Thesis (Ph. D.)--Swedish University of Agricultural Sciences, 2001. / Includes bibliographical references.

Thesis (Ph. D.)--University of North Texas, Aug., , 2009. / Title from title page display. Includes bibliographical references.

Thesis (Ph. D.)--University of North Texas, Dec., 2009. / Title from title page display. Includes bibliographical references.

Thesis (Ph. D.)--University of Adelaide, Dept. of Animal Science, 1998. / Corrigenda inserted behind title page. Copies of author's previously published articles inserted. Includes bibliographical references (leaves 193-210).

Thesis (Ph.D.) -- University of Western Sydney, 2000. / "A thesis submitted for the degree of Doctor of Philosophy at the University of Western Sydney, Macarthur, Faculty of Informatics, Science and Technology" Bibliography : leaves 172-188.

This study was conducted to determine the effect of egg weight on hatchability and chick hatch-weight of Cobb 500 broiler chickens. A total of 396 Cobb 500 hatchable eggs classified according to three different egg weight groups as small: (<49 g) medium: (50-59 g) and large: (60-69 g) were used in the experiment. A complete randomized design of three treatments with three replicates and each replicate having” 44 eggs was used for the experiment. Simultaneously a linear type equation was used to determine the relationship between egg size and responses in hatchability values and chick hatch-weight. Results indicated that large-sized eggs produced chicks with higher (P<0.05) hatch-weight than medium and small-sized eggs. However, no differences were detected with fertility rate percentage, hatchability percentage and percentage hatch of fertile. It was therefore concluded from the result of the present study that sorting of Cobb 500 broiler chicken breeder eggs by weight prior to incubation might be advantageous in producing uniform size Cobb 500 broiler chicken hatchlings to meet specific market demands with improved efficiency. / Agriculture and  Animal Health / M. Sc. (Agriculture)

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.

This study was conducted to determine the effect of egg weight on hatchability and chick hatch-weight of Cobb 500 broiler chickens. A total of 396 Cobb 500 hatchable eggs classified according to three different egg weight groups as small: (<49 g) medium: (50-59 g) and large: (60-69 g) were used in the experiment. A complete randomized design of three treatments with three replicates and each replicate having” 44 eggs was used for the experiment. Simultaneously a linear type equation was used to determine the relationship between egg size and responses in hatchability values and chick hatch-weight. Results indicated that large-sized eggs produced chicks with higher (P<0.05) hatch-weight than medium and small-sized eggs. However, no differences were detected with fertility rate percentage, hatchability percentage and percentage hatch of fertile. It was therefore concluded from the result of the present study that sorting of Cobb 500 broiler chicken breeder eggs by weight prior to incubation might be advantageous in producing uniform size Cobb 500 broiler chicken hatchlings to meet specific market demands with improved efficiency. / Agriculture and  Animal Health / M. Sc. (Agriculture)

Thesis (M. Tech.(Environmental Health)) -- Central University of Technology Free State, 2005 / In developing countries such as South Africa commercial chicken farmers produce the majority of eggs, approximately 5.8kg of eggs per capita per annum. Despite this, many people, especially in rural and marginal-urban areas, still consume eggs produced by backyard systems. Backyard systems are characterised by fragmented and small-scale production units that require minimal management and chickens are often unhoused or poorly housed. In most cases, eggs from backyard systems are laid in nests in poor hygienic condition. Eggs are a cheap, readily available and a good source of animal protein and are consumed by the majority of the people in the community, including the young, the old and people with HIV/AIDS. With little information available regarding the microbiological quality of eggs produced by backyard chickens in Southern Africa, the risks posed by these eggs to consumers are unknown. In this study the microbiological quality of eggs from randomly selected household near Hennenman keeping backyard chickens was determined. The study was done over three seasons which included the cold-dry (May-July), mild-dry (October- February) and the warm-wet (August-September) seasons. The following organisms were isolated: Salmonella spp., Pseudomonas spp., Staphylococcus spp., Escherichia coli and Total Coliforms. Staphylococcus spp. was further characterised to species level. Most of the species were of human origin, with the exception of only two species, S. hyicus and S. lentus, which have previously been associated with chickens. Furthermore, questionnaires were administered to the backyard chicken keepers to assess their knowledge regarding chicken keeping and nest hygiene, the proper method of egg collection and storage, and the preparation of eggs. The decrease of vitamins and Staphylococcus spp. occurring during different preparation methods (scrambling, frying and boiling) was also determined. The results obtained showed that the eggshells were more contaminated than the egg contents. This had been expected as the eggshell is more in contact with the external environment than the egg contents are. Faecal contaminants (Salmonella spp., Escherichia coli and Total Coliforms) were present in both the eggshell and the egg contents during all seasons and this could be attributed to the infrequent cleaning of chicken nests as ascertained from the questionnaires. From the vitamin analysis it was observed that backyard-produced eggs had lower concentrations of vitamins A and E compared to commercially-produced eggs. When determining the best preparation method, causing the most degradation of Staphylococcus spp., while on the other hand preserving vitamins, it was found that scrambling was the best method, followed by the frying and boiling methods respectively.