The objectives of this thesis were to investigate some physiological, cellular and molecular changes from genetic selection, flock age and egg storage on embryonic metabolism, cell viability and gene expression in poultry species. Embryonic heat production (EHP), the parameter used to evaluate metabolic status of two turkey genetic strains (Nicholas and Hybrid) and four flock ages (30 wk, 34 wk, 55 wk, 60 wk) were determined. The results showed that embryos of older flocks had higher EHP than all other flock ages. The higher metabolism can cause overheating in embryos from older flocks during the later part of incubation. The EHP values can assist incubator manufacturers and hatchery managers to manage incubation temperatures to increase embryo survival. The EHP was also determined in two Ross 308 broiler breeder egg storage durations (4 d and 14 d) to assess the impact of long-term egg storage on embryonic metabolism. The embryos from 4 d stored eggs had higher body weight and EHP than embryos from 14 d stored eggs. To investigate what could be the fundamental reasons for the metabolic differences, blastoderms from eggs in these egg storage treatments were isolated, dissociated into single cells, stained with fluorescent dyes and subjected to flow cytometry analysis to differentiate between viable (live), apoptotic and necrotic cell populations. Quantitative real time PCR analysis was then used to compare the expression of selected apoptotic genes (Bak, Bax, Bok, Bcl-2, Bcl-xL) in blastoderms and embryos from 6 d incubated eggs. While percentage of viable cells decreased significantly, an unregulated amount of apoptosis increased with egg storage duration (p < 0.0001). Expression of pro-apoptotic genes (Bak, Bax, and Bok) were up regulated as storage duration increased at the blastodermal level but all genes were down regulated after 6 d of incubation. This suggests that an increment in egg storage duration can cause activation of apoptotic cell death mechanisms at the blastodermal level, which can be one of the molecular mechanisms that led to the reduced daily embryonic growth and metabolism observed in 14 d stored eggs. The thesis suggests there are molecular and cellular implications of egg storage. / Animal Science
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:AEU.10048/1725 |
| Date | 06 1900 |
| Creators | Hamidu, Jacob Alhassan |
| Contributors | Guan, Leluo (Agricultural, Food and Nutritional Science), Barreda, Daniel (Agricultural, Food and Nutritional Science and Biological Science), Guan, Leluo (Agricultural, Food and Nutritional Science), Barreda, Daniel (Agricultural, Food and Nutritional Science and Biological Science), Fasenko, Gaylene (Animal and Range Science, New Mexico State University), Feddes, John (Agricultural, Food and Nutritional Science), Tierney, Keith (Biological Science), Mozdziak, Paul (Animal and Poultry Science, North Carolina State University) |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | 2386372 bytes, application/pdf |
| Relation | Hamidu, J. A., G. M. Fasenko, L. L. Guan, D. R. Barreda, and J. J. R. Feddes. (In press) Influence of parent flock age on embryonic metabolism in modern turkey strains. Accepted for publication in Poult. Sci., Hamidu, J. A., A. Rieger, G. M. Fasenko and D. R. Barreda. 2010. Dissociation of chicken blastoderm for examination of apoptosis and necrosis by flow cytometry. Poult. Sci. 89: 901-909., Hamidu, J. A., J. J. R. Feddes, C. A. Ouellette and G. M. Fasenko. 2010. The respiration of an avian embryo measured by an indirect calorimetric system. Canadian Biosystems Engineering 52:4-9., Fasenko, G. M. E. E. O’Dea Christopher, and J. A. Hamidu. 2009. Embryo metabolism. Aust. Poult. Sci. Symp. 99-105. |
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