Orientador: Daniella Jorge de Moura / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agrícola / Made available in DSpace on 2018-08-17T14:08:00Z (GMT). No. of bitstreams: 1 Lima_KarlaAndreaOliveirade_D.pdf: 5594209 bytes, checksum: 2fd1cc47487130c9ee71f42506d49d72 (MD5) Previous issue date: 2011 / Resumo: A produção de gases no interior de galpões e suas emissões estão intimamente ligados ao microclima estabelecido no galpão pela sua temperatura, umidade e velocidade do ar. Sendo assim, o ambiente gerado no galpão, é por sua vez influenciado pela tipologia construtiva dos galpões e pelo sistema de ventilação. Este trabalho teve por objetivo geral avaliar os ambientes aéreo e térmico de galpões visando caracterizar as condições de criação de frango de corte, com base na qualidade da cama e do ar, gerados em galpões com ventilação mecânica positiva e negativa. Este projeto foi realizado em três granjas localizadas no estado de São Paulo pertencentes a duas integradoras distintas, onde oito aviários, sendo 4 do tipo pressão positiva e 4 do tipo do tipo pressão negativa, chamados de Blue house e Dark house. Foram avaliados Nestes galpões foi realizado o monitoramento das variáveis climáticas, a performance dos sistemas de ventilação utilizados, os níveis de concentração e emissão da amônia e dióxido de carbono, as condições da cama, seu pH, umidade, temperatura e condição microbiológica e serão correlacionadas a qualidade da cama gerada com a porcentagem de problemas locomotores e mortalidade dos lotes criados em galpões com ventilação mecânica positiva e negativa, em lotes com cama nova e reutilizada. Os resultados mostraram a influência dos galpões de pressão negativa na taxa de emissão de gases, CO2 e NH3 devido às suas maiores taxas de ventilação com valores que variaram de 0,25 - 0,51 gNH3/ave/dia e 387 a 907 KgCO2/galpão/dia. De acordo com o tipo de cama, se nova ou reutilizada os valores de emissão foram mais baixos para os galpões com cama nova, mesmo quando comparado os sistemas dentre si, p-valor <0,05. Os sistemas de ventilação negativa apresentaram maior consumo energético caracterizado pela potência dos seus exaustores e pelo manejo da ventilação constantemente usada durante todo o ciclo de criação. Os galpões não apresentaram diferenças estatisticamente significativas entre os seus dados zootécnicos o que caracterizou que o manejo adotado pelas integradoras foi satisfatório à produção. Através desta avaliação foi possível observar a distinção entre os sistemas de ventilação positiva e negativa quanto à emissão de gases, ao consumo energético e a sua produtividade e a viabilidade do sistema de pressão negativa na produção de frangos de corte. / Abstract: Gases production and its emission in broilers housing are related to the microclimate established in terms of temperature, humidity and air speed inside the housing. So, the environment generated in the housing is influenced by the constructive characteristics of the barn and by the adopted ventilation system. This work had as general objective to evaluate aerial and thermal environments of broiler housings aiming to characterize the conditions of broiler production, looking for the litter and air quality generated in barns with positive and negative ventilation systems. This project was carried out in three farms located in São Paulo State, under two different integrator companies responsible for the flocks management. In the total eight broiler houses were evaluated being four houses named positive pressure and four named negative pressure. Both systems were mechanically ventilated systems. Climatic variables, the performance of ventilation systems, gases concentration levels and emissions were monitored in these houses. Further research was carried out about the litter condition, its pH, humidity, temperature and its correlation between litter quality and mortality and lameness incidence on the flocks The results showed the influence of the negative pressure systems on the, CO2 and NH3 emission rate due to their higher ventilation rates with values ranging from 0.25 to 0.51 and from 387 to 907 gNH3/bird/day and KgCO2 /house /day. The emissions rates were lower according to the type of litter, new or built-up even when compared among the systems themselves, p-value <0.05. Negative pressure systems had higher energy consumption characterized by the power of exhausters motor and ventilation management that was constantly running throughout the growing period. The broiler houses showed no statistically significant differences between their data production that means that management adopted by integrator companies was satisfactory. Through this assessment it was possible to observe the distinction between the positive and negative ventilation systems on the emissions rates, energy consumption and its productivity where it was also noticed the viability of the negative pressure system in the broilers production. / Doutorado / Construções Rurais e Ambiencia / Doutor em Engenharia Agrícola

Foi realizado um experimento no aviário experimental do Departamento de Zootecnia da Universidade de São Paulo (USP), na Faculdade de Zootecnia e Engenharia de Alimentos (FZEA), em Pirassununga/SP com o objetivo de avaliar o efeito de dois níveis vitamínicos (comercial e OVN) com ou sem aflatoxina em dietas de frangos de corte no período de 1 a 42 dias. Foram utilizados 1800 pintinhos, machos, Cobb 500, distribuídos em um delineamento inteiramente casualizado em esquema fatorial 2 x 2 x 2 (2 níveis vitamínicos - comercial e OVN, 2 níveis de aflatoxina - 0 ppm e 0,5 ppm, e 2 níveis de adsorventes - 0 e 10 kg/ton), totalizando 8 tratamentos com 15 repetições de 15 aves cada. As dietas foram fornecidas fareladas e a base de milho e farelo de soja, formuladas segundo os níveis praticados por uma integradora da região. Para avaliar o desempenho foram analisados o consumo de ração, ganho de peso e conversão alimentar de 1 a 49 dias. Para avaliação de carcaça (rendimento de carcaça, peito e pernas), determinação de incidência de BBS e determinação do peso das vísceras abdominais e coração foram abatidas duas aves por repetição aos 45 dias. Os resultados mostraram que frangos de corte, machos, alimentados com nível OVN de vitaminas, apresentaram melhor ganho de peso, conversão alimentar, rendimento de carcaça e peito quando comparado com o nível comercial de vitaminas (P&lt;0,05) e que as dietas contendo 0,5 ppm de aflatoxinas resultaram em menor ganho de peso, rendimento de carcaça, porcentagem de peito e aumentou o tamanho do coração e fígado do animal (P&lt;0,05). O uso de 10kg/ton de adsorvente só apresentou resultado positivo no final da vida dos animais (dos 39 a 49 dias) (P&lt;0,05) e somente na conversão alimentar. Esse estudo permite concluir que a aflatoxina resulta em perdas de desempenho e rendimento de carcaças e que o fornecimento de níveis ótimos de vitaminas melhora os resultados dessas características. O uso de adsorventes se mostrou inviável nesse estudo. / An experiment was conducted in an experimental aviary the Department of Animal Science, University of São Paulo (USP), the Faculty of Animal Science and Food Engineering (FZEA) in Pirassununga/SP, to evaluate the performance, carcass characteristics and weight of offal in broiler chickens fed with two levels of vitamins (commercial and VNO) with or without aflatoxin in broiler diets. Were used 1800 chicks, male, Cobb 500 distributed in a completely randomized 2 x 2 x 2 factorial arrangement (two vitamin levels, two levels of aflatoxin and two levels of adsorbents), totaling eight treatments with 15 replicates of 15 birds each. Diets were fed mash and corn and soybean meal, formulated according to the levels charged by an integrator in the region. To evaluate the performance were analyzed feed intake, weight gain, feed conversion from 1 to 49 days. For evaluation of carcass yield (carcass, breast and legs), determination of the incidence of BBS and determination of the weight of the abdominal viscera and heart were killed two birds per replicate at 45 days. The results showed that broilers, males fed VNO level of vitamins showed better weight gain, feed conversion, carcass yield and breast when compared to the commercial level of vitamins (P&lt;0.05) and that diets intoxicated with 0.5 ppm of aflatoxin resulted in less weight gain, carcass yield, percentage of breast and increased the size of the heart and liver of the animal (P&lt;0.05). The use of adsorbent 10kg/ton only had a positive result at the end of life of animals (from 39 to 49 days) (P&lt;0.05) and only in the feed. This study indicates that aflatoxin results in loss of performance and carcass yield and the provision of optimal levels of vitamins improved the results of these characteristics. The use of adsorbents in this study proved to be unfeasible.

O objetivo deste trabalho foi avaliar a utilização da levedura hidrolisada como fonte de nucleotídeos para frangos de corte. As aves foram suplementadas com diferentes níveis de inclusão nas dietas iniciais de 1 a 14 dias de idade. Foram utilizados um total de 576 pintos da linhagem Ross 708, os quais foram distribuídos em 6 tratamentos com 8 repetições (12 aves por box). Os tratamentos consistiram da inclusão de 0, 2, 4, 6, 8 e 10 kg de levedura hidrolisada/tonelada de ração. A levedura hidrolisada foi adicionada na dieta no lugar do material inerte da ração. A dieta inicial foi fornecida na forma triturada enquanto as dietas de crescimento, final e de retirada foram fornecidas na forma de pellets. Durante todo o experimento o acesso à água e ração foi ad libitum. Todas as dietas foram feitas à base de milho, farelo de soja e gordura de frango e foram formuladas para atender as exigências nutricionais recomendadas pelo manual de recomendações nutricionais Ross 708. Aos 42 dias, as aves alimentadas com 1% de levedura hidrolisada tiveram maior peso corporal e ganho de peso quando comparadas aos demais tratamentos (P<0,05). Não houveram diferenças estatísticas entre os tratamentos para as variáveis mortalidade e densidade de vilos. Contudo aves que não foram suplementadas com levedura hidrolisada (tratamento controle) apresentaram menor profundidade de cripta e a suplementação de 1% de levedura resultou em maior altura de vilos. Aves as quais receberam dietas com 0,2% de inclusão de levedura hidrolisada apresentaram menor rendimento de peito que as aves que receberam os demais níveis de levedura, mas foram iguais as aves do tratamento controle. Contudo, o rendimento de carcaça, sassami e gordura abdominal não foram influenciados pelos tratamentos experimentais. Estes resultados demostraram a eficácia da utilização de levedura hidrolisada na dieta de frangos de corte no período de 1 a 14 dias sobre as características de produção. / The objective of this work was to evaluate hydrolyzed yeast utilization as nucleotides source to broilers. Birds were supplemented with different inclusion levels on starter diets from 1 to 14 days of age. A total of five hundred seventy six Ross 708 chicks were allotted to 6 experimental treatments with 8 replications (12 broilers per pen). Birds were randomly distributed in following treatments: 0, 2, 4, 6, 8 and 10 kg hydrolyzed yeast/ton of feed. Hydrolyzed yeast was added to the test diet in place of filler. Starter diets were supplied in crumbled form while grower, finisher, and withdrawal were supplied in pellet form. Throughout experiment water and feed were supplied ad libitum. All diets were based on corn, soybean meal and poultry fat, and were formulated to achieve nutritional requirements from recommendations guide for Ross x Ross 708 broilers. At 42 d chicks fed 1% hydrolyzed yeast demonstrated higher body weight and body weight gain over birds fed other treatments (P<0.05). Mortality and villous density did not differ among treatments. However birds fed control treatment showed lower crypt depth and 1% hydrolyzed yeast supplementation promoted higher villous high. Birds fed 0.2% hydrolyzed yeast showed lower breast meat yield than birds received other yeast levels, but were equals to control treatment control. However, carcass and tender yield, and abdominal fat were not influenced by treatments. These results indicated efficacy of hydrolyzed yeast utilization on broiler diets from 1 to 14 on production characteristics.

O sucesso da produção animal consiste em menores custos dos fatores de produção. A busca por fontes alternativas na alimentação de frangos de corte, que reduzam custos e mantenham a produtividade, é uma estratégia importante em períodos de crise do setor. Dessa forma, o presente estudo teve como objetivo avaliar os efeitos de diferentes níveis de grãos de sorgo secos por destilação com solúveis em dietas para frangos de corte sobre as características zootécnicas de desempenho (ganho de peso, consumo de ração, conversão alimentar, rendimento de carcaça e cortes), digestibilidade aparente, coloração da carne e viabilidade econômica da utilização do ingrediente. Foram realizados dois ensaios experimentais. No primeiro ensaio, 864 frangos de corte machos da linhagem Cobb, foram distribuídos em seis tratamentos, com 12 repetições de 12 aves cada, criados de 1 a 41 dias de idade para avaliação do desempenho. Aos 42 dias de idade, as aves foram abatidas e submetidas a avaliações da carcaça. No segundo ensaio experimental, 336 pintainhos foram distribuídos em seis tratamentos, com oito repetições de sete aves cada. Foi realizada a coleta de total de excretas de 16 a 19 dias de idade das aves e verificados os parâmetros de digestibilidade aparente. Os tratamentos experimentais atenderam as exigências de Rostagno et al. (2011), sendo isoprotéicas e isoenergéticas. O delineamento experimental foi inteiramente casualizado em ambos ensaios experimentais, sendo 0, 5, 10, 15, 20 e 25% de inclusão de DDGS de sorgo nas dietas. As aves apresentaram menores ganhos de peso médio (p<0,0001) com inclusões de 20 e 25% de DDGS, respectivamente, em relação aos demais tratamentos, nas dietas pré-inicial, inicial, crescimento e durante o período total de criação (1 a 41 dias). O consumo médio de ração também foi menor (p<0,0001) pelas aves com o fornecimento do nível máximo (25% de DDGS de sorgo) nas fases inicial, crescimento e durante todo o período de criação. A conversão alimentar também foi pior (p<0,0001) nas fases pré-inicial, inicial e de 1 a 41 dias nas aves que consumiram dietas com 25% de DDGS de sorgo. Inclusões de 20 ou 25% de DDGS de sorgo nas dietas resultaram em menor (p<0,0001) rendimento de carcaça e rendimento de peito. As digestibilidades aparentes da matéria seca, do extrato etéreo e da energia não diferiram entre o fornecimento de dieta convencional ou com 5% de inclusão de DDGS de sorgo na dieta (p<0,0001). A digestibilidade aparente da proteína bruta e do fósforo não diferiram (p<0,0001) com o fornecimento de dieta convencional ou com até 10% de inclusão do DDGS de sorgo. A luminosidade foi menor (p<0,0001) com inclusão de 20 ou 25% de DDGS nas dietas em relação aos demais tratamentos. Já a intensidade da cor vermelha foi maior (p=0,0009) com o maior nível de inclusão de DDGS de sorgo. A margem bruta foi menor (p<0,0001) no período total de criação com inclusão de 20 e 25% de DDGS de sorgo nas dietas, respectivamente, em relação aos demais tratamentos. É viável a inclusão de até 15% de DDGS de sorgo em dietas para frangos de corte machos. / The success of animal production is based in its lower costs of production factors. The search for alternative sources in broilers diet wich reduce costs and maintain productivity, is an important strategy in times of industry recession. Thus, the present study aimed to evaluate the effects of different levels of sorghum dried distillers grains with solubles in broilers diets on the zootechnical performance features (weight gain, feed intake, feed conversion, yield carcass and cuts), apparent digestibility, meat color and economic viability of the ingredient usage. Two experimental trials were performed. In the first trial, 864 Cobb male broilers, were distributed into six treatments, with 12 replicates of 12 birds each, raised from 1 to 41 days of age for performance evaluation. At 42 days of age, birds were slaughtered and submitted to carcass evaluations. In the second experimental trial, 336 chicks were distributed into six treatments with eight repetitions of seven chicks each. Total excreta was collected for 16-19 day old birds and checked the parameters of apparent digestibility. Experimental treatments met the requirements of Rostagno et al. (2011) and there were isoprotein and isoenergetic feed intakes. A completely randomized design was used in both experimental essays, with 0, 5, 10, 15, 20 and 25% inclusion of sorghum DDGS in diets. The birds gained less average weight (p<0.0001) with inclusions of 20 and 25% sorghum DDGS in diets, respectively, compared to other treatments, in pre-starter, starter, grower and also during the total period of growing (1-41 days). Average feed intake was also lower (p<0.0001) for the supply of birds maximum level (25% sorghum DDGS) at initial, growth and throughout the rearing period. The feed conversion ratio was also worse (p<0.0001) in the pre-starter, starter phases and 1-41 days on the birds fed with 25% sorghum DDGS in diets. Inclusions of 20 or 25% sorghum DDGS in diets resulted in lower (p<0.0001) carcass yield and breast meat yield. Apparent digestibility of dry matter, ether extract and energy did not differ between the supply of conventional diet or 5% inclusion of sorghum DDGS in the diet (p<0.0001). Apparent digestibility of crude protein and phosphorus did not differ (p<0.0001) with providing conventional diet or with up to 10% inclusion of sorghum DDGS. The brightness was lower (p<0.0001) with the inclusion of 20 or 25% DDGS in the diets compared to other treatments. Already the red color intensity was higher (p=0.0009) with the highest level of inclusion of sorghum DDGS. Gross margin was lower (p<0.0001) in the total period including 20 and 25% sorghum DDGS in diets, respectively, compared to other treatments. It is recommended to include up to 15% sorghum DDGS in broilers diets.

Foram utilizados 504 pintos de corte, machos, da linhagem Cobb, de 1 dia de idade, distribuídos aleatoriamente em 18 tratamentos com 4 repetições pelo período de 21 dias, para determinar a biodisponibilidade relativa do fósforo (BRP) em farelo de trigo, soja integral tostada ou extrusada com e sem a adição de fitase. Foram adicionados dois níveis de fitase (0 ou 750 FTU/kg dieta) e dois níveis de fósforo suplementar (0,05 ou 0,10%) à dieta basal semi-purificada com baixo nível de fósforo total (0,40%) sendo a fonte padrão de fósforo o fosfato bicálcico. Ao término do experimento, foram removidas as tíbias esquerdas e os dedos médios direitos para posterior análise de cinzas ósseas. A BRP para cada fonte orgânica foi calculada pelo método do “slope ratio” através da regressão dos valores de peso de cinzas na tíbia em função dos níveis de fósforo suplementar ingerido (mg/dia). Os valores de BRP para farelo de trigo, soja integral tostada e extrusada sem a adição de fitase foram de 74,4; 56,9 e 56,5%, respectivamente. Com a adição de fitase estes valores foram para 79,4; 93,5 e 100%, respectivamente. / Five hundred and four male Cobb chicks were used in a 21 day study to determine the relative bioavailability of phosphorus (RBP) in wheat midds, or soybean roasted or extruded with and without added microbial phytase (0 or 750 FYT/kg of diet).The reference standart was a purified grade calcium phosphate dibasics (DPS). The experimental ingredients, as well as the DPS, were added to the semi-purified starch-soybean meal control diet (22% protein; 0,32% P + 0,08% P from DPS) provinding 0,05 and 0,10% additional P, for a total of 9 experimental diets containing 0 FYT/kg, plus a second group of 9 diets containg 750 FYT/kg of diet. Slope ratio technique was used to calculate RBP, based on tibia bone ash weigt (TIAW) or toe bone ash weight (TOAW), regressed on added P intake within each P source. Coefficient of determination were higher to TIAW, so these values were used to express RBP. With no phytase added to the diet RBP values were 74,4 (wheat midds), 56,9 (soybean roasted) and 56,5% (soybean extruded), and the addition of 750 FYT/kg of diet increased these values to 79,4; 93,5 and 100%, respectively.

This study has two purposes; first to describe the marketing boards of British Columbia with regard to their nature, scope of power, organizational structure, quota and pricing policies, distribution of returns and policing, and secondly to evaluate the effectiveness of marketing boards with particular attention to the B.C. Broiler Marketing Board. The theory of cartels provides a framework for the analysis of the marketing boards and their effects. Data for the study were obtained primarily from the various boards, the Dominion Bureau of Statistics, and the Canada Department of Agriculture. The B.C. Broiler Board was examined in more detail than the other boards. This Board was used as a case study in analyzing some of the propositions developed in the marketing board model, against actual data of the broiler industry of British Columbia. The conclusions of this study are based upon detailed analysis of the effect of the Broiler Board and more casual observations of the other boards. In general, the producers receive a higher and more stable price for their product, and their membership in the marketing boards appears to engender higher and more stable incomes than could have been obtained by independent producers. This implies that consumers are paying higher prices for the products, provided all other things are held equal. In some instances consumers may benefit from a longer marketing season for local produce, and a wider range of processed products than would have been possible without the marketing boards. / Business, Sauder School of / Graduate

Orientadores: Irenilza de Alencar Nääs, Marta dos Santos Baracho / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agrícola / Made available in DSpace on 2018-08-29T18:46:56Z (GMT). No. of bitstreams: 1 Jacob_FlaviaGerbi_M.pdf: 1951471 bytes, checksum: 1e0b39ce6c3f39342609d2a934a42561 (MD5) Previous issue date: 2015 / Resumo: A produção de frango de corte tem como principal finalidade maximizar o peso da ave em um breve período e com baixo custo. E para isto os parâmetros de ambiência são fundamentais, como a cama aviária, que tem como proposito fornecer qualidades apropriadas para que a ave não desenvolva problemas locomotores, como a pododermatite. O objetivo deste trabalho foi identificar a associação entre a ambiência e a ocorrência de problemas locomotores em frangos de corte. O trabalho foi realizado em uma granja comercial. Os experimentos foram realizados durante dois lotes de produção de frango de corte e conduzidos em quatro condições. O primeiro lote foi aviário (A1), com pressão positiva e cama reutilizada com quatro lotes, e outro aviário (A2) com pressão positiva e cama nova tipo pó de serra. O segundo lote foi aviário (A3), com pressão positiva e cama nova tipo casca de arroz e aviário (A4), com sistema de pressão negativa e cama reutilizada com quatro lotes. Foi realizada uma observação no campo com 75 aves de 28, 35 e 42 dias por aviário, identificando a frequência de aves com cada nível de gait score, foi observado também visualmente os coxins plantares atribuindo o grau de lesão com pododermatite, e através da câmera termográfica verificou a inflamação da lesão em um total de 30 aves de 5, 12, 19, 29 e 40 dias por aviário. Foram registradas as condições de ambiência, bem como as características da cama. Os dados foram analisados buscando-se conhecer as associações. Os resultados mostraram que as idades interagiram com as condições dos aviários em relação ao gait score. O aviário A3 apresentou uma maior incidência de podermatite devido a presença da granulometria do substrato da cama e foi possível melhorar a acurácia do diagnóstico sub-clínico de pododermatite em frangos de corte utilizando termografia infravermelho / Abstract: The broiler production main purpose is to maximize the weight of the broiler in a short time and at low cost. And for this the ambience parameters are fundamental, such as litter, which has the purpose to provide appropriate qualities so that the bird doesn¿t develop locomotor problems such as foot pad dermatitis. The objective of this study was to identify the association between the environment and the existence of locomotor problems in broilers. The project was carried out in a commercial farm. The experiments were followed for two flocks of broiler, and conducted inside four houses. The first broiler flock was house A1, with positive pressure and re-used litter, and other house A2 had positive pressure and new litter type powder saw. The second flock was house A3 with positive pressure and a new litter type of rice husk, and house A4 had with negative pressure and re-used litter. The frequency of birds with each level of gait score was identified, and it was also observed visually the degree of injury with footpad dermatitis. Using the infrared thermal camera the injury inflammation was observed in a total of 30 broilers of 5, 12, 19, 29 and 40 days old. The conditions of the rearing environment as well as the litter characteristics were recorded. Data were analyzed in an attempt to find out the associations. The results showed that the effects of age interacted with the condition of avian to gait score, the house A3 indicated a higher incidence of foot pad dermatitis due the measure of grain size used as substrate and have improved the accuracy of the subclinical diagnosis of foot pad dermatitis in broilers using infrared thermography / Mestrado / Construções Rurais e Ambiencia / Mestra em Engenharia Agrícola

No presente trabalho foram realizadas análises de enterobactérias e Salmonella em cecos e papos de frangos de corte criados sem reaproveitamento de cama e com baixa densidade, submetidos a períodos de jejum de 3, 6, 9, 12, 15 e 18 horas; também foram feitas análises das mesmas bactérias, incluindo esporos de Bacillus subtilis e bactérias ácido lácticas em papos e cecos de frangos de corte alimentados com probióticos (bactérias lácticas, Bokashi e esporos de B. subtilis) e antibiótico (bacitracina de zinco) nas rações. Não houve diferença significativa entre as populações de enterobactérias nos períodos de jejum analisados, e não foram isoladas cepas de Salmonella nos diferentes tratamentos. Houve diminuição significativa na população de enterobactérias nos cecos em relação ao grupo controle quando os frangos foram alimentados com bactérias ácido lácticas nas rações. Com Bokashi e antibiótico nas rações, a população de enterobactérias nos cecos foi maior que no grupo controle. Nos papos, não houve diferença significativa entre as populações de enterobactérias para os diferentes tratamentos, mas o tratamento com Bokashi foi o que obteve menor população das enterobactérias nesse habitat. As contagens de bactérias ácido lácticas e esporos de B. subtilis dos cecos e papos analisados não sofreram alteração significativa devido aos diferentes aditivos presentes nas rações, quando comparadas ao grupo controle. Novamente não foram isoladas cepas de Salmonella nos cecos e papos dos frangos analisados. A ausência de Salmonella pode ter explicação no modo de criação dos frangos, com baixa densidade (12 aves/m2) e sem reaproveitamento de cama, pois foi um resultado encontrado nas duas fases do trabalho. A diminuição de enterobactérias nos cecos por parte das bactérias ácido lácticas administradas na ração pode ter sido devido à exclusão competitiva, apesar da população dessas bactérias não ter aumentado significativamente neste habitat. O tratamento com administração de Bokashi obteve menor contagem de enterobactérias no papo possivelmente devido ao fato de ser um produto fermentado, com pH baixo, que poderia agir prontamente no papo. A administração de esporos de B. subtilis não surtiu efeito nas populações das bactérias analisadas nos cecos e papos dos frangos de corte. / This study analyzed the population of enterobacteria and Salmonella in the crop and caeca of broiler chickens submitted to 3, 6, 9, 12, 15 and 18 hours of feed withdrawal, and raised without reutilization of the litter, in low density. The same bacteria were analyzed, plus Bacillus subtilis spores and lactic acid bacteria, in the crop and caeca of broiler chickens fed rations with probiotics (lactic acid bacteria, Bokashi and B. subtilis spores) and antibiotic (zinc bacitracin). There were no significant differences between enterobacteria populations on the analyzed withdrawal periods, and Salmonella and antibiotic (zinc bacitracin). There were no significant differences between enterobacteria populations on the analyzed withdrawal periods, and B. subtilis spores populations from the caeca and crops of analyzed broiler chickens did not differ from the control group when the different additives were fed through the ration. Again there were no Salmonella isolates in the analyzed crop and caeca. The absence of Salmonella may have an explanation on the way that chickens were raised, with low density (12 birds/m2) and no litter reutilization, because this result was found on the two phases of the study. The lower caeca enterobacteria population found when the broilers were fed lactic acid bacteria may have been due to competitive exclusion, even though the lactic acid bacteria counting did not increase significantly in this habitat. Treatment with Bokashi administration had lower counting of enterobactérias in the crop, possibly due to the fact that Bokashi is a fermented product, with low pH, that could act readily in the crop. The administration of B. subtilis spores did not have any effect on the populations of the analyzed bacteria, in the crop and caeca of broiler chickens.

<p>For this dissertation, four experiments were conducted to evaluate the effect of dietary addition of exogenous protease and amylase enzymes on growth performance and nutrient utilization in broiler chickens. An additional fifth experiment was designed to determine the role of central and peripheral appetite regulators in birds fed diets deficient in dietary phosphorus (P). This arose from consistent reports in literature of a direct effect of dietary P concentration on feeding response in broiler chickens. </p><p>Experiment 1 examined the growth performance and protein utilization responses of broiler chickens to purified trypsin inhibitors (TI) and exogenous protease additions. Experimental diets were arranged as a 2 × 2 factorial with factors being dietary TI (1,033 or 10,033 TIU/g) and exogenous protease (0 or 15,000 PROT/kg). Protease supplementation improved BW gain (<i>P < </i>0.01) and gain to feed ratio (<i>P < </i>0.05) of birds. The relative weight of pancreas increased (<i>P < </i>0.05) with added TI on d 14 and 21 but was reduced (<i>P < </i>0.001) with protease supplementation. Apparent ileal digestibility (AID) of all amino acids (AA), except methionine, decreased (<i>P < </i>0.001) with added TI, but increased (<i>P < </i>0.05) with protease supplementation. Duodenal trypsin and chymotrypsin activities were reduced (<i>P < </i>0.05) with added TI but increased <i>(P < </i>0.01) with protease supplementation. It was concluded that dietary addition of purified TI negatively affects nutrient utilization by broiler chickens and that the efficacy of the exogenous protease might be independent of dietary TI concentration. A follow-up experiment was conducted (Experiment 2) to evaluate the impact of TI and exogenous protease supplementation on endogenous AA loss in broiler chickens. Four diets were arranged as a 2 × 2 factorial with factors being dietary TI (0 or 8,000 TIU/g) and exogenous protease (0 or 15,000 PROT/kg). There was no effect of TI, exogenous protease, or their interaction on growth performance of birds. Endogenous nitrogen (N) loss and all AA (except Cys) increased (P < 0.05) due to added dietary TI. Exogenous protease had no effect on endogenous loss of N and all AA. The AID of Ca, Fe, Mg, Mn, and Cu was reduced (P < 0.05) by added dietary TI. Protease supplementation improved the AID of Cu (P < 0.01) and K (P < 0.05). Secretion of crude mucin and sialic acid (g/kg DM intake) increased (P < 0.05) with increased dietary TI and was not recovered by protease supplementation. It was concluded from this study that TI increases the endogenous loss of AA, reduces the digestibility of minerals in broiler chickens, and that exogenous protease had no effect on endogenous AA flow, irrespective of added dietary TI. </p><p>In Experiment 3, the responses of broiler chickens fed corn-soybean meal-based diets to dietary α-amylase supplementation during 4 growth phases were evaluated. Birds were assigned to 8 treatment diet in a 2 × 4 factorial arrangement of 2 dietary levels of α-amylase supplementation (0 or 80 kilo-Novo alpha amylase units (KNU) per kg diet) and 4 post hatching growth phases (d 0 to 11, d 11 to 21, d 21 to 42, or d 42 to 56). Body weight gain and feed efficiency of birds improved (<i>P</i> < 0.01) with α-amylase supplementation. There were main effects of α-amylase, growth phase and interaction (<i>P</i> < 0.01) on AID of starch. The total tract retention (TTR) of starch increased (<i>P</i> < 0.05) with amylase supplementation but was not different across growth phases. Amylase supplementation improved (<i>P</i> < 0.05) gross energy utilization in birds, and specifically, during d 11 to 21 post hatching, the viscosity of jejunal digesta and pancreatic amylase activity increased (<i>P</i> < 0.01) with amylase supplementation. The conclusion from the study was that the growth phase of birds may affect the response to exogenous amylase. Following the result of this study, Experiment 4 was conducted to evaluate the effect of amylase supplementation on starch and energy digestibility at various intestinal sites in broiler chickens. Experimental diets comprised 3 concentrations of α-amylase supplementation (0, 80, or 160 KNU/kg diet) and sampling was done on 4 intestinal sites: anterior jejunum (AJ), posterior jejunum (PJ), anterior ileum (AI) and posterior ileum (PI). There were linear and quadratic (<i>P</i> < 0.01) responses of increasing α- amylase supplementation on starch and energy digestibility at the PJ and AI, with only linear effects on TTR of starch (<i>P</i> < 0.05). A linear increase in starch disappearance and digestible energy (kcal/kg) was observed (<i>P</i> < 0.01) with digesta flow from AJ to PJ with increasing amylase supplementation, which may be related to the observed decrease in the viscosity of the jejunal digesta (<i>P</i> < 0.05). Results from this experiment demonstrate the efficacy of exogenous amylase to improve starch, and energy digestibility in broiler chickens, with the highest impact observed in the posterior jejunum.</p><p>A final study (Experiment 5) was conducted to evaluate the impact of dietary phosphorus (P) concentration on hypothalamic molecular regulation of appetite by broiler chickens. Birds were randomly assigned to 3 experimental diets which contained 1.2 (P-deficient), 2.8 (P-marginal) or 4.4 (P-adequate) g/kg non-phytate P (nPP). A decrease in feed intake and BW gain was observed (P < 0.001) in birds fed the P-deficient diet. There was upregulation (P < 0.05) in the mRNA expression of Sodium-phosphate cotransporter (NaPi-IIb), anorexia-related hypothalamic cholecystokinin receptor (CCKAR) and melanocortin receptors (MC3R and MC4R) in birds fed P-deficient diets, whereas cholecystokinin (CCK) mRNA was downregulated (P < 0.01). It may be concluded that a deficiency in dietary P decreases feed intake in broiler chickens by altering the expression of anorexigenic genes in the gut and hypothalamus.</p>

This study was conducted with the aim to investigate the efficacy of exogenous enzyme supplementation in releasing metabolisable energy in broiler feeds. Two performance trials were conducted during this study. Effects were measured in terms of the body weight gain, feed intake, feed conversion ratio, mortality and production efficiency factor in broilers. Correct interpretation and practical application of the positive effects of exogenous enzyme supplementation to commercial broiler feeds can aid nutritionists to develop nutritionally balanced broiler feeds at lower costs. The negative effects of anti-nutritional factors in broilers feeds can be greatly reduced with the strategic use of exogenous enzyme addition to the feed. In the first performance trial, four treatment feeds were fed to broilers. The Positive control feed was a balanced diet, formulated according to standard nutrient specifications used by Daybreak Farms, with only the metabolisable energy marginally lower than the standard to ensure that energy was the first limiting nutrient. Nutrient specification met or exceeded recommendations by the NRC (1994). A Negative control feed, similar to the Positive control, was formulated with 0.35 MJ ME / kg feed less than the Positive control. An Avizyme treatment and a Hemicell treatment were formulated similar to the Negative control, with the addition of 0.05% Avizyme and 0.0125% Hemicell to the respective treatments. The addition of Avizyme and Hemicell to the respective treatments was hypothesised to release an additional 0.35 MJ ME / kg feed. Four thousand three hundred and twenty day-old Ross 788 chicks were randomly divided into four treatment groups, each with eight replicates and 135 birds per replicate for the first seven days. After seven days birds were reduced to 126 birds per replicate. In the second performance trial, five treatment feeds were fed to broilers. The Positive control feed was a balanced diet, formulated according to standard nutrient specifications used by Daybreak Farms, with only the metabolisable energy marginally lower than the standard to ensure that energy was the first limiting nutrient. Nutrient specification met or exceeded recommendations by the NRC (1994). Results of the first performance trial indicated that more than the hypothesised 0.35 MJ ME / kg feed was being released from the feed with exogenous enzyme addition. Subsequently, the difference in metabolisable energy between the Negative control and Positive control treatments were increased for the second trial. A Negative control feed, similar to the Positive control, was formulated with 0.45 MJ ME / kg feed less than the Positive control. An Avizyme treatment and a Hemicell treatment were formulated similar to the Negative control, with the addition of 0.05% Avizyme and 0.0125% Hemicell to the respective treatments. A Combination treatment was formulated similar to the Negative control, with the addition of both 0.05% Avizyme and 0.0125% Hemicell to the feed. Seven thousand five hundred and sixty day-old Ross 788 chicks were randomly divided into five treatment groups, each with 12 replicates and 126 birds per replicate. For both trials, birds were housed in environmentally controlled houses with a similar lighting schedule and ad libitum access to feed and water. Body weights, feed intake and mortality were recorded weekly for the duration of the five week performance trials. The data was statistically analysed, using the general linear model function in SAS (Statistical Analysis Systems, 1989; Statistical Analysis Systems, 1994). Fischer’s protected test was used for the post hoc multiple comparison test. Repeated tests were included in the model. The confidence interval was set at 95%. Initial body weight was tested as a covariate in all the analyses. Incorrect dosing of the trial feeds during the first performance trial prevented the evaluation of the treatments for the entire 35 day period. The difference between the Positive control and the Negative control treatments were not large enough to enable the exact determination of the amount of metabolisable energy that the Avizyme released in the feed. It could, however, be concluded that Avizyme addition to a broiler feed increased broiler production efficacy. The Avizyme treatment was contributed at least 0.35 MJ ME / kg feed during the trial released more than 0.35 MJ ME / kg feed during the extended starter phase of the trial. The above mentioned conclusions served as a motivation to increase the metabolisable energy difference between the Positive control and the Negative control treatments for the next performance trial. Addition of Hemicell to the feed contributed 0.35 MJ ME / kg feed over a five week growing period. With the second performance trial, the Avizyme and Hemicell treatments released an additional 0.45 MJ ME / kg feed, supported by broiler production variables similar to the Positive treatment. The Combination treatment was shown to release more than 0.45 MJ ME / kg feed and significantly increased broiler performance. It was concluded that the combination of Hemicell and Avizyme in a broiler ration had a positive synergistic effect on each other in the young broiler, indicating that exogenous enzymes could be more effective in younger broilers. Although exogenous enzymes resulted in the release of a significant amount of additional metabolisable energy in the feed, the addition of these enzymes should undergo economical evaluation to ensure that the addition of these enzymes is viable under commercial circumstances. Addition of Avizyme with a calculated energy contribution of 0.35 MJ ME / kg and 0.45 MJ ME / kg to the feed realised an income over feed cost (IOFC) of 25 c / kg live weight and 4 c / kg live weight, respectively, during the five week period. The Hemicell treatment showed a negative IOFC (suggesting that Hemicell inclusion will decrease profit) of 24 c / kg live weight during the first four weeks of the first production trial and an IOFC of 2 c / kg live weight during the five week period of the second trial. The combination of both enzymes in the feed returned an IOFC of 16 c / kg live weight. In general the income over feed cost was the highest during the starter phase because of a higher efficacy of exogenous enzyme addition in younger broilers. / Dissertation (MSc(Agric))--University of Pretoria, 2012. / Animal and Wildlife Sciences / unrestricted