Title page, table of contents and abstract only. The complete thesis in print form is available from the University of Adelaide Library. / Feed is the largest single cost factor (60%) in production of chicken meat with cost of energy being a major consideration given that birds eat to satisfy an energy requirement. The Australian chicken meat industry is highly dependent on supply of energy from cereals such as wheat and barley that are known to vary widely in apparent metabolisable energy (AME). In contrast, sorghum is a relatively consistent source of energy. Diets for broiler chickens are comprised mainly of cereal grains, legumes and protein-rich meals of plant and animal origin. The diets are formulated to provide essential nutrients for maintenance and rapid growth of the flock as a whole. However, some dietary ingredients may also have chemical and physical properties that can be detrimental to the processes of ingestion, digestion, absorption, transport and utilisation of nutrients. Soluble non-starch polysaccharides (NSP) in cereal grains such as wheat and barley can depress digestion of energy by broiler chickens. This thesis examined the general hypothesis that the effects of soluble NSP in cereal grains on gut structure and function, digesta transit time, and gut microflora differ substantially between individual chickens within a flock, thus contributing to variation in the digestion of energy by the flock as a whole. A major goal of the research was to determine what characteristics of the gastrointestinal tract of broiler chickens were the key determinants of digestion of energy. Twelve experiments were conducted during this study. Breath tests involving measurements of carbon dioxide, hydrogen and methane were developed as noninvasive indicators of digestive function, and were used in conjunction with conventional methods for measuring energy digestion in commercial strains of chickens. Sex of the chicken had a significant effect (P<0.05) on AME values obtained for a diet based on wheat with a high soluble NSP content. Females were superior to males (14.6 vs 14.0 MJ/kg DM), but strain of chicken had no effect on AME. Villus height and crypt depth in the intestinal epithelium were measured to determine if any relationships between gut morphology and AME could explain why males and females differed. Males had significantly greater ileal villus height than females (P<0.05). In one of the two strains of chickens studied, villus heights in the duodenum and jejunum tended to be greater in males than females (0.05<P<0.10). In the second strain of chicken, villus heights in the duodenum and ileum were lower (P<0.05) than those in the first strain, with little differences observed between males and females. Crypt depth was unaffected by strain or by sex of the chickens. Thus, individual measurements of gut morphology were poor indicators of AME. Furthermore, only 33% of the total variation in apparent metabolisable energy (AME) could be accounted for by combinations of measurements of villus height and crypt depth in the duodenal, jejunal and ileal sections of the small intestine. It was concluded that other determinants of digestive capacity were collectively more important than gut morphology. Energy excretion by male chickens was observed to rise in an exponential manner relative to energy intake, whereas the increase in females was linear. It was reasoned that increased energy excretion by males could be due to increased endogenous energy losses from the distal part of the intestinal tract, reduced production of volatile fatty acids (VF A) by microbial fermentation in the caeca, or reduced absorption of VFA by caeca. These possibilities pointed to the need for a closer examination of the role of gut microbiota on the digestive function of chickens. It was also clear that further studies should differentiate between digestion of energy in the small intestine (by measurement of ileal digestible energy) and whole of tract digestion (by measurement of AME). ileal digestible energy (DE) values for wheat and barley were unaffected by sex of chickens, whereas AME values were lower in male chickens compared with females. These results suggested that the sex-specific effects of microbiota occurred mainly in the hindgut. Furthermore, the influence of the gut microbiota on between-bird variation in AME was partially dependent on the type of cereal grain used in the diet, as indicated by the observation that the differential between males and females in expiration of hydrogen and methane in the breath changed according to the type of grain consumed. That is, the metabolic activity of the gut microbiota was influenced both by the sex of the chicken and by the properties of the diet. The results of these studies provided evidence that microbial colonisation of the gut is a key determinant of the digestive function of chickens. Further work is needed to determine why microbial colonisation of the gut is variable and why it differs substantially between male and female chickens. Then it may be possible to control the initial colonisation of newly hatched chicks and to maintain a health-promoting profile throughout the life of chickens in order to enhance efficient production, and product quality and safety. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1080042 / Thesis (Ph.D.) -- University of Adelaide, Dept. of Animal Science, 2003

No description available.

Omega-3 polyunsaturated fatty acids can reduce the risk of cardiovascular disease and cancers. Enriching broiler meat opportunities lack research on product quality. The fatty acid (FA) profile of birds fed flaxseed for various periods was analyzed. Another experiment assessed FA profile and oxidation products in frozen-raw and cooked thigh meat in birds fed 20% linPRO (50% extruded flaxseed) with antioxidant combinations. Males deposited more omega-3 in breast meat than females. It required 26.2 d (10%flax) or 11.3 d (17%flax) feeding to achieve the 300 mg omega-3/100g of breast. Eicosapentaenoic and docosahexaenoic acids were deposited in the phospholipids whereas a-linolenic acid associated with triacylglycerols. Oxysterol appearance was reduced in thighs of high vitamin E birds while the high selenium treatment had no effect or even raised oxysterols during roasting. Antioxidants inhibited thiobarbuturic reactive acid substances in stored frozen-raw meat. Stability of omega-3 broiler meat was improved with increased dietary antioxidant levels. / Food Science and Technology

Dietary omega-3 long chain polyunsaturated fatty acids (n-3 LCPUFAs), eicosapentaenoic acid (EPA, 20:5n-3), docosapentaenoic acid (DPA, 22:5n-3) and docosahexaenoic acid (DHA, 22:6n-3), have beneficial health effects and hence increasing the consumption of these fatty acids is recommended by health authorities. The most common dietary source of EPA, DPA and DHA is seafood, but few Australians habitually consume fish and on average eat less than one meal of fish per week. Thus if Australians are to meet the dietary guidelines for n-3 fatty acid intake, there is a need to develop a source of n-3 rich foods that fit into a typical Australian diet. Feeding fish oils rich in n-3 LCPUFA to chickens has proven problematic due to alteration in organoleptic properties. The incorporation of vegetable oils rich in n-3 PUFA, alpha-linolenic acid (ALA, 18:3n-3) into the diet of chickens is potentially an alternative way to provide meat rich in n-3 LCPUFAs as ALA is the precursor of EPA and DHA. However, most vegetable oils also contain the n-6 (n-6) PUFA, linoleic acid (LA, 18:2n-6) which competes with ALA for the same enzymes in their metabolism to LCPUFA. This thesis addressed two crucial issues relating to the conversion of ALA into EPA, DPA and DHA of chicken tissues. The objectives of the first experiment were to examine the effects of increasing the ALA content of diets on the conversion of ALA into EPA, DPA and DHA by measuring their accumulation in chicken meat (breast and thigh) and to determine if there was an optimum level of ALA (at a fixed level of LA) in this process. The ratio of LA to ALA of the diets ranged from 10.5:1 to 0.6:1. The findings in this study demonstrated that there was no optimum level of dietary ALA and as indicated by the observation that EPA, DPA and DHA continued to increase in breast and thigh as the ratio of LA to ALA decreased in the diet. In general, DPA achieved higher levels than DHA. The experimental diets with the lowest LA to ALA ratio elevated the incorporation of EPA and DHA into breast and thigh meat to levels 5 and 4-fold, respectively relative to birds fed the highest LA to ALA ratio. In contrast, arachidonic acid (AA, 20:4n-6) in all groups reduced with decreasing LA to ALA ratio in the diets. The results indicated that the dietary treatments did not significantly change the growth performance of chickens. The objective of the second experiment was to assess the regulatory effect of dietary LA on the conversion of ALA into EPA, DPA and DHA. While in the first experiment the diets varied in the level of ALA but had a constant LA level, in this experiment the level of ALA in the diets was held constant and the level of LA was varied. The LA to ALA ratio of experimental diets ranged from 1.4:1 to 2.1:1. The results of this study indicated that the highest LA to ALA ratio (2.1:1) resulted in the lowest n-3 LCPUFAs, EPA, DPA and DHA in meat samples. For example, the total n-3 LCPUFA levels in the breast meat of birds fed with the lowest LA to ALA ratio was 16% higher than the n-3 LCPUFA in the breast of birds fed the highest LA to ALA ratio. This study indicated that the strongest influence on EPA, DPA and DHA accumulation in chicken tissues was the level of ALA in the diet. The experimental diets did not appear to affect the growth performance of chickens. In conclusion, increasing the ALA content of chicken diets may result in a meat source high in n-3 LCPUFAs that may reduce pressure on diminishing marine stocks as well as offering health benefits to Australians. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1369065 / Thesis (M.Ag.Sc.) - University of Adelaide, School of Agriculture, Food and Wine, 2009

The study has defined the position with regard to existing and evolving United Kingdom (UK) and European Union (EU) legislation, world trade agreements and institutions, global trade in chicken meat and market Quality Assurance (QA) standards in a series of peer-reviewed published papers and working papers. The development of global food supply chains can be a key driver in the harmonisation of international legislation, product and private assurance standards. Indeed compliance with legislation and retailer requirements has been a key market driver in the development of private assurance standards. The key objectives of the research were to examine current assurance schemes within the integrated poultry meat supply chain and the influence of regulation and external market drivers within the integrated poultry meat supply chain; develop and test a QA model for the poultry meat supply chain with a view to both baseline and higher level standards including the development of a business benchmarking system utilising a pre-requisite programme (PRP) and key performance indicators (KPI); and to assess the ability of the QA model to deliver regulatory and policy compliance whilst meeting varied business and market needs for an internationally traded product. This study has shown that a QA model is capable of providing a framework within which the poultry meat supply chain can operate. The legislative and performance requirements have been translated into quantifiable performance indicators which can be used to measure supply chain performance. This can assist differentiation of products at the point of consumption and give a quantifiable measure of the extrinsic value that has been added. This approach will therefore aid the communication of the benefits of differing methods of poultry meat production and afford the consumer the opportunity to make a more informed choice when purchasing meat products.

Atualmente, a campilobacteriose representa uma importante zoonose tanto em países desenvolvidos quanto em países em desenvolvimento. No Brasil, vários estudos relatam a alta frequência de suínos eliminando o agente nas fezes, porém, a contaminação da carne suína comercializada tem sido pouco avaliada, principalmente no que diz respeito à presença de Campylobacter spp. A incidência deste agente em cortes de carne de aves é mais descrita, porém ainda faltam estudos que esclareçam a epidemiologia da doença. Os objetivos principais do presente estudo foram avaliar a presença de Campylobacter spp. em cortes de carne de frangos e suínos vendidos em mercados municipais, açougues e mercados de pequeno porte distribuídos nas cinco regiões do município de São Paulo. Das 115 amostras de origem suína avaliadas sete se mostraram positivas ao isolamento de Campylobacter coli e, das 105 amostras de carne de frango, 31 estavam contaminadas por Campylobacter jejuni ou Campylobacter coli. Dentre as 38 amostras de carne de frango e suíno positivas foram selecionadas 60 estirpes, as quais foram caracterizadas quanto à espécie, utilizando a reação em cadeia pela polimerase e a espectrometria de massa MALDI-TOF, foram ainda avaliadas quanto ao perfil de resistência a antimicrobianos e foram submetidas a genotipagem pelo polimorfismo de comprimento de fragmentos amplificados (AFLP). A partir dos resultados obtidos seis estirpes foram selecionadas para realização do sequenciamento do genoma completo e a partir da análise dos genomas foram identificados os STs, os genes de resistência e genes de virulência. / Currently, Campylobacteriosis represents an important zoonosis in both developed and developing countries. In Brazil, several studies report a high frequency of pigs excreting the agent in the feces, but the contamination of marketed pork has been insufficiently evaluated, especially with regard to the presence of Campylobacter spp. The incidence of this agent in cuts of poultry meat is more detailed; however, there are still studies lacking that clarify the epidemiology of the disease. The main aims of the present study were to evaluate the presence of Campylobacter spp. in chicken and pork cuts sold in municipal markets, butchers and small markets distributed in the five regions of the city of São Paulo. Of the 115 pork samples evaluated, seven were Campylobacter coli isolation positive and 31 of the 105 chicken samples were contaminated with Campylobacter jejuni or Campylobacter coli. Of the 38 chicken and pork positive samples, 60 strains were selected, which were characterized by species using polymerase chain reaction and MALDI-TOF mass spectrometry. They were also assessed for antimicrobial resistance profile and were genotyped by amplified fragment length polymorphism (AFLP). From the results obtained six strains were selected to carry out the complete genome sequencing and from the genome analysis the STs, the resistance genes and the virulence genes were identified.

Introdução. A introdução dos antimicrobianos na prática clínica no século XX foi um grande avanço para a medicina. Entretanto, seu uso indiscriminado, tanto na medicina (humana e animal) quanto na agricultura e pecuária, possibilitou a seleção e disseminação de microrganismos resistentes. A transferência genética horizontal é um dos principais mecanismos responsáveis pela disseminação de genes que codificam resistência aos antimicrobianos, pois possibilita a transmissão da resistência de uma célula bacteriana (comensal ou patogênica) para outra. Genes codificadores de resistência a antimicrobianos de importância clínica são encontrados em microrganismos de origem ambiental, clínica e alimentar. Objetivo. O objetivo do presente estudo foi detectar genes que codificam resistência aos antibióticos -lactâmicos, Tetraciclinas e Quinolonas, em amostras de carne de frango, visando estudar a ocorrência da resistência antimicrobiana nesse produto considerado um alimento comum na dieta do homem. Materiais e Métodos. Foram utilizadas 30 amostras de carne de frango. Após a inoculação da carne de frango em caldo Luria 0,5 por cento , o DNA total das bactérias cultivadas nesse meio foi extraído por choque térmico e utilizado na pesquisa de genes de resistência pela técnica de PCR seguida de eletroforese em gel de agarose. Foi também realizada a pesquisa de Coliformes Termotolerantes por meio da técnica dos tubos múltiplos para estimar a qualidade higiênico sanitária das amostras. Resultados: Oito (26,7 por cento ) amostras apresentaram um ou mais genes codificadores de resistência à antimicrobianos -Lactâmicos, 28 (93,3 por cento ) amostras apresentaram um ou mais genes codificadores de resistência às Tetraciclinas e 28 (93,3 por cento ) amostras apresentaram um ou mais genes codificadores de resistência às Quinolonas. Conclusões: A realização deste estudo contribuiu com informações a respeito da circulação de genes de resistência na carne de frango e alerta as autoridades de Saúde Pública do Brasil quanto à disseminação da resistência bacteriana e a necessidade de mais estudos a respeito desse problema, já que esses são raros ou inexistentes no País. / Introduction. The introduction of antibiotics in clinical practice in the twentieth century was a breakthrough for medicine. However, their indiscriminate use in both medicine (human and animal) as in agriculture and livestock, enabled the selection and spread of resistant microorganisms. Horizontal gene transfer is a major mechanism responsible for the spread of genes encoding antimicrobial resistance, since it allows the transmission of resistance from one bacteria to another. Genes encoding resistance to antimicrobials of clinical importance are found in microorganisms present in food, environment and clinical sources. Objective. The aim of this study was to detect genes encoding resistance to -lactam antibiotics, tetracyclines and quinolones in meat samples from chicken samples, to study the occurrence of antimicrobial resistance in this product considered a common food in human diet. Materials and Methods. Thirty samples of chicken were used. After inoculation of chicken meat in Luria broth 0.5 per cent , the total DNA of the bacteria cultured was extracted by heat shock and used to search resistance genes by PCR followed by agarose gel electrophoresis. The search for thermotolerant coliforms was also conducted using the technique of multiple tubes in order to estimate the sanitary quality of the samples. Results: Eight (26,7 per cent ) of the samples had one or more genes encoding for resistance to -lactam antimicrobials, 28 (93,3 per cent ) had one or more genes encoding resistance to tetracyclines and 27 (93,3 per cent ) samples had one or more genes encoding resistance to quinolones. Conclusions: This study contributes to the scientific community and sanitary agencies, bringing information regarding the occurrence and distribution of resistance genes in chicken, alerting the Public Health authorities in Brazil about the spread of bacterial resistance and the need for more studies in this field, as these are rare or nonexistent in the country.

O presente trabalho teve como objetivo identificar os pontos críticos e estabelecer os pontos críticos de controle em preparações à base de carne de frango, nas lanchonetes/restaurantes do \"CAMPUS\" de uma Universidade. Em cada uma das 23 unidades foram analisadas três preparações à base de carne de frango as quais representam a grande preferência dos consumidores. A pesquisa foi dividida em duas etapas: - Levantamento das instalações. Acompanhamento das preparações e elaboração dos respectivos fluxogramas para identificação dos pontos críticos. Os dados foram colhidos com auxilio de \"Ficha de Inspeção\" preparada para o trabalho em questão, termômetros digitais de penetração, termômetros químicos, cronômetros e reagente para determinação de concentração de cloro em soluções para higienização. Constatou-se que, a maioria das instalações foi projetada para funcionar apenas como lanchonete sendo que, os serviços de restaurante são realizados de forma precária. Este fato associado ao despreparo dos manipuladores de alimentos, resulta num comprometimento sério à manipulação e proteção dos alimentos e, conseqüentemente à sanidade dos mesmos. / The present paper intends to identify critical points and critical control points in preparations of chicken meat in luncheonettes and restaurants of a University campus. In each of the twenty-three units three such preparations were analyzed; the preparations represented the major preference of consumers. The study was divided in two phases: - Study of equipments. - Follow-up of preparations and elaboration of flow diagrams for identification of critical points. Data were collected with the aid of an inspections form especially prepared for the study, penetration digital reading thermometers, chemical thermometers, chronometer and reagent to stablish the chlorine concentration in sanitizing solutions. The data showed that instalations of all establishments were originally planned for luncheonettes and were being used as restaurants under precarious conditions. This fact plus the lack of training of food handlers resulted in the serious jeopardizing of food handling; thus protection of food was jeopardized as well as its sanity.

Introdução. A introdução dos antimicrobianos na prática clínica no século XX foi um grande avanço para a medicina. Entretanto, seu uso indiscriminado, tanto na medicina (humana e animal) quanto na agricultura e pecuária, possibilitou a seleção e disseminação de microrganismos resistentes. A transferência genética horizontal é um dos principais mecanismos responsáveis pela disseminação de genes que codificam resistência aos antimicrobianos, pois possibilita a transmissão da resistência de uma célula bacteriana (comensal ou patogênica) para outra. Genes codificadores de resistência a antimicrobianos de importância clínica são encontrados em microrganismos de origem ambiental, clínica e alimentar. Objetivo. O objetivo do presente estudo foi detectar genes que codificam resistência aos antibióticos -lactâmicos, Tetraciclinas e Quinolonas, em amostras de carne de frango, visando estudar a ocorrência da resistência antimicrobiana nesse produto considerado um alimento comum na dieta do homem. Materiais e Métodos. Foram utilizadas 30 amostras de carne de frango. Após a inoculação da carne de frango em caldo Luria 0,5 por cento , o DNA total das bactérias cultivadas nesse meio foi extraído por choque térmico e utilizado na pesquisa de genes de resistência pela técnica de PCR seguida de eletroforese em gel de agarose. Foi também realizada a pesquisa de Coliformes Termotolerantes por meio da técnica dos tubos múltiplos para estimar a qualidade higiênico sanitária das amostras. Resultados: Oito (26,7 por cento ) amostras apresentaram um ou mais genes codificadores de resistência à antimicrobianos -Lactâmicos, 28 (93,3 por cento ) amostras apresentaram um ou mais genes codificadores de resistência às Tetraciclinas e 28 (93,3 por cento ) amostras apresentaram um ou mais genes codificadores de resistência às Quinolonas. Conclusões: A realização deste estudo contribuiu com informações a respeito da circulação de genes de resistência na carne de frango e alerta as autoridades de Saúde Pública do Brasil quanto à disseminação da resistência bacteriana e a necessidade de mais estudos a respeito desse problema, já que esses são raros ou inexistentes no País. / Introduction. The introduction of antibiotics in clinical practice in the twentieth century was a breakthrough for medicine. However, their indiscriminate use in both medicine (human and animal) as in agriculture and livestock, enabled the selection and spread of resistant microorganisms. Horizontal gene transfer is a major mechanism responsible for the spread of genes encoding antimicrobial resistance, since it allows the transmission of resistance from one bacteria to another. Genes encoding resistance to antimicrobials of clinical importance are found in microorganisms present in food, environment and clinical sources. Objective. The aim of this study was to detect genes encoding resistance to -lactam antibiotics, tetracyclines and quinolones in meat samples from chicken samples, to study the occurrence of antimicrobial resistance in this product considered a common food in human diet. Materials and Methods. Thirty samples of chicken were used. After inoculation of chicken meat in Luria broth 0.5 per cent , the total DNA of the bacteria cultured was extracted by heat shock and used to search resistance genes by PCR followed by agarose gel electrophoresis. The search for thermotolerant coliforms was also conducted using the technique of multiple tubes in order to estimate the sanitary quality of the samples. Results: Eight (26,7 per cent ) of the samples had one or more genes encoding for resistance to -lactam antimicrobials, 28 (93,3 per cent ) had one or more genes encoding resistance to tetracyclines and 27 (93,3 per cent ) samples had one or more genes encoding resistance to quinolones. Conclusions: This study contributes to the scientific community and sanitary agencies, bringing information regarding the occurrence and distribution of resistance genes in chicken, alerting the Public Health authorities in Brazil about the spread of bacterial resistance and the need for more studies in this field, as these are rare or nonexistent in the country.

Made available in DSpace on 2014-06-11T19:32:57Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-07-28Bitstream added on 2014-06-13T19:22:50Z : No. of bitstreams: 1 canizares_mc_dr_botfmvz.pdf: 438720 bytes, checksum: d971a194cb5b8bfcd6bfa22dd4288473 (MD5) / Universidade Estadual Paulista (UNESP) / Fun-Sul / Foram utilizados 144 peitos desossados e sem pele de frangos de corte abatidos aos 42 dias de idade, provenientes de um frigorífico comercial com inspeção sanitária oficial (SIF), com o objetivo de avaliar parâmetros de qualidade da carne de frango submetida ao processo de irradiação e período de armazenamento sob resfriamento ou congelamento. Foram realizados dois ensaios em que as amostras foram mantidas sob duas formas de armazenamento: resfriada (4°C) e congelada (-18°C). Foi utilizado um delineamento inteiramente casualizado, em esquema fatorial 2x3, para os dois ensaios, em que no primeiro foram aplicados duas doses de irradiação (0 e 3kGy) e três períodos de armazenamento (01, 14 e 21 dias) para amostras mantidas sob refrigeração e para o segundo foram aplicados duas doses de irradiação (0 e 3kGy) e três períodos de armazenamento (1, 45 e 90 dias) para carnes armazenadas congeladas. Foram avaliados pH, L* a* e b*, perda por cozimento, força de cisalhamento, perda de exsudado, capacidade de retenção de água, desnaturação protéica, composição centesimal, TBARS, medidas morfométricas das fibras musculares e análise sensorial. A irradiação e o tempo de armazenamento contribuíram para alterações de parâmetros de qualidades das carnes de frango crua, sem alterar, no entanto, características nutricionais. As alterações estruturais as fibras musculares em função da irradiação foram mais evidentes nas condições de armazenamento sob congelamento. As características sensoriais da carne cozida não foram alteradas pelo processo de irradiação, no entanto, houve percepção de aroma estranho na carne crua tanto quanto em condições de armazenamento sob resfriamento como sob congelamento. / Boneless and skinless breasts (n=144) of broilers slaughtered at 42 days of age were collected in a commercial processing plant with the aim of assessing quality parameters of chicken meat submitted to radiation and then either to cold (4°C) or frozen (-18°C) storage in two different trials. A completely randomized experimental design in a 2x3 factorial arrangement was applied in both trials. In the first trial, two radiation doses (0 and 3kGy) and three cold storage periods (01, 14, and 21 days) were applied, whereas in the second experiment, two radiation doses (0 and 3kGy) and three cold storage periods (01, 45, and 90 days) were used. The following parameters were evaluated: pH, L* a* e b*, cooking loss, shear force, drip loss, water retention capacity, protein denaturation, percentage composition, TBARS, muscle fiber morphometric measurements, and sensorial analysis. Radiation and storage time changed raw chicken meat quality parameters, but did not influence its nutritional characteristics. Structural changes in muscle fibers caused by radiation were pre evident when the meat was frozen. Sensorial characteristics of cooked meat were not affected by radiation; however, a strange odor was perceived when meat was raw and submitted to cold and frozen storage.