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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Modelling the Interaction of Fishing with Size Structure, Dimorphism, and Egg Production of Clawed Lobsters

Theberge, Kaitlyn 24 January 2023 (has links)
Many management strategies are available to fishery managers to improve the sustainability of a fishery; however, it is not always clear how implemented strategies interact with the demographics of the exploited species. Management decisions are often made in order to maximize egg production and recruitment or to preserve specific size classes to increase reproductive output. Consequences of these strategies could include variation from a natural size structure of the population, exaggerated sexual dimorphism, skewed sex ratios, and suboptimal mating conditions. To examine the possibility of these consequences, I ran a series of deterministic models to simulate the fished and unfished population dynamics of two clawed lobster species, American lobster (Homarus americanus) and European lobster (Homarus gammarus), under a variety of management strategies. Protection of ovigerous females takes two forms in this model. The American fishery in the Gulf of Maine requires fishers to v-notch ovigerous females for up to four years of protection from fishing. The European fishery in southern Norway bans the harvest of ovigerous females, which translates to one year of protection. I compared the relative impact of the two levels of ovigerous female protections on factors that may be important for reproductive success: size structure, dimorphism, sex ratio, and egg production for both species. I then considered a case study on European lobster to evaluate the interaction of a no-take marine protected area with a slot limit to compare relative impacts to egg production, overall size structure and dimorphism. Results showed that American lobster females benefitted greatly from strict protections such as v-notching in terms of mean size increase and egg production, but mean size dimorphism and the overall proportion of females also increased with higher fishing pressure. European lobster females also benefitted from protections, but less dramatically than American lobsters, and with lower size dimorphism. In the case study, European lobsters benefited most from the implementation of a no-take marine protected area in combination with a slot limit to preserve the largest individuals of both sexes which improved overall egg production. By taking a simulation approach to evaluate these different management strategies on two closely related species of lobster, this thesis provides a basis for understanding how fishery decisions can achieve their sustainability goals in addition to quantifying some of the unintended impacts of management on parameters that may be important to overall reproductive success. / Master of Science / Fishery managers make decisions about a fishery based on the species' biology to optimize catch while also ensuring that enough individuals remain to keep the population alive for years to come. However, it is not always clear what types of unintended consequences these decisions may have. Management decisions are often made in order to maximize egg production, to keep small individuals alive until they can reproduce, or to preserve the large individuals that have high reproductive potential. Some consequences of these strategies could include a reduction in the number of large individuals with high fishing pressure, increased female body size compared to males, unequal numbers of females and males, and less optimal conditions for mating. To examine the possibility of these consequences, I ran a series of models to simulate the fished and unfished populations of two clawed lobster species, American lobster (Homarus americanus) and European lobster (Homarus gammarus), under a variety of management strategies. The American lobster fishery in the Gulf of Maine requires a practice known as v-notching, which protects egg-bearing females for up to four years. The Norwegian fishery for European lobster bans the harvest of egg-bearing females, which is protection that lasts for one year. I compared the impact of the two types of egg-bearing female protections on factors that may be important for reproductive success: abundance of large lobsters, unequal numbers of females and males, difference in size between females and males, and overall production of eggs for both species. I then considered a case study on European lobster to test how a no-take marine protected area and a slot limit (minimum and maximum harvest size limits) affected those same factors. Results showed that American lobster females benefited greatly from longer lasting protections by growing to larger sizes and producing more eggs, but the average size difference between females and males and the overall proportion of females also increased as fishing became more intense. European lobster females also benefitted from protections, but less dramatically than American lobsters, and with lower mean differences in size between females and males. In the case study, European lobsters benefitted most from the no-take marine protected area in combination with a slot limit to preserve the largest individuals of both sexes which improved overall egg production. Using a simulation makes it easier to tease apart the effects of these different management strategies on two closely related species of lobster. This thesis helps managers see how fishery decisions affect lobsters in both desired and unintended ways. With this information, managers can better improve the sustainability of the fishery through considering what a specific species needs to improve reproductive success.
42

Effect of housing environment and laying hen strain on performance, egg quality and bone properties as well as cloacal and eggshell microbiology

Sharma, Milan Kumar 01 May 2020 (has links)
Laying hen welfare is gaining importance in the United States and several states have passed legislation for a welfareriendly housing environment, which has forced the egg industry to explore alternative housing environments. For this reason, our first objective was to determine the effect of housing environment and laying hen strain on production performance and egg quality. Results showed that production performance of the hens raised in the alternative housing system was similar to the conventional system. The second objective was to compare the eggshell and cloacal microbiology. Our results indicated that the microbial load observed was higher in the alternative system compared to the conventional system. The third objective was to determine the effects of housing environment and laying hen strain on tibia and femur bone properties. The results demonstrated that the alternative system provided better tibia and femur bone characteristics, but it varied among laying hen strains.
43

Estudo do processo para a aceleração da geração de amônia a partir de resíduos avícolas visando à produção de hidrogênio / Study of the acceleration of ammonia generation process from poultry residues aiming at hydrogen production

Egute, Nayara dos Santos 17 December 2010 (has links)
O hidrogênio, utilizado em células a combustível, pode ser produzido a partir de diferentes espécies químicas, entre elas a amônia. O gás amônia como matéria prima para produção de H2 tem sido utilizado devido ao seu alto conteúdo energético e de hidrogênio, pela sua facilidade de decomposição, grande disponibilidade, baixo custo, pelas baixas pressões de armazenamento e pelos subprodutos do processamento serem ambientalmente corretos. Uma das fontes de amônia são os sistemas produtivos de frango de corte e ovos. Nesses sistemas a amônia é gerada a partir da decomposição do ácido úrico encontrado na excreta das aves. O resíduo proveniente dos sistemas de frango de corte é a cama de frango e nos sistemas de produção de ovos é a excreta sem qualquer substrato. A caracterização desses resíduos foi realizada por meio das análises de Espectrometria de Fluorescência de Raios-X por Dispersão de Comprimento de Onda (WDXRF), Análise Elementar CHN, Termogravimetria e Cromatografia a gás acoplada à Espectrometria de massa GC/MS. Os fatores estudados e que influenciam a volatilização da amônia foram: teor de nitrogênio, tempo de criação, enzima urease, temperatura, pH e teor de umidade. Os resultados dos experimentos com a cama de frango e com a excreta permitem concluir que a manipulação dos seguintes parâmetros aumentaram a emissão de amônia: o pH, o teor de nitrogênio, o tempo de criação, idade das aves e acúmulo de excreta, enzima urease e a temperatura. A adição de diferentes quantidades de areia na excreta e de volumes de água na cama de frango inibiram a emissão de amônia. A variação da quantidade de material (cama ou excreta) e do volume do frasco utilizado como câmara incubadora não demonstraram alterações significativas para serem escolhidos como uma variável. Na comparação da cama de frango com a excreta, a excreta foi considerada mais adequada aos objetivos do trabalho, pois a concentração de amônia determinada nos experimentos foi maior nesse material. Devido à grande quantidade de cama de frango e de excretas resultantes dos processos de produção, o reaproveitamento dos resíduos avícolas para a obtenção de amônia se faz necessário para melhorar a qualidade do meio ambiente local. A possibilidade do aumento da emissão de amônia, verificada nesse trabalho, e a sua utilização em um sistema geração de amônia - produção de hidrogênio - célula a combustível, poderá produzir eletricidade no próprio empreendimento, reduzindo os gastos das granjas e destinando adequadamente esses resíduos. / The hydrogen, utilized in fuel cells, can be produced from a variety of intermediate chemicals, between them, the ammonia. The ammonia gas as a raw material for the hydrogen production has been used due to its high energetic content, facility of decomposition, high availability, low prices, low storage pressure and its by-products are environmentally correct. One of the sources of ammonia is poultry and egg production systems. In these systems the ammonia is produced from the decomposition of uric acid present in the excreta of birds. The residue from the poultry-rearing farms is the broiler litter and from the egg production system is the excreta without any substrate. The characterization of these residues was performed using the Wavelength-Dispersive X-Ray Fluorescence (WDXRF), Elementary Analysis (CHN), Termogravimetry and GC/MS Gas chromatography/ Mass spectrometry. The studied factors which influence the ammonia volatilization were: nitrogen content, raising period, urease enzyme, temperature, pH and moisture content. The experiment results with poultry litter and excreta allow to conclude that the manipulation of the following parameters increased the ammonia emission: pH, nitrogen content, raising period, age of birds and excreta accumulation, urease enzyme and the temperature. The addition of different amounts of sand in the excreta and different volumes of water in the poultry litter inhibited the emission of ammonia. The variation of the quantity of material (broiler litter or excreta) and the volume of the flask used as incubator chamber showed no significant alterations to be chosen as a variable. The excreta was considered more appropriate than poultry litter for the objectives of this work due to the higher ammonia concentrations determined in this material. Due to the large amount of poultry litter and excreta from the production processes, the reuse of poultry residues to obtain ammonia is necessary to improve the quality of the local environment. The possibility of ammonia emission increment observed in this study, and its use in a system of ammonia generation - hydrogen production - fuel cell might produce electricity in the enterprise, reducing the expenses of the farms and providing a properly destination for these residues.
44

Partição da energia metabolizável para codornas japonesas na fase de produção de ovos / Partition of metabolizable energy for japanese quails in the egg production phase

Nóbrega, Ingryd Palloma Teodósio da 23 February 2018 (has links)
Submitted by Ingryd Palloma Teodósio da Nóbrega (palloma_nobrega@hotmail.com) on 2018-04-19T12:42:22Z No. of bitstreams: 1 Dissertação de Mestrado_definitivo.pdf: 1192753 bytes, checksum: 780733e53b843a769b459dd932674e60 (MD5) / Approved for entry into archive by Alexandra Maria Donadon Lusser Segali null (alexmar@fcav.unesp.br) on 2018-04-19T12:57:20Z (GMT) No. of bitstreams: 1 nobrega_ipt_me_jabo.pdf: 1192753 bytes, checksum: 780733e53b843a769b459dd932674e60 (MD5) / Made available in DSpace on 2018-04-19T12:57:20Z (GMT). No. of bitstreams: 1 nobrega_ipt_me_jabo.pdf: 1192753 bytes, checksum: 780733e53b843a769b459dd932674e60 (MD5) Previous issue date: 2018-02-23 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Compreender o metabolismo energético das aves e como a energia é utilizada para mantença, ganho de peso e produção de ovos, permite a elaboração e avaliação de modelos que estimam a exigência nutricional considerando as diferenças de peso corporal (P), ganho de peso (GP) e massa de ovo (MO) na avicultura industrial. Objetivou-se com esta pesquisa analisar os coeficientes que representam a partição da energia ingerida por codornas japonesas na fase de produção de ovos, a partir de um estudo dose-resposta. Foram utilizadas 70 codornas japonesas da linhagem VICAMI®, com 24 semanas de idade, durante 8 semanas, alojadas em galpão convencional. Duas dietas foram formuladas, uma com alto (3.600 kcal/kg) e a outra com baixo (2.100 kcal/kg) teor de energia. Para modificar a energia retida pelas aves, foi empregada a técnica da diluição, obtendo os níveis crescente de energia metabolizável da dieta. Foram utilizados sete tratamentos distribuídos inteiramente ao acaso, com dez repetições e uma codorna por unidade experimental. Os tratamentos foram 2.118; 2.381; 2.557; 2.776; 2.908; 3.171 e 3.435 kcal/kg, com base na composição analisada das dietas determinadas em ensaio de metabolismo. As variáveis analisadas foram ingestão de energia metabolizável (IEM), produção de calor (PC) e energia retida (ER) expressas em kcal/kg0,67. A energia metabolizável para mantença (EMm) foi obtida a partir da relação entre ER e IEM, considerando a condição ER = 0. A exigência metabolizável para ganho de peso (EMg) foi estimada pela relação entre eficiência de utilização de energia (k) e energia líquida para ganho (ELg). A exigência de energia metabolizável para massa de ovo (EMo), foi obtida por meio da energia retida no ovo, dividida pela eficiência de utilização de energia para massa de ovo (ko). Os valores estimados para EMm, EMg e EMo foram 155,60 kcal/kg P0,67; 5,89 kcal/g e 2,74 kcal/g, respectivamente. Os modelos que predizem a IEM baseados nos parâmetros que representam exigência de energia de acordo com seu fracionamento, foram avaliados por meio da decomposição linear do erro (observado - predito), em erro escalar e viés de predição, obtidos por regressão linear entre os erros e valores preditos. O modelo obtido foi IEM = 155,60 × P0,67 + 5,89 × GP + 2,74 × MO, a composição do erro analisado (3,79 kcal/ave.dia) mostrou que o modelo é imparcial, com 93% de precisão nas estimativas, portanto, capaz de predizer o conjunto de dados analisados, o que valida seu uso. / – To understand the energy metabolism of birds and how energy is used for maintenance, weight gain and egg production, allow the elaboration and evaluation of models that estimate the nutritional requirement considering the differences of body weight (BW), body weight gain (BWG) and egg mass (EO) in industrial poultry. The objective of this research was to analyze the coefficients that represent the partition of the energy ingested by Japanese quails in the egg production phase, from a doseresponse study. In a conventional shed it was housed 70 Japanese quails of VICAMI® line, at 24 weeks old, during 8 weeks. Based on the dilution technique it was formulated two energy levels diets, one with high (3,600 kcal/kg) and other with low (2,100 kcal/kg). Seven treatments were randomly distributed, with ten replicates and one quail per experimental unit. Treatments were levels of metabolizable energy in the diet being: 2,118; 2,381; 2,557; 2,776; 2,908; 3,171 and 3,435 kcal/kg. The variables analyzed were metabolizable energy intake (MEI), heat production (HP) and retained energy (RE) expressed in kcal/kg0.67. The metabolizable energy for maintenance (MEm) was obtained from the relation between RE and MEI, solving the equation RE = 0. The metabolizable requirement for weight gain (MEg) was estimated by the relation between use efficiency of energy (k) and net energy for gain (NEg). The metabolizable energy requirement for egg mass (MEe) was obtained by the relation between energy retained in the egg, divided by the energy utilization efficiency for egg mass (ke). The estimated values for MEm, MEg, MEe were 155.60 kcal/kg BW0.67 , 5.89 kcal/g and 2.74 kcal/g; respectively. The models that predict MEI based on the parameters that represent the energy requirement according to its fractionation were evaluated by linear error decomposition (observed - predicted), in scalar error and prediction bias obtained by linear regression between errors and predicted values. The obtained model was MEI = 155.60 × BW0.67 + 5.89 × BWG + 2.74 × EO, the analyzed error composition (3.79 kcal/bird.day), of display showing the model is unbiased, with 93% accuracy in the estimates, therefore, able to predict the analyzed data set, which validates its use.
45

COMPOSIÇÃO CORPORAL DE MATRIZES DE CORTE SUBMETIDAS A DIFERENTES HORÁRIOS DE ARRAÇOAMENTO / CORPORAL COMPOSITION OF BROILER BREEDERS FED WITH DIFFERENT FEEDING SCHEDULES

Toledo, Taiani dos Santos de 24 February 2015 (has links)
The different feeding schedules used in the poultry industry contribute to improve the nutrients distribution in the animal, as well as egg production. The study was carried out to analize the corporal composition of broiler breeders fed in different feeding schedules and their effect in body weight and body weight gain, as well as egg production. The broiler breeders were fed in three feeding schedules. The feeding schedules evaluated were: 1- a single feeding at 08:00 am, 2- twice daily feeding (50% at 08:00 am and 50% at 3:00 pm), 3- a single feeding at 3:00 pm. The hens were allocated in a completely randomized design of 3 treatments with 5 replications of 22 females and 3 males per repetition, to evaluate the corporal composition parameters were slaughtered two hens per repetition. Body weight, body weight gain, egg production, dry matter, mineral matter, crude protein, ether extract, calcium and phosphorus levels were evaluated. The feeding schedule late had higher body weight (P=0.0273) and body weight gain (P=0.0981) than early feeding schedule used. The first feeding schedule showed better egg production (P=0.0300) than the third feeding schedule. The percentage of ash (P=0.0741) and phosphorus (P=0.0875) were higher in broilers breeders fed at 8 am than hens fed at 3 pm, not different from the treatment 2. The calcium content were not affected by feeding scheduler used. The broiler breeder feeding at 8:00 am had more level of dry matter, crude protein and lower ether extract than feeding schedule late. Broiler breeder fed with feeding schedule late had lower egg production and higher body weight gain than others, consequently the most body fat deposition. / A utilização de horários de arraçoamento distintos ao empregado pela indústria visa contribuir para a melhoria na distribuição dos nutrientes requeridos para mantença, assim como para a produção das aves. O presente experimento foi conduzido com o intuito de analisar a composição corpórea de reprodutoras de corte avícolas submetidas a diferentes horários de arraçoamento e o seu impacto mediante o peso e ganho corporal, bem como, a produção de ovos. Os animais foram submetidas a 3 tratamentos: 1- horário de arraçoamento único às 08h00min, 2- horário de arraçoamento dual (50% de manhã 08h00min e 50% à tarde 15h00min), 3- horário de arraçoamento único às 15h00min. Foi utilizado um delineamento inteiramente casualizado com três tratamentos e cinco repetições de vinte e duas aves, sendo que para parâmetros referentes à composição corporal foram utilizadas duas aves abatidas para cada repetição. Foram avaliados: Peso e ganho corporal, taxa de postura, matéria seca, matéria mineral, proteína bruta, extrato etéreo, cálcio e fósforo. O horário de arraçoamento tardio apresentou aves mais pesadas (P=0,0273), com consequente ganho de peso mais elevado (P=0,0981) do que o horário matinal. O tratamento 1 apresentou a maior produção total de ovos (P=0,0300) em relação ao horário 3 A porcentagem de cinzas (P=0,0741) e fósforo (P=0,0875) foi maior em matrizes de corte alimentadas às 08h00min do que aves alimentadas às 15h00min, não diferindo do tratamento 2. Aves arraçoadas no período da manhã apresentaram maior teor de matéria seca e umidade, refletindo em um maior percentual de proteína bruta e consequentemente em um menor porcentual de extrato etéreo do que o horário de arraçoamento tardio. Reprodutoras avícolas alimentadas em horários tardios apresentaram uma menor produção de ovos com maior ganho de peso e consequentemente, maior deposição de gordura corporal.
46

Determinação do segundo aminoácido limitante para codornas japonesas / Determination of the second limiting amino acid for japanese quails

Cavalcante, Danilo Teixeira 06 September 2013 (has links)
Submitted by Katiane Souza (katyane.souza@gmail.com) on 2016-03-24T02:06:02Z No. of bitstreams: 1 Arquivototal.pdf: 966557 bytes, checksum: c19daaa99d213c5d7276024fa929f04b (MD5) / Made available in DSpace on 2016-03-24T02:06:02Z (GMT). No. of bitstreams: 1 Arquivototal.pdf: 966557 bytes, checksum: c19daaa99d213c5d7276024fa929f04b (MD5) Previous issue date: 2013-09-06 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This study aimed to determine the second limiting amino acid for Japanese quails fed with corn and soybean meal. Were used 1296 Japanese quail, females, divided into three experiments. The first experiment was conducted with birds aged 1-21 days, the second experiment with birds of 22-42 days and the experiment III with birds laying phase. The treatments in the three experiments consisted of reduction of crude protein in seven percentage points, approximately, with supplementation of the DL-methionine plus an L-amino acid essential: T1 (Met), T2 (T1+Lys), T3 (T1+Thr) and T4 (T1+Trp), T5 (T1+Val), T6 (T1+Arg), T7 (T1+Ile) and T8 (All). The parameters evaluated were feed intake (g/bird), weight gain (g/bird), feed conversion (g/g), laying rate (%), average egg weight (g), egg mass (g ), feed conversion per egg mass (kg feed/kg egg), feed conversion per dozen eggs (kg feed/dozen eggs), average weight of constituents (yolk, albumen and shell) eggs (g) , bark thickness (mm) and specific gravity (g/cm³). The statistical design was a completely randomized and the test for comparison of means was SNK at 5% probability. For performance results of 1-21 and 22-42 days, the weight gain and feed conversion were affected by amino acid supplementation. In the laying phase, feed intake, egg production, egg mass, and mass conversion per dozen, yolk weight and albumen weight were affected. We conclude that the second limiting amino acid for Japanese quails in phases 1-21 and 22-42 days, is lysine. During the laying period, it was not possible to determine the second limiting amino acid, meeting the requirements of methionine + cystine, lysine, threonine, tryptophan, valine, arginine and isoleucine digestible to obtain better results is required. / Objetivou-se determinar o segundo aminoácido limitante para codornas japonesas alimentadas com dietas compostas principalmente por milho e farelo de soja. Foram utilizadas 1296 codornas japonesas, fêmeas, divididas em três experimentos. O experimento I foi conduzido com aves com idade de 1-21 dias; o experimento II com aves de 22-42 dias e o experimento III com aves em fase de postura. Os tratamentos nos três experimentos consistiam em redução da proteína bruta em sete pontos percentuais, aproximadamente, com a suplementação de DL-metionina mais um L-aminoácido essencial: T1 (Met); T2 (T1+Lys); T3 (T1+Thr); T4 (T1+Trp); T5 (T1+Val); T6 (T1+Arg), T7 (T1+Ile) e T8 (Todos). Os parâmetros avaliados foram consumo de ração (g/ave), ganho de peso (g/ave), conversão alimentar (g/g), taxa de postura (%), peso médio dos ovos (g), massa dos ovos (g), conversão alimentar por massa de ovos (kg de ração/kg de ovo), conversão alimentar por dúzia de ovos (kg de ração/dúzia de ovos), peso médio dos constituintes (gema, albúmen e casca) dos ovos (g), espessura de casca (mm) e gravidade específica (g/cm³). O delineamento estatístico utilizado foi o inteiramente casualisado e o teste para comparação de médias foi o SNK a 5% de probabilidade. Para os resultados de desempenho de 1-21 e 22-42 dias, o ganho de peso e a conversão alimentar foram afetados pela suplementação aminoacídica, sendo o tratamento que atendia as exigências mínimas de metionina+cistina e lisina o que proporcionou os melhores resultados. Na fase de postura, o consumo de ração, a produção de ovos, a massa de ovo, conversão por massa e por dúzia, peso de gema e peso de albúmen foram afetados pelas diferentes suplementações aminoácidicas. Conclui-se que o segundo aminoácido limitante para codornas japonesas nas fases de 1-21 e 22-42 dias, é a lisina. Na fase de postura, não foi possível determinar o segundo aminoácido limitante, sendo necessário o atendimento das exigências de metionina+cistina, lisina, treonina, triptofano, valina, arginina e isoleucina digestíveis para obtenção de melhores resultados.
47

Estudo do processo para a aceleração da geração de amônia a partir de resíduos avícolas visando à produção de hidrogênio / Study of the acceleration of ammonia generation process from poultry residues aiming at hydrogen production

Nayara dos Santos Egute 17 December 2010 (has links)
O hidrogênio, utilizado em células a combustível, pode ser produzido a partir de diferentes espécies químicas, entre elas a amônia. O gás amônia como matéria prima para produção de H2 tem sido utilizado devido ao seu alto conteúdo energético e de hidrogênio, pela sua facilidade de decomposição, grande disponibilidade, baixo custo, pelas baixas pressões de armazenamento e pelos subprodutos do processamento serem ambientalmente corretos. Uma das fontes de amônia são os sistemas produtivos de frango de corte e ovos. Nesses sistemas a amônia é gerada a partir da decomposição do ácido úrico encontrado na excreta das aves. O resíduo proveniente dos sistemas de frango de corte é a cama de frango e nos sistemas de produção de ovos é a excreta sem qualquer substrato. A caracterização desses resíduos foi realizada por meio das análises de Espectrometria de Fluorescência de Raios-X por Dispersão de Comprimento de Onda (WDXRF), Análise Elementar CHN, Termogravimetria e Cromatografia a gás acoplada à Espectrometria de massa GC/MS. Os fatores estudados e que influenciam a volatilização da amônia foram: teor de nitrogênio, tempo de criação, enzima urease, temperatura, pH e teor de umidade. Os resultados dos experimentos com a cama de frango e com a excreta permitem concluir que a manipulação dos seguintes parâmetros aumentaram a emissão de amônia: o pH, o teor de nitrogênio, o tempo de criação, idade das aves e acúmulo de excreta, enzima urease e a temperatura. A adição de diferentes quantidades de areia na excreta e de volumes de água na cama de frango inibiram a emissão de amônia. A variação da quantidade de material (cama ou excreta) e do volume do frasco utilizado como câmara incubadora não demonstraram alterações significativas para serem escolhidos como uma variável. Na comparação da cama de frango com a excreta, a excreta foi considerada mais adequada aos objetivos do trabalho, pois a concentração de amônia determinada nos experimentos foi maior nesse material. Devido à grande quantidade de cama de frango e de excretas resultantes dos processos de produção, o reaproveitamento dos resíduos avícolas para a obtenção de amônia se faz necessário para melhorar a qualidade do meio ambiente local. A possibilidade do aumento da emissão de amônia, verificada nesse trabalho, e a sua utilização em um sistema geração de amônia - produção de hidrogênio - célula a combustível, poderá produzir eletricidade no próprio empreendimento, reduzindo os gastos das granjas e destinando adequadamente esses resíduos. / The hydrogen, utilized in fuel cells, can be produced from a variety of intermediate chemicals, between them, the ammonia. The ammonia gas as a raw material for the hydrogen production has been used due to its high energetic content, facility of decomposition, high availability, low prices, low storage pressure and its by-products are environmentally correct. One of the sources of ammonia is poultry and egg production systems. In these systems the ammonia is produced from the decomposition of uric acid present in the excreta of birds. The residue from the poultry-rearing farms is the broiler litter and from the egg production system is the excreta without any substrate. The characterization of these residues was performed using the Wavelength-Dispersive X-Ray Fluorescence (WDXRF), Elementary Analysis (CHN), Termogravimetry and GC/MS Gas chromatography/ Mass spectrometry. The studied factors which influence the ammonia volatilization were: nitrogen content, raising period, urease enzyme, temperature, pH and moisture content. The experiment results with poultry litter and excreta allow to conclude that the manipulation of the following parameters increased the ammonia emission: pH, nitrogen content, raising period, age of birds and excreta accumulation, urease enzyme and the temperature. The addition of different amounts of sand in the excreta and different volumes of water in the poultry litter inhibited the emission of ammonia. The variation of the quantity of material (broiler litter or excreta) and the volume of the flask used as incubator chamber showed no significant alterations to be chosen as a variable. The excreta was considered more appropriate than poultry litter for the objectives of this work due to the higher ammonia concentrations determined in this material. Due to the large amount of poultry litter and excreta from the production processes, the reuse of poultry residues to obtain ammonia is necessary to improve the quality of the local environment. The possibility of ammonia emission increment observed in this study, and its use in a system of ammonia generation - hydrogen production - fuel cell might produce electricity in the enterprise, reducing the expenses of the farms and providing a properly destination for these residues.
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Prioris para modelos probabilísticos discretos em ciências agrárias

SARAIVA, Cristiane Almeida 30 March 2007 (has links)
Submitted by Mario BC (mario@bc.ufrpe.br) on 2016-07-26T16:30:42Z No. of bitstreams: 1 Cristiane Almeida Saraiva.pdf: 654226 bytes, checksum: e8f2868121f9f239abad81f4e3eba456 (MD5) / Made available in DSpace on 2016-07-26T16:30:42Z (GMT). No. of bitstreams: 1 Cristiane Almeida Saraiva.pdf: 654226 bytes, checksum: e8f2868121f9f239abad81f4e3eba456 (MD5) Previous issue date: 2007-03-30 / With the propose to choose priors more fited for discrete data, we study technics for determination of priors just as Laplace’s Methods, Jeffreys’s Methods and Haldane’s Methods which are conjugated prior. We take a sample of ten grange among the fifty three ones existent of the Pernambuco’s State to estimate the probability of commercial egg (big type). We suppose that the distribution from the sample data is binomial and we use the methods quoted above. The software used for that was the package Winbugs 1.4 where we compute the average, standard deviation, 95% credible interval and their amplitude. For each one of the methods it was observed that 20.000 iterations were sufficient since the balance of the chain already had established with 12.500 iterations. The estimated parameter p=0,664 was obtained by the Laplace’s Method, Jeffreys’s Method and Haldane’s Method. / Objetivando selecionar prioris mais adequadas para dados discretos estudamos técnicas para determinação de prioris, tais como métodos de Laplace, método de Jeffreys e método de Haldane em que as prioris sâo conjugadas. Foi tomada uma amotra de dez granjas dentre as 53 existentes do Estado de Pernambuco com o propósito de estimar a probabilidade de ovos comerciais (grandes). Tendo em vista que os ovos são classificados como industrial, pequeno, médio, grande, extra e jumbo, classificamos os ovos em pequeno e grande. Os ovos industriais, pequenos e médios foram tidos como pequeno e os ovos grandes, extra e jumbo , como grande. Com a suposição de que os dados amostrais seguem uma distribuição binomial e utilizando prioris determinadas pelos métodos acima descritos, utilizamos o software Winbugs 1.4 com o qual foram calculados a média, desvio padrão, intervalo de credibilidade de 95% e sua amplitude. Para cada um dos métodos utilizamos 20.000 iterações das quais as 10.000 primeiras foram descartadas observando-se que o equilíbrio da cadeia iniciou-se com 12.500 iterações. Obtivemos uma estimativa média do parâmetro p o qual foi semelhante nos métodos de Laplace, Jeffreys e Haldane, correspondendo a aproximadamente p= 0,664.
49

Edible Environmental Enrichments in Littered Housing Systems: Do Their Effects on Integument Condition Differ Between Commercial Laying Hen Strains?

Schreiter, Ruben, Damme, Klaus, Freick, Markus 23 March 2022 (has links)
The aim of this study was to investigate the effect of additional enrichment materials (EMs; pecking stones and alfalfa bales) on the occurrence of plumage damage, skin injuries, and toe injuries, with an emphasis on the possible differences between commercial hybrid strains of laying hens. During rearing (weeks 1–18, 16 compartments, 4000 pullets) and laying periods (weeks 21–72, 24 compartments, 2808 hens) in a littered housing system, EMs were permanently provided to the study groups (EXP), while control groups (CON) did not receive additional EM. In a two-factorial study design (two groups with four strains) with 351 hens per variant, the brown egg-laying Lohmann Brown classic (LB) and Bovans Brown (BB) strains as well as the white egg-laying Lohmann Selected Leghorn classic (LSL) and Dekalb White (DW) strains were investigated. Compared to the CON, the EXP showed reduced body mass during rearing (p < 0.001) and reduced albumen consistency in the laying period (p < 0.001). Regarding integument condition, the LSL in the EXP showed more toe injuries than in the CON (p = 0.018). Remarkably, genotype-environment interactions between strains and groups were evident (p < 0.001). In groups with an EM supply, plumage damage decreased in LB (p ≤ 0.033) and LSL (p ≤ 0.005) but increased in BB (p ≤ 0.003). Moreover, there were fewer skin injuries in LSL (p = 0.001) but more in BB (p = 0.001) in groups with access to EM. In view of the diverging effects between strains, future practical recommendations for laying hen husbandry should be strain-specific.:Introduction Materials and Methods Results Discussions Author Contributions Funding Acknowledgments Conflicts of Interest References
50

Enhancing competitiveness of small scale poultry egg production farm in the Democratic Republic of Congo

Tshibambe Ndjibu, Zephyrin January 1900 (has links)
Master of Agribusiness / Agricultural Economics / Vincent R. Amanor-Boadu / The rapidly changing economic environment in the Democratic Republic of Congo (DR Congo) offers significant opportunities for businesses. The food and agribusiness sector is one of the major opportunities for growth given that increasing incomes are going to enhance the food and nutrition security needs of an increasing segment of the population. Animal protein in the form of chicken meat and eggs are relatively inexpensive and offer an opportunity for entry and differentiation in a markets located in DR Congo’s largest cities of Kinshasa and Kananga. This thesis uses the case of Z-CO Farm in DR Congo to explore the strategic opportunities for small-scale egg production in a low-income but growing country. Having been in operation for a number of years, Z-CO Farms has been producing chicken eggs for the general consumer market. This thesis explores the opportunity to differentiate the market that Z-CO Farms targets with the view to enhance its competitiveness, expand the market boundaries and create new value for customers that produce significant rewards. The off-take for the project is the creation of Blue Ocean markets for chicken eggs in a market that is increasingly exposed to food safety risks by assuring consumers a safe product. This project, when implemented, would be the first in DR Congo. However, would it be profitable? Under what conditions would it be profitable? We employ three primary methods to answer the foregoing questions. First, we evaluate the literature and the available secondary data. Second, we use an economic and financial model to develop the foundation for conducting the analyses for assessing the feasibility of building a small-scale table egg production system to address the emerging higher income consumers in DR Congo. We draw on the blue ocean strategy eloquently presented by Kim and Mauborgne for insight and guidance in building a unique product and service offering for the identified markets in Kinshasa and Kananga. We assess four strategies: the base scenario of the current market conditions where Z-CO maintains its commodity red ocean engagement in the market; innovating its feeding program for the birds; pursuing a market segmentation program whereby it offers high value food safety value proposition to the middle and upper-middle class of consumers; and a combination of a feed innovation and market segmentation initiative. The results show that while the first two strategies returned a positive net present value (NPV) in Kananga, they failed in Kinshasa. This is because of the level of competition in Kinshasa compared to Kananga as well as the cost of operations in the two locations. The results also show that while the remaining two strategies were profitable in both markets, they offered higher NPV and internal rates of return in Kananga than in Kinshasa. The best outcome in operating in both cities involved the fourth strategy, producing a combined NPV of about $493,867. The principal driver for this superior performance in Kananga is cost of feed. There is, therefore, value in thinking about how to leverage this cost advantage in Kananga to enhance the profitability in Kinshasa because of the population and income advantage in the latter. The study provides insights for the management of Z-CO to pursue their future investment planning and in selecting the locations and size of their operations to maximize their NPV and IRR. It also identifies the principal sources of risks that Z-CO’s management must avoid or effectively manage to achieve their desired business outcomes.

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