The neuroendocrinology of masculine sexual behavior was examined in Japanese quail selected bi-directionally for adult mating frequency. Experiments were conducted with brain tissues from functionally castrated, High (HM) and Low Mating (LM) line quail to compare (1) the in vivo aromatization of ³H-testosterone and (2) cytosolic estradiol-binding by in vitro saturation analyses. After in vivo incubation with ³H-testosterone, all radioactivity recovered in brain tissues was in the form of testosterone, dihydrotestosterone, or estradiol. Neither the total ³H nor ³H-testosterone metabolite radioactivity differed upon comparison of the two genetic lines. Of all ³H-testosterone metabolite radioactivity, ³H-estradiol represented 45 ± 6% in the HM line and 46 ± 6% in the LM line, indicating that the line difference in mating frequency was not due to a corresponding difference in aromatase activity. Inasmuch as both the HM and LM line birds actively converted testosterone to estradiol, these results implicated a neural mechanism involving estradiol-receptor interactions. Estradiol-receptor binding parameters were estimated in subsequent experiments by fitting a hyperbolic saturation curve to point measurements of total binding. Using this single-class binding site model, the apparent dissociation constant (K_d) for the estradiol-receptor interaction in the HM line was 0.40 ± .06 nM and the number of specific estradiol binding sites (B_max) was 10.4±.4 fmoles/mg cytosol protein. For the LM line, an apparent Kd of 0.41 ± .20 nM and a B<max> of 9.50 ± 1.0 fmoles/mg cytosol protein were obtained. The similarity between corresponding binding parameters for the divergent mating lines indicated that the number and/or estradiol-binding affinity of a single class of cytosol receptors was also not responsible for the line difference in mating frequency. Though these results confirm that interaction of estradiol with cytosol receptors was not the limiting neuroendocrinological mechanism in the differential expression of masculine sexual behavior in quail, the possible involvement of dynamic interrelationships between cytoplasmic and nuclear estrogen binding was discussed. / Ph. D.

Feeding behavior is a complex trait that is regulated by various hypothalamic neuropeptides and neuronal populations (nuclei). Understanding the physiological regulation of food intake is important for improving nutrient utilization efficiency in agricultural species and for understanding and treating eating disorders. Knowledge about appetite in birds has agricultural and biomedical relevance and provides evolutionary perspective. I thus investigated hypothalamic molecular mechanisms associated with appetite in broilers, layers, chicken lines selected for low (LWS) or high (HWS) body weight, and Japanese quail, which provide a unique perspective to understanding appetite. Broiler-type chicks have been genetically selected for rapid growth and consume much more feed than do layer-type chicks which have been selected for egg production. Long-term selection has caused the LWS chicks to have different severities of anorexia while the HWS chicks become obese, thus making these lines a valuable model for metabolic disorders. Lastly, the Japanese quail have not undergone as extensive artificial selection as the chicken, thus this model may provide insights on how human intervention has changed the mechanisms that regulate feeding behavior in birds. This research involved applying a variety of different treatments including fasting and refeeding, diets differing in macronutrient composition, and/or central administration of neuropeptide Y, xenopsin, neuropeptide K, oxytocin, mesotocin, gonadotropin-inhibitory hormone, and prolactin-releasing peptide, after which I measured feeding behavior and various aspects of hypothalamic physiology. I measured nuclei activation in hypothalamic appetite-associated regions including the lateral hypothalamus, paraventricular nucleus, ventromedial hypothalamus, dorsomedial nucleus, and arcuate nucleus and I measured gene expression of various appetite-associated factors in the whole hypothalamus and individual nuclei. These data provided information about the regions of the brain involved in mediating effects on appetite and the molecular pathways involved in the effect on appetite. There were differences in dose threshold sensitivity to various injected factors in the different stocks, differential responses to fasting and refeeding, and differences in nuclei and genes that were activated in response to the various treatments. These data provide valuable insights on the molecular mechanisms that are associated with the short-term regulation of feeding behavior and pathways that may be genetically stock-dependent. / PHD / Poultry production and welfare may be enhanced by regulating food intake of chickens during specific stages of growth, resulting in improved nutrient utilization efficiency. For example, broiler breeders are feed restricted to achieve target weights in order to prevent obesity and other disorders and improve performance. To affect the appetite of chickens, an understanding of the neural mechanisms mediating food intake is needed but there is a lack of information in this area. Thus, the purpose of this dissertation was to elucidate some of these mechanisms that control appetite regulation in poultry using chickens and quail as models. Several neuropeptide-associated pathways were studied and appetite-related molecular mechanisms were elucidated for neuropeptides K and Y, oxytocin, mesotocin, gonadotropin-inhibitory hormone, prolactin-releasing peptide, xenopsin, different macronutrient composition diets, and fasting and refeeding.

Four experiments were conducted on hens of turkey and Japanese quail. In Experiment I, turkey hens were fed diets containing either 0% added fat, 3.5% animal-vegetable fat blend (AV) or 3.5% dry fat product (DF). In Experiment II with turkey hens, 2 holding diets and 4 breeder diets were investigated. The holding diets contained either 0% added fat or 5% of AV. The breeder diets contained 0% added fat of 5% of one of the following: AV, corn oil (CO) or olive oil (OO). In Experiment III with Japanese quail, 3 pre-breeder (PB) and 3 breeder diets (BD) were studied. They contained either 0, 3.5 or 7% added AV. In Experiment IV with Japanese quail, all diets contained 97% of a semi-purified basal diet and 3% of one of the following: corn starch (CS), corn oil (CO), palmitic acid (PA), oleic acid (OA), linoleic acid (LA) or linolenic acid (LN). The fatty acid composition of plasma and yolk lipids of both turkeys and quail was influenced by the fatty acid composition of the diets. Quail fed a CO diet deposited more linoleic acid in the egg than did those on a LA diet. (Abstract shortened by UMI.)

No description available.

Call number: LD2668 .T4 1979 O26 / Master of Science

No description available.

Thesis (Ph.D.)--McMaster University, 2005. / Advisor: Bennett Galef. Includes bibliographical references. Also available online.

Japanese quail hens were used to study the effect of feeding palmitic, oleic or linoleic acids on the reproductive performance, tissue fatty acid composition and embryo lipid metabolism. Quail fed palmitic acid consumed more feed than those fed either oleic or linoleic acids. The highest level of reproductive performance was observed in quail fed palmitic acid followed by those fed oleic and linoleic acids. The highest level of embryo survival, observed in the palmitic acid fed group, was associated with more rapid mobilization and assimilation of yolk material by the embryo during incubation and it was not related to changes in eggshell quality. High levels of oleic and linoleic acids were found in egg yolk, plasma and liver lipids from quail fed oleic and linoleic acids, respectively. However, feeding palmitic acid resulted in elevated levels of palmitoleic acids in all three tissues. The fatty acid profiles of phospholipid, triglyceride and cholesterol esters of embryonic tissues were consistently influenced by the fatty acid composition of the yolk lipids and the stage of development. Feeding palmitic acid promoted more retention of labeled fatty acids in embryo lipids. Labeled oleic acid was preferentially esterified in the cholesterol ester fraction of yolk sac membrane lipids, and it appears that this fatty acid is utilized to a great extent by the quail embryo during its development.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1968. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph.D.)--McMaster University, 2004. / Advisor: Bennett Galef. Includes bibliographical references (leaves 73-90). Also available online.