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  • 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.
471

NEW INPUT AND OUTPUT RISK MANAGEMENT STRATEGIES FOR LIVESTOCK PRODUCERS

Coffey, Brian K. 01 January 2001 (has links)
Backgounding beef cattle is an inherently risky venture. Producers faceproduction risks as well as marketing risks. If a backgrounding operation is to be viable,these risks should be addressed and effectively managed. While some effective riskmanagement tools are currently available to livestock producers, some other potentiallyuseful risk management tools, for various reasons, have been previously unavailable.Two such tools which could help livestock producers achieve the overall goal ofmanaging net income risk are a program for managing feed ingredient nutrient and pricevariability in the selection of minimum cost feed rations and government subsidizedlivestock price insurance.Due to lack of data and limited computational power of solvers, risk has seldombeen introduced into the feed ration selection process. Presently, both feed ingredientnutritional data and appropriate solvers are available, allowing for risk to be fullyconsidered in this decision-making process. Only recently has there been policy effortsto establish subsidized price or revenue insurance for livestock producers. Theintroduction of such insurance to livestock producers offers potential risk managementbenefit but also has the potential to introduce improper incentives to livestock producers.This study will evaluate both of the aforementioned livestock risk managementtools. In addition to evaluating their effectiveness, the policy concerns of subsidizedlivestock insurance will also be addressed. Results will be relevant to a broad range ofentities. In addition to livestock producers wishing to manage the risks associated withtheir operations, agribusinesses that provide service to these producers such as feed salesor financial lending will benefit from knowing how these risk management strategiesperform. Furthermore, policy makers who will structure livestock insurance products canhopefully do so more efficiently based on the results of the livestock insurance analysis.
472

Verfahrenstechnik für eine wirtschaftliche Ebermast

Meyer, Eckhard, Alert, Hans-Joachim, Böhm, Anke 29 January 2014 (has links) (PDF)
Im Rahmen eines Projektes wurden Haltungs- und Fütterungsfaktoren für die Mast unkastrierter männlicher Schweine abgeleitet. Die Ebermast ist verfahrenstechnisch umsetzbar. Sie kann den Betrieben Kostenvorteile insbesondere durch Futterersparnis bringen, solange der Absatz gesichert ist. Je nach Schlachtgewicht und Abstammung realisieren die Eber etwas geringere Masttagszunahmen, aber eine deutlich bessere Futterverwertung und bilden Schlachtkörper mit weniger Fett und mehr Fleisch als die männlichen kastrierten Schweine. Die Verlustrate liegt bei den Ebern etwas höher. Das Problem des Ebergeruchs kann nur durch die Optimierung einer darauf ausgerichteten Zucht, Haltung und Fütterung gelöst werden. Dazu wurden einzelne Faktoren, wie z. B. die Aufstallungsform, die Buchtenhygiene und die Zunahmegeschwindigkeit identifiziert.
473

Automatische Melksysteme in Sachsen

Pommer, René, Pache, Steffen, Heber, Ingo, Rindfleisch, Annett 02 October 2013 (has links) (PDF)
In ausgewählten Betrieben mit automatischen und konventionellen Melksystemen wurden die ökonomischen Ergebnisse des Betriebszweiges Milch (BZA), die Verfahrenskosten der Milchgewinnung sowie die Leistungsentwicklung und Produktqualität analysiert und ausgewertet. Die Gesamtkosten der AMS-Betriebe in der BZA lagen um mindestens 1,5 Ct/kg verkaufter Milch über denen konventionell melkender Betriebe. Der Einsatz von AMS in großen Betrieben rechnet sich ab einem Lohnniveau deutlich über 20 EUR je Arbeitskraftstunde. In kleinen Betrieben ist das Melken mit AMS günstiger als mit einem Melkstand. Die Analyse der Leistungskennzahlen zeigt, dass Handlungsbedarf zur Verbesserung der Eutergesundheit und Fruchtbarkeit besteht.
474

Conflicts Between Humans And Wolf: A Study In Bozdag, Konya Province, Turkey

Tug, Senem 01 October 2005 (has links) (PDF)
Canis lupus is one of the most important but least studied species of Turkish fauna, however, livestock depredation and recently increased number of publications on attacks on humans intensifies human-wildlife conflict. In this study, wolf depredation is studied in Bozdag in the province of Konya where conflicts between wolves and livestock holders are well known. The study site holds &gt / 50,000 sheep and covers 9 villages and a small town. A total of 13 shepherds are interviewed in 2004 and 2005 to reveal husbandry methods and vulnerability of livestock to wolf attacks in Bozdag. Each flock is attended by a shepherd and several livestock guarding dogs (LGDs), and experiences 1.96 wolf attacks per year, on average, independent of flock size. The flocks attended by less LGDs experience less attacks and therefore, the quality of the LGDs &amp / #8211 / not their numbers- are more important. Confining sheep in corrals that are attended by a shepherd and good quality LGDs appears to be the most effective husbandry method to decrease depredation. Human attitude towards wolf is also assessed and the perception of wolf is generally negative / 8 out of 11 shepherds are in favour of the eradication of this carnivore. Publicized wolf attacks on humans are compiled from 21 news sources on the internet and records of wolf rabies are sought from various sources. There were five publicized cases of attacks on humans, no verified records of human death between 2000 and 2005. Rabies stands out as the primary reason of wolf attacks, but it requires further research because proper records are missing.
475

Venison to beef and deviance from truth: biotelemetry for detecting seasonal wolf prey selection in Alberta

Morehouse, Andrea 11 1900 (has links)
An abrupt interface between mountains and prairies in southwestern Alberta means wilderness areas and carnivore populations overlap cattle grazing lands. Consequently, there is concern about the effects of large carnivores, especially wolves, on livestock. I used GPS clusters and scat samples to determine year-round wolf diets in this region. Both methods indicated a significant seasonal shift in wolf diets from wild prey during the non-grazing season to cattle in the grazing season. The GPS cluster method effectively identified wolf kills but this method relies on telemetry with high accuracy and precision. In southwestern Alberta, Argos satellite radicollars have been used extensively by wildlife managers. I compare how differences in precision between GPS and Argos technologies affect the estimation of habitat-selection models. Differences in accuracy and precision can lead to erroneous conclusions about animal selection of habitat. / Ecology
476

Gefährdete einheimische Nutztierrassen in Sachsen

Klemm, Roland, Walther, Regina, Karwath, Matthias, Golze, Manfred, Gschwender, Felicitas, Wehlitz, Romi 26 May 2011 (has links) (PDF)
Die bebilderte Broschüre stellt die Zuchtgeschichte, die Nutzung, die Gefährdung und den Bestand sächsischer Nutztierrassen vor. Damit das wertvolle Kulturgut und ihre Vielfalt für nachfolgende Generationen erhalten bleiben, fördert der Freistaat Sachsen die Haltung zahlreicher Rassen. Die Broschüre informiert Züchter und Halter über die Voraussetzungen der Förderung und geht auf spezielle Fördermöglichkeiten bei einzelnen Rassen ein.
477

Abluftführung in der Legehennenhaltung

Lippmann, Jens 20 July 2011 (has links) (PDF)
Zur Klimagestaltung in Legehennenställen werden primär Unterdrucklüftungssysteme mit einem Luftwechsel nach dem Strahllüftungsprinzip entlang der Querachse des Stalls eingesetzt. Zur besseren Frischluftversorgung im Tierbereich werden zunehmend Unterdrucklüftungssysteme mit einem Luftwechsel nach dem Tunnelprinzip entlang der Längsachse des Stalls eingesetzt. Im Projekt werden die beiden Luftwechselvarianten verglichen, um Kenndaten zu ausgewählten Stallraumlasten sowie zum Luft- und Volumenstrom für die Varianten zu bestimmen und hieraus Bewertungen zu Staub-, Geruchs- und Ammoniakemissionen abzuleiten. Die Ammoniakemissionen sind bei der Tunnellüftung gegenüber Strahllüftung niedriger, die Staubemissionen sind dagegen bei der Strahllüftung geringer. Für die Geruchsemissionen wurden keine Unterschiede festgestellt. Die Voliereblöcke erzeugen im Stallraum Strömungsbarrieren und werden von der Frischluft weitgehend umströmt. Hierdurch entstehen deutliche Luftwechselunterschiede zwischen dem frei durchströmbaren Stallraum und dem Innenbereich der Voliereblöcke.
478

EVALUATION OF METARHIZIUM ANISOPLIAE FOR BIOPESTICIDE CONTROL OF LIVESTOCK ECTOPARASITES

Diana Leemon Unknown Date (has links)
THESIS ABSTRACT Current control strategies for livestock ectoparasites are limited by problems associated with chemical resistance and residues. Fungal biopesticides could provide an alternative control without these problems. However, a strategic approach is needed to first evaluate the suitability of selected fungal isolates for fungal biopesticide development. Two ectoparasites of significance to cattle and sheep are the cattle tick Rhipicephalus (Boophilus) microplus (Canestrini) and the Australian sheep blowfly Lucilia cuprina (Wiedmann). The fungus Metarhizium anisopliae (Metsch.) Sorokin) was evaluated for its potential to control these livestock ectoparasites. The growth characteristics of 30 isolates of M. anisopliae were investigated. Radial growth measurements were used to identify vigorous isolates that grew well at 30C and were capable of growing at 35C. A qualitative assessment of sporulation capacity further refined the candidate isolate group. A possible nutritive role of oil in the formulation was also investigated. However, there was no clear support for the theory that oil as a formulation additive could boost the germination and growth of the fungal conidia in vitro. Quantal response bioassays were conducted with cattle ticks and sheep blowflies using a range of conidial doses of three different isolates of M. anisopliae and different methods of inoculation. Ticks were either dosed with 2 µl or immersed in the conidial doses. Blowflies were either dosed with 2 µl of the conidial doses or fed conidia mixed with sugar. Probit analyses were carried out on the mortality data to compare the virulence of these isolates to ticks and blowflies and look for indications of different virulence mechanisms employed by M. anisopliae isolates when invading these hosts. One isolate (ARIM16) showed high virulence to both hosts killing 95 % of ticks after two days and 88 (±2) % of blowflies after four days. Strikingly different mortality patterns indicated quite different virulence mechanisms operating when M. anisopliae invades ticks or blowflies. The mortality pattern seen with ticks suggested that the number of conidia adhering per unit area of the cuticle was more important for rapid tick death than the total number of conidia contacting the entire tick surface. Blowflies fed conidia mixed with food died rapidly after an initial lag phase regardless of dose. Microscopic investigations were carried out to resolve the basis of the virulence patterns observed. The spatial and temporal aspects of the invasion of ticks and blowflies by M. anisopliae isolate ARIM16 were investigated with different types of microscopy. The scanning electron microscope and stereo light microscope were used to record surface changes and events and the compound light microscope revealed internal changes. Two distinctly different patterns of invasion were found in ticks and blowflies. Fungal conidia germinated on the surface of ticks then hyphae simultaneously penetrated into the tick body and grew across the tick surface. There was extensive fungal degradation of the tick cuticle with a preference for the outer endocuticle. While large numbers of conidia adhered to the surface of blowflies, no conidia were recorded germinating on external surfaces. One germinating conidium was seen in the entrance to the buccal cavity. Investigations of the fly interior revealed a higher density of hyphal bodies in the haemolymph surrounding the buccal cavity than in haemolymph from regions of the upper thorax. This pattern suggested that fungal invasion of the blowfly is through the buccal cavity. Plentiful extracellular mucilage was seen around the hyphae on ticks, and crystals of calcium oxalate were seen amongst the hyphae on the surface of ticks and in the haemolymph of blowflies killed by M. anisopliae isolate ARIM16. It was considered that cattle ticks are more suited for control with fungal biopesticides than adult blowflies. Three field trials were conducted over twelve months to assess the pathogenicity of M. anisopliae to parasitic stages of R. microplus on dairy heifers under different environmental conditions. Two isolates were selected based on their high optimal growth temperature (30oC), good conidial production characteristics and ability to kill adult engorged ticks in the laboratory in minimum time. Conidia were formulated in an oil emulsion and applied using a motor driven spray unit. Surface temperatures of selected animals were monitored, as were the ambient temperature and relative humidity. Unengorged ticks sampled from each animal immediately after treatment were incubated under laboratory conditions to assess the efficacy of the formulation and application. Egg production by engorged ticks collected in the first 3 days after treatment was monitored. Side counts of standard adult female ticks were conducted daily, before and after treatment to assess the performance of the fungus against all tick stages on the animals. At each trial the formulation caused 100% mortality in unengorged ticks that were removed from cattle and cultured under laboratory conditions. A significant reduction in egg production was recorded for engorged ticks collected in the three days post treatment. In the field, the fungal formulation had an inconsistent effect on ticks, which might be due to the influence of environmental temperature and humidity.
479

Protein metabolism and nitrogen dynamics in Rusa Deer (Cervus timorensis)

Tomkins, N. Unknown Date (has links)
No description available.
480

The use of deslorelin with centrifuged and non-centrifuged frozen equine semen and its influence on the reproductive endocrinology of the mare

Chopin, J.B. Unknown Date (has links)
No description available.

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