Dissertations / Theses on the topic 'Eggs'
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Caudill, Amber Brooke. "Effects of cool water washing of shell eggs on Haugh unit, vitelline membrane strength, aerobic bacteria, yeast, and mold." Auburn, Ala., 2007. http://repo.lib.auburn.edu/2007%20Fall%20Theses/Caudill_Amber_2.pdf.
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Stallard, Rachel. "Eggs." Cleveland State University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=csu1304547649.
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Thamaga, Marupine Windy. "The effect of egg weight hatchability, chick hatch-weight and subsequent productivity of Venda chickens." Thesis, University of Limpopo, 2010. http://hdl.handle.net/10386/519.
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Thesis (M.Sc. (Agric)) --University of Limpopo, 2010An experiment was conducted to determine the effect of egg weight on hatchability, hatch-weight and subsequent productivity of Venda chickens. A total of 360 Venda chicken eggs based on their weights were collected within one week and assigned to four treatments with five replicates of 18 eggs per replicate. A randomized design was used. The four treatment weights were below 49 g, between 50 and 59 g, between 60 and 69 g and above 70 g. the eggs were incubated for 21 days. The chicks were raised up to 13 weeks based on their treatments but fed a similar diet. Egg weight was positively and strongly correlated (r2 = 0.727) with hatchability. Similarly, egg weight was positively and strongly correlated (r2 = 0.0.953) with chick hatch-weight. Between one and seven weeks old, Venda chicks hatched from heavier eggs ate less (P< 0.05) than those hatched from lighter eggs. Heavier eggs hatched chicks with better (P< 0.05) feed conversion ratio. However, chicks hatched from heavier eggs tended to have higher (P< 0.05) live weight at seven weeks old than those hatched from lighter eggs. Heavier eggs tended to hatch chicks that had higher (P< 0.05) mortality rates. However, metabolisable energy and nitrogen retention of the chicks aged seven weeks was not (P> 0.05) affected by egg weight. Growth rate and live weight of the chicks aged between one and seven weeks were optimized at different Venda chicken egg weights of 56 (r2 = 0.514) and 60 (r2 = 0.870) g, respectively. Egg weight had no (P> 0.05) effect on metabolisable energy, feed conversion ratio, growth rate, live weight, carcass weight and carcass parts of Venda chickens aged between eight and 13 weeks except fat pad weight. Venda chickens hatched from lighter eggs had lower (P< 0.05) fat pad weights than those hatched from heavier eggs. Meat samples of chickens hatched from lighter eggs had higher (P< 0.05) nitrogen contents. It is concluded that Venda chicken egg weight affects (P< 0.05) egg hatchability, chick hatch-weight, growth rate, live weight and carcass characteristics of the chicken. However, these variables are optimized at different egg weights. This has implications on selecting eggs for incubation.
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Nelwamondo, Nditsheni Constance. "Effect of management and socio-economic factors on the performance of the Vhembe District Egg Production Project." Thesis, University of Limpopo, Turfloop Campus, 2013. http://hdl.handle.net/10386/1115.
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Thesis (MA.Agricultural Management (Animal Production)) -- University of Limpopo, 2013The objectives of the study were to evaluate the productivity of the Vhembe egg production project and determine the management and socio-economic factors affecting productivity. The data were collected from 2005 to 2007. Thirty-two farmers from four municipalities were randomly selected. Each household received a once-off unit consisting of a cage with eighteen point of lay chickens 4x50 bags of laying mesh, feeding and drinking troughs. Production records from sampled farmers were used in the analysis. Data included monthly egg production, eggs consumed, eggs sold, income from eggs, production costs, monthly feed utilization and mortality. Primary data on educational standards, socio-economic characteristics (age and gender of the household head, farming size, level of education and alternative income, were collected using a questionnaire. The study revealed that sex, age and educational level had impact on production as low production was associated with older farmers and low level of education. These factors should be considered when planning community projects. Chicken rearing and ownership is often shared among the family members, in this study, the management was predominantly by women (63%) and children (18%). This may be an indication that if assistance efforts are targeted towards women, village poverty could be significantly reduced. It is concluded that the low income accrued from the project explains the reason for high abandonment or neglect of the project. The income received from the project is smaller than the government grants and as such not attractive. It is not surprising that presently most farmers have abandoned the project. It is noted that if labour costs had been taken into consideration, the project would be running at a serious loss and the resultant output would discourage even the most enthusiastic farmers.
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Kretszchmar, McCluskey Vanessa Kirsten Curtis Patricia A. "Microbial analysis of shelled eggs and chemical and functional analysis of liquid eggs." Auburn, Ala., 2007. http://hdl.handle.net/10415/121.
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Esteban, Raquel. "The significance of Listeria monocytogenes in eggs and egg products /." St. Lucia, Qld, 2003. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe17528.pdf.
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Mudau, Mavhulawa Sylvia. "Functional properties of microwave pasteurised and oil coated whole shell eggs." Pretoria : [s.n.], 2007. http://upetd.up.ac.za/thesis/available/etd-07302008-080923.
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Kamotani, Setsuko. "Consumer acceptance of ozone-treated whole shell eggs." Columbus, Ohio : Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1243631693.
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Juliano, Pablo. "High pressure thermal sterilization of egg products." Online access for everyone, 2006. http://www.dissertations.wsu.edu/Dissertations/Spring2006/p%5Fjuliano%5F050106.pdf.
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Zhao, Liang. "Post-translational modifications of SEL24K from salmon eggs and ZPA from Xenopus laevis eggs." Scholarly Commons, 2011. https://scholarlycommons.pacific.edu/uop_etds/160.
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Post-translational modifications (PTMs) of proteins play significant roles in regulation of biological activities and signal transduction. Examining their diversity is critical for understanding the mechanisms of cellular regulations. Among the various techniques employed for identification of PTMs, mass spectrometry has become a more and more important tool for detecting and mapping these covalent modifications and quantifying their changes. The two projects described in this dissertation focus mainly on the method development for characterization of two major PTMs, disulfide bonds and glycosylation. In the first project, the disulfide bond pattern of a rhamnose-binding lectin SEL24K from the Chinook salmon Oncorhynchus tshawytscha was assigned unambiguously based on a multi-enzyme digestion strategy in combination with MALDI-TOF mass spectrometry analysis. The disulfide bond pattern was found to be symmetrical in the tandem repeat sequence of SEL24K. More importantly, an interesting phenomenon of gas-phase scrambling of disulfide bonds was observed during MALDI mass spectrometry analysis and a possible mechanism for this surprising scrambling was proposed. To the best of our knowledge, this is the first report of disulfide bond scrambling in the gas phase during MALDI-MS analysis. This observation has important ramifications for unambiguous assignment of disulfide bonds. In the second project, the glycosylation of a glycoprotein ZPA from the vitelline envelope of Xenopus laevis was determined by applying a strategy of general proteolysis coupled with mass spectrometry. The vitelline envelope glycoproteins were first separated through SDS-PAGE. A nonspecific in-gel pronase digestion was performed on the excised band of ZPA to produce informative small glycopeptides. Lectin affinity chromatography was used for the enrichment of these glycopeptides. An in-gel PNGase F digestion was also carried out to release the N-linked glycans from ZPA. The enriched glycopeptides and glycans were finally analyzed by MS and MS/MS techniques on MALDI-TOF and MALDI-TOF/TOF instruments.
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Barker, Gavin A. C. "Bacterial associations with salmonid eggs." Thesis, Aston University, 1989. http://publications.aston.ac.uk/12523/.
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Rainbow trout eggs Salmo gairdneri, Richardson, were incubated under a range of different environmental conditions. Recovery of bacteria from egg surfaces revealed that increased water temperature, slow water flow rates and high egg density all significantly increased egg surface bacterial populations. Live eggs were mainly colonized by Cytophaga sp., pseudomonas fluorescens and Aeromonas hydrophila. In contrast, dead eggs supported considerable numbers of fluorescent Pseudomonas sp. Analysis of potential nutrient sources for bacteria colonizing live egg surfaces revealed that small amounts of amino acids, phosphate and potassium may be lost by incubating eggs. Subsequently these nutrients were shown to be capable of supporting limited bacterial growth and reproduction. Dead eggs `leaked' increased amounts of the above nutrients which in turn supported higher bacterial numbers. In addition, biochemical analysis of eggs revealed amino acids and fatty acids that might be utilized by bacteria colonizing dead egg surfaces. Assessment of adhesion properties of bacteria frequently recovered from egg surfaces revealed high cell surface hydrophobicity as an important factor in successful egg colonization. Analysis of egg mortalities from groups of rainbow trout and brown trout (S.trutta L.) eggs maintained under two different incubation systems revealed that potentially a close correlation existed between egg surface bacterial numbers and mortalities in the egg during incubation. Innoculation of newly-fertilized eggs with bacteria demonstrated that groups of eggs supporting high numbers of P.fluorescens suffered significantly higher mortalities during the early part of their incubation. Exposure of incubating eggs to oxolinic acid, chlortetracycline and chloramphenicol demonstrated that numbers of bacteria on egg surfaces could be significantly reduced. However, as no corresponding increase in egg hatching success was revealed, the treatment of incubating eggs with antibiotics or antimicrobial compounds can not be recommended. In commercial hatcheries bacteria are only likely to be responsible for egg deaths during incubation when environmental conditions are unfavourable. High water temperatures, slow water flow rates and high egg density all lead to increased bacterial number of egg surfaces, reduced water circulation and low levels of dissolved oxygen. Under such circumstances sufficient amounts of dissolved oxygen may not be available to support developing embryos.
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Hartmann, Camilla. "Selection for yolk production in laying hens /." Uppsala : Swedish Univ. of Agricultural Sciences (Sveriges lantbruksuniv.), 2001. http://epsilon.slu.se/avh/2001/91-576-5807-2.pdf.
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Amini, Keyvan. "Strategies for improving fatty acid profile of eggs for production of omega-3 enriched eggs." Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=100759.
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Two experiments were carried out to evaluate the effects of Pearl Millet in combination with different levels of flaxseed and natural pigment (Oro Glo 15RTM) on quantity of n-3 fatty acids in eggs, laying performance and yolk pigmentation. In the first experiment, six different diet treatments were used for six weeks, with 24 hens per treatment (three birds per cage, eight cage replicates). Control diet was a corn-soybean meal diet, and diets containing 0, 2, 4, 8 or 12% ground flaxseed in which all the corn was replaced by pearl millet. In the second experiment, the diet treatments consisted of pearl millet and three inclusion levels of ground flaxseed (4%, 6% and 8%) and two levels (0.1% and 0.2%) of natural pigment in a factorial arrangement. The experiment lasted for twelve weeks, with 18 hens per treatment (three birds per cage, six cage replicates). In each of the experiments, all the diets were formulated to be isocaloric and isonitrogenous and to meet or exceed NRC requirements. Body weight of the birds and feed consumption were recorded at weekly (first experiment) and biweekly (second experiment) intervals. Number of eggs and egg mass produced were measured and recorded on a daily basis. At the end of each of the experiments, all the hens were euthanized to determine liver integrity. In both of the experiments, flock performance parameters were not different among treatments. In regard to egg traits, in the second experiment after 8 week of the start of the experiment, birds fed with diets containing 8% flaxseed produced significantly ( P < 0.05) smaller eggs compared to hens fed 4% flaxseed. Yolk pigmentation was lower (P < 0.05) for the eggs produced by hens fed diets containing pearl millet compared with those produced by feeding corn-based diet. However, 0.1% or 0.2% inclusion of the pigment both proved to be suitable to restore yolk pigmentation to marketable levels. No difference was observed among diets in regard to liver haemorrhage. Evaluation of FA profiles indicated that birds fed a diet containing PM as the sole grain source, and low levels of flaxseed (6%) can produce eggs with more than 350 mg/egg of n-3 FA, which is the lower standard to market eggs as "n-3 FA enriched".Keywords: laying hens, pearl millet, flaxseed, natural pigment, flock performance, eggs, liver haemorrhage.
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Portilla, Enrique. "Improving egg production estimates for mackerel and horse mackerel using multi-stages eggs." Thesis, University of Strathclyde, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.425954.
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Ostergaard, Lindsey Eubank. "Automatic Detection and Characterization of Parasite Eggs by Image Processing." Thesis, Virginia Tech, 2013. http://hdl.handle.net/10919/51856.
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The accurate identification of parasites allows for the quick diagnosis and treatment of infections. Current state-of-the-art identification techniques require a trained technician to examine prepared specimens by microscope or other molecular methods. In an effort to automate the process and better facilitate the field identification of parasites, approaches are developed to utilize LabVIEW and MATLAB, which are commercially available image processing software packages, for parasite egg identification. The goal of this project is to investigate different image processing techniques and descriptors for the detection and characterization of the following parasite eggs: Ascaris lumbricoides, Taenia sp., and Paragonimus westermani. One manual approach and four automated approaches are used to locate the parasite eggs and gather parasite characterization data. The manual approach uses manual measurements of the parasite eggs within the digital images. The four automated approaches are LabVIEW Vision Assistant scripts, MATLAB separation code, MATLAB cross-section grayscale analysis, and MATLAB edge signature analysis. Forty-four separate measurements were analyzed through the four different approaches. Two types of statistical tests, single factor global Analysis of Variance (ANOVA) test and Multiple Comparison tests, are used to demonstrate that parasite eggs can be differentiated. Thirty-six of the measurements proved to be statistically significant in the differentiation of at least two of the parasite egg types. Of the thirty-six measurements, seven proved to be statistically significant in the differentiation of all three parasite egg types. These results have shown that it is feasible to develop an automated parasite egg detection and identification algorithm through image processing. The automated image processing techniques have proven successful at differentiating parasite eggs from background material. This initial research will be the foundation for future software structure, image processing techniques, and measurements that should be used for automated parasite egg detection.Master of Science
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Rosell, R. S. "Incubation of crustacean eggs in vitro." Thesis, University of Liverpool, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.377136.
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Bountra, Charanjit. "Physiology of fertilization of mammalian eggs." Thesis, University of Edinburgh, 1986. http://hdl.handle.net/1842/29937.
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Vargas, Galdos Dante Miguel Marcial. "Quantification of Soy Isoflavones in Commercial Eggs and Their Transfer from Poultry Feed into Eggs and Tissues." The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1236706764.
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Metcalf, Kelly A. "Defenses of the anamniotic egg: an injured conspecific egg cue causes early hatching of zebrafish (Danio rerio) eggs." Thesis, Boston University, 2003. https://hdl.handle.net/2144/27721.
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Boston University. University Professors Program Senior theses.PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you.
2031-01-02
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Edin, Malin. "Miljöpåverkan av äggproduktion : En jämförelse mellan Lilluns ägg och andra svenska äggproducenter." Thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-105590.
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The purpose of this report was to compare Lilluns egg production with other Swedish egg producers based on the flow of nutrients (nitrogen, phosphorus and potassium) in the egg production systems. The main focus in the report was the utilization rate of the forage and the excess of nutrients per kg egg. Additionally, the purpose was to identify the environmental impact from Lilluns egg production and compare the results with other egg producers. The inflow of nutrients associated with forage and poultry was compared with the nutrients that were exported from the production. All of the egg producers in this study had an excess of nutrients. The utilization rate of the forage for Lilluns egg was 47 %, the other egg producers in this study had an utilization rate between 45-50 %. The results showed that Lilluns egg had an excess of nitrogen of 0,04 kg/kg eggs. Lilluns egg also had an excess of phosphorus and potassium. The excess of phosphorus was 0,01 kg/kg eggs and 0,013 kg/kg eggs for potassium. The results showed that all the egg producers in this study had an excess of all the nutrients. The conclusion is that the egg production systems in this study have a similar utilization rate and the excess of nutrients per kg egg was also similar for all the egg producers.
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Golding, Berenice Jane. "Exploring the lived experiences of egg share donors : can women consent to share their eggs?" Thesis, University of Huddersfield, 2011. http://eprints.hud.ac.uk/id/eprint/10780/.
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The thesis explores the 'lived experiences' of egg share donors in the United Kingdom (UK) and in particular, has examined the extent to which they are able to consent to becoming an egg share donor. Specific emphasis was given to exploring the factors that motivated their decision-making in view of the criticism egg sharing schemes have met with since their emergence in the early 1990s. Egg sharing provides women who are themselves undergoing assisted reproduction treatment (ARTs) with the opportunity to share their eggs with up to two recipients(s). The donor‘s treatment costs are subsidised by the recipient(s). Thus some women are able to access cheaper, expeditious treatment. Advocates perceive the schemes as 'win-win'. Conversely, critics challenge egg sharing on both psychosocial and ethical grounds. The thesis conveys the accounts provided by a self-selected sample of seventeen women recruited via two online infertility support websites and a charitable organisation. Hermeneutic phenomenology and the voice-centered relational method (VCRM) of analysis were employed to assess women‘s motivations to donate and their ability to provide informed consent. Four asynchronous e-mail interviews and data collected from an online self-completion questionnaire were utilised in order to enable the experiences of egg share donors to be revealed. Drawing extensively upon philosophical, social anthropological, social philosophical, sociological, and social psychological literature, the study demonstrates the complexities associated with the decision to egg share within the context of the UK regulatory framework for ART provision. This includes existing empirical accounts of egg sharing. The thesis describes how it is one of the first to examine the experiences of egg share donors since the removal of donor anonymity in the UK in 2005. Significantly, it makes an original contribution to current understandings of the experiences, motivations, ability to consent, and post-treatment implications for egg share donors.
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Rajalakshmi, Sivaramakrishnan SatyanarayanDev. "Microwave pasteurization of shell eggs - a prelude." Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=18270.
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Eggs are potential hosts and carriers for pathogenic microbes like Salmonella enteritidis, due to their rich nutritive value. Heat pasteurization is a best solution for controlling these pathogens. Egg is used as a vital ingredient in several foods, especially for their exceptional functional properties. These properties mainly depend on the protein quality of the eggs and are severely affected when heated, due to protein denaturation. Thus a heat pasteurization technique with minimal changes to these proteins needs consideration. In this study, microwave heating has been considered for in-shell egg pasteurization. First of all, the effects of temperature (0-62oC) and frequency (200 MHz to 10 GHz) on the dielectric properties of egg components were investigated. Then, individual egg components as well as intact in-shell eggs were brought to pasteurization temperature in a laboratory scale microwave oven working at 2450 MHz using different power densities (0.75, 1 and 2 W/g) and heating curve was analyzed to determine the heating time required for different power levels. Laboratory trials on microwave heating of in-shell eggs indicated that the heating rates of both albumen and yolk were similar. Therefore, microwave heating appeared perfectly suited for in-shell egg pasteurization. Combination of egg geometry, dielectric properties, and size were the main factors responsible for the enhanced interior heating. Models for calculating the ε’ and ε” at a given frequency and temperature for shell egg components were also presented. Heat pasteurization affects the functional quality of the eggs. In the final part of this study, the heat induced changes with respect to physical properties like enthalpy of denaturation, viscosity, foam density, foam stability and turbidity and also the dielectric properties, brought about by microwave and water bath heating for in-shell pasteurization of the egg white were compared with that of the raw egg white. Microwave heateLes œufs peuvent être hôtes et porteurs de microbes pathogènes comme Salmonella enteritidis, étant donné leur haute valeur nutritive. La pasteurisation par échauffement est une excellente solution pour contrôler les éléments pathogènes. L’œuf est utilisé comme un ingrédient essentiel dans plusieurs préparations culinaires, spécialement pour ses propriétés fonctionnelles exceptionnelles. Ces propriétés dépendent principalement sur la qualité de la protéine présente dans l’œuf et sont sévèrement affectées lorsque chauffé, dénaturant ainsi la protéine. Ainsi, une technique de pasteurisation par échauffement ayant des effets minimaux sur la modification des protéines nécessite considération. Dans cette étude, l’échauffement par micro-onde fut considéré pour la pasteurisation de l’œuf à l’intérieur de sa coquille. Premièrement, les effets de la température (0-62 °C) et de la fréquence (200 MHz à 10 GHz) sur les propriétés diélectriques des parties de l’œuf furent investiguées. Ensuite, les composantes individuelles de l’œuf ainsi que des œufs complets avec leurs coquilles furent amenés à des températures de pasteurisation à l’aide d’un four micro-onde de laboratoire fonctionnant à 2450 MHz, utilisant différentes densités de puissance (0.75, 1 et 2 W/g). De plus, une courbe d’analyse thermique simple à l’échauffement fut analysée pour déterminer le temps d’échauffement nécessaire pour différents niveaux de puissance. Les essais de laboratoire sur l’échauffement par micro-onde sur les œufs avec coquille indiquèrent que les taux d’échauffement pour l’albumine et le jaune d’œuf étaient similaires. Donc, l’échauffement par micro-onde apparaît parfaitement appliqué pour la pasteurisation de l’œuf en coquille. La combinaison de la géométrie et dimensions de l’œuf et des propriétés diélectriques furent les principaux facteurs responsables favor
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Kim, Miran. "Eggs, incubation and hatching asynchrony in gulls." Thesis, University of Glasgow, 2008. http://theses.gla.ac.uk/526/.
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Birds can influence the embryonic development through incubation behaviour because avian embryos develop using parent’s body heat. Although previous studies assumed that incubation behaviour influences hatching patterns, few studies have studied the effect of incubation behaviour during egg-laying and early incubation on hatching patterns due to difficulties to determine onset of incubation during egg-laying. I investigated whether incubation behaviour during egg-laying and early incubation affects hatching patterns in gulls using measurements of mean nest attendance and daily change of nest attendance. Hatching patterns were influenced by incubation behaviour during egg-laying and early incubation behaviour. As parents spent more time in their nests, a brood hatched more synchronously and hatching success of the first-laid eggs increased when gulls laid relatively smaller first-laid eggs than other pairs. Within-clutch variation in eggshell colour related to daily change of incubation behaviour. This might relate to hormonal change during egg-laying. Increase of prolactin initiates incubation and accompanies decline of steroid hormones which relate to accumulation of eggshell pigments. Hatching patterns may also be influenced by accelerated development of last-laid eggs. When eggs were swapped to increase interval between eggs, last-laid eggs of herring gulls accelerated their development to catch up. Accelerated development may increase the survival of chicks from last-laid eggs by reducing the disadvantage of small size within a clutch. However, the costs of accelerated development seem to appear during the embryonic period. Hatching success was low in eggs with accelerated development, although there were no differences in growth rate and early nestling survival between accelerated and control last-laid eggs. Eggshell characteristics might be a factor affecting hatching patterns because they are related to embryonic metabolism. Hatching duration was not related to eggshell thickness and total functional area, but chicks which hatched from eggs with higher proportion of mammilllary cone contact area took longer to hatch. Chicks hatched from thicker eggshells showed longer “head plus bill” at hatching and grew faster in skeleton size after hatching. Diet during egg-laying and early incubation affected nest attendance. Females which consumed more marine food during egg formation had lower nest attendance during egg-laying and early incubation. This may relate to longer foraging time required to obtain marine food. In conclusion, this thesis suggests that parents can influence hatching patterns by altering incubation behaviour during egg-laying and early incubation and hatching patterns also may be affected by accelerated development of last-laid eggs, diet during egg-laying and early incubation and eggshell characteristics (proportion of mammillary cone contact area).
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Georgiou, Panayiotis Paulou. "Calcium-activated potassium-channels in mammalian eggs." Thesis, University of Edinburgh, 1985. http://hdl.handle.net/1842/29774.
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Powers, Elizabeth. "Breaking Eggs: A Collection of Short Fiction." Wittenberg University Honors Theses / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=wuhonors1148673690.
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Wilson, Charles Morgan. "Maternal thyroid hormones in Japanese quail eggs." Thesis, This resource online, 1996. http://scholar.lib.vt.edu/theses/available/etd-08222008-063658/.
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Asplen, Mark K., David E. Bellamy, and David N. Byrne. "Eggs of Eretmocerus eremicus, a Whitefly Parasitoid." College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2001. http://hdl.handle.net/10150/214910.
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Reproductive traits of wasp parasitoids are thought to be strong indicators of their success as biological control agents. Our study looks at the number of eggs produced by the whitefly parasitoid Eretmocerus eremicus. A series of experiments conducted on female wasps reared in the absence of whitefly hosts demonstrated that adult wasps emerge with a large (approximately 54) number of eggs that is retained during the first 2 days of adult life. Eggs are then absorbed steadily until at least 8 days following emergence. The results of this study suggest that the mode of egg production exhibited by E. eremicus is the type where they emerge with all, or nearly all, of their eggs, i.e. they do not produce additional eggs as they age. This information is significant when considering how they find their whitefly hosts and how effective they might be in controlling whitefly numbers.
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Köhncke, Arnulf. "When and where to lay your eggs?" Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2013. http://dx.doi.org/10.18452/16822.
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Bei der Eiablage müssen sich Pflanzen fressende Insekten wiederholt entscheiden, Eier auf Wirtspflanzen niedriger Qualität zu legen oder auf bessere Pflanzen zu warten. Diese Entscheidungen sind Fitness relevant, weil Larven sich je nach Wirt unterschiedlich entwickeln und weil Weibchen in diesem inter-temporären Optimierungsproblem sowohl zu wählerisch als auch nicht wählerisch genug sein und so nicht alle Eier bzw. Eier in zu geringer Qualität legen können. Meine Arbeit nutzt vier Ansätze um zu untersuchen, wie diese Entscheidungsprobleme entstehen und wie Weibchen diese strategisch lösen. Erstens benutze ich analytische Optimierungsmodelle um zu zeigen, dass ein evolutionärer Trade-Off zwischen Vermehrung und Überleben variierender evolutionär stabiler Ei- und Zeit-Limitierung führen kann, dass aber keiner dieser zwei Faktoren ignoriert werden darf. Zweitens stelle ich klar, dass in der Vergangenheit vorgeschlagene schematische Zeit- und Ei-Kosten der Eiablage sich nicht mit den wirklichen Selektionskräften auf die Ei-Anzahl decken und daher kein gutes Werkzeug zur Analyse von Eiablage-Strategien darstellen. Drittens zeige ich mit Optimierungs- und populationsgenetischen Modellen, dass räumliche Heterogenität in der Wirtsverfügbarkeit keine notwendige Bedingung für die Evolution von Generalismus ist, weil emergente Quellen-Senken Dynamiken die Anpassung der Insekten an marginale Habitate verhindern, wenn Migrationsraten nicht hoch sind. Viertens zeige ich an Agenten basierte Simulationen zum Beispiel des Aurorafalters, Anthocharis cardamines, dass der phänologische Spezialismus der Larven dieser Art den Eiablage-Generalismus der Weibchen zur Folge hat. Insgesamt zeigen diese vier Ergebnisse, wie nützlich theoretische Ansätze zur Untersuchung spezifischer Szenarios der strategischen Eiablage sein können und machen deutlich, dass die Evolution von Generalismus leichter aus zeitlicher denn aus räumlicher Heterogenität folgt.Ovipositing phytophagous insects repeatedly face the decision problem of laying eggs on lower-quality host plants or waiting out for higher-quality ones. These choices carry fitness costs and benefits because larvae develop differentially on different hosts and because, in this inter-temporal optimization task, females may be too choosy and die before laying all eggs (i.e. become time-limited) or not be choosy enough and run out of eggs before their death (i.e. become egg-limited). This thesis employs four approaches to examine how oviposition decision problems arise and how they are strategically solved by female insects. First, I use analytical optimization models to show that a life-history trade-off between survival and reproduction can lead to varying evolutionarily stable levels of egg and time limitation, but that neither egg nor time limitation can be ignored in evolutionary analyses of oviposition. Second, I highlight that such schematic time and egg costs of oviposition as advocated in the past do not match the actual forces of natural selection on egg number as partitioned between egg and time limitation and therefore represent a less useful practice to analyze oviposition strategies. Third, I use optimality and population genetic models to show that spatial heterogeneity in host availability is not a sufficient condition for the evolution of generalism because emergent source-sink dynamics preclude adaptation of insects to marginal habitats unless migration rates are high. Fourth, I employ individual-based simulations built around the case study of the orange tip butterfly, Anthocharis cardamines, to show that this species’ larvae’s phenological specialism may drive the adult females’ oviposition generalism. All these findings show the usefulness of theoretical approaches to examine specific questions of strategic oviposition. Moreover, they demonstrate that evolution of generalism more likely results from resource unpredictability in time than in space.
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Van, Schalkwyk Salmon Jacobus. "Improvement of fertility and hatchability of artificially incubated ostrich eggs in the little Karoo." Thesis, Rhodes University, 1998. http://hdl.handle.net/10962/d1005399.
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Ostriches are an important commercial species in South Africa and are becoming increasingly so in other parts of the world. Fertility and hatchability of artificially incubated ostrich eggs, however, is generally regarded as low compared to other poultry species and to ostriches in the wild. Investigation into specific farming practices at present indicated scope for an overall improvement in productivity through a sound breeding strategy. This thesis investigated factors that affect egg production, fertility, and hatchability of artificially incubated eggs in the Little Karoo region of South Africa. Specific breeding pair combinations accounted for the major variations in egg weight, hatchability, chick production and offspring weight at slaughter age. An appreciable proportion of variation in reproductive traits was attributable to the repeatable nature of breeding pair performance from year to year, even from first breeding attempts, suggesting that selection of good breeding stock can be made from an early age. Artificially incubated eggs showed improved hatchability when eggs were collected two to three hours after lay rather than the following morning. Storing position of eggs did not significantly effect hatchability when eggs were stored for a maximum of one week. The critical zero temperature for ostrich eggs, below which no embryonical development takes place, was found to be ± 25°C and cooling eggs to temperatures below 20°C for complete cessation of embryonic development during storage resulted in better hatchabilities compared to eggs stored at 25°C room temperature. Hatchability decreased when incubator temperatures were raised from 36 to 37.3°C. Large temperature fluctuations and gradients, which encompass detrimental temperatures, persist within forced draught wooden incubators of the type most commonly in use in the Little Karoo region. The highest temperatures occurred at the top of these incubators and will consequently have a negative impact on hatchability. The ontogeny of ostrich egg metabolism showed an exponential increase during the first 70% of incubation followed by a decline to 75% of the peak value between days 31 and 38 of incubation. From peak levels of embryonic development it was calculated that single stage incubators needs an airflow of 54.4 1/egg.hour to maintain oxygen levels just below 21% and carbon dioxide levels below 0.5%. Lower embryonic mortalities were observed when eggs were turned twenty-four times/day in an electronic incubator compared to hand turning twice a day. Eggs rotated through increasing angles between 60 and 90° resulted in a linear improvement in hatchability. In incubators where turning angles were fixed at 60°, lower hatchabilities were overcome by incubating eggs for 2 - 3 weeks in a horizontal position before placing them vertically. No specific farming practice could be singled out as the main cause of low fertility or hatchability but rather a combination of certain practices applied wrongly.
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Ganeco, Aline Giampietro [UNESP]. "Qualidade de ovos embalados com atmosfera modificada e armazenados em temperatura ambiente." Universidade Estadual Paulista (UNESP), 2012. http://hdl.handle.net/11449/96509.
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O estudo avaliou as características físicas, químicas e microbiológicas de ovos armazenados com atmosfera modificada em temperatura ambiente. Foram utilizados 1224 ovos comerciais e embalados em estojos de plástico de doze ovos, envoltos em sacos plásticos. Os ovos acondicionados à vácuo, à vácuo com sequestradores de gás oxigênio, à vácuo com sequestradores de gás oxigênio e sequestradores de gás carbônico e à vácuo com sequestradores de gás oxigênio e gerador de gás carbônico, submetidos a 7, 14, 21 e 28 dias de armazenamento, sob temperatura ambiente. Foi utilizado um delineamento inteiramente casualizado em esquema fatorial 4x4+1 com 3 repetições de 4 ovos cada. As características avaliadas foram: manutenção de peso durante armazenamento, unidade Haugh, índice gema, coloração da gema, atividade de água, pH da gema e do albúmen e o teste de Substâncias Reativas ao Ácido Tiobarbitúrico (TBARs). As embalagens com atmosfera modificada mantiveram os pesos dos ovos por um período de 28 dias e a com vácuo com sequestrante de O2 e geradores de CO2, foi a que apresentou melhores valores para a unidade Haugh e para o índice gema. Conclui-se que o vácuo provocou efeito positivo na qualidade interna dos ovos, e estes, quando armazenados em estojos que continham sequestrador de gás oxigênio (O2) e gerador de gás carbônico (CO2) preservaram ainda mais suas características internas. Foram quantificados também bolores e leveduras, cujos resultados foram transformados em número de UFC por ovo para Log 10. As embalagens que continham saches sequestrantes de gás oxigênio e as com saches sequestrantes de gás oxigênio e gás carbônico, mantiveram as características de ovos frescos na população de bolores e leveduras até aos sete dias de armazenamento em temperatura ambiente
The study evaluated the physical, chemical and microbiological characteristics of eggs stored at different vacuum conditions and ambient temperature. Were used 1224 commercial laying hens eggs and were packed in plastic cases of twelve eggs and each envolved in plastic bags (types of vacuum packaging: case; hijacker case with oxygen gas (O2); hijacker case with oxygen gas (O2) and carbon dioxide (CO2); case with hijacker oxygen gas (O2) and generates carbon dioxide (CO2)) and subjected to 7, 14, 21 and 28 days of storage at room temperature. Were used a completely randomized factorial 4x4 +1 (types of packaging and storage periods + control - fresh eggs), with three repetitions of four eggs each. These characteristics were: maintenance of weight during storage, Haugh unit, yolk index, yolk color, water activity, pH of yolk and albumen and testing of Thiobarbituric Acid Reactive Substances. The atmosphere modified packaging keeps the weights of the eggs for a period of 28 days and the vacuum scavenger of O2 and CO2 generators, showed the best values for Haugh unit and yolk index. Analysis and quantification of molds and yeasts, whose results were transferred in the number of CFU per egg molds, yeasts and Log 10. Concluded that the vacuum caused positive effect on internal egg quality, and these, when stored in kits containing kidnapper of oxygen gas (O2) and generates carbon dioxide (CO2) preserved even its internal characteristics. The packaging sachets containing sequestrants with oxygen gas and oxygen gas sachets and sequestering carbon dioxide, provided eggs with characteristic patterns of fresh eggs to seven days of storage at room temperature
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Khan, Sultan Mahmood. "The relationship of egg-yolk cholesterol to hepatic HMG CoA reductase, diet and cholesterol in the domestic laying hen." Thesis, University of Wolverhampton, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.259585.
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Tong, Qin. "Optimising incubation of broiler eggs using external stimuli." Thesis, Royal Veterinary College (University of London), 2015. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.701661.
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Rajalakshmi, Sivaramakrishnan SatyanarayanDev. "Microwave pasteurization of shell eggs-a comprehensive study." Thesis, McGill University, 2010. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=95086.
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Due to their rich nutritive value, eggs are potential hosts and carriers of pathogenic microbes like Salmonella enteritidis. Heat pasteurization is the best solution for controlling these pathogens, but affects the egg's vital functional properties due to protein denaturation. Therefore, microwave heating was considered for in-shell egg pasteurization. Based on a few laboratory trials, finite difference time domain (FDTD) and finite element models (FEM) were developed to simulate the electric field and power distribution in the egg components (egg white and yolk), taking into consideration the complex shape, dielectric properties and heterogeneous composition of the in-shell egg. Using the simulation results, process optimization was carried out to determine the most effective procedure and design for the process. Laboratory-scale experimental trials were conducted to test the validity and effectiveness of the optimized parameters. Operations under the optimal parameters set forth were found to be very efficient in terms of heating time and uniformity. Based on the optimal parameters obtained by simulations, a slotted waveguide applicator for heating shell eggs was designed and built. The applicator consisted of a standard waveguide with an array of SParabolic slots. The issue of non-uniformity in microwave heating was overcome by optimizing the power density used for the process and by rotating the egg during the heating process. A power density of 1.5 W g-1 and an angular velocity of rad s-1 were found to be optimal. The applicator enhanced both penetration and focus, as well as providing the necessary temperature gradient from the egg yolk to the shell for pasteurization. The pasteurization process was validated by inoculating eggs with a microbial contaminant and pasteurizing them in the designed applicator. Heat-induced changes in the egg white's physical properties brought about by in-shell pasteurization by microwave or water bath heating of the eggLa grande valeur nutritive de l'uf le rend potentiellement susceptible de servir comme hôte et porteur de microbes pathogéniques tel Salmonella enteritidis. La pasteurisation par la chaleur est la meilleure solution au contrôle de ces pathogènes, mais, suite à une dénaturation des protéines, elle a un effet néfaste sur d'importantes propriétés fonctionnelles de l'uf. C'est pourquoi la possibilité d'une pasteurisation par réchauffement par micro-onde fut considérée pour les ufs en coquille. Fondé sur quelques épreuves en laboratoire, des modélisations par domaine de différence finie en temps et par éléments finis furent mise au point pour simuler la distribution du champ électrique et de la puissance dans différents constituants de l'uf (blanc et jaune d'uf), en tenant compte de la forme complexe, des propriétés diélectriques, et de la composition hétérogène d'un uf en coquille. Se basant sur les résultats de simulation, un procédé d'optimisation fut exécuté afin de déterminer le procédé et la conception les plus efficaces pour ces fins. Des essais expérimentaux à l'échelle du laboratoire visèrent à évaluer la validité et l'efficacité des paramètres optimisés. Le procédé opérant sous les paramètres optimisés énoncés se montra plus efficace en termes de la durée de mise en température et de son uniformité, que le procédé de pasteurisation à l'eau chaude. Ces paramètres optimaux, ayant leur origine dans des simulations, dirigèrent le design d'un applicateur équipé d'un guide d'ondes à fentes, servant au réchauffement d'ufs en coquille. Cet applicateur consiste en un guide d'ondes conventionnel avec une série de fentes paraboliques en forme de S. Les difficultés liées au manque d'uniformité du réchauffement par micro-ondes furent surmontées en optimisant la densité de puissance en place durant le procédé, et en tournant l'uf durant toute la période de chauffage. Une densité$
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Kannan, Shrikalaa. "Radio frequency heating of shell eggs-a prelude." Thesis, McGill University, 2012. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=106620.
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Owing to their rich nutritive value, eggs serve as potential hosts to pathogenic microbes like Salmonella enteritidis. Administering heat treatments is the best solution for controlling these pathogens. However, heating affects the quality of the egg due to denaturation of proteins. Therefore a technique which causes minimal changes to the functional properties of the egg protein needs consideration.In this study, the suitability of Radio frequency (RF) treatments of eggs is evaluated for effectiveness in terms of reducing/eliminating the microbial load. Finite difference time domains (FDTD) and Finite element models (FEM) were developed based on preliminary laboratory trials to simulate the electric field and temperature distribution in the egg components keeping in mind the dielectric properties, shape and composition of in-shell eggs.Laboratory scale experiments were conducted to determine the dielectric properties of individual egg components followed by an investigation of the heating rates of individual egg components as well as intact in-shell eggs at different electric field strengths, where the electrode voltages are 2.5 kV, 3.5 kV and 4.25 kV with 60 mm spacing between the electrodes. The heating trends were then analyzed to obtain the time required to attain the targeted temperature. Models for calculating the dielectric parameters were presented.As heat treatments invariably affect the functional properties of eggs the heat induced changes with respect to properties like foam stability, foam density, viscosity and turbidity were studied and compared with the physical properties of raw eggs. RF treated eggs showed minimal changes at lower power levels. However the change in properties was more pronounced at higher power levels. The coagulation taking place within the eggs at higher power levels with a view to assessing the quality of heat treated eggs was studied by means of hyperspectral imaging (400-1700 nm).The heat treatment process was validated by inoculating egg with a microbial contaminant and treating them in an RF applicator. The results indicated that RF heating may possibly serve as a way to pasteurize the eggs provided the process is improved and optimized to reach the required pasteurization temperature with minimum damage to the functional properties of the egg.En raison de leur riche valeur nutritive, les œufs frais peuvent potentiellement être contaminés par des microorganismes pathogènes comme la Salmonella enteritidis. Il est possible de contrôler les pathogènes alimentaires par l'utilisation judicieuses de traitements thermiques. Cependant, les traitements thermiques conventionnels causent la dénaturation totale ou partielle des protéines présentent dans le blanc et le jaune d'oeuf. Par conséquent, une technique qui permettrait de contrôler la contamination dans les œufs frais tout en maintenant les propriétés fonctionnelles des protéines de l'œuf doit être examinée.Dans cette étude, l'adéquation de l'énergie des fréquences radios (RF) à 27 MHz pour le traitement thermique des œufs frais a été est évaluée. Des modèles en différences finies à dimension temporelle (FDTD) et des modèles d'éléments finis (FEM) ont été développés et utilisés pour simuler le champ électrique et pour prédire la distribution de la température dans les œufs frais en coquille et cela, en tenant compte des propriétés diélectriques, de la géométrie et la composition.Les propriétés diélectriques des composants de l'œuf ont été mesurées en tenant compte de leur dépendance à la température. Par la suite, des essais en laboratoire ont été effectués pour déterminer les taux de chauffage des composants exposés à des niveaux de puissance de 2,5 3,5 et 4,25 kV. Les tendances de chauffage diélectrique ont été analysées et les temps requis pour atteindre la température cible ont été déterminés. Les modèles de prédiction des paramètres diélectriques ont aussi été développés.Les effets des traitements thermiques sur les propriétés fonctionnelles des composants des oeufs ont été étudiés. Les paramètres retenus étaient : la stabilité et la densité de la mousse, la viscosité et la turbidité des blancs d'œufs. Les résultats on indiqués que propriétés fonctionnelles des œufs traités aux niveaux de puissance de 2,5 et 3,5 kV étaient presque identiques à celles des œufs frais non-traités. Cependant, les changements observés étaient plus prononcés 4,25 kV. L'imagerie hyperspectrale (400 à 1 700 nm) a été utilisée pour déceler la coagulation du blanc d'œuf après le traitement thermique des œufs en coquille.Le processus de traitement thermique a été validé par l'inoculation d'œufs frais avec une souche non-pathogénique de E. Coli. Par la suite, les œufs inoculés ont été traités thermiquement à l'aide du chauffage RF. Les résultats ont indiqué que le chauffage RF à 27 MHz était une méthode qui offrait un bon potentiel pour pasteuriser les œufs frais en coquille. D'autres études seront nécessaires pour optimiser la distribution de l'énergie RF et minimiser ses effets sur les propriétés fonctionnelles du blanc d'œuf.
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Lu, Junren. "Separation of proteins from Chicken Eggs using ultrafiltration." Thesis, University of Oxford, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.509984.
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Chebotareva, Tatiana Nikolayevna. "Molecular mechanisms of spontaneous activation in rat eggs." Thesis, University of Edinburgh, 2012. http://hdl.handle.net/1842/17283.
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The aim of this research was to identify the molecular mechanisms that promote spontaneous activation in rat eggs after their recovery from the oviduct. Typically, mammalian eggs await fertilisation arrested at the second metaphase II of meiosis. However, ovulated rat eggs spontaneously enter anaphase II when exposed to in vitro culture. After extrusion of the second polar body, these spontaneously activated eggs do not proceed to interphase but become arrested at metaphase III stage with chromatids scattered in the egg cytoplasm. This instability may be one factor that has made it more difficult to establish reliable protocols for somatic cell nuclear transfer in rats. The triggers of spontaneous activation and signalling pathways leading to the metaphase III progression are largely unknown. Analyses of signalling pathways that are involved in the regulation of final stages of meiosis during fertilisation revealed several anomalies that were associated with spontaneous activation and the transition from metaphase II to metaphase III. Metaphase II arrested eggs usually exhibit an increased level of maturation promoting factor (MPF) activity. Spontaneous activation in rat eggs was associated with a drop in MPF activity at the time of the second polar body extrusion. MPF is composed of a catalytic subunit, CDK1, and a regulatory subunit, cyclin B1. Interestingly, the level of cyclin B1 was stable throughout spontaneous activation. Post-translational modifications of CDK1 can influence MPF activity: whereas no inhibitory phosphorylation on Tyr15 of CDK1 was found; a decrease in activating Thr161 phosphorylation of CDK1 was associated with the time of the second polar body extrusion, and hence could contribute to the transient MPF inactivation. MAPK (p42/p44) activity has been shown to decrease during egg activation in fertilisation. By contrast, during spontaneous activation, MAPK (p42/p44) remained active and thus resembled the profile usually found between two meiotic divisions (metaphase I to metaphase II). Securin, a protein which prevents premature chromatid separation, was degraded in eggs going through spontaneous activation. Cytostatic factor (CSF) is a biochemical activity, which enables stable metaphase II arrest in ovulated eggs of vertebrates. Recently, the endogenous meiotic inhibitor 2, EMI2, was confirmed as the major component of CSF. For egg activation to occur, the CSF must be destroyed. At the beginning of egg activation, Ca2+/calmodulin kinase (CaMKII) promotes posttranslational modifications of EMI2, leading to its degradation. In the rat, inhibition of CaMKII activity stably prevented the onset of spontaneous activation in a subset of metaphase II eggs. However, no degradation of EMI2 protein was found at the start of abortive metaphase II exit. This finding revealed that one of the central elements of the CSF pathway, EMI2, could be preserved in the rat eggs going through spontaneous activation. In order to study the mechanisms regulating EMI2 stability in rat oocyte maturation and spontaneous activation, functional analysis of ectopically expressed synthetic mRNA was performed. The mechanism enabling EMI2 degradation became active 12 hours after the start of oocyte maturation. The C-terminal fragment of EMI2, known to be non-degradable in Xenopus oocyte maturation, was significantly more stable than the full-length counterpart in matured rat eggs but not during oocyte maturation. Interestingly, C-terminal EMI2 became degraded in parthenogenetic rat embryos. This indicated that additional not previously reported mechanisms responsible for EMI2 degradation might exist in the rat. The microinjection of metaphase II rat eggs with the C-terminal fragment of EMI2 or IVT full-length EMI2 protein had little effect on the progression of spontaneous activation. Taken together, these observations suggest that abortive spontaneous activation in rat eggs was a result of incomplete engagement of signalling pathways normally triggered in fertilisation or parthenogenetic activation. Activation of CaMKII initiated pathways that allowed anaphase entry and chromatid segregation. At the same time, not all pathways normally triggered during fertilisation or parthenogenetic activation were fully engaged, possibly due to the presence of non-degraded component of CSF. Abortive incomplete activation results in the re-establishment of high level of MPF activity in metaphase III eggs. Early prevention of CaMKII activation, perhaps by blocking [Ca2+ i] signalling, may provide a means of holding ovulated eggs at metaphase II prior to enucleation and somatic cell nuclear transfer.
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Kan, Cornelius Adriaan. "Residues of veterinary drugs in eggs and possible explanations for their distribution between egg white and yolk." [S.l.] : [s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=969173644.
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Ganeco, Aline Giampietro. "Qualidade de ovos embalados com atmosfera modificada e armazenados em temperatura ambiente /." Jaboticabal : [s.n.], 2012. http://hdl.handle.net/11449/96509.
Full textAbstract:
Orientador: Hirasilva BorbaBanca: Maria Regina Barbieri de Carvalho
Banca: Marcel Manente Boiago
Resumo: O estudo avaliou as características físicas, químicas e microbiológicas de ovos armazenados com atmosfera modificada em temperatura ambiente. Foram utilizados 1224 ovos comerciais e embalados em estojos de plástico de doze ovos, envoltos em sacos plásticos. Os ovos acondicionados à vácuo, à vácuo com sequestradores de gás oxigênio, à vácuo com sequestradores de gás oxigênio e sequestradores de gás carbônico e à vácuo com sequestradores de gás oxigênio e gerador de gás carbônico, submetidos a 7, 14, 21 e 28 dias de armazenamento, sob temperatura ambiente. Foi utilizado um delineamento inteiramente casualizado em esquema fatorial 4x4+1 com 3 repetições de 4 ovos cada. As características avaliadas foram: manutenção de peso durante armazenamento, unidade Haugh, índice gema, coloração da gema, atividade de água, pH da gema e do albúmen e o teste de Substâncias Reativas ao Ácido Tiobarbitúrico (TBARs). As embalagens com atmosfera modificada mantiveram os pesos dos ovos por um período de 28 dias e a com vácuo com sequestrante de O2 e geradores de CO2, foi a que apresentou melhores valores para a unidade Haugh e para o índice gema. Conclui-se que o vácuo provocou efeito positivo na qualidade interna dos ovos, e estes, quando armazenados em estojos que continham sequestrador de gás oxigênio (O2) e gerador de gás carbônico (CO2) preservaram ainda mais suas características internas. Foram quantificados também bolores e leveduras, cujos resultados foram transformados em número de UFC por ovo para Log 10. As embalagens que continham saches sequestrantes de gás oxigênio e as com saches sequestrantes de gás oxigênio e gás carbônico, mantiveram as características de ovos frescos na população de bolores e leveduras até aos sete dias de armazenamento em temperatura ambiente
Abstract: The study evaluated the physical, chemical and microbiological characteristics of eggs stored at different vacuum conditions and ambient temperature. Were used 1224 commercial laying hens eggs and were packed in plastic cases of twelve eggs and each envolved in plastic bags (types of vacuum packaging: case; hijacker case with oxygen gas (O2); hijacker case with oxygen gas (O2) and carbon dioxide (CO2); case with hijacker oxygen gas (O2) and generates carbon dioxide (CO2)) and subjected to 7, 14, 21 and 28 days of storage at room temperature. Were used a completely randomized factorial 4x4 +1 (types of packaging and storage periods + control - fresh eggs), with three repetitions of four eggs each. These characteristics were: maintenance of weight during storage, Haugh unit, yolk index, yolk color, water activity, pH of yolk and albumen and testing of Thiobarbituric Acid Reactive Substances. The atmosphere modified packaging keeps the weights of the eggs for a period of 28 days and the vacuum scavenger of O2 and CO2 generators, showed the best values for Haugh unit and yolk index. Analysis and quantification of molds and yeasts, whose results were transferred in the number of CFU per egg molds, yeasts and Log 10. Concluded that the vacuum caused positive effect on internal egg quality, and these, when stored in kits containing kidnapper of oxygen gas (O2) and generates carbon dioxide (CO2) preserved even its internal characteristics. The packaging sachets containing sequestrants with oxygen gas and oxygen gas sachets and sequestering carbon dioxide, provided eggs with characteristic patterns of fresh eggs to seven days of storage at room temperature
Mestre
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Wall, Helena. "Laying hens in furnished cages : use of facilities, exterior egg quality and bird health /." Uppsala : Department of Animal Nutrition and Management, Swedish Univ. of Agricultultural Sciences, 2003. http://epsilon.slu.se/a406.pdf.
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Harper, R. Given Thompson Charles F. "Hatching asynchrony in the house wren." Normal, Ill. Illinois State University, 1990. http://wwwlib.umi.com/cr/ilstu/fullcit?p9101114.
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Thesis (Ph. D.)--Illinois State University, 1990.Title from title page screen, viewed November 4, 2005. Dissertation Committee: Charles F. Thompson (chair), Dale E. Birkenholz, Angelo Capparella, Steven A. Juliano, Scott K. Sakaluk. Includes bibliographical references (leaves 61-67) and abstract. Also available in print.
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Hoffmann, Alexandra. "Incubation behavior of female western snowy plovers (Charadrius alexandrinus nivosus) on sandy beaches /." California : Humboldt State University, 2005. http://hdl.handle.net/2148/19.
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Maldjian, Andre. "The transfer of essential polyunsaturated fatty acids from the yolk to the tissues during avian embryonic development." Thesis, University of Glasgow, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.294170.
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Brind, Sophie Elizabeth. "The role of inositol 1,4,5-triphosphate receptors in mammalian oocytes and preimplantation embryos." Thesis, University College London (University of London), 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.368946.
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Mohanty, Basant Kumar. "A cytochemical study of the distribution of Na'+, K'+-ATPase and Ca'2'+-ATPase in Xenopus laevis oocytes." Thesis, University of Cambridge, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.281962.
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Stoddard, Mary Caswell. "The evolution of colour, pattern and structure in avian eggs." Thesis, University of Cambridge, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.610588.
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Bolin, Greta M. Burggren Warren W. "Incubation humidity as an environmental stressor on the osmoregulatory developmental program of the chicken, Gallus gallus domesticus." [Denton, Tex.] : University of North Texas, 2009. http://digital.library.unt.edu/permalink/meta-dc-11055.
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OSIR, ELLIE ONYANGO. "VITELLOGENIN OF THE TOBACCO HORNWORM, MANDUCA SEXTA: PROPERTIES AND ENDOCYTOTIC INCORPORATION INTO FOLLICLES." Diss., The University of Arizona, 1986. http://hdl.handle.net/10150/188160.
Full textAbstract:
Manduca sexta vitellogenin is a phosphoglycolipoprotein (Mᵣ ∼ 500,000) that contains two copies of the apoproteins (apovitellogenin-I, Mᵣ 180,000 and apovitellogenin-II Mᵣ 45,000), 13 percent lipids, 3 percent carbohydrates and 0.6 percent phosphorus. The two apoproteins are immunologically distinct and apovitellogenin-II is not completely accessible to the aqueous environment in the intact molecule. The carbohydrate moiety located on apovitellogenin-I has a high mannose structure (Man₉ GlcNAc₂). Follicle membranes bind ¹²⁵I-labeled vitellogenin with high affinity and specificity (K(D) ≃ 1.3 x 10⁻⁸ M). Total binding sites were estimated at 4 x 10¹⁴ sites/g of follicle membrane protein. The binding was sensitive to pH and calcium. Competition studies showed that binding of vitellogenin was blocked by vitellin and deglycosylated vitellogenin but not by lipophorin, microvitellogenin or apovitellogenin-II. These results suggest that the uptake of vitellogenin involves binding to specific receptors on follicle membranes and the carbohydrate moiety and apovitellogenin-II are not involved in the interaction with the receptors.
48
Rauf, Muhammad Muneeb. "Hatchability of Nile crocodile (Crocodylus niloticus) eggs : association with bacteria and fungi in incubation boxes and in eggs that failed to hatch." Diss., University of Pretoria, 2015. http://hdl.handle.net/2263/53309.
Full textAbstract:
The South African crocodile industry has the potential to produce Nile crocodile skins, which are
in high demand by the global fashion industry. The crocodile industry is an important economic
resource to South Africa and Southern Africa. The main purpose of rearing Nile crocodiles at
intensive production units is to produce viable hatchlings which will be grown to produce quality
skins. The production of sufficient hatchlings depends on high hatching percentage of clutches. It
has been observed that the hatching percentage varies among clutches. We do not know that
whether the poor hatching percentages are associated with the microbial load from the incubation
boxes or not. The aims of the study were to determine whether eggs in boxes that had more
aerobic bacterial colonies and more fungal colonies before they received vermiculite and eggs
are more prone to become lost from the pool potentially capable of yielding conceptuses
developing to term than eggs in boxes that had fewer colonies before they received vermiculite
and eggs, and whether there are species of aerobic bacteria, anaerobic bacteria and fungi that are
present in unhatched eggs from clutches with low hatching percentage but not in clutches with
high hatching percentage without the converse being true.
At the time of hatching the farm personnel classify hatchlings or unhatched eggs into different
categories e.g. hatchling survived, culled, foetus died in the shell, hatchling died, unfertilised
egg, banded (the foetus died long before hatching), or rotten egg (putrefaction rendering the
fertilisation status unknown). We assumed that banded or rotten eggs are more likely to have lost conceptuses due to the microbial load that was present in the incubation boxes before they were
loaded with vermiculite and eggs than the other classes of eggs. A response variable
Perhapsloststatus was therefore created. For each egg that was either classified as Banded or
Rotten Perhapsloststatus was assigned the value of one. For each egg belonging to other
categories Perhapsloststatus was assigned the value of zero. Eggs classified as unfertilised were
excluded from Perhapsloststatus.
The microbial load of aerobic bacteria and fungi from the incubation boxes before they were
loaded with vermiculite and eggs was measured as colony forming units (CFU). The independent
variable of interest was Count category (a categorical variable of aerobic bacteria and fungi
colony counts), which was compiled as follows:
0 = Counts zero to below the 25th percentile, 1 = Counts from the 25th percentile to below the
50th percentile, 2 = Counts ranging the 50th percentile to below the 75th percentile, 3 = Counts
from the 75th percentile to the maximum that was countable and 4 = Too numerous to count.
Sterile swabs were used to collect samples from unhatched eggs for isolation and identification
of aerobic bacteria, anaerobic bacteria and fungi from the 10 boxes with the lowest and highest
hatching percentages, respectively.
We used a population-averaged mixed-effect logistic regression model to determine the effect of
Count category on Perhapsloststatus.
The odds for eggs being banded or rotten (Perhapsloststatus = 1) in boxes with too numerous to
count aerobic bacterial colonies (Count category 4) tended to be higher than for eggs in boxes
with colony counts between zero and the 25% percentile (Count category 0) (P = 0.06). The odds of eggs being banded or rotten (Perhapsloststatus = 1) in boxes with fungal colony counts falling
in any count categories 1 to 4 were the same as the odds of eggs being banded or rotten in boxes
with fungal colony counts falling in Count category 0.
The variety and frequency of species of aerobic bacteria, anaerobic bacteria and fungi from
unhatched eggs of lowest hatching boxes and highest hatching boxes was almost the same. The
species isolated from unhatched eggs are more likely pertaining to contamination from the cloaca
of female crocodile or from the environment i.e. nesting material, personnel handling,
vermiculite, incubation box or the incubator environment, as most of the isolated species present
are normally present in soil, water, dust and also opportunistic pathogens in animals.
This observational study shows that there is a trend of association between the aerobic bacterial
load from the incubation boxes and the eggs in them to become either banded or rotten.Dissertation (MSc)--University of Pretoria, 2015.
tm2016
Production Animal Studies
MSc
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Du, Preez J. H. "The effect of different incubation temperatures on chick quality." Thesis, Link to the online version, 2007. http://hdl.handle.net/10019/1013.
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Davutluoglu, Ayten. "Detection Of Helminth Eggs And Protozoan Cysts In Wastewaters." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12605921/index.pdf.
Full textAbstract:
The withdrawal of water sources concluded the reuse of treated wastewaters, especially for non-potable purposes. Agricultural use of the reclaimed wastewaters is one of the reuse options.
However health considerations of the reuse of reclaimed wastewaters for public related purposes are underestimated, since wastewaters contain a variety of microbial pathogens, which may be transmitted to workers and consumers through the crops irrigated. Of these, parasitic eggs have a special place, as they are capable of surviving in the soil for months or even years, depending on environmental conditions.
There is insufficient accumulated information on the health related criteria for the reuse of treated wastewaters in Turkey.
The aim of this study was therefore to determine the helminthic eggs in raw sewage and in effluents of ASKi municipal wastewater treatment plant in Ankara. The study involved examining to decide whether these organisms exist in the wastewaters at all, and if so in what concentrations.
Modified Bailenger&rsquos method, which published in the &ldquo
WHO Laboratory Manual of Parasitological and Bacteriological Techniques&rdquo
and &ldquo
U.S.EPA ICR Microbial Laboratory Manual&rdquo
were used in developing the specific methods used in this study.