Thesis (M.S.)--West Virginia University, 2005 / Title from document title page. Document formatted into pages; contains vii, 51 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 46-51).

Includes bibliographical references (leaves 276-2970. / xiii, 297 leaves : ill. (chiefly col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Investigations presented involve 18 hour to 5 day old South Australian merino lambs. Some twin lambs were available for comparative studies. Examines the relationship between the strength of ewe-lamb bond and the lamb's ability to follow the mother, the energy availability and usage in the lamb, particularly for locomotion, and the metabolic and cardiorespiratory responses to locomotion. / Thesis (Ph.D.)--University of Adelaide, Dept. of Animal Sciences, 1992

This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.

No description available.

Call number: LD2668 .T4 1957 S86 / Master of Science

O presente estudo foi dividido em dois experimentos, tendo como objetivo determinar a curva de excreção do cortisol fecal e sua estabilidade nas fezes perante exposição à diferentes períodos de tempo e temperatura entre as colheitas e análises, correlacionando os níveis de cortisol fecal com o pico de cortisol sanguíneo. No experimento 1, seis fêmeas mestiças (Dorper x Santa Inês) tiveram suas fezes totais colhidas durante 24 horas após a aplicação do hormônio adrenocorticotrófico (ACTH), além de colheitas de sangue realizadas antes da aplicação do ACTH, 60, 120 e 300 minutos depois; durante as quais foram atribuídos escores de reatividade para cada animal. Logo após as análises foi iniciado o experimento 2, no qual 9 cordeiros mestiços (Dorper x Santa Inês) foram submetidos a uma situação de estresse térmico durante os horários das 11 às 15 horas da tarde, tendo suas fezes colhidas às 23 horas do mesmo dia. Após a colheita, as fezes foram agrupadas e homogeneizadas em três grupos distintos, de onde retiraram-se alíquotas referentes aos tratamentos propostos: três temperaturas (15°, 25° e 35°) e quatro tempos (1, 3, 6 e 12 horas). Os dados da curva de excreção foram analisados por ANOVA, bem como pela correlação entre os valores de cortisol sanguíneo, fecal e reatividade. Para análise da estabilidade foi utilizada ANOVA multifatorial com dois fatores (temperatura e intervalo de tempo). Para avaliação das variáveis comportamentais foi realizada a transformação de escala dos dados para \"arco-seno raiz de porcentagem\", procedendo-se à análise de variância. O modelo estatístico contemplou os efeitos de dia (1, 2 e 3) com análise individual por animal. Os parâmetros de cortisol sanguíneo, frequência respiratória e temperatura retal foram analisados pelo teste t e correlação de Pearson. Todas as comparações de médias foram realizadas por teste F e teste t (PDIFF). A reatividade durante a colheita não exerceu efeito significativo sobre os valores de cortisol sanguíneo, os quais demonstraram médias maiores 60 minutos após a aplicação do ACTH e, após 300 minutos as ovelhas apresentaram níveis de cortisol considerados normais para ovinos sem estresse. Por outro lado, o pico de cortisol nas fezes foi verificado aproximadamente 10 a 12 horas após o pico de cortisol no sangue, não sendo verificadas diminuições significativas nas concentrações que indicassem o retorno aos níveis basais durante o período de 24 horas (P>0,05). Não foram observadas diferenças significativas entre os tempos e temperaturas aos quais as amostras de fezes foram submetidas (P>0,05), verificando-se uma tendência a manutenção da concentração do cortisol fecal em ovinos durante o período de 12 horas após a colheita. / This present study was divided into two experiments, aiming to determine the excretion curve of faecal cortisol and its stability over different periods of time and temperature between harvest and analyzes, correlating the fecal cortisol levels with peak blood cortisol. The project was developed in Biometeorology and Ethology Lab, Faculty of Animal Science and Food Engineering, University of São Paulo, Pirassununga - SP. In the first experiment, six crossbred (Dorper x Santa Inês) females sheep had their total feces collected during 24 hours after the application of adrenocorticotropic hormone (ACTH), beyond the blood samples taken before the application of ACTH, and one, two and five hours after application; in which was attributed reactivity scores to each animal. Soon after the analysis was started the second experiment, in which nine crossbred lambs (Dorper x Santa Inês) underwent a situation of thermal stress from 11 to 15 pm, and their feces were collected at 23 hours the same day. After harveting, the feces were pooled and homogenized in three different groups, where aliquots were withdrawn relating to the treatments proposed: three temperatures (15, 25 and 35°C) and four times (1, 3, 6 and 12 hours). The excretion curve data were analyzed by ANOVA, as well as the correlation between blood cortisol levels, faecal and reactivity. For stability analysis were used multifactor ANOVA with two factors (temperature and time range). To evaluate the behavioral variables was performed the transformation of the data range for \"arc sine percentage root\", proceeding to the analysis of variance. The statistical model included effects of day (1, 2 and 3) with individual analysis by animal. The blood cortisol parameters, respiratory rate and rectal temperature were analyzed by t test Pearson correlation. All comparisons of means were performed by F and t test (pdiff). The reactivity during harvest did not exert significant effect on blood cortisol levels, which showed higher averages 60 minutes after the application of ACTH, and after 300 minutes, the sheep showed cortisol levels considered normal to them, without stress. On the other hand, the peak of cortisol in the feces was observed approximately 10-12 hours after the peak of cortisol in the blood, not being observed significant decreases that indicate the return to the basal levels during the 24 hour period (P>0, 05). Were not observed no significant differences between the time and temperature in which the faecal samples were subjected (P>0.05), verifying a tendency on the maintenance of the concentration of faecal cortisol in sheep during the 12 hour period after harvest.

Based on a large series of epidemiological studies, it has been proposed that exposure to an increased nutrient supply before birth increases the risk of developing obesity in postnatal life. The physiological mechanisms underlying the association between increased nutrition before birth and later obesity are, however, poorly understood. This thesis has investigated the impact of an increased fetal nutrient supply on the programming of key systems within the appetite - regulating network and / or the adipocytes before and after birth. The studies in this thesis have demonstrated that plasma concentrations of the adipostatic hormone leptin are directly related to adiposity and the size of adipose cells in fetuses of ewes fed at or above maintenance energy requirements, which suggests that leptin may act as a peripheral signal of fat mass before birth. It has also been demonstrated that the components of the central network for appetite regulation are expressed in the hypothalamus of the fetal sheep from at least 110 d gestation ( term = 150 ± 3 d gestation ), and that the expression of the appetite - regulating neuropeptides is responsive to signals of increased nutrient supply before birth. This thesis has also demonstrated that an increase in maternal nutrition in late pregnancy results in increases in both food intake and glucose concentrations in the lamb in early postnatal life and in a significant increase in subcutaneous adiposity on postnatal day 30. Importantly, increased maternal nutrition resulted in an altered relationship between signals of increased fat mass and nutrition and expression of a central appetiteinhibitory neuropeptide, CART, in the lamb hypothalamus. It was also demonstrated that there was an interaction between the prenatal and postnatal nutritional environments in the determination of lipogenesis in the early postnatal period. The findings presented in this thesis provide evidence that programmed changes to the sensitivity of the appetite - regulating neuropeptides to signals of increased adiposity and nutritional status in early postnatal life are an important part of the physiological pathway through which exposure to an increased nutrient supply before birth may lead to an increased risk of obesity in later life. / Thesis (Ph.D.)--School of Molecular and Biomedical Science, 2006.

No description available.

No description available.

No description available.