[Truncated] Emus exhibit seasonal decreases in appetite and adiposity. Adipose tissue is the most profitable component of the carcass. As such, the reduction in adipose stores limits slaughtering to a brief window, and is a major constraint to productivity and industry development. To minimise the detrimental effects of seasonality on the productivity of farmed emus it is necessary to develop ways of manipulating appetite and adiposity. The general model for the control of appetite and adiposity is mediation of appetite and satiety centres in the hypothalamus by peripheral signals indicative of energy reserves and metabolic status. The relevance of this general model to the emu has not been investigated. The general hypothesis in this thesis was that seasonal variation in appetite and adiposity in the emu operates under the general model developed in other species. The experimental models used to test the general hypothesis were increased appetite and adiposity (high fat diet, dexamethasone treatment), decreased appetite and adiposity (incubation) and increased appetite and decreased adiposity (starvation). To determine the role of leptin in the control of appetite and adiposity attempts were made to clone and sequence the emu leptin gene. The concentrations of metabolic hormones were measured in all of the experiments, and the role of NPY in the control of appetite and adiposity was investigated by quantifying the mRNA expression of NPY from the mediobasal hypothalamus and preoptic area in the glucocorticoid treatment, incubation and starvation experiments.
|Qualification||Doctor of Philosophy|
|Publication status||Unpublished - 2002|