A estrutura social é a rede de relações estabelecidas entre os indivíduos do grupo e essa estrutura pode ser afetada por fatores como o parentesco e a condição nutricional. Um comportamento intrigante, que foi associado ao parentesco e à condição nutricional, é a alo-amamentação, em que uma fêmea amamenta filhotes de outras fêmeas. Este estudo teve por objetivos determinar a influência do parentesco e da condição nutricional na estrutura social de catetos (Tayassu tajacu) em cativeiro e descrever os eventos de alo-amamentação, buscando verificar variáveis que possam ajudar a compreender o comportamento nesta espécie. Para tal, foram observados dois grupos de animais cativos, um com dez indivíduos (grupo B2) e outro com sete (grupo B3). O grupo B2 foi submetido a uma dieta com 16% de proteína bruta e o B3, com 12%. Os animais dos dois grupos tiveram seu sangue coletado para a análise de parentesco, que foi feita utilizando-se marcadores moleculares microssatélites. Como ainda não tinham sido desenvolvidos primers de microssatélites para catetos, foram testados primers desenvolvidos para suínos. Essa metodologia mostrou-se eficaz para acessar locos de microssatélites em catetos e foi possível, através dela, estimar o coeficiente de parentesco entre os indivíduos. As interações afiliativas e agonísticas e os eventos de alo-amamentação foram registrados pelo método de todas as ocorrências. A proximidade espacial foi obtida registrando-se o padrão de subgrupos formados pelos indivíduos por meio de varredura instantânea. No geral, o grupo B2 apresentou maior ocorrência de interações agonísticas e afiliativas do que o B3, e foi caracterizado por uma estrutura igualitária quanto às relações de dominância, enquanto que o B3 se apresentou mais organizado hierarquicamente. O parentesco não pareceu influenciar diretamente a freqüência das interações agonísticas, mas foi possível associar esta variável com a freqüência de interações afiliativas e proximidade espacial. Os indivíduos aparentados ficaram mais próximos na estrutura espacial e, principalmente no B3, interagiram mais afiliativamente. Os eventos de alo-amamentação foram pouco freqüentes e não pareceram acarretar muitos custos para a fêmea. Foi levantada a questão de que tal comportamento possa ser um comportamento afiliativo e possibilitar a formação de vínculos entre os filhotes e as fêmeas alheias. / The network of relationships established among individuals of a group is called social structure, and may be affected by factors as relatedness and nutritional conditions. Allonursing is an intriguing behavior characterized by the non-parental female nursing of infants. The goals of this study were determine the influence of relatedness and nutritional conditions in the social structure of collared peccaries (Tayassu tajacu) in captivity, and describe allonursing events to identify variables that may help the understanding of this behavior. Two groups of captive animals were studied, one with ten and another with seven individuals (B2 and B3 respectively). The B2 group diet contained 16% of crude protein, while the B3 group was fed with a 12% protein diet. Animals from both groups had blood samples collected for microsatellite analysis. Porcine primers were used to amplify microsatellites in collared peccary and this methodology was successfully applied to estimate genetic relationships among individuals. Agonistic and affiliative interactions as well as allonursing events were recorded using the all occurrences method, while spatial proximity among individuals was recorded using scan sampling. The B2 group presented a higher occurrence of agonistic and affiliative interactions than the B3 group, while the latter group was the most hierarchically organized. Genetic relationships did not directly influence the frequency of agonistic interactions, but influenced the frequency of affiliative interactions, as well as level of spatial proximity. Closely related individuals were generally more spatially close, and specially in the B3 group had more affiliative interactions. Allonursing events were rare and do not appear to cause much cost to the females. We raise the hypothesis of the latter behavior as an important factor to the formation of bonds among infants and non-parental females.

A estrutura social é a rede de relações estabelecidas entre os indivíduos do grupo e essa estrutura pode ser afetada por fatores como o parentesco e a condição nutricional. Um comportamento intrigante, que foi associado ao parentesco e à condição nutricional, é a alo-amamentação, em que uma fêmea amamenta filhotes de outras fêmeas. Este estudo teve por objetivos determinar a influência do parentesco e da condição nutricional na estrutura social de catetos (Tayassu tajacu) em cativeiro e descrever os eventos de alo-amamentação, buscando verificar variáveis que possam ajudar a compreender o comportamento nesta espécie. Para tal, foram observados dois grupos de animais cativos, um com dez indivíduos (grupo B2) e outro com sete (grupo B3). O grupo B2 foi submetido a uma dieta com 16% de proteína bruta e o B3, com 12%. Os animais dos dois grupos tiveram seu sangue coletado para a análise de parentesco, que foi feita utilizando-se marcadores moleculares microssatélites. Como ainda não tinham sido desenvolvidos primers de microssatélites para catetos, foram testados primers desenvolvidos para suínos. Essa metodologia mostrou-se eficaz para acessar locos de microssatélites em catetos e foi possível, através dela, estimar o coeficiente de parentesco entre os indivíduos. As interações afiliativas e agonísticas e os eventos de alo-amamentação foram registrados pelo método de todas as ocorrências. A proximidade espacial foi obtida registrando-se o padrão de subgrupos formados pelos indivíduos por meio de varredura instantânea. No geral, o grupo B2 apresentou maior ocorrência de interações agonísticas e afiliativas do que o B3, e foi caracterizado por uma estrutura igualitária quanto às relações de dominância, enquanto que o B3 se apresentou mais organizado hierarquicamente. O parentesco não pareceu influenciar diretamente a freqüência das interações agonísticas, mas foi possível associar esta variável com a freqüência de interações afiliativas e proximidade espacial. Os indivíduos aparentados ficaram mais próximos na estrutura espacial e, principalmente no B3, interagiram mais afiliativamente. Os eventos de alo-amamentação foram pouco freqüentes e não pareceram acarretar muitos custos para a fêmea. Foi levantada a questão de que tal comportamento possa ser um comportamento afiliativo e possibilitar a formação de vínculos entre os filhotes e as fêmeas alheias. / The network of relationships established among individuals of a group is called social structure, and may be affected by factors as relatedness and nutritional conditions. Allonursing is an intriguing behavior characterized by the non-parental female nursing of infants. The goals of this study were determine the influence of relatedness and nutritional conditions in the social structure of collared peccaries (Tayassu tajacu) in captivity, and describe allonursing events to identify variables that may help the understanding of this behavior. Two groups of captive animals were studied, one with ten and another with seven individuals (B2 and B3 respectively). The B2 group diet contained 16% of crude protein, while the B3 group was fed with a 12% protein diet. Animals from both groups had blood samples collected for microsatellite analysis. Porcine primers were used to amplify microsatellites in collared peccary and this methodology was successfully applied to estimate genetic relationships among individuals. Agonistic and affiliative interactions as well as allonursing events were recorded using the all occurrences method, while spatial proximity among individuals was recorded using scan sampling. The B2 group presented a higher occurrence of agonistic and affiliative interactions than the B3 group, while the latter group was the most hierarchically organized. Genetic relationships did not directly influence the frequency of agonistic interactions, but influenced the frequency of affiliative interactions, as well as level of spatial proximity. Closely related individuals were generally more spatially close, and specially in the B3 group had more affiliative interactions. Allonursing events were rare and do not appear to cause much cost to the females. We raise the hypothesis of the latter behavior as an important factor to the formation of bonds among infants and non-parental females.

La dispersion est un trait d'histoire de vie clé pour les processus écologiques et évolutifs dans les populations naturelles. Les dernières recherches se sont notamment focalisées sur les corrélations entre traits comportementaux et la dispersion, ceci afin de mettre en évidence des syndromes comportementaux de dispersion, tout en démontrant la base génétique de la dispersion. Les dispersants ne seraient donc pas une part aléatoire d'une population, mais des individus montrant des stratégies particulières qui augmenteraient leur chances de succès. Cette thèse s'est orientée vers trois objectifs de recherche majeurs. Le premier est la mise en évidence d'une base génétique de la probabilité de disperser dans une population fragmentée de gobe-mouches à collier Ficedula albicollis. Les résultats nous ont montré, au-delà de l'estimation de la base génétique de la dispersion, une distribution spatiale non aléatoire de l'apparentement dans cette population, qui pourrait être dû à des effets génétiques sur les règles de décision de choix de l'habitat. Le deuxième s'intéresse à la corrélation phénotypique et génétique entre le comportement de dispersion natale et le comportement de défense du nid, chez le martinet alpin Tachymarpis melba. Nous avons montré que la dispersion natale et le comportement de défense du nid sont négativement corrélés au niveau phénotypique mais aussi génétique dans ces populations. Enfin, le troisième nous à conduit à tester l'existence de syndromes comportementaux de dispersion, c'est-à-dire si les dispersants présentent un profil comportemental particulier, leur permettant en particulier de coloniser de nouveaux sites, chez le gobe-mouche à collier / Dispersal is a key like history trait for ecological and evolutionary processes in wild population. The last researching particularly focused on the correlation between behavioural trait and dispersal, in order to emphasize the existence of behavioural syndromes of dispersal, and on the estimation of the genetic basis of the dispersal behaviour. Dispersant individuals could not be a random part of the population, but individuals showing particular strategies, that help them to succeed in their dispersal attempt. This thesis has three main aims of research. The first is to show a genetic basis of the dispersal propensity in a fragmented population of collared flycatchers (Ficedulla albicollis). We shown not only the genetic bases of the dispersal, but also a non-random spatial distribution of relationship between individuals in this population, that might be due to genetic effects on the decision rules of habitat choice in this population. The second aim concerns phenotypic and genetic correlation between the natal dispersal and a behavioural trait, the nest-defense behaviour, in the alpin swift (Tachymarpis melba). We shown that natal dispersal and nest-defense behaviour are negatively correlated at a phenotypic level, but also at a genetic level in theses populations. Finally, the third aim attempt to test the existence of behavioural syndrome of dispersal, that is if dispersant individuals have a particular behavioural profile, which enable them to colonize new sites, in the collared flycatcher

This thesis considers the nature of pottery and its wider roles in the Highlands and Northern Isles of Scotland from 2500-1800 BC. The period under study represents a key moment in British prehistory with the introduction of metallurgy and wide-ranging changes in society. Since the inception of early Bronze Age studies pottery has played an important role in examinations of identity and chronology. As identified by several scholars there has been a recurrent emphasis on a select number of interpretive themes and regions such as Wessex and Aberdeenshire. This has marginalised certain areas creating an imbalance in our understanding of the tempo and dynamics of change during the period. Recent reviews have begun to address this issue, highlighting the importance of regional studies to our overall understanding of change in the later 3rd millennium. At present, there is no synthesis of ceramic material from the Highlands and Northern Isles that considers the diverse array of pot types and the contexts in which they are found. In response, this thesis aims to characterise the range of ceramic types, their contexts and associations. Through the course of this thesis a series of detailed regional datasets and interpretations are constructed. This is coupled with a review of the longer-term ceramic sequence across the study area, situating the advent of novel pot types within the existing ceramic repertoire. Secondly, this thesis examines the dynamics of ceramic similarity and difference, and what this reveals about regional preferences and identities alongside broader intra and supra regional networks. Drawing on recent relational approaches this thesis explores how ceramic categories came into being, persisted and dissipated at a range of scales. These approaches highlight the fluid nature of change and the need to consider pots as elements of wider assemblages. Through this examination it is possible to detect distinct trends in regional ceramics, allowing for the construction of narratives that extend beyond defining visual similarities, contributing towards understanding the wider significance of similarity and difference.

Made available in DSpace on 2016-08-15T20:30:56Z (GMT). No. of bitstreams: 1 KeillaMM_DISSERT.pdf: 1345823 bytes, checksum: a6ff218a65e6e176cd8e848fa7952f14 (MD5) Previous issue date: 2011-06-03 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / The aim of this research was to study the estrous cycle physiology of female collared peccaries bred in captivity at Semiarid. At the first experiment, the changes in hormonal status (estrogen and progesterone), vaginal cytology and ovarian ultrasonographic patterns were described and correlated in four mature females. It was monitored 1.5 estrous cycle per animals during 45 days evaluation, with an average duration of 21 ± 5.7 days, estrogen presented a peak value of 55,57 ± 20,47 pg/mL and during the luteal phase, the peak values for progesterone were 35.3 ± 4.4 ng/mL. The diameter of the ovarian follicles was 0.23 ± 0.1 cm during the moment of the estrogen peak and corpora lutea measured 0.36 ± 0.2 cm identified during the luteal phase, through ultrasound evaluation. No relations amongst the hormonal profiles and vaginal cytology were identified during any moment of the cycle (P > 0.05), it was suggested that the second method was not accurate for estrus monitoring in the above mentioned species. In the second experiment, we tested a protocol for synchronization of estrus in five female collared peccaries, using two doses of 0.8 mL (60 μg) of the prostaglandin analogue, cloprostenol, with an interval of nine days, performing alongside the dosage of estrogen to monitor the estrous cycle. The occurrence of estrogen peak was verified in all the animals after the second application at 9.2 ± 1.1 days, with an average of 28.05 ± 10.41 pg / ml estrogen, and the external signs of estrus, as opening vulvar, vaginal mucosa hyperemic and vaginal mucus were observed in four animals (80%). Therefore, it was proved the efficiency of the application of a prostaglandin analogue, cloprostenol, on estrus synchronization in this species. / O objetivo do presente trabalho foi estudar a fisiologia do ciclo estral de fêmeas de cateto mantidas em cativeiro no semi-árido brasileiro e desenvolver um protocolo para a sincronização de estro nesta espécie. Em um primeiro experimento, buscou-se descrever e correlacionar as alterações no perfil hormonal (estrógeno e progesterona), citologia vaginal e padrão ultra-sonográfico dos ovários durante o ciclo estral de quatro fêmeas de catetos. Foram observados 1,5 ciclo estral por animal em 45 dias de avaliação, com duração média de 21 ± 5,7 dias, o estrógeno apresentou um valor de pico de 55,57 ± 20,47 pg / mL e durante a fase lútea, os valores de pico de progesterona foram de 35,3 ± 4,4 ng / mL. O diâmetro dos folículos ovarianos foi de 0,23 ± 0,1 cm no momento do pico de estrógeno e corpos lúteos mediram 0,36 ± 0,2 cm, identificados durante a fase lútea, por imagem ultrassonográfica. Não foram observadas relações significativas entre o perfil hormonal e citologia vaginal, durante nenhum momento do ciclo estral (P > 0.05), sugerindo-se que o segundo método não é exato para o monitoramento do estro na espécie. No segundo experimento, foi testado um protocolo de sincronização de estro em cinco fêmeas de cateto, utilizando duas doses de 0,8 mL (60 μg) do análogo da prostaglandina, com intervalo de nove dias, realizando-se paralelamente dosagem de estrógeno para o acompanhamento do ciclo estral. Obtendo-se ocorrência de pico de estrógeno em todos os animais após a segunda aplicação em 9,2 ± 1,1 dias, com em média, 28,05 ± 10,41 pg/mL de estrógeno, sendo observados sinais externos de estro, como abertura vulvar, mucosa vaginal hiperêmica e presença de muco vaginal em quatro animais (80%). Os resultados sugerem que a aplicação do análogo da prostaglandina, cloprostenol, foi eficiente para sincronização de estro nesta espécie.

Made available in DSpace on 2016-08-15T20:31:37Z (GMT). No. of bitstreams: 1 ThiberioSC_DISSERT.pdf: 700205 bytes, checksum: 7a5563445307116480b9ce4be88608c4 (MD5) Previous issue date: 2010-03-05 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / We evaluated the effect of centrifugation and the use of Tris-based extender supplemented with different sugars as well as different rates of thawing on the kinematic pattern of motility and other characteristics of frozen-thawed semen from captive collared peccaries. Semen from 13 collared were collected by electroejaculation and evaluated subjectively for motility, vigor and by computer analysis (CASA). Other features such as sperm viability, membrane integrity and morphology of spermatozoa were also evaluated. Semen was divided into four portions: two were subjected to centrifugation and then diluted in a tris plus fructose and the other in tris supplemented with glucose, the other two forms were immediately diluted in the same way. Egg yolk (20%) and glycerol (6%) were added to all groups. The samples were frozen in liquid nitrogen and thawed using two thawing rates (37ºC/1min and 55°C/7s). The results showed a reduction in total motility immediately after the dilution using both extenders and interference in some kinematic parameters such as BCF, LIN and STR for the samples centrifuged, , in addition, an increase in the number of total and secondary morphological defects were observed in centrifuged samples, independent to the sugar used (P <0.05). No significant differences among the extenders supplemented with fructose or glucose were verified at any time (P> 0.05). Furthermore, no interaction between the supplementation of sugar and thawing rates were observed for any semen parameter evaluated (P> 0.05). In conclusion, it is not necessary to centrifuge the semen from collared prior to the procedure of freezing and thawing, which can be achieved through a Tris-based extender supplemented with either fructose or glucose, as well as using different thawing rates (37ºC/1min and 55°C/7s). / Avaliou-se o efeito da centrifugação e da utilização de diluentes a base Tris suplementados com diferentes açúcares além de diferentes taxas de descongelação sobre os padrões cinemáticos de motilidade e outras características do sêmen congeladodescongelado de catetos em cativeiro. O sêmen de 13 catetos foi coletado por eletroejaculação e avaliados subjetivamente e através de análise computadorizada (CASA) para motilidade, vigor. Outras características como viabilidade espermática, integridade da membrana e morfologia dos espermatozóides também foram avaliadas. O sêmen foi dividido em quatro alíquotas: duas foram submetidas à centrifugação e em seguida diluídas, uma em tris acrescido de frutose e a outra em tris acrescido de glicose, as outras duas forma imediatamente diluídas da mesma forma. Gema de ovo (20%) e glicerol (6%) foram adicionados para todos os grupos. As amostras foram congeladas em nitrogênio líquido e descongeladas usando duas taxas de descongelação (37ºC/1min e 55ºC/7s). Os resultados demonstraram uma redução na motilidade total imediatamente após a diluição em ambos diluentes para as amostras centrifugadas, bem como em alguns parâmetros cinemáticos como BCF, LIN e STR além do aumento no número de alterações morfológicas totais e secundarias independente do açúcar utilizado (P<0,05), tendo em vista não ter apresentado diferenças entre os diluentes suplementados com frutose ou glicose em nenhum momento (P> 0,05). Além disso, nenhuma interação entre a suplementação de açúcar e as taxas de descongelação foi observada para qualquer parâmetro seminal avaliado (P> 0,05). Em conclusão, não é necessário centrifugar o ejaculado de catetos antes dos procedimentos de congelação e descongelação, para os quais pode-se utilizar um diluente a base de Tris suplementado tanto com frutose ou glicose, bem como utilizando taxas de descongelação diferentes (37ºC/1min e 55ºC/7s).

La dispersion est définie comme le mouvement d'un individu entre le site de naissance et le premier site de reproduction ou entre deux sites de reproduction. La dispersion se traduit par des échanges d'individus et des flux de gènes entre les populations et est donc reconnue comme un trait d'histoire de vie clé de part son rôle déterminant sur de nombreux processus écologiques et évolutifs comme la dynamique ou la génétique des population, la répartition spatiale des espèces ou encore la capacité des espèces à faire face aux changements brutaux induits par les activités humaines. Pourtant les conséquences de la dispersion en terme de valeur sélective individuelle restent mal connues malgré leur importance dans l'évolution de la dispersion. Le but de cette thèse est d'identifier plus précisément les conséquences de la dispersion en terme de valeur sélective individuelle en utilisant à la fois des approches corrélative et expérimentale dans une population sauvage de passereaux migrateurs, le gobe mouche à collier (Ficedula albicollis). Grâce à des données à long terme comprenant plus de 20 ans de suivi, des différences entre les individus dispersants et philopatriques ont pu être mises en évidence à la fois à l'échelle de la vie des individus et à l'échelle annuelle, celle de l'événement de reproduction. Les résultats mettent en évidence des effets de la dispersion dépendant à la fois des conditions et du phénotype des individus et soulignent donc le fait que la balance entre les coûts et les bénéfices est le résultat d'interactions subtiles entre l'environnement et les caractéristiques de l'individu. D'autre part, l'expérience de dispersion forcée a permis de démontrer clairement l'existence de coûts liés à l'établissement dans un environnement non familier que seuls certains individus sont capables de surmonter. Enfin, l'absence de différence dans les décisions majeures de reproduction une fois les individus établis, suggère que la dispersion doit majoritairement être adaptative, une fois les coûts de l'installation surmontés / Dispersal is commonly defined as the movement of an individual from its natal or previous breeding site to a new breeding site. Because dispersal involves movements of individuals and genes among populations, it is widely recognized as a key life history trait with strong effects on many ecological and evolutionary processes, such as population dynamics and genetics but also species spatial distribution or response to brutal environmental variations induced by human activities. Yet, the consequences of dispersal in terms of individual fitness remain poorly understood despite their crucial importance in the understanding of the evolution of dispersal. The aim of this PhD is to get better insights in the fitness consequences of dispersal using both correlative and experimental approaches at different scales, i.e. annual and lifetime scales, in a wild patchy population of migratory passerine bird, the collared flycatcher (Ficedula albicollis). Using a long term data set encompasses more than 20 years of data, differences between dispersing and philopatric individuals were showed both at a lifetime and annual scale. The results highlighted strong phenotypic- and condition-dependent effects of dispersal and underline that the balance between the costs and benefits of dispersal is likely to be the result of subtle interactions between environmental factors and individuals’ phenotype. Moreover, the experiment of forced dispersal demonstrated that dispersal might entail costs linked with settlement in a new habitat, which only some individuals may overcome. Nevertheless, the absence of difference in major fitness related decisions after settlement suggests that dispersal is mostly adaptive for individuals overcome such costs

Climate change is affecting the distribution of species, sometimes making previously separated species come into secondary contact. For closely related species, this often leads to competition and sometimes also hybridization, which can have negative effects on genetic bio? diversity. Collared flycatcher (Ficedula albicollis) and pied flycatcher (Ficedula hypoleuca) are two closely related species that hybridize where they meet on the Swedish islands Gotland and Öland. Studies from Gotland and the north of Öland have shown that the pied flycatcher is outcompeted and displaced from favourable, high-quality habitat by the collared flycatcher, leading to a decrease in the number of pied flycatchers in deciduous forest. However, this has not been shown for the ecologically important and one of the largest deciduous forests in Sweden, the Mittland forest located in central Öland. Here I use census data collected during two periods separated by 37 years from the Mittland forest to investigate habitat choice and competition between the two species. Although the number of collared flycatcher has greatly increased in the area, I show that the collared flycatcher has not outcompeted the pied flycatcher from favourable habitat. I also show that pied flycatcher does not have a preference for coniferous forest. Lastly, I show that the two species have a near complete overlap of habitat niches. These results indicate that they are in direct competition over the favourable habitat, that there is no equilibrium between the species and the collared flycatcher might still be expanding in the Mittland forest. Allowing more time to pass and further research will show if the pied flycatcher will be displaced from the high-quality habitats in this area or not.

Dispersal is a key life history trait for ecological and evolutionary processes in wild populations. The latest research has particularly focused on the correlation between behavioural traits and dispersal, in order to emphasize the existence of behavioural syndromes of dispersal, and on the estimation of the genetic basis of the dispersal behaviour. Dispersing individuals are not a random part of the population, but are individuals showing particular strategies, that help them to succeed in their dispersal attempt. This thesis has three main aims of research. The first is to show a genetic basis of the dispersal propensity in a fragmented population of collared flycatchers (Ficedulla albicollis). We show, not only, the genetic bases of the dispersal, but also a non-random spatial distribution of relationship between individuals in this population, that might be due to genetic effects on the decision rules of habitat choice in this population. The second aim concerns phenotypic and a genetic correlation between the natal dispersal and a behavioural trait, the nest-defense behaviour, in the alpin swift (Tachymarptis melba). We showed that natal dispersal and nest-defense behaviour were negatively correlated at a phenotypic level, but also at a genetic level in these populations. Finally, the third aim attempts to test the existence of a behavioural syndrome of dispersal, that is if dispersing individuals have a particular behavioural profile, which enable them to colonize new sites, in the collared flycatcher. / <p>The exmination will be videolinked to seminar room 1003 Evolutionary Biology Centre, EBC, Uppsala University.</p>

A utilização racional da fauna silvestre é um processo benéfico, por resultar em vantagens econômicas e sociais, e ao mesmo tempo auxiliar no processo de conservação das espécies silvestres. Entre as espécies silvestres brasileiras com potencial zootécnico, destaca-se o cateto (Pecari tajacu), um animal que consome diversos tipos de alimentos e que produz carne e couro com elevada demanda nos mercados nacional e internacional, respectivamente. Uma característica desta espécie é a presença de um pré-estômago, onde ocorre fermentação microbiana que confere a esta espécie capacidade para digerir alimentos volumosos. Objetivou-se com o presente trabalho: (i) medir a capacidade digestiva usando doses crescentes de uréia como fonte de nitrogênio não protéico (NNP) na dieta de catetos; (ii) avaliar a eficiência da microbiota do pré-estômago de catetos em proceder à fermentação anaeróbica da dieta, através da técnica de produção de gases para diferentes doses de uréia; (iii) estimar a síntese de nitrogênio microbiano in vitro utilizando o isótopo estável 15N como marcador. O trabalho foi dividido em três capítulos. No primeiro foi utilizado delineamento com distribuição inteiramente aleatória, no qual as possíveis seqüências dos tratamentos (doses de uréia: 0,0; 1,0; 1,5; 2,0 %) foram atribuídas aleatoriamente em cinco ensaios com quatro animais cada. No segundo e terceiro capítulos, o delineamento empregado foi com distribuição inteiramente aleatória em arranjo fatorial 4 X 2, no qual foram utilizados quatro doses de uréia, duas fontes de inóculo (espécie animal: cateto e ovino) e cinco repetições. Os resultados para digestibilidade da MS, PB e FDN não foram influenciados (P>0,05) pelas doses de uréia, contudo, podem ter proporcionado incremento na síntese microbiana melhorando a digestibilidade da fibra. O BN cresceu linearmente com o incremento das doses de uréia (R2 = 0,97), apresentando retenção de 8,95 g dia-1 de N para maior dose e 5,22 g dia-1 de N para a dieta sem uréia, não havendo efeito significativo (P>0,01) para as perdas de N fecal e urinário. No segundo trabalho, houve produção de gases (197 mL g-1 MS) utilizando inóculo de cateto, contudo, não apresentou correlação com os tratamentos. A digestibilidade da MS (MSD), MO (MOD) e FDN (FDND) e a produção de gases em função da MSD, MOD e FDND apresentaram diferença significativa (P<0,01) para os tratamentos, havendo crescimento linear (P>0,01) para digestibilidade de FDN (R2 = 0,50) e regressão linear inversa para produção de gases em função da FDND (R2 = 0,51). A produção de gás metano em função da MS, MO, MSD e MOD utilizando inóculo de cateto, apresentou diferença significativa (P<0,01) para os tratamentos, porém com baixo coeficiente de correlação entre as doses crescentes de uréia. A síntese de nitrogênio microbiano para o inóculo de cateto, não apresentou efeito significativo (P>0,05) para os tratamentos. A produção de nitrogênio amoniacal foi significativa (P<0,01) para as diferentes doses de uréia com ajuste de regressão linear aditiva (R2 = 0,50). A produção de gases mostra que a dieta concentrada foi degradada devido à presença de microrganismos no inóculo de cateto. Estes microrganismos foram capazes de hidrolisar a uréia em amônia e esta, por sua vez, convertida em compostos nitrogenados para síntese microbiana, mostrando a eficiência da fisiologia digestiva deste animal no aproveitamento do NNP. Além disso, os resultados in vivo indicam que o pré-estômago dos catetos foi capaz de utilizar uréia como fonte NNP, podendo substituir parte da proteína dietética em sua alimentação / The rational use of wild fauna is a beneficial process, as it results in economical and social advantages, and at the same time helps in the conservation process of wild species. Among the wild Brazilian species with zootechnical potential, the collared peccary (Pecari tajacu) stands out as an animal that consumes several kinds of foods and produces meat and pelt with a high demand in national and international markets, respectively. A characteristic of this species is the presence of a forestomach, where the microbial fermentation occurs, which enables this species to digest coarse roughage. The objective of this study was (i) to measure the digestive efficiency in the using increasing doses of urea as source of non protein nitrogen (NPN) in the collared peccary diet; (ii) to evaluate the efficiency of collared peccary fore-stomach microorganisms in proceed to anerobic fermentation of diet, using the in vitro gas production technique at different urea doses; (iii) to estimate the in vitro microbial nitrogen synthesis using stable isotope 15N as marker.This study is divided into three chapters. In the first chapter, an experimental design with entirely randomized distribution was used where the urea doses (0.0; 1.0; 1.5; 2.0 %) were randomly used in five assays with four animals each. In the second and third chapters, the experimental design used had an entirely randomized distribution, resulting in a 4 x 2 factorial experiment, in which four urea doses, and two sources of inoculum (collared peccary and sheep) and five replications. The DM, CP, and NDF digestibility results were not influenced (P>0.05) by the urea doses, however, they may have increased the microbial synthesis, improving fiber digestibility. The NB increased linearly with the increasing doses of urea (R2 = 0.97), presenting an N retention of 8.95 g day-1, for the highest dose of urea and 5.22 g day-1 for a non urea diet, without significant effect (P>0.01) to the losses of fecal and urinary N. In the second study, there was gas production (197 mL g-1 DM) using the collared peccary inoculums; however there was no correlation with the treatments. The DM (DMD), OM (OMD) and NDF (NDFD) digestibility and gas production as a function of DMD, OMD and NDFD showed a significant difference (P<0.01) for the treatments, showing a linear increase (P>0.01) in NDF digestibility (R2 = 0.50) and inverse linear regression for gas production as a function of NDFD (R2 = 0.51). The methane gas production as a function of DM, OM, DMD, and OMD using peccary fore-stomach inoculum showed significant difference (P<0.01) for the treatments, but with a low correlation coefficient between increasing doses of urea. The microbial nitrogen synthesis for the peccary inoculum did not show significant effect (P<0.01) for the treatments, in contrast, the production of ammoniacal nitrogen was significant (P<0.01) at different urea doses with an adjustment of additive linear regression (R2 = 0.50). The gas production showed that concentrated diet was degraded because of microorganisms presents in the collared peccary inoculum. These microorganisms present in the inoculum could hydrolyse the urea in ammonia and this, in its turn, is converted into nitrogen compounds for microbial synthesis, showing the efficiency of this animal´s digestive physiology in NPN use. Furthermore, in vivo results show that the pre-stomach of the collared peccary was capable to use urea as source NPN, thus could substitute part of the dietary protein in his/her feeding