Scholarship & Research
Permanent URI for this communityhttps://scholarworks.montana.edu/handle/1/1
Browse
3 results
Search Results
Item On the origin of growth-associated protein-43 (GAP-43) immunoreactive processes present in the rat anterior pituitary(Montana State University - Bozeman, College of Letters & Science, 2000) Kuhl, Jason MichaelItem Consumer response to biotech food labeling : the effects of voluntary rBGH-free labels on fluid milk demand(Montana State University - Bozeman, College of Agriculture, 2002) Kiesel, Kristin; Chairperson, Graduate Committee: Vincent H. Smith; David E. Buschena (co-chair)Consumer response to labeling policies for genetically modified organisms (GMO) in food products is investigated by considering voluntary labeling with respect to the use of the genetically modified Bovine Growth Horri:lone (rBGH) in fluid milk. Existing theoretical approaches on the provision and acquisition of information are extended to develop a framework that specifically addresses the effects of labeling on the relationship between consumer knowledge, information search and product choice. A new data set is utilized in the data analysis. The data set combines national-level supermarket scanner data for fluid milk demand with information about the use of rBGH in milk production and product specific labeling. Estimated parameter coefficients indicate that consumer beliefs previously measured in survey responses lead to an observable and statistically significant change in market behavior. Demand for fluid milk products labeled as rBGH-:free is significantly higher than demand for conventional fluid milk products and increases slightly over time. A positive demand effect is identified for rBGH-:free labeled products but not for unlabeled products, indicating that the provision of labeling information is necessary for market segmentation between conventional and rBGH-:free products. Demand estimates with regard to organic certification of products appear to be affected by market penetration of organic products during the time period analyzed. In addition, price elasticity estimates for half gallons of milk suggest that consumers are less responsive to price changes in rBGH-:free labeled milk products than in conventional milk products.Item The biostimulatory effect of bulls on the hypothalamic-pituitary-adrenal and ovarian axes and on temporal aspects of resumption of ovarian cycling activity in primiparous, postpartum, anestrous, suckled, beef cows(Montana State University - Bozeman, College of Agriculture, 2008) Tauck, Shaun Austin; Chairperson, Graduate Committee: James G. Berardinelli.Exposing cows to bulls or excretory products of bulls stimulates resumption of ovarian cycling activity in postpartum, suckled, anestrous cows. This biostimulatory effect may be mediated by pheromones produced by bulls that stimulate physiological changes in the hypothalamic-pituitary-ovarian (HPO) and/or -adrenal (HPA) axes of cows. In Experiment 1, the hypothesis tested was that the biostimulatory effect of bulls is associated with adrenal regulation and/or function in anestrous cows. The biostimulatory effect of bulls was associated with mean concentrations of cortisol in postpartum cows. Experiment 2 was designed to determine if acute (5-h daily) bull exposure alters characteristics of patterns of cortisol and luteinizing hormone (LH) concentrations in postpartum, anestrous cows. Cows exposed acutely to bulls exhibited fewer pulses of cortisol and more frequent pulses of LH than cows exposed to steers. However, it was not known if these changes were related to resumption of ovarian cycling activity in postpartum, anestrous cows. Experiment 3 was designed to test the hypothesis that patterns of cortisol concentrations are altered by continuous, 24-h daily, bull exposure, before and after resumption of ovarian cycling activity in postpartum, anestrous cows. Continuous bull exposure decreased cortisol pulse frequency before cows resumed ovarian cycling activity. Experiment 4 tested the hypothesis that the overall shape of patterns of cortisol and/or LH concentrations may differ between cows exposed acutely to bulls or steers in Experiment 2. Cows exposed acutely to bulls had more uneven patterns of LH concentrations than cows exposed to steers and as patterns of cortisol concentrations became smoother, patterns of LH become more uneven in cows exposed acutely to bulls. In Experiment 5, the hypothesis tested was that interval to resumption of ovarian cycling activity may depend upon duration of daily bull exposure. Cows resumed ovarian cycling activity sooner as duration of daily bull exposure increased. In conclusion, as duration of daily bull exposure increases, the biostimulatory effect of bulls alters activity of the HPA axis and this change may facilitate or support the function of the HPO axis and accelerate resumption of ovarian cycling activity in primiparous, postpartum, suckled, anestrous cows.