The prophylactic use of antibiotics is rapidly being phased out of poultry operations. Diseases such as coccidiosis are extremely costly, and typically prevented with coccidiostats and antibiotics. New regulation banning antibiotics is mandating a search for new alternatives, such as probiotics and phytogenic feed additives (PFAs). Two separate studies were performed to evaluate the performance and microbial profiles of commercial broilers fed either PFAs or Eimeria challenged broilers fed probiotics. During the probiotics study, 1056 day-old male Ross broiler chicks were assigned to one of 6 treatments, 8 replicates per treatment, with 22 birds per floor pen in a 2x3 factorial arrangement, with DFM mix and coccidiosis challenge being the main factors. Treatments included a non-infected control (NC), a non-infected low level DFM-fed group (DL), a non-infected high level DFM-fed group (DH), an infected control (PC), an infected low level DFM-fed group (DL+), and an infected high level DFM-fed group (DH+). Performance measurements were taken on d0, d7, d14, d21, and d28. Mucosal scrapings from the ileum were obtained on d7, d14, d21, and d28 to determine microbial profiles. On d15, birds in the three infected groups were challenged with a mixed inoculum containing Eimeria maxima, E. tenella, and E. acervulina. Lesion scores were assessed on d21. Body composition was analyzed via Dual Energy X-Ray Absorptiometry (DXA) on d28. Results indicated a trend (P < 0.1) toward improved D28 body composition, lower Clostridium in DFM-fed challenged broilers compared to PC, and higher Bacillus in DH compared to DH+. Results were not significant for BW, BWG, FI, or lesion scores. The second study evaluated the effects of PFA provided as a dietary supplement over a 6-week period on performance and immune responses in broilers. In total, 1056 day-old male chicks were randomly assigned to 8 replicate pens (22 birds/pen) with 6 treatments including a standard corn/wheat basal diet, a basal with antibiotics, and 4 various combinations of PFA (PHY 1, 2, 3, and 4). Performance was assessed on day 7 (D7), 14, 28, and 42. Starter diet was fed D0-14, grower D14-28, and finisher D28-42. Microbial profiling was assessed on D7, 14, and 42, and body composition measured on D42 using Dual Energy X-Ray Absorptiometry (DXA). Results varied by week, but cumulatively, body weight gain (BWG) per bird was higher in PHY1 and 4, statistically similar to AGP and CTRL. With feed conversion ratio (FCR), PHY2 was higher than any other treatment between D0-42, while all other treatments were similar. PCR results were not statistically significant; however, DXA results indicated a higher lean to fat ratio in birds from PHY1-4 when compared to AGP, indicating an overall leaner bird in PHY treatments. The results of these studies suggest that diets supplemented with DFMs or PFAs result in improved broiler performance. / Master of Science / The prophylactic use of antibiotics is rapidly being phased out of poultry operations. Diseases such as coccidiosis are extremely costly, and typically prevented with coccidiostats and antibiotics. New regulation banning antibiotics is mandating a search for new alternatives, such as probiotics and phytogenic feed additives (PFAs). Two separate studies were performed to evaluate the performance and microbial profiles of commercial broilers fed either PFAs or Eimeria challenged broilers fed probiotics. During the probiotics study, 1056 day-old male Ross broiler chicks were assigned to one of 6 treatments, 8 replicates per treatment, with 22 birds per floor pen in a 2x3 factorial arrangement, with DFM mix and coccidiosis challenge being the main factors. Treatments included a non-infected control (NC), a non-infected low level DFM-fed group (DL), a non-infected high level DFM-fed group (DH), an infected control (PC), an infected low level DFM-fed group (DL+), and an infected high level DFM-fed group (DH+). Performance measurements were taken on d0, d7, d14, d21, and d28. Mucosal scrapings from the ileum were obtained on d7, d14, d21, and d28 to determine microbial profiles. On d15, birds in the three infected groups were challenged with a mixed inoculum containing Eimeria maxima, E. tenella, and E. acervulina. Lesion scores were assessed on d21. Body composition was analyzed via Dual Energy X-Ray Absorptiometry (DXA) on d28. Results indicated a trend (P < 0.1) toward improved D28 body composition, lower Clostridium in DFM-fed challenged broilers compared to PC, and higher Bacillus in DH compared to DH+. Results were not significant for BW, BWG, FI, or lesion scores. The second study evaluated the effects of PFA provided as a dietary supplement over a 6-week period on performance and immune responses in broilers. In total, 1056 day-old male chicks were randomly assigned to 8 replicate pens (22 birds/pen) with 6 treatments including a standard corn/wheat basal diet, a basal with antibiotics, and 4 various combinations of PFA (PHY 1, 2, 3, and 4). Performance was assessed on day 7 (D7), 14, 28, and 42. Starter diet was fed D0-14, grower D14-28, and finisher D28-42. Microbial profiling was assessed on D7, 14, and 42, and body composition measured on D42 using Dual Energy X-Ray Absorptiometry (DXA). Results varied by week, but cumulatively, body weight gain (BWG) per bird was higher in PHY1 and 4, statistically similar to AGP and CTRL. With feed conversion ratio (FCR), PHY2 was higher than any other treatment between D0-42, while all other treatments were similar. PCR results were not statistically significant; however, DXA results indicated a higher lean to fat ratio in birds from PHY1-4 when compared to AGP, indicating an overall leaner bird in PHY treatments. The results of these studies suggest that diets supplemented with DFMs or PFAs result in improved broiler performance.

Eimeria is an apicomplexan parasite causing disease coccidiosis that is most prominent in poultry farming industry. This thesis is aimed to develop new molecular tools and resolve issues that would be a valuable contribution in the field from both research and industry perspective. Because immunity to Eimeria is strictly species- specific, it is important to know and recognize correctly all species that parasitize the host. Traditional diagnostic approaches rely on classical methods such as oocyst morphology determination under the microscope, measurement of prepatent period or in-vivo assessment of lesions caused by this parasite. However, diagnostics of individual species using these methods is very time-consuming and it is often unreliable, especially when mixture of multiple species whose parameters overlap is analyzed. Methods utilizing conventional PCR to distinguish species already exist, however, they lack advantages offered by quantitative real-time PCR (qPCR). The first aim of this thesis was to develop qPCR assays for detection and quantification of seven Eimeria species which infect chicken utilizing single-copy non-polymorphic targets in order to ensure maximal specifity and coverage of all strains of each species. Usefulness of this method was demonstrated by analysis of field...

Neospora caninum é um parasita Apicomplexa que causa doença neuromuscular em cães e abortamento em bovinos. Cães e coiotes são as únicas espécies reconhecidas como hospedeiros definitivos, nas quais ocorre a fase sexuada do ciclo evolutivo do N. caninum, com eliminação de oocistos através das fezes, os quais esporulam no ambiente e tornam-se infectantes. Apesar da importância dos oocistos como fonte de infecção para várias espécies de hospedeiros, a viabilidade e resistência desses oocistos a tratamentos físicos e químicos ainda são desconhecidas. Este estudo teve por objetivo avaliar a viabilidade de oocistos esporulados de N. caninum após tratamentos com diferentes desinfetantes, temperaturas e tempos de exposição. Três cães foram alimentados com tecido cerebral de búfalos soropositivos para anticorpos anti-N.caninum pela reação de imunofluorescência indireta (RIFI 100) para a obtenção de oocistos. Desses, somente um cão eliminou oocistos tipo Neospora-Hammondia sendo confirmado serem de N. caninum por bioensaio em gerbilos e por métodos moleculares (PCR-RFLP). Os oocistos esporulados foram purificados e 11 alíquotas contendo aproximadamente 3000 oocistos por alíquota constituíram cada um dos tratamentos, sendo estes: Formol 10% por 1h; Amônia 10% por 1h; Álcool 70% por 1h; Álcool absoluto por 1h; Iodo 2% por 1h; Hipoclorito de sódio 10% por 1h; Temperatura ambiente, controle; -20ºC por 6h; 4ºC por 6h; 60ºC por 1m e 100ºC por 1m. Os tratamentos químicos foram todos realizados à temperatura ambiente. Após tratamento os oocistos foram divididos em alíquotas com 1000 oocistos cada e estas foram administradas, via oral, a gerbilos (1000 oocistos por gerbilo) sendo cada grupo experimental constituídos por três animais. Depois de 63 dias os gerbilos foram sacrificados e colheu-se sangue para a pesquisa de anticorpos anti-N. caninum (RIFI e western blotting) e tecidos para a pesquisa de cistos em esfregaço direto de cérebro e DNA do parasito (PCR em tempo real), além de pesquisa do agente por técnicas histopatológicas e imuno-histoquímica. Considerou-se eficaz o tratamento que confirmou a inviabilidade dos oocistos por resultados negativos em todas as cinco provas realizadas. Dos tratamentos realizados mostrou-se eficaz o uso de calor a 100ºC por 1 minuto e do hipoclorito de sódio a 10% por 1 hora, podendo ser estes indicados para o controle dessas formas no ambiente. / Neospora caninum is an Apicomplexan parasite that causes neuromuscular disorders in dogs and abortion in cattle. Dogs and coyotes are the only species identified as definitive hosts. The sexual phase of the N. caninum life cycle occurs within the host, and results in the shedding of oocysts in the feces that will sporulate in the environment and become infective. Despite their relevance as a source of infection for a number of different hosts, the resistance and viability of such oocysts to physical and chemical treatments are yet to be known. The purpose of this study was to assess the viability of N. caninum sporulated oocysts after exposure to treatments using different disinfectants, temperatures and periods of time. For acquisition of the oocysts, three dogs were fed brain tissue from buffaloes positive for antibodies to N. caninum by an indirect fluorescent antibody test (IFAT 100). Only one of the dogs excreted Neospora-Hammondia type oocysts. Such oocysts were confirmed to be N. caninum by bioassay in gerbils and molecular methods (PCR-RFLP). The sporulated oocysts were purified and 11 doses with approximately 3,000 oocysts each were treated as follows: 10% formaldehyde (formol) for 1 h; 10% ammonia for 1 h; 70% alcohol for 1 h; absolute alcohol for 1 h; 2% iodine for 1 h; 10% sodium hypochlorite for 1 h; Room temperature, control; -20ºC for 6 h; 4ºC for 6 h; 60ºC for 1 min, and 100ºC for 1 min. All chemical treatments were performed at room temperature. After treatment, the oocysts were divided into doses of 1,000 oocysts each and administered into three gerbils (Meriones unguiculatus) orally (1,000 oocysts per gerbil) per treatment. The gerbils were euthanized after 63 days. Blood samples were taken to be tested for the presence of N. caninum antibodies (IFAT and Western blotting analysis), and tissues samples to be tested for the presence of cysts by brain smear technique and detection of the parasite DNA (real-time PCR), and the identification of the parasite by immunohistochemical and histopathological examinations. In order to be considered an effective treatment, negative results should be observed in the gerbils of all five evaluations conducted. Out of the treatments carried out in this study, exposures to a temperature of 100ºC for 1 min and to a 10% sodium hypochlorite solution for 1 h were effective.

Este estudo teve por objetivos avaliar diferentes níveis de suplementação de ?-ácidos do lúpulo como aditivos de rações para frangos de corte sobre o desempenho e a manutenção do equilíbrio da microbiota intestinal após desafio com Eimeria. No experimento 1, foram alojados 1440 pintos de corte da linhagem Cobb 500, no período de 1 a 42 dias de idade, com 6 tratamentos e 6 repetições. Os tratamentos utilizados foram: controle negativo, ração sem antimicrobiano; controle positivo, ração com 30 mg/kg de bacitracina de zinco e rações com 30, 60, 120 ou 240 mg/kg de ?-ácidos do lúpulo, compondo 4 tratamentos adicionais. Os ?-ácidos foram microencapsulados com 30%de extrato. As rações foram formuladas à base de milho e farelo de soja, com inclusão de 5% de farelo de trigo e 5% de farinha de penas e vísceras. Aos 7 dias de idade todas as aves foram vacinadas contra coccidiose. As aves e as rações foram pesadas semanalmente para cálculo de desempenho. No experimento 2, foram alojados 1440 pintos de corte da linhagem Ross 308, no período de 1 a 42 dias de idade, com 6 tratamentos e 6 repetições. Os tratamentos foram: controle negativo, dieta basal; controle positivo, ração com 30 mg/kg de bacitracina de zinco; controle negativo mais desafio; controle positivo mais desafio; controle negativo suplementado com 30 mg/kg de ?-ácidos mais desafio; controle negativo suplementado com 240 mg/kg de ?-ácidos mais desafio. As rações foram formuladas à base de milho e farelo de soja com inclusão de 5% de farinha de penas e vísceras. Aos 14 dias de idade, as aves dos tratamentos 3, 4, 5 e 6 foram desafiadas, via oral, com 2x105 e 5x104 oocistos de Eimeria acervulina e E. tenella, respectivamente. As aves e as rações foram pesadas semanalmente para obtenção dos dados de desempenho. Aos 21 e 35 dias de idade das aves, coletou-se o conteúdo do intestino delgado e cecos das aves para análise da microbiota intestinal, com auxílio de técnicas moleculares. No experimento 1, aos 21 dias de idade as aves os tratamentos com 30 ou 60 mg/kg de ?-ácidos apresentaram desempenho semelhante às do controle positivo. Aos 42 dias houve melhora na conversão alimentar das aves recebendo 30 e 240 mg/kg de ?-ácidos ou antimicrobiano. No segundo experimento, a coccidiose causou significativa redução no desempenho das aves e nenhum dos aditivos utilizados foi capaz de reverter esta situação. Houve aumento de bactérias do gênero Clostridium no intestino delgado aos 21 dias, em consequência do desafio, entretanto, o maior nível de ?-ácidos reduziu esta população. Aos 35 dias de idade a infecção de coccidiose não alterou a comunidade bacteriana do intestino delgado, mas nos cecos houve aumento do gênero Bacteroides.Os ?-ácidos possuem potencial para serem utilizados nas dietas de frangos de corte em situações de baixo desafio, e podem auxiliar no controle da proliferação de Clostridium, embora ineficazes contra a Eimeria. / The objective was to evaluate increasing level of hops ?-acids in the feed on performance of broiler chickens. A pen trial using 1440 one-day old chickens, from 1 to 42 days, with 6 treatments and 6 replicates was conducted (Experiment 1). The experimental treatments were: negative control, basal diet; positive control, basal diet supplemented with zinc bacitracin, 30 mg/kg; and basal diet supplemented with 30, 60, 120 or 240 mg/kg of hops ?-acids, for 4 additional treatments. The corn soybean meal basal diet was formulated with inclusion of 5% poultry by-product meal and 5% wheat bran. At 7 days of age all birds were vaccinated against coccidiosis. The chickens and the feed were weighted weekly to calculate the performance. In the second experiment, the objective was to evaluate the supplementation of hops ?-acids on performance and the balance of intestinal microbiota of broilers, following challenge with Eimeria acervulina and E. tenella. A pen trial using 1440 one-day-old chickens, from 1 to 42 days, with 6 treatments and 6 replicates was conducted. The experimental treatments were: negative control, basal diet; positive control, basal diet supplemented witn zinc bacitracin, 30 mg/kg; negative controle + challenge; Positive control + challenge; negative control supplemented with 30 mg/kg of hops ?-acids + challenge; negative control supplemented with 240 mg/kg of hops ?-acids + challenge. The corn soybean meal basal diet was formulated with inclusion of 5% poultry byproduct meal. At 14 days of age, the birds in treatments 3, 4, 5 and 6 were challenged with 2x105 and 5x104 oocists of Eimeria acervulina and E. tenella, respectively. The chickens and the feed were weighted weekly to calculate the performance. At 21 and 35 days of age, the small intestine and ceca content was collected to analyze the intestinal microbiota, using molecular techniques. In the first experiment, at 21 days of age the treatment with 30 or 60 mg/kg of ?-acids had the same performance of chickens in positive control. At 42 days, the treatments containing 30 or 240 mg/kg of ?-acids and positive control had improved feed conversion. In the second experiment, there was worse performance in broilers chickens challenged with coccidiosis and the additives were not able to oppose this situation. There was increase in the Clostridium population in the small intestine at 21 days, due to challenge, however, the highest level of ?-acids decreasead this genus. At 35 days, the coccidiosis did not alter the bacterial community in the small intestine, although the ceca had higher level of Bacteroides. The hops ?-acids have the potential to be used in the diets of broiler chickens, under low level of challenge, and to proliferation of Clostridium, although ineffective against Eimeria.

Foram conduzidos três experimentos com os objetivos de avaliar a influência da glutamina e nucleotídeos nas dietas de frangos de corte, considerando o desempenho, desenvolvimento e atividade enzimática da mucosa intestinal. No 1º experimento, foi determinado os melhores níveis de suplementação das fontes de glutamina, isolado (L-Gln) ou associado com ácido glutâmico (Aminogut®), e de acordo com resultados obtidos para as características de desempenho e atividades enzimáticas (mucosa intestinal e pâncreas), observou-se melhor desempenho para aves suplementadas com 1,5% de L-Gln e 3,0% de Aminogut®. No 2º experimento, foi determinado o melhor período (1 a 7, 1 a 14 ou 1 a 21 dias de idade) de suplementação dos níveis ótimos das fontes de glutamina observados no experimento 1. Segundo dados de desempenho, atividades enzimáticas e morfometria do intestino delgado (duodeno, jejuno e íleo), determinou-se que as fontes de glutamina podem ser suplementadas durante os primeiros sete dias de vida das aves, proporcionando aumento nas atividades das enzimas digestivas e pancreáticas nos frangos. No 3º experimento, foram avaliados os efeitos de três fontes de ação trófica (L-Gln, Aminogut® e nucleotídeos) associadas à vacinação contra a coccidiose, sobre o desenvolvimento do intestino delgado e algumas respostas imunológicas das aves. Pode ser observado efeito negativo da vacinação sobre o desempenho e morfometria da mucosa intestinal, entretanto, ao final do período experimental, as fontes de glutamina mostraram-se eficiente em recuperar perdas epiteliais da mucosa intestinal das aves desafiadas contra a coccidiose. Portanto, a suplementação destas fontes de ação trófica pode ser uma estratégia para o bom desenvolvimento dos frangos quando submetidos à estresse vacinal, considerando ainda a viabilidade econômica pelo segmento produtivo. / Three experiments were carried out to evaluate the influence of glutamine and nucleotides in diets of broiler chickens, on performance, development and enzymatic activity of the intestinal mucosa. In the first experiment, was estimated the best levels of glutamine sources supplementation, isolated (L-Gln) or associated with glutamic acid (Aminogut®). According to results for performance characteristics and enzymatics activities (intestinal mucosa and pancreas), was observed best performance for birds supplemented with 1.5% of L-Gln and 3.0% of Aminogut®. In the second experiment, was determined the best supplementation period (1 to 7; 1 to 14 or 1 to 21 days of age) of levels of glutamine sources observed in the first experiment. The results of performance, enzymatics activities and small intestine morphometry (duodenum, jejunum and ileum), suggested that glutamine sources evaluated can be supplemented during the first seven days of age, providing an increase in the enzymatics digestives and pancreatic activities at the broiler chickens. In the third experiment, were evaluated the effects of three sources with action trophic (L-Gln, Aminogut® and nucleotides) associated with vaccination against coccidiosis on development of small intestine and immune responses of the broilers. It was observed negative effect of vaccination on performance and morphometry of intestinal mucosa, however, at the end of experimental period, the glutamine sources showed efficiency to recovery epithelial losses of intestinal mucosa of birds, which were challenged against coccidiosis. Therefore, the supplementation of the trophic sources can be a strategy for optimum development of broilers when submitted to vaccination stress, considering the economic viability by the productive segment.

Eimeria tenella é umas das principais espécies que causam a coccidiose aviária. Para se estudar o perfil de expressão gênico quantitativo em estágios infectantes bibliotecas de LongSAGE foram geradas a partir de merozoítos e esporozoítos. Mais de 35.000 tags foram obtidas, das quais, 9.516 eram únicas. Para a identificação e anotação de genes diferencialmente expressos, as tags foram extraídas, contadas e analisadas estatisticamente por um pacote desenvolvido pelo nosso grupo, SAGE Analysis. Um total de 197 seqüências foram reconstruídas e anotadas automaticamente. Foi observado uma expressão estágio-específica e perfil transcricional distinto entre os estágios. Em merozoítos, foram encontradas proteínas envolvidas na tradução e manutenção da conformação protéica e em esporozoítos, os resultados positivos foram relacionados à cromatina, transporte e atividade catalítica. Para validação da técnica, a expressão diferencial de um pequeno conjunto de genes foi quantificada por RT-qPCR. Os resultados demonstraram uma boa correlação entre estas duas plataformas. / Eimeria tenella is one of the most important causing agents of poultry coccidiosis. To study the quantitative gene expression profile in zoite stages of LongSage libraries were generated from merozoites and sporozoites. More than 35.000 tags were obtained, whose 9.516 were unique. For identification and annotation of differential expressed genes, tags were extracted, counted and submitted to statistical analysis by Sage Analysis, software developed by our group. A total of 197 tags were reconstructed and automatic annotated. Stage-specific expression genes and distinct transcriptional profile were observed between these stages. In merozoites the results were related to protein translation and folding, and in sporozoites the proteins were involved to chromatin structure, transport and catalytic activity. To LongSAGE validation, differential expression was quantified using RT-qPCR to a small group of genes. Good correlation was observed between these platforms.

Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2017-05-05T14:21:03Z No. of bitstreams: 1 2012 - Cleide Domingues Coelho.pdf: 19229976 bytes, checksum: 94c069047adceba0bbb1974c338db08e (MD5) / Made available in DSpace on 2017-05-05T14:21:03Z (GMT). No. of bitstreams: 1 2012 - Cleide Domingues Coelho.pdf: 19229976 bytes, checksum: 94c069047adceba0bbb1974c338db08e (MD5) Previous issue date: 2012-02-28 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Parasites can affect the physical condition, survival and reproduction of birds may be an important factor in the life history of the host, exerting strong pressure ecological and evolutionary. Among the most important parasites affecting passerine birds, Isospora species were included, and the oocysts counts were used for estimating infection in wild birds as well as essential for studies of prevalence, diagnosis and control of coccidiosis in birds from seizures of wild animals, and keeping under quarantine at Wild Animal Sorting Center and latter for the release. This study aimed to determine the circadian rhythm or periodicity in the elimination of oocysts of Isospora species in Passeriformes, and identify the species of parasite found and verify the effectiveness and prophylaxis of anticoccidial drugs during the quarantine period. In a total of 1393 fecal samples were collected from birds of the order Passeriformes belonging to different families and species, from the apprehensions of wild animals and sent to CETAS (Wild Animal Sorting Center)/IBAMA at Municipality of Serop?dica in the State of Rio de Janeiro. After a period of sporulation, the samples were subjected to centrifugal flotation technique with sucrose, quantified and the results expressed in OoPD (oocysts per defecation). The results showed that, regardless of the continent where the birds live, photoperiod is an important factor in maintaining the schedule for the elimination of oocysts of the genus Isospora. Birds of several families had an OoPD means, in relationship of shedding oocysts in the feces, the highest eliminations is in the afternoon. For control of coccidiosis in these birds, throughout the use of anticoccidial drugs were observed that the effectiveness may vary with the species of the parasite and the birds, because they have different feeding habits and behavior, which may influence the response to treatment / Os parasitos podem afetar a condi??o f?sica, sobreviv?ncia e reprodu??o das aves, podendo ser um importante fator na hist?ria de vida do hospedeiro, exercendo forte press?o ecol?gica e evolucion?ria. Dentre os parasitos mais importantes que afetam os Passeriformes podemos citar os cocc?dios do g?nero Isospora, e a estimativa da infec??o em p?ssaros silvestres ? essencial para os estudos de preval?ncia, diagn?stico e controle deste cocc?dio nas aves oriundas de apreens?es do tr?fico de animais silvestres, encaminhadas e mantidas sob regime de quarentena nos centros de triagem de animais silvestres e destinadas ? soltura. Este trabalho teve por objetivo, determinar o ritmo circadiano ou periodicidade na elimina??o de oocistos de Isospora spp. em Passeriformes, assim como identificar as esp?cies do parasito encontradas e verificar a efic?cia dos anticocc?dios na profilaxia durante o per?odo de quarentena. Foram coletadas 1393 amostras fecais de aves da ordem Passeriformes pertencentes ? diversas fam?lias e esp?cies, oriundas da apreens?es do tr?fico de animais silvestres e encaminhadas ao CETAS/IBAMA, Serop?dica, RJ. Ap?s um per?odo de esporula??o, as amostras foram submetidas a t?cnica de centr?fugo-flutua??o com sacarose, quantificadas e os resultados expressos em OoPD (oocistos por defeca??o). Os resultados demonstraram que independentemente do continente onde as aves habitam, o fotoper?odo ? um fator importante na manuten??o da periodicidade da elimina??o dos oocistos de Isospora spp. e os Passeriformes de diversas fam?lias apresentaram um valor m?dio de OoPD mais elevado no per?odo da tarde. Foi verificado o controle da coccidiose nestes p?ssaros atrav?s do uso de anticocc?dios e observou-se que a efic?cia pode variar de acordo com a esp?cie do parasito e dos p?ssaros, os quais apresentam h?bitos comportamentais e alimentares diversificados que podem influenciar na resposta ao tratamento.

Feed accounts for the highest cost associated in poultry production, with energy-containing feedstuffs being the most expensive portion of the cost of feeding. The increasing demand for poultry meat gives reason to determine accurate apparent metabolizable energy (AME) values for various feedstuff through measuring energy utilization in the birds. The adaptation length of birds fed an experimental diet may affect the determined AME value due to the diet matrix and physiochemical properties of the feedstuff. Therefore, the objective of this thesis was to evaluate a select group of energy-containing feedstuff with different diets and with factors such as coccidia challenge and exogenous enzyme supplementation that may influence the determined AME values in broiler chickens.

Diss. (sammanfattning). Uppsala : Sveriges lantbruksuniv. / Härtill 6 uppsatser.

Eimeria tenella est l’un des parasites apicomplexes à l’origine de la coccidiose aviaire, l’une des plus importantes maladies parasitaires de l’industrie avicole. Dans le but de caractériser les facteurs de pathogénicité d’E. tenella, nous nous sommes intéressés aux protéases et plus particulièrement aux aminopeptidases N. Nous avons caractérisé Et-ApN1 et identifié Et-ApN3, deux aminopeptidases d’E. tenella. Et-ApN1 présente de fortes homologies avec PfA-M1, l’homologue de Plasmodium falciparum, au niveau des séquences, des structures, des propriétés biochimiques, du clivage et de la localisation. L’ensemble des résultats suggèrent qu’Et-ApN1 est impliquée dans le développement parasitaire. Pour évaluer son rôle de cible thérapeutique potentielle, nous avons criblé une bibliothèque de molécules et identifié une nouvelle molécule le C36, qui inhibe directement l’activité d’Et-ApN1 et entraîne un arrêt du développement d’E. tenella in vitro. Cet effet inhibiteur est également observé chez Toxoplasma gondii et P. falciparum. Dans le but d’améliorer la solubilité du C36 pour de futures études in vivo, le C36 a été pharmaco-modulé. Les perspectives de ces travaux viseront à prouver l’implication directe des Et-ApN dans le développement d’E. tenella. / Eimeria tenella is an apicomplexan parasite causing avian coccidiosis, one of the most important parasitic diseases in world poultry industry. To identify E. tenella pathogenesis factors, we were interested in proteases and more specifically in aminopeptidases N. We characterized Et-ApN1 and identified Et-ApN3, two aminopeptidases of E. tenella. We revealed strong homologies in the sequences, structures, biochemical properties, cleavage patterns and localization between Et-ApN1 and PfA-M1, the homologue from Plasmodium falciparum. Taken together, our results suggest that, as PfA-M1, Et-ApN1 is involved in parasite development and could be considered as a therapeutic target. To confirm this hypothesis, we screened a small molecule library and identified the compound C36. This molecule not only inhibits Et-ApN1 but also the in vitro development of E. tenella. This inhibition of parasite development was also observed for Toxoplasma gondii and P. falciparum. In perspectives, a pharmaco-modulation approach will be performed to improve chemical properties of the compound C36. New molecules derived from C36 will then be tested in vivo. Future studies will aim to prove the direct implication of Et-ApN in E. tenella development.