• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 61
  • 13
  • 10
  • 5
  • 1
  • Tagged with
  • 113
  • 27
  • 14
  • 12
  • 10
  • 10
  • 10
  • 10
  • 9
  • 8
  • 8
  • 8
  • 8
  • 8
  • 8
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Formation of key flavour precursors in bison longissimus dorsi muscle: effect of chilled storage conditioning

Williamson, Jennifer 31 August 2011 (has links)
Water and lipid-soluble meat flavour precursors are gradually formed post-mortem via biochemical reactions. Storage time and temperature can affect final flavour precursor concentrations which in turn will affect the sensory quality of cooked meat. Selected key flavour precursors were monitored in Bison bison longissimus dorsi muscles from six animals stored at 2, 4, 8, 15 and 21 days at 4°C, in order to evaluate the effect of post-mortem conditioning on the formation of flavour precursors. Results were correlated with sensory data obtained using quantitative descriptive analysis with 8 trained panelists. While lipid-soluble flavour precursors remained mostly unchanged, significant increases (P<0.05) in concentrations of water-soluble flavour precursors including reducing sugars (eg. ribose, xylose), free amino acids (eg. valine, leucine) and adenosine-5’-triphosphate (ATP) degradation products (eg. inosine and hypoxanthine) were obtained with chilled storage conditioning post-mortem. The overall balance and correlations of water-soluble flavour precursors with storage day 15 and 21 were reported and can potentially impact the eating quality of cooked bison meat.
52

Epidemiology of anthrax outbreaks in wood bison (Bison bison athabascae) of the Mackenzie bison population

2014 December 1900 (has links)
Wood bison (Bison bison athabascae) conservation in Northern Canada is negatively affected by diseases that kill these animals, such as anthrax caused by the bacterium Bacillus anthracis. Although this disease is considered ancient and was identified more than 2000 years ago in Egypt, little is still known about this disease in wild bison, such as why adult males are often predominantly affected and if the reason there are mortalities in some years and not in others is due to environmental, pathogen, or host factors. The overall objective of this thesis was to use descriptive and serological epidemiology to provide evidence needed to enhance our understanding of anthrax in wild wood bison. The first chapter explored the 2012 anthrax outbreak in bison of the Mackenzie bison population using descriptive epidemiology. Field crews discovered 451 bison carcasses during the outbreak. The carcasses were found between late June and early August, and it was estimated that the epidemic peaked between July 13-19 based on the date carcasses were found and the estimated length of time the animal had been deceased. A unique feature of this outbreak compared with the two previous outbreaks in the same population, as well as outbreaks in other wild wood bison herds, is that numerous calves, yearlings and adult females died rather than mostly adult males. Three separate geographic regions were identified by a field wildlife veterinarian, and examined for differences in outbreak characteristics. One region had proportionally more male carcasses than the others, and one had more calf deaths. Lack of complete data made it difficult to ascertain if the outbreak truly started in one of these regions before the others, or if it began simultaneously in all three. The second component of this project used serological epidemiology of anthrax in the Mackenzie bison population to gain an understanding of wood bison exposure to the bacterium. Serological samples were collected through various sources between 1986 and 2009, and later tested for anti-PA antibodies. Of the 278 samples tested, 191 (69%) were positive, indicating previous exposure to B. anthracis. Of the samples with a recorded gender, approximately 18.2% of those from females and 35.5% from males tested positive. The dataset spanned only one anthrax outbreak year in this population of animals, and the year with the highest proportion of positive samples was the year following this known epidemic (1994, 90% positive submissions). Adults had a higher prevalence of being seropositive than any of the other age categories, for both sexes. This research has revealed that in some outbreak years, all age classes and both genders of bison are affected by anthrax unlike in most outbreaks where predominantly adult males succumb to disease. Furthermore, bison are likely exposed to B. anthracis in non-outbreak years, indicating that they either experience subclinical disease or recover from clinical disease.
53

Sustaining a conservation legacy? an in depth perspective on the interagency bison management plan and the potential for collaboration /

Brininstool, Jason Alan. January 2010 (has links)
Thesis (MS)--University of Montana, 2010. / Contents viewed on April 9, 2010. Title from author supplied metadata. Includes bibliographical references.
54

The Tongue River bison jump (24RB2135) the technological organization of late prehistoric period hunter-gatherers in southwestern Montana /

Hamilton, Joseph Shawn. January 2007 (has links)
Thesis (M.A.)--University of Montana, 2007. / Title from title screen. Description based on contents viewed July 12, 2007. Includes bibliographical references (p. 100-108).
55

Faunal analysis of the Tongue River bison kill (24RB2135) in southeastern Montana

Sutton, Hilleary Allison. January 2007 (has links)
Thesis (M.A.)--University of Montana, 2007. / Title from title screen. Description based on contents viewed July 25, 2007. Includes bibliographical references (p. 55-60).
56

SUPEROVULATION AND EMBRYO COLLECTION IN WOOD BISON (Bison bison athabascae): TOOLS TO PRODUCE DISEASE-FREE EMBRYOS

2015 December 1900 (has links)
Reclamation of Canada’s threatened wood bison (Bison bison athabascae) herd is complicated by cattle diseases. As part of an overall goal to conserve bison genetics, five studies were conducted to develop or adapting present reproductive technologies to produce disease-free in vivo-derived wood bison embryos. In Chapter 4, the efficacy of pLH and hCG for inducing ovulation and whether the effect was related to the size of the dominant follicle at the time of treatment was examined in wood bison during the anovulatory season . Ovulation rate with hCG (94%) was nearly two times greater than with pLH (54%), and bison with a growing follicle of ≥10 mm had a greater ovulatory response than those of 8-9 mm. In Chapter 5, the efficacy of pLH and hCG after superstimulation with single or two doses (48 hours apart) of FSH diluted in 0.5% hyaluronan was determined in wood bison. A greater superovulatory ovarian response was found in cows treated with hCG vs. LH during the anovulatory and ovulatory seasons (6.6 vs. 2.8 and 6.3 vs. 3.8 corpora lutea respectively). In addition, dividing the dose of FSH two resulted in greater superovulatory response in wood bison. However, the number of corpora lutea was still lower than expected as compared to cattle using the same two dose method of superovulation (15 corpora lutea; Tribulo et al., 2012). Therefore, in Chapter 6, the effect of the addition of a low dose of eCG at the end of the superstimulation protocol on ovarian response and embryo quality was examined. Although the number of ova/embryos recovered was higher in this study when compared with previous reports in wood bison, no effect of eCG on the number of corpora lutea and embryo quality was found. In Chapters 5 and 6, the effect of exogenous progesterone on embryo quality in wood bison during the anovulatory season was evaluated. We found that progesterone did not improve the number of freezable embryos in either study. In Chapter 7, the effect of lengthening of FSH treatment protocol on superovulatory response and embryo quality during the ovulatory and anovulatory seasons was examined. There was no effect of lengthening the FSH treatment protocol on ovarian response and embryo quality during the anovulatory season. However, embryo quality and ovulation rate were increased by the lengthened treatment protocol during the ovulatory season. Additionally, more freezable embryos (Grades 1 and 2) were obtained during the ovulatory season (1.8 embryos) vs. the anovulatory season (0.3 embryos). Overall, results confirm that superovulation can be performed in wood bison throughout the year, but a higher number of freezable embryos were obtained during the ovulatory season. The final chapter (Chapter 8) focused in the production of disease-free embryos in wood bison. Following superovulation, in vivo-derived wood bison embryos were exposed in vitro to Brucella abortus biovar 1. After incubation, embryos were submitted to the 10-step washing procedures recommended by the IETS to remove the pathogen. When the washing medium contained antibiotics, 100% Brucella-free embryos were obtained. These findings validate the washing procedures for the production of Brucella-free embryos in wood bison.
57

Enclosed Elk and Bison in Land Between The Lakes, Kentucky: Dietary Overlap

Whittaker, Clare C. Weickert 01 May 2011 (has links)
I evaluated the potential for interspecific competition for forage between elk (Cervus elaphus) and bison (Bison bison) in the 265.5-ha Elk & Bison Prairie enclosure at Land Between The Lakes National Recreation Area in western Kentucky. I studied diet composition of elk and bison based on microhistological analysis of fecal samples collected monthly for 36 months from September 1996 through August 1999. Elk diet was more variable than that of bison, but no significant seasonal differences in diet composition were found for either species throughout the study. As expected, elk and bison differed significantly in their feeding habits. As seen in studies of wild sympatric populations, bison consumed more graminoids, less browse and fewer forbs than did elk, regardless of season. Dietary overlap varied considerably, but with little apparent seasonal pattern. Overlap did not consistently increase during winter, when quantity and quality of available forage might be reduced. Competition between elk and bison for available forage may have been alleviated by supplemental feeding and the ability of elk to adapt to alternative forages.
58

Chov zubra evropského ve farmovém chovu / Breeding of european bison in stock farme

HYŠPLEROVÁ, Klára January 2011 (has links)
Breeding of European bison (Bison bonasus) in the Czech Republic has begun to expand recently. The main aim of this graduation theses is to aquaire foreign information of this European breed and map breeding of this species in our country. Furthermore this thesis includes description of breeding European bison on one specific farm in Radany in South Bohemia and monitoring of ethologic knowledge of this certain herd. Bisons are kept in semi-natural conditions on the farm in the area of 14 ha. The basic herd of bisons forms 13 heads of Low-Caucasus genetic line. This part concludes with presentation of information boards of nature trail which is part of the Radany farm.
59

The Baker Cave Bison Remains: Bison Diminution and Late Holocene Subsistence on the Snake River Plain, Southern Idaho

Breslawski, Ryan P 01 May 2014 (has links)
The role of bison in the prehistoric subsistence in southern Idaho is not fully understood. Bison remains from Baker Cave, a late Holocene archaeological site dating to cal A.D. 1042-1265, however, provide evidence of pre-contact subsistence strategies in the region. This thesis focuses on the paleoecology of bison and their role in prehistoric subsistence on the Snake River Plain (SRP). The ecological study of bison focuses on the hypothesized trans-Holocene diminution in bison body size in southern Idaho, while a second study focuses on how these animals figured into prehistoric responses to seasonal fat scarcity. Although bison diminution and its ecological determinants are well understood on the Great Plains, the history of diminution west of the Rocky Mountains is less clear. Bison morphometrics from Baker Cave present the opportunity to assess bison diminution on the Snake River Plain. Bison morphometrics from Baker Cave are indistinguishable not only from other late Holocene bison on the Snake River Plain but iv also from late Holocene bison from the Great Plains. Further, the Baker Cave bison are smaller than early Holocene bison from the Great Plains and Snake River Plain. These results suggest morphological similarity between Snake River Plain bison and Great Plains bison through the Holocene, pointing to similar bottom up ecological constraints on body size. Although bison are common components of SRP archaeofaunas, their role in prehistoric subsistence is poorly understood. To shed light on this problem, I hypothesize that the Baker Cave bison assemblage resulted from hunters seeking skeletal fat. I test predictions drawn from this hypothesis with assemblage-level patterns in element representation, impact scar distribution, and fragmentation. These assemblage-level patterns track the skeletal fat utility of elements. These patterns, combined with winter procurement evidenced by fetal remains, support the hypothesis that fat-seeking behavior was a response to winter fat scarcity. A comparison with smaller bison assemblages from southern Idaho suggests that this fat-seeking behavior might have persisted as far back as the middle Holocene, although this requires confirmation from future studies.
60

Cross-Hedging Bison with Live Cattle Futures

Movafaghi, Olivia Shahrzad 14 August 2014 (has links)
Bison production is an emerging retail meat industry. As demand increases, it creates opportunity for supply-side growth. However, the bison market is volatile and the potential for a drop in the value of bison makes price risk an important factor for producers. Following price risk theory, hedging opportunities for bison producers are investigated using the live cattle futures contract. For the time periods researched, there is no clear evidence that cross-hedging reduces price risk for bison producers. However, there is a possibility that after the bison industry becomes more established and consumer knowledge plays lesser of a role in prices, cross-hedging strategies will be advantageous to producers. / Master of Science

Page generated in 0.023 seconds