Thesis (M.S.)--University of Delaware, 2009. / Principal faculty advisor: Calvin L. Keeler, Jr., Dept. of Animal & Food Sciences. Includes bibliographical references.

M.Sc. (Geography) / Republiek Voedsel (Edms) Bpk. was established in 1981 with the purpose of owning and operating KFC restaurants in South Africa and today successfully operates 40 KFC restaurants in Gauteng, the Free State, Northern Cape and North-West Province. This study endeavoured to create a model that could be used as an instrument to ensure that all possible variables influencing the selection of a site were considered when deciding where to build a KFC restaurant. The creation and use of an analogue data base containing the market variables, operational requirements and financial performance of all the Company's restaurants were fundamental to the success of the model. In general, the model should enable the researcher to identify under-utilized as well as non-utilized markets. Shortcomings in respect of existing restaurants and missed opportunities in the market area would be identified and exploited for the benefit of the market population and KFC/Republiek Voedsel. The specific purpose of this study was to test the validity of the proposed site selection model in the town of Edenvale, where the existing KFC is more than 10 years old. The market population characteristics, trade zone borders, market competition and traffic generators, all factors that influence the purchase pattern of the existing KFC customer base, were determined through a sample study.

Despite their beneficial effects, concerns have been raised about the role of antimicrobial growth promoters (AGP) in the emergence of antibiotic resistant bacteria. This study evaluated the effects of approved AGP on the emergence of antibiotic resistance in commensal E. coli and foodborne pathogen Salmonella. A survey of antibiotic resistance levels in commercial broiler chicken farms in the Fraser Valley (B.C.) and an experimental feeding trial were conducted from May 2004 to February 2005 and May to November 2005, respectively. The latter examined the effects of ten AGP formulations (bambermycin, penicillin, salinomycin, bacitracin, combination of salinomycin and bacitracin, chlortetracycline, virginiamycin 11ppm, virginiamycin 22ppm, monensin and narasin) on bird performance as well. Multiple antibiotic resistant commensal E. coli and Salmonella carrying virulence genes were found at commercial broiler chicken farms and therefore may serve as reservoirs for these genes. There was no significant difference between feed formulations on the phenotypic or genotypic characteristics of the isolates, except for tetracycline resistance gene tet(B). In the experimental feeding trial, broiler chickens were fed a diet including or excluding AGP. Birds were sampled prior to and weekly during feeding of the control and the AGPP containing diets. Although not detected on day 0, E. coli increased after day 7 to more than 9.9 log10 CFU/g in ceca. Multi-drug resistant E. coli were isolated from birds fed the ten AGP containing diets as well as the control diet. Except for penicillin, none of the AGP containing diets significantly improved bird performance compared to the control diet (P>0.05). Good management practices can significantly improve broiler chickens performance and decrease the mortality rate. / Land and Food Systems, Faculty of / Graduate

In 1957, strains 3 and 4, two highly selected but unrelated strains of Single Comb White Leghorn chickens from Agriculture Canada's Animal Research Station at Ottawa were crossed to establish the Agassiz strain (strain 6). Further selection was imposed on strain 6 for improvements in hen-housed egg production (HHEP) based on part-records to 273 days and maintenance of egg weight, fertility, hatchability and viability. Data from 1957 to 1963 were analysed utilizing the SAS programs. There were no significant improvements in performance for HHEP, but egg weight, fertility, hatchability and viability were maintained. The lack of response to selection for HHEP was probably due to the following reasons: 1) too many traits were considered in the selection program at the same time, 2) negative genetic correlations existed among the selected traits, 3) strict adherence to a selection scheme was not practiced, 4) most of the traits under selection had low heritabilities, 5) the duration of the study was not long enough, and 6) the population size of strain 6 may not have been large enough. There was a significant decrease in body weight at 365 days (-4.33 ± 0.48, p < 0.0009). This decrease may be because of selection within full-sibs for more refined birds with better conformation as parents of the next generation. There were significant decreases in egg specific gravity at 225 and 450 days, and in Haugh units at 225 days, although Haugh units were increasing when measured at 450 days. The mean h²s for HHEP was 0.45, and the mean h²s for egg production to 273 days was 0.20 and the mean h²d for the same trait was 0.33. The mean h²s and h²d estimates for egg weight at 225 days were 0.60 and 0.50, respectively. The mean h²s and h²d for age at sexual maturity were 0.22 and 0.33, respectively, and those for body weight at 365 days were 0.53 and 0.62, respectively. The mean h²s and h²d for egg specific gravity at 225 were 0.64 and 0.33, respectively while those for Haugh units at 225 days were 0.57 and 0.68, respectively. These estimates were consistent with those found in the literature. The sctual selection differentials showed that selection was positive for egg production, while those for egg weight at 225 days were zero, and those for body weight at 365 days showed that selection was in the downward direction on the sires. / Land and Food Systems, Faculty of / Graduate

Orientadores: Irenilza de Alencar Naas, Marta dos Santos Baracho / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agricola / Made available in DSpace on 2018-08-14T11:27:11Z (GMT). No. of bitstreams: 1 Menezes_AdrianaGomesde_M.pdf: 3659236 bytes, checksum: 9ed106bcdf2c0254a5318139cf5e3141 (MD5) Previous issue date: 2009 / Resumo: O presente trabalho propôs um estudo exploratório para determinar os pontos críticos de controle, gargalos e possíveis riscos do incubatório e da granja de produção de frango de corte. A pesquisa foi conduzida em um incubatório e em dois aviários na região do interior do Estado de São Paulo. O experimento foi conduzido nas seguintes salas do incubatório: sala de ovos, câmera fria, pré-aquecimento, incubadora e nascedouro. Os seguintes dados foram coletados no incubatório e nos aviários: dados de temperatura (T,?C) e umidade (UR,%), velocidade do ar (VA, m s-1), temperatura superficial do ovo e do pintinho (tS,?C), níveis de amônia (NH3) e luminosidade. Na avaliação dos aviários foi aplicado o questionário do manual de Boas Práticas de Produção de Frango de Corte, bem como entrevistas com os colaboradores/produtores e posterior aplicação da matriz de análise de risco para determinar os pontos críticos de controle. Após a coleta dos dados foi aplicado o Controle Estatístico do Processo (CEP), através da análise de Índice de Capacidade do Processo utilizando o software Minitab15®. Os pontos críticos identificados no incubatório e nas duas granjas analisadas foram a temperatura ambiente e umidade relativa. As categorias que se configuraram como pontos críticos de controle foram: cama de aviário, alimentação, água, higiene e saúde do trabalhador, manejo e biosseguridade, normas e legislações, instalações e planejamento das atividades. Pôde-se concluir que a análise dos PCCs associada às ferramentas de controle CEP, às diretrizes de boas práticas de produção e às demais literaturas consultadas, contribuíram para a garantia da segurança alimentar da produção avícola industrial, resultando em maior confiança na cadeia de produção. / Abstract: This research presents an exploratory study to determine the critical control points, bottlenecks and possible risks of the incubation process and farm production of broilers. The research was conducted in an incubatory and two aviaries in the state of São Paulo. The experiment was conducted in the following rooms of the incubatory: egg room, cold camera, pre-heating and hatchery. The following data were collected in the incubatory and in the aviaries: temperature (T?C), humidity (% RH), air velocity (AV m s-1), surface temperature of the egg and the chick (ST), ammonia levels and light intensity. In the assessment of the aviaries, the following tools were applied: the questionnaire from the Manual of Good Practices for Broiler Production, interviews with employees/producers and subsequent application of the matrix of risk analysis to determine the critical control points. After collection of data, the Statistical Process Control (SPC) was applied, through the analysis of the Process Capability Index PCI and PC, using the software Minitab15®. The critical points identified in the incubatory and in the two farms were T(ºC) and RH(%). The topics that were taken into consideration as critical control points were: poultry litter, food, water, hygiene and health of workers, husbandry and biosecurity, legislation, facilities and planning of activities. It was observed that the analysis of PCCs associated with statistical control tools, guidelines of good practices for production as well as information from existing literature, contributed to ensuring the food safety of the poultry production industry, resulting in higher levels of trust in the production chain. / Mestrado / Construções Rurais e Ambiencia / Mestre em Engenharia Agrícola

La crête neurale céphalique (CNC) est une structure pluripotente à l'origine de la totalité du squelette de la face et de la voûte crânienne.
L'absence de la CNC est associée à des malformations du cerveau antérieur et des défauts oculaires qui reproduisent les malformations congénitales humaines: microcéphalie, holoprosencéphalie, aniridie, chambre antérieure manquante, colobome congénital, désorganisation du cristallin, agénésie des
paupières,
strabisme précoce (Alward 2000, Creuzet 2009, Williams and Bohnsack 2015). Dans notre étude, l'augmentation hétérochronique de la signalisation Bmp7 au niveau de la plaque préchordale (PPC) a engendré une perturbation de la migration de la CNC associée à une fusion des deux champs oculaires en un seul œil cyclope. Cette cyclopie, contrairement aux études antérieures (Chiang et al. 1996, Golden et al. 1999) est précédée par une perturbation de la constriction apicale au niveau des vésicules optiques (VO) au stade Hamburger-Hamilton (HH) 12 et qui est responsable de l'invagination dorsale des VO et leur séparation du reste du tube neural. Au niveau moléculaire, nous avons enregistré une augmentation de la signalisation Wnt1 très tot après le traitement (2h) dans la CNC. Cette augmentation s'étend rostralement ce qui suggère que Wnt1 pourrait etre impliqué dans la perturbation du développement oculaire. Pour tester cette hypothèse, nous avons tenté des expériences de sauvetage par l'inactivation de la signalisation Wnt1 par ARN interférence. Nous avons observé une amélioration du phénotype mais les yeux sont restés morphologiquement en hypotélorisme, c'est-à-dire trop proches. Des coupes coronales au stade E8 (32-33HH) ont montré que les yeux sont synophtalmiques, deux yeux dans un seul orbite, et sont restés fusionnés au télencéphale. Au niveau moléculaire, nous avons observé aussi une diminution de l'expression de Wnt2b au niveau des VO chez l'embryon cyclope et que cette diminution persiste malgré le sauvetage par Wnt1. Pour comprendre cette signalisation, nous avons tenté une deuxième expérience de sauvetage avec ARN interférence contre Wnt1 et un vecteur plasmidique exprimant Wnt2b dans le tube neural et les VO respectivement. Vers E8 l'embryon ressemble au contrôle mais avec persistance de fusion entre les VO et le télencéphale. L'hybridation in situ a montré une diminution du niveau d'expression de Foxg1 à 12HH dans la partie dorsale des VO au niveau de la frontière entre la partie rostrale du diencéphale et le télencéphale (RD/T) dans les deux tentatives de sauvetage ce qui suggère que ce gène pourrait être impliqué dans la séparation rostrale des VO du télencéphale. / Cephalic neural crest (CNC) is a pluripotent structure giving rise to entire skeleton of the face and skull. Absence of CNC is associated with forebrain and eye defects that mimic human congénital malformations: microcephaly, holoprosencephaly, aniridia, missing anterior chamber, coloboma, congenital dislocation of the lens, agenesis of eyelid and early strabismus. (Alward 2000 Creuzet 2009, Williams and Bohnsack 2015). In our study, heterochronic increased Bmp7 signaling in the prechordal plate (Pcp), caused disruption of CNC migration associated with fusion of two optical fields into one cyclopic eye. This cyclopia, unlike previous studies (Chiang et al. 1996, Golden et al. 1999), is preceded by a disturbance of the apical constriction in optic vesicles at Hamburger-Hamilton (HH)12 stage witch is responsible for dorsal invagination of OVs and their separation from the rest of the neural tube. At the molecular level, we recorded an increase in Wnt1 expression very early after treatment (2h) in CNC and this increase extends rostrally suggesting that Wnt1 could be involved in the disturbance of eye development. To test this hypothesis, we attempted rescue experiments by inactivating Wnt1 signaling by RNA interference and we observed an improvement of the phenotype but the eyes remained morphologically in hypotelorism, too close,. At E8 (32-33HH) stage the eyes are remained fused to the forebrain and are synophtalmic, two eyes in a single orbit,. We also observed a decrease in Wnt2b expression in OV in the cyclopic embryo and that this decline persists despite Wnt1 rescue. To understand Wnt2b signaling, we attempted a second rescue experience with RNA interference against Wnt1 and a plasmid vector expressing Wnt2b in the CNC and OV respectively. Coronal sections at E8 stage resemble the control but with persistence of dorsal fusion between OVs and telencephalon. In situ hybridization showed a decrease in Foxg1 expression at 12HH in the dorsal part of OVs in the RD/T boundry in the two rescue attempts suggesting that this gene may be involved in the separation of OVs at 12HH stage rostrally from the telencephalon.

The South African broiler industry is the greatest contributor to the South African agricultural sector, while at the same time providing the cheapest form of protein to the South African consumer. In light of a recent application for increased tariffs due to the industry’s inability to compete with the price of imported products, the need for a tool that is able to quantify the benefit of increased tariff protection to producers, while at the same time considering the cost of increased tariffs on South African consumers became apparent. The integrated nature of the industry however raised the concern that the assumptions associated with traditional quantitative modelling techniques, particularly that of a perfectly competitive market, would not allow the current broiler model within the BFAP sector modelling framework to represent the industry accurately. The primary objective of the study was to determine the true method of price discovery within the South African broiler market, in order to specify a price equation that is able to capture the dynamics surrounding price formation with improved accuracy. This price formation mechanism was then integrated into a simulation model that represents the industry accurately. Due to its ability to represent reality within the market with greater accuracy, the New Institutional Economic (NIE) framework was used to analyse the structure of the South African broiler industry as action domain. The actors and activities in the value chain were evaluated, followed by an analysis of the institutions that govern exchange within the market, highlighting the implications of these institutions for price formation within this coordinated market structure. Upon evaluation of compensation structures used within broiler production contracts, it became evident that the market for live broilers produced by contract growers could be considered as a market for grower services, as opposed to a market for live broilers. Compensation based on a broiler production tournament offers significant incentives for greater efficiency, effectively ensuring that production efficiency increases on a continuous basis. Despite the contractual obligation of integrated producers to pay their contracted growers based on a formula including the cost of production, the broiler producer price is negotiated between integrators and retailer, within a concentrated market structure. The cost of production is used as bargaining tool in price negotiations, yet the availability of imported products at extremely competitive prices limits the extent to which increased production costs can be passed up through the value chain. This was confirmed by the fact that the response of the domestic broiler producer price was much more elastic to changes in the international price than to changes in feed costs. The theoretical factors that drive broiler producer prices in South Africa were confirmed econometrically through the use of an error correction model, estimated empirically using secondary monthly data from 2007 to 2012. The estimated equations were integrated into a partial equilibrium framework using an import identity to establish equilibrium in the market, rather than a price equilibrator. The inelastic response from the domestic broiler producer price to changes in broiler feed prices raised questions regarding South African producers’ ability to compete with imported products and produce sustainably in the long run. Given the higher costs of production domestically, as well as the relative size and importance of the broiler industry within the South African agricultural sector, the need to evaluate the tariff application objectively was clear. Policy decisions should weigh the benefit of increased producer prices on broiler producers against the cost of protective policy to consumers, while also considering the specific consumers that would be required to bear the cost of increased tariffs. Integration of the partial equilibrium model of the broiler industry into the BFAP sector modelling framework enabled the simulation of various tariff scenarios, quantifying the effect on the agricultural sector, as well as chicken consumption. At the same time, the successful simulation of different scenarios and policy shocks validated the model. Simulation of the tariffs applied for by SAPA resulted in a producer price increase of 6%, which would be a significant margin on the bottom line for domestic producers. The cost to consumers of a 3.3% increase in retail prices also seems digestible; however the underlying factors that drive competitiveness should also be addressed in order to ensure long run sustainability for the industry. / Dissertation (MSc Agric)--University of Pretoria, 2013. / gm2014 / Agricultural Economics, Extension and Rural Development / unrestricted

We are the first lab to report the occurrence of a diet-induced transsulfuration (TS) blockade associating with elevated S-adenosylmethionine (i.e. SAM) synthesis, enhanced lifespan and enhanced reproductive capacity, in a vertebrate animal model. In this paradoxical study, we used LC-MS/MS-derived metabolomics data to report the effects of flaxseed (Linum Usitatissimum) on one-carbon metabolism in White Leghorn laying hens (Gallus gallus). Flaxseed contains a vitamin B6-antagonizing molecule called ‘linatine’ that is particularly effective at reducing vitamin B6 levels in small rodents and poultry. Linatine reduces TS flux through its inhibition of the vitamin B6-dependent enzymes cystathionine beta synthase (CBS) and cystathionine gamma lyase (CSE). In this study, our flaxseed-fed hens displayed decreased 4-pyridoxic acid and decreased pyridoxamine, concomitant with 15-fold elevated cystathionine. Homocysteine levels were stable in flaxseed-fed hens despite such highly elevated cystathionine. This is an astonishing finding, because mammalian models would predict the induction of hyperhomocysteinemia (i.e. elevated homocysteine) when cystathionine is so highly elevated (1). We are therefore reporting a phenomenon that might be unique to birds. Our metabolomics data indicate increased consumption of one-carbon donor molecules (e.g. choline, betaine, dimethylglycine, serine, etc) in flaxseed-fed hens, probably as a means of fueling the betaine homocysteine methyltransferase (BHMT) and methionine synthase-B12 (MS-B12) reactions. This modeling approach provides a rationale that flaxseed-fed hens increase their rate of homocysteine remethylation via BHMT and MS-B12, and in turn this would maintain stable homocysteine levels in the animal. We observed that the culminating outcome is elevated synthesis of SAM and an elevated SAM:SAH ratio. The associated biological outcomes are extended lifespan and increased reproductive capacity (i.e. increased daily egg laying) in flaxseed-fed hens. Our data further indicate that flaxseed tremendously stimulates a glucagon-like phenotype in hens. Specifically, flaxseed-fed hens exhibit 3-fold elevated glycated hemoglobin (HbA1c), 2-fold elevated serum free fatty acids (FFAs), 10 to 14% reduced body weight, and slightly reduced plasma pyruvate. These phenotypic markers suggest that glucagon might also play a large role in extending lifespan and enhancing reproductive capacity in flaxseed-fed hens. We predict that the anti-vitamin B6 effects of flaxseed are responsible for stimulating this glucagon-like phenotype in hens. Therefore, we conclude that the vitamin B6-antagonizing effects of linatine (via flaxseed dieting) improve liver function, body leanness, egg laying and survival, in a manner associated with increased SAM synthesis, increased blood FFA levels and increased blood glucose levels, in laying hens. The second part of this dissertation is used to test the hypothesis that polyunsaturated fatty acids (PUFAs) regulate lipid metabolism, increase mitochondrial respiration and decrease E-cadherin expression, in laying hen ovarian tumors. Researchers are unaware of the mitochondrial effects of PUFAs within laying hen ovarian tumors, and only a few publications exist regarding the analysis of E-cadherin in laying hen ovarian cancer. The results of this present work suggest that dietary PUFAs accumulate within laying hen ovarian tumors, and these same tumors exhibit decreased gene transcripts that govern de novo lipogenesis (i.e. FASN). Simultaneously, these tumors exhibit elevated transcripts for oxidative phosphorylation (OXPHOS) and decreased transcripts for phase 2 antioxidant enzymes. These patterns associated with decreased transcript levels of CDH1 (the gene for E-cadherin) in ovarian tumors, but no effect on full length 120kDa protein was observed by PUFAs versus our control diet. Interestingly, the effect of PUFAs on E-cadherin occurred at the level of the cleaved 37kDa and 80kDa E-cadherin fragments, such that PUFAs reduced their levels in hen ovarian tumors. We therefore developed a system for depleting the 80kDa E-cadherin fragment from hen ascites fluid (i.e. fluid from a hen that had ovarian cancer), so that we could test our hypothesis that the 80kDa E-cadherin fragment is important for supporting mitochondrial respiration in normal ovarian surface epithelial cells (IOSE80s). Mitochondrial membrane potential was decreased in IOSE80s when the 80kDa fragment was removed from the ascites; however, there was no effect on basal oxygen consumption in subsequent tests using extracellular flux analysis with Seahorse XFp. During our analysis of microRNA-200a-3p (miR-200a) we did not observe any effect of diet on miR-200a within hen ovarian tumors; however, we did observe that miR-200a levels increased within the tumor when going from stage 2 to stage 4 disease. Overall, we observed reduced risk of ovarian cancer, stage 4 ovarian cancer, multiple peritoneal tumor involvement and cancer-associated mortality, in laying hens that consumed a diet that was supplemented with PUFAs.

The research is motivated by the significant increase in multiproduct mergers in the meat-protein processing sector, whereby the largest firms now process beef, pork, and chicken. This thesis conducts a theoretical merger analysis, accounting for both within- and across-submarket substitution of demand related goods. The model developed is suitable for analyzing markets in which there are identifiable consumer submarkets within a larger market. The results indicate two primary findings. The first finding is that Bertrand firms have a unilateral incentive to merge. Firms involved in a given merger increase profit, as well as those not included in the merger. Second, it is found that without sufficient realized scope economies by the merged firm, significant anticompetitive price increases are likely. However, as substitutability within and across submarkets tend towards each other in magnitude, the required cost reductions for welfare neutrality increase vastly. Additionally, guidelines for future empirical analysis are discussed.

The objective of this study was to evaluate the efficacy of buffered vinegar in a marinade solution on inhibiting Listeria monocytogenes growth on cooked broiler breast meat. Broiler breasts were vacuum-tumbled for 30 min in a marinade consisting of dry (0%, 0.4% DV, 0.6%DV, and 0.8%) or liquid vinegar (1.5%), sodium chloride, sodium tripolyphospate, and water. The chicken breasts were then cooked to an internal temperature of 75°C. The breast meat was inoculated with L. monocytogenes, placed into modified atmosphere packaging, and stored at 2°C plus/minus 2 for 0-60 days. L. monocytogenes growth was stable on treatments for up to 30 days. However, from 35 to 60 days, the buffered vinegar treatments had fewer L. monocytogenes counts (P<0.05) than the control treatment. In addition, the 0.8 % DV and 1.5 % LV treatments had fewer than 2.0 log counts of L. monocytogenes after 60 days of storage.