Mosquito surveillance is an integral part of understanding mosquito-borne disease, including and not limited to the La Crosse virus. The primary container-inhabiting Aedeni vectors include Aedes triseritatus, Aedes albopictus, and Aedes japonicus. To better understand the efficacy of gravid traps and oviposition traps as surveillance methods for these mosquitoes, field studies were conducted in three different habitat types. Ae. triseriatus, Ae. albopictus, Ae. japonicus, and Aedes aegypti eggs were described with the aid of color images and SEM. All eggs were broadly cigar shaped with Ae. triseriatus and Ae. japonicus eggs being dull or matte black while Ae. albopictus and Ae. aegypti eggs were shiny jet black. Ae. triseriatus eggs were larger, lighter in color, and have a rougher appearance when compared to Ae. japonicus. Ae. albopictus and Ae. aegypti can be differentiated by the distinct presence of a micropylar collars in Ae. aegypti. Ovitrap and gravid trap efficacy for the surveillance of Ae. triseriatus, Ae. albopictus, and Ae. japonicus were measured in three different habitats on two different sites. Both sites contained the same 2ha habitats with varying degrees of forest canopy disturbance. Ae. triseriatus was the most abundant mosquito on all sites. Ovitraps and gravid traps were efficient in collecting Ae. triseriatus, while ovitraps were not efficient in collecting Ae. japonicus and Ae. albopictus. / Master of Science in Life Sciences

Egg yolk contamination of egg whites continues to be a serious problem in the egg industry. The ability of egg whites to form stable and voluminous foams is greatly inhibited by accidental yolk contamination, even at extremely small levels. Experiments were conducted to determine if lipase can regenerate the functional properties of yolk-contaminated egg whites. Treatments included control, 0.2% yolk-contamination, and 0.2% yolk-contamination that was treated with lipase and colipase and heated at 37°C for 1 hour. Lipase from Mucor meihei and colipase from porcine pancreas were added to yolk-contaminated egg white samples to target and hydrolyze the triglycerides from egg yolk. Enzymatic hydrolysis was confirmed using thin-layer chromatography. Treatment of yolk-contaminated samples with lipase, colipase and heat yielded a drastic improvement in a number of the functional properties, including the final foam volume, foam capacity, and foaming power. These functional properties showed complete restoration to control levels. However, foam stability and foam drainage levels were not statistically different from yolk-contaminated samples that had not been enzymatically treated. Enzyme treated yolk-contaminated egg whites were also tested in an angel food cake system. There were three treatments, including an uncontaminated control, a contaminated control, and a lipase and colipase treated yolk-contaminated sample. Comparison between treatments was performed by volume analysis. The enzyme treated yolk-contaminated egg whites performed similarly to uncontaminated control angel food cakes. / Master of Science

Thesis (MA.Agricultural Management (Animal Production)) -- University of Limpopo, 2013 / The 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.

Thesis (M.A. Agricultural Management (Animal Production)) -- University of Limpopo, 2013 / The 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.

A genetic selection study to determine the effects on egg hatchability and subsequent chick performance of Japanese quail (Coturnix japonica) eggs incubated at 100 F dry bulb temperature (Control, Line C) when compared to other eggs incubated at 102 F (Selected, Line S) was conducted over 10 consecutive generations. Eggs from a randomly mated population (designated as Generation 0) of Japanese quail maintained at the Oregon Agricultural Experiment Station were randomly allocated to two treatment groups (Lines C and S) and incubated at the different temperatures in separate but identical Jamesway 252 machines. On day 14 of incubation all eggs were transferred to a common hatcher (98.5 F). Using family-based selection, the chicks that hatched from the two lines were subsequently used as breeders (25 paired matings per line) and the resulting eggs from each line incubated at their respective temperatures for 10 consecutive generations. Following the 10th generation percent egg fertility and percent hatch of fertile eggs were greater in Line C vs. Line S (p<O.O3 and p<O.0001, respectively). Embryo development time was shortened in Line S by 24 hours and mean 4- or 5- week body weights were greater (p<0.001) in Line S. Ten-day post-hatch mortality increased greatly in Line S vs. Line C after generation 6 (p<0.001) and hen-day egg production decreased after generation 4 in Line S vs. Line C (p<0.0001). The results indicate that embryo development time can be reduced by high temperature incubation, but at the expense of reproductive traits such as egg production, fertility, and hatchability of fertile eggs. / Graduation date: 2005

Polybrominated flame retardants (BFRs), organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were analysed in eggs of various wild bird species from industrialised areas in South Africa. Eggs were collected during the 2008 – 2009 breeding season, homogenised and sent to the Norwegian School of Veterinary Science (NVH) for gas chromatography-mass spectrometry (GC-MS) analysis. The concentration, contamination profile, and risk assessment were conducted for each pollutant class, while effects of species-specific variation, feeding guild, and feeding habitat were investigated. Levels of BFRs ranged between 2.6 – 44 ng g-1 wet mass (wm). The predominant congeners were BDE-153, -154, - 183 and -47. Results indicated species, in close contact to humans, had higher levels of BFRs, even at lower trophic levels. Therefore, diet was not the primary route of exposure. High concentrations and the occurrence of nona-PBDE congeners and HBCD indicated exposure to current use BFRs. There were measurable levels of OCPs and PCBs in all eggs analysed. Median OCP concentration ranged from 4.2 – 623 ng g-1 wm. DDE was the predominant compound in all species with the exception of the Crowned Lapwing (Vanellus coronatus) where chlordanes were predominant. This may indicate a species-specific attribute in the metabolic efficiency or diet of the genus, since these findings have been reported elsewhere in literature. Congener profiles indicated historic sources of lindane and DDT, while low levels of p,p’-DDT in al species indicate long-range or atmospheric transport. Even though levels of p,p’-DDE were approaching toxicological thresholds, no eggshell thinning was evident. Concentrations of OCPs and PCBs showed an increase with increasing tophic level. PCB concentrations ranged between 0.9 – 296.4 ng g-1 wm. When studying the metabolic potential of PCBs, metabolic groups showed good agreement with the biodegradability of the individual congeners. Phenobarbital-type (PB-type) inducer PCBs were prevalent, indicating the predominance of less toxic PCB congeners. However, non-ortho PCBs were not analysed. These congeners aslo could impact on the toxic potential of PCBs in wild bird eggs. Principle component analysis (PCA) indicated that variances within datasets could be attributed to congener profiles within species as they were affected by exposure, diet, position in the food web, and association with human activities. Although the individual groups of organohalogens were below no observed effect levels (NOELs), negative effects could occur through interactions of various compounds with each other, as well as the unique exposure profiles of South African bird populations. To assess the dietary exposure of low-income human populations living close to large industries, the occurrence of organohalogens was investigated in backyard chicken eggs. Levels of dioxins in these eggs were above the European Union (EU) recommended limits, whereas BFRs and OCPs levels were below levels of concern. Nevertheless, areas where DDT is actively applied to dwellings for malaria control should be urgently investigated. The presence of measureable levels of all the compounds considered, indicate an environment seriously impacted by anthropogenic activity that in the long term could negatively affect both the environment and human health, if it has not already done so. / Thesis (Ph.D. (Environmental Science))--North-West University, Potchefstroom Campus, 2011.

Polybrominated flame retardants (BFRs), organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were analysed in eggs of various wild bird species from industrialised areas in South Africa. Eggs were collected during the 2008 – 2009 breeding season, homogenised and sent to the Norwegian School of Veterinary Science (NVH) for gas chromatography-mass spectrometry (GC-MS) analysis. The concentration, contamination profile, and risk assessment were conducted for each pollutant class, while effects of species-specific variation, feeding guild, and feeding habitat were investigated. Levels of BFRs ranged between 2.6 – 44 ng g-1 wet mass (wm). The predominant congeners were BDE-153, -154, - 183 and -47. Results indicated species, in close contact to humans, had higher levels of BFRs, even at lower trophic levels. Therefore, diet was not the primary route of exposure. High concentrations and the occurrence of nona-PBDE congeners and HBCD indicated exposure to current use BFRs. There were measurable levels of OCPs and PCBs in all eggs analysed. Median OCP concentration ranged from 4.2 – 623 ng g-1 wm. DDE was the predominant compound in all species with the exception of the Crowned Lapwing (Vanellus coronatus) where chlordanes were predominant. This may indicate a species-specific attribute in the metabolic efficiency or diet of the genus, since these findings have been reported elsewhere in literature. Congener profiles indicated historic sources of lindane and DDT, while low levels of p,p’-DDT in al species indicate long-range or atmospheric transport. Even though levels of p,p’-DDE were approaching toxicological thresholds, no eggshell thinning was evident. Concentrations of OCPs and PCBs showed an increase with increasing tophic level. PCB concentrations ranged between 0.9 – 296.4 ng g-1 wm. When studying the metabolic potential of PCBs, metabolic groups showed good agreement with the biodegradability of the individual congeners. Phenobarbital-type (PB-type) inducer PCBs were prevalent, indicating the predominance of less toxic PCB congeners. However, non-ortho PCBs were not analysed. These congeners aslo could impact on the toxic potential of PCBs in wild bird eggs. Principle component analysis (PCA) indicated that variances within datasets could be attributed to congener profiles within species as they were affected by exposure, diet, position in the food web, and association with human activities. Although the individual groups of organohalogens were below no observed effect levels (NOELs), negative effects could occur through interactions of various compounds with each other, as well as the unique exposure profiles of South African bird populations. To assess the dietary exposure of low-income human populations living close to large industries, the occurrence of organohalogens was investigated in backyard chicken eggs. Levels of dioxins in these eggs were above the European Union (EU) recommended limits, whereas BFRs and OCPs levels were below levels of concern. Nevertheless, areas where DDT is actively applied to dwellings for malaria control should be urgently investigated. The presence of measureable levels of all the compounds considered, indicate an environment seriously impacted by anthropogenic activity that in the long term could negatively affect both the environment and human health, if it has not already done so. / Thesis (Ph.D. (Environmental Science))--North-West University, Potchefstroom Campus, 2011.

Orientador: Edir Nepomuceno da Silva / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-05T13:16:01Z (GMT). No. of bitstreams: 1 Pinto_AndreaTroller_D.pdf: 1260936 bytes, checksum: df21a83a56a9b358c3745669a0ae4ab3 (MD5) Previous issue date: 2005 / Resumo: A salmonelose humana é epidêmica no mundo todo. O consumo de ovos in natura crus ou parcialmente cozidos está associado a esta ocorrência, principalmente quando possuem defeitos de casca e são submetidos a estocagem inadequada. Os trabalhos com contaminação experimental de ovos de galinha geralmente utilizam grandes inóculos e a imersão de ovos em culturas bacterianas puras. Este trabalho teve como objetivo utilizar metodologia de contaminação de ovos com casca íntegra ou com defeitos que se aproximam da realidade operacional de granjas e entrepostos de ovos a fim de avaliar alguns riscos de contaminação por Salmonella Enteritidis (SE) e Escherichia coli em ovos de consumo, a partir da simulação de condições reais como contaminação pós lavagem, lavagem manual, oscilação de temperatura em ovos submetidos a diferentes condições de armazenagem, bem como verificar indicadores de perda de qualidade como a perda de peso e mudanças de pH. Também foi verificado o comportamento destes dois microrganismos em albúmen e gema de ovos de galinha submetidos a duas temperaturas de armazenagem. Os microrganismos estudados tem sua viabilidade diminuida na superfície de ovos com casca íntegra ou com defeitos quando os mesmos são submetidos a temperatura de 30°C, enquanto que a 8°C eles permanecem viáveis na casca. A temperatura de 30°C é responsável pela tendência maior de invasão dos microrganismos no conteúdo interno de ovos de galinha. Foi possível verificar, também, que há uma maior perda de peso em ovos armazenados a 30°C, independentemente da qualidade da casca. O pH de albúmen e gema aumentou ao longo do tempo, independentemente da forma de armazenagem, entretanto a velocidade de alteração do pH do albúmen foi maior na temperatura mais alta / Abstract: Human salmonelosis is epidemic all over the world. Food containing raw and partially coocked eggs is associated with this occurrence. Mainly when they have shell defects and/or are submitted to inadequate storage. The researches with experimental hem eggs contamination use big innocua and dipping eggs into bacterial cultures. This research had as objective, by using egg shell contamination methodology, evaluate some risks of contamination by Salmonella Enteritidis (SE) and Escherichia coli in consumption eggs. It was done by simulation of real operacional system, in an egg grading plant, like post-washing and post-manual washing contamination, oscillation of storage temperature; and by submitting eggs under different temperatures, as well as verifying loss of quality as the loss of weight and changes of pH. Also, the behavior SE and E. coli was verified in albumen and yolk that were submitted by 8° and 30°C. The results were that SE and E. coli decresase their viability on the egg surface, in intact and in imperfect shells, when the eggs were stored by 30°C, while that 8°C they remain viable on the surface. By 30°C, the bacteria can penetrate more easily in the egg contens. It was possible to verify that thre are a bigger loss of weight in the eggs stored at 30°C, independently of the shell quality. The pH of the albumen and the yolk increased, independently of the storage temperature, however the speed of alteration of pH of albumen it was bigger in the highest temperature / Doutorado / Doutor em Tecnologia de Alimentos

Orientador: Luiz Antonio Rossi / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agricola / Made available in DSpace on 2018-08-12T17:09:32Z (GMT). No. of bitstreams: 1 Jacome_IanglioMarcioTravassosDuarte_D.pdf: 5116180 bytes, checksum: b74e5dd1ca4372ee12b5edd91dd3b490 (MD5) Previous issue date: 2009 / Resumo: O desenvolvimento genético das poedeiras produziu aves de postura comercial mais eficientes com menor peso corporal e baixo consumo de ração. Pela mesma razão, são necessárias novas práticas de manejo e adequação destas aves às novas instalações, cada vez mais automatizadas, com ambientes controlados e alojando com maior densidade. Em aves de postura é conhecida a função da luz elétrica nos programas de iluminação, aumentando o fotoperíodo e estimulando a produção de ovos. O objetivo da pesquisa foi avaliar o consumo de energia elétrica dentro de uma instalação avícola de postura, utilizando diferentes tecnologias de lâmpadas e sua influência na qualidade dos ovos de poedeiras comerciais. Utilizou-se duas tecnologias de iluminação, sendo uma a de lâmpadas com alta intensidade de descarga e a outra de filamento incandescente. Na tecnologia de alta intensidade de descarga, foram testadas as lâmpadas fluorescente compacta de 23W de vapor de sódio de 70W e vapor de mercúrio de 125W. Estas foram comparadas com as lâmpadas de filamento incandescente de 60W já utilizadas. Foram avaliados os índices ambientais, parâmetros zootécnicos, qualidade dos ovos e consumo de energia elétrica. A partir de diferentes níveis de altura com iluminância distinta (lux), considerando-se os quatro tipos de lâmpadas, foi realizada uma análise qualitativa do desempenho das aves. Através da análise de variância foi possível constatar diferenças significativas (P<O,05) entre os níveis de iluminância de acordo com as alturas de acondicionamento das aves, afetando a qualidade dos ovos, ocorrendo redução significativa no peso do ovo e seus componentes na medida em que aumentaram os níveis de luxo Não houve efeito de significância entre as tecnologias (P<O,05), porém houve redução de produção para aves expostas a lâmpada vapor de mercúrio de 125W. Observou-se um menor consumo de energia elétrica e uma menor interferência na qualidade dos ovos, no tratamento composto por lâmpadas fluorescentes compactas de 23W. / Abstract: The genetic development of the commercial layers 100 to more productive birds, with lesser corporal weight and low ration consumption. For this reason, the use of new rearing conditions with a high level of automatization, a better environmental control and a larger housing capacity, requires the development of new handling techniques, to provide a better adequacy of the birds to these installations. The light programs with electric light bulbs, for layers play an important role for the estimulum of eggs production as they increase the light period to which the birds are exposed. The objectives of this research were the analysis of the electric energy consumption in an egg production plant, using different lamps technologies, and the evaluation of The of influence these technologies in the quality of the laid eggs. Two different lighting technologies were tested, one of them was the high pressure discharge lamps and the other, incandescent filament light bulbs. Three types of discharge lamps were used during the treal23 W compact fluorescent lamps, 70 W sodium vapor lamps and 125 W mercury vapor, together with a 60 W incandescent bulbo The environmental indexes, productive parameters, eggs quality and energy consumption were evaluated. For different heights with distinct i11!minance levels (in lux) and considering the four different lamps, a qualitative analysis of the layers performance was carried out. According to anaIysis of variance, it was possible to detect significant differences (P> 0.05) among the iluminance levels to which the birds were reared. The quality of the eggs decreased as the lux levels increased. There was no significance effect among the lighting technologies (P > 0.05), although there was a production decrease for the birds that were exposed to the 125 W mercury vapor ilumination. A smaller energy consumption and interference on eggs quality were observed for the utilization of 23 W compact fluorescent lamps. / Doutorado / Construções Rurais e Ambiencia / Doutor em Engenharia Agrícola

This study was prompted by the need to remedy the situation that existed with respect to the poor status of our knowledge regarding the ichthyoplankton assemblage of the nearshore region along the south-east Cape coast of South Africa. The first chapter provides a brief introduction to the field of ichthyoplankton research and includes a summary of the status of research in southern Africa and an explanation of early life history terminology. The selection of all sample sites, times and strategies is also outlined. The study area along the south-east Cape coast with respect to its location, climate and physical oceanography is described in the second chapter, as is the gear used, bongo nets and an RMT1x6. A sampling protocol for the use of bongos from a small ski-boat, and the RMT from the research vessels, and for the handling and processing of samples was established. The selection of Middlebank as the main monthly sampling site within the Tsitsikamma National Park (TNP) was based on taxonomic diversity as well as logistical and safety constraints. The effect of mesh size and time of sampling with bongo nets on the catchability of ichthyoplankton was investigated in chapter three. Most data was accumulated during Sea Fisheries research cruises, with additional collections coming from the National Parks vessel. Although the differences were not significant, the 505 μ mesh nets captured larger larvae, with catches comprising higher percentages of flexion and postflexion larvae. Larval concentration and size were consistently greater in samples from periods of reduced light intensity, but significant differences were the exception. It was decided that sampling with 505 μ mesh nets during daylight would provide a representative sample of the available ichthyoplankton assemblage, while at the same time being the most practical and least time consuming with respect to handling, clogging and backflushing. In chapter four, the early life history stages of thiny of the seventy-five taxa sampled are described, reflecting the paucity of information which existed on the ichthyoplankton of the nearshore zone in the south-east Cape. These descriptions are seen as an important contribution towards any future research efforts in the region, but as many of these descriptions are based on few or single specimens, it is realised that the description of egg and larval stages will be an ongoing process. Based upon the data collected during this study, an ichthyoplankton species checklist was established in chapter five. Seventy-five taxa of fish larvae were identified to either family, genus or species level. A number of squid para-larvae were also encountered. Similarities and discrepancies with a previous survey in the region are presented. The temporal distribution of eggs and larvae between August 1993 and October 1996 was established, and the spatial distribution of ichthyoplankton along an offshore transect was determined between January 1995 and May 1996. Only 7 species from Middlebank and twelve from all stations combined displayed seasonal trends, with most of these being prevalent during winter months. Egg production, both over Middlebank and from all stations combined, appeared to be consistent, with no seasonal trends. Based upon the results from the offshore transect samples, it would appear that a single ichthyoplankton assemblage exists from Storms River out to fifteen nautical miles. Although a variety of statistical methods were applied to the data during this study, low egg and larval concentrations and a low sampling frequency meant that results had to be interpreted carefully. Chapter six describes the preliminary investigation into the vertical distribution of eggs and larvae. During two research cruises, discrete depth sampling using an RMT1x6 net was performed, with the majority of samples being accompanied by physical data provided by a CTD rosette sampler. No definite patterns could be seen as larval concentrations were low, and the short time scale did not allow for the identification of any diel migratory patterns. The relationship between total larvae and the physical environment was poor. The only possible relationship was that between plankton volume and total egg and total larval concentrations. The TNP may play an important role in the conservation of reef fish and the seeding of nearby fishing grounds through the export of pelagic eggs and larvae. Chapter seven describes a preliminary investigation into the dispersal potential of ichthyoplankton from the TNP. Based upon longshore currents determined from drogues, ADCP vectors and current meter readings, it was clear that if larvae were passive drifters, the potential for their dispersal from the TNP did exist. This pilot study showed that future work should concentrate not only on the oceanographic aspects, but on behavioural aspects of larvae which may enhance or retard dispersal. In the final discussion, it is emphasised that while this study went a long way to increasing our knowledge of the nearshore ichthyoplankton community, the true picture of the temporal and spatial dynamics of the species assemblage may only be revealed once more intensive sampling has been performed. The resolution of the early life history stages of the sparids and the identification of eggs to species level are seen as priorities for the near future. A complete species checklist for the TNP is provided based upon previous surveys (both on adult and larval fishes), this work and personal observations. A total of 171 species of fish from 70 families were identified, illustrating that the eggs and larvae of many species in the TNP have yet to be sampled. A brief description of the collaborative effort which is envisaged for the TNP over the next few years is provided.