 6.0g of xylitol in chewing gums, every day in 4 weeks, gave significantly less visible plaque and a significantly reduced sucrose-induced lactic acid formation (p<0.05) in saliva. Furthermore, the proportion of MS decreased significantly (p<0.05) compared to baseline. In paper V, the salivary uptake of [14C]-xylitol was compared with a specific assay determining xylitol-sensitive MS and a fair positive correlation (p<0.05) between the two assays was found. In a controlled trial, the proportions of MS and the salivary xylitol uptake decreased significantly (p<0.05) in the xylitol gum test group after 4 weeks compared to baseline which was in contrast to the control gum group. No serious adverse effects were reported in any of the investigations. The main conclusions from this thesis were: a) various xylitol-containing products increased the xylitol levels in saliva and plaque, b) 6.0g of xylitol could counteract the interdental pH-drop after sugar consumption and reduce lactic acid formation in saliva c) a daily dose of 6.0g xylitol reduced the amount of visible plaque and altered the salivary microbial composition, d) a transient shift of MS strains in saliva was demonstrated during periods of regular intake of xylitol products but no long-term impact was found after its termination. The relatively high amount of xylitol needed for a beneficial effect on the oral ecology calls for a further development of effective and safe routes for administration.

Thesis (Ph. D.)--University of Oklahoma. / Bibliography: leaves 109-119.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2005. / Härtill 5 uppsatser.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2005. / Härtill 5 uppsatser.

Diss. (sammanfattning) Linköping : Univ., 2003. / Härtill 6 uppsatser.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2005. / Härtill 5 uppsatser.

Thesis--University of Oklahoma. / Bibliography: leaves 81-83.

Thesis--University of Oklahoma. / Bibliography: leaves 78-79.