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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
131

Abundance, behaviour and habitat use patterns of Indo-Pacific bottlenose dolphins (<em>Tursiops aduncus</em>) in the Clarence and Richmond River estuaries in northern New South Wales, Australia

Fury, Christine Ann Unknown Date (has links)
Bottlenose dolphins (Tursiops spp.) are a widely studied species in marine habitats, however, information on estuarine populations in Australia is very limited. To fully understand the importance of estuaries as habitats for dolphins there needs to be clear quantitative data on dolphin populations and their habitat use in estuaries. This study provides the first published data on Indo-Pacific bottlenose dolphins (Tursiops aduncus) abundance estimates, site fidelity, individual ranging patterns, habitat use, flood impacts and sexual segregation patterns over a 3- year period in the Clarence River (CR) and Richmond River (RR) estuaries in northern New South Wales, Australia.The results indicate that, at present, the CR estuary is sustaining a larger dolphin community with a predominantly resident population compared to the RR estuary, which supports a smaller community with lower site fidelity. The CR estuary dolphin abundance estimate of 71 (62-81 95% CI, CV = 0.07) is more than twice the size of the RR estuary abundance estimate of 34 (19- 49 95% CI, CV = 0.23). Differences in site fidelity were observed between the estuaries with 60% and 37% of identified dolphins determined as residents, 26% and 21% as occasional visitors, and 14% and 42% as transients for the CR and RR, respectively. Resource partitioning was apparent in both estuaries with the mean distance resident dolphins were found upstream from the River mouth being greater than for the occasional visitors and transients.Tursiops aduncus was seen all year round in the CR and RR estuaries, with peak sightings occurring in spring at both sites. In the CR the dolphin population showed consistent seasonal fluctuations, whereas this did not occur in the RR population. In the CR the largest spatial distribution of dolphins in the estuary was observed in spring and winter, while in summer they were primarily restricted to the main estuary channel. Different behaviours that were observed; feeding, socialising, travelling, and milling and resting, were found to be influenced by season, tidal phase and tidal range. In both estuaries the core habitat areas used by the population for feeding consisted of areas with considerable slope near the edge of tidal sand banks, adjacent to deeper channels at the entrances of canals, creeks or artificial breakwalls. In addition, the core habitat areas used by the population for milling and resting behaviour in both estuaries occurred in shallow, sheltered areas, often associated with seagrass beds. Socialising occurred more frequently in the CR throughout most of the deeper waters of the estuary, whereas in the RR it was primarily restricted to a small area of medium depth in the estuary.The major determinant of T. aduncus occupancy in the two estuaries was the flood events that occurred, which resulted in the dolphins abandoning the estuary. The mean predicted probabilities for sighting dolphins during non-flood periods were 0.87 and 0.71, during a flood 0.21 and 0.04, and during a post-flood recovery period 0.83 and 0.80 in the CR and RR, respectively. Principal Components Analysis (PCA) showed that when the dolphins were absent from the estuaries, three components were extracted from the water quality parameters in the CR, and two components in the RR. High loadings from the PCA were associated with the changing salinity, turbidity, pH, dissolved oxygen and temperature associated with the flood events. The return of the dolphins to the estuary following a flood depended on the length and severity of the flood event, but generally the dolphins seemed to prefer waters with salinity levels above 29 ‰. This could be associated with higher salinities being important for their physiological health, or because their prey returned to the estuaries during these higher salinity conditions, more likely a combination of both of these factors.Sexual segregation patterns were observed in T. aduncus populations with mixed gender and female groups mainly recorded in the CR, whereas in the RR female groups dominated the estuary. In the CR, significant differences occurred in sightings between the mixed and female groups in relation to water depth and behaviour. Mixed gender groups were sighted predominantly in deeper water and were involved in social behaviour including sexual behaviour and male herding of females. In contrast, the female groups were observed across all water depths, predominately feeding and also participating in more milling and resting behaviours.The high occurrence of aggressive herding behaviour by males in the CR was significantly different at varying depths, tides and seasons, occurring more often in deeper water, at higher tides and in non-breeding seasons. Female groups were found to utilise the small, shallow tributaries and travel for longer distances up these smaller tributaries than the mixed groups, which were concentrated in the deeper main channel of the estuary.The deeper water of the channels may facilitate the males in herding the females, while the female groups’ habitat selection of shallow estuary areas may provide a sanctuary from aggressive males, access to suitable prey items or prey density for mothers and their calves, or a combination of these factors.This study has provided the first detailed research on T. aduncus dolphin population dynamics, habitat use, occupancy and sexual segregation patterns in two Australian subtropical estuaries. To ensure the long-term survival of both of these dolphin populations, management of future increased anthropogenic disturbances from boat traffic, pollution, dolphin watching, industrial or urban development, over-fishing and habitat degradation of the catchment is needed. Good quality water conditions, the protection of the core feeding areas and small shallow tributaries for females and their calves, and sheltered areas for resting behaviour all need to be maintained for the continued conservation of these important dolphin populations.
132

Starling (Sturnus vulgaris L.) predation on grass grub (Costelytra Zealandica (White), Melolonthinae) populations in Canterbury

East, R. January 1972 (has links)
The main object of this study was to investigate the effects of predation by starlings (Sturnus vulgaris) on populations of the grass grub (Costelytra zealandica) in Canterbury, with the secondary objective of investigating the feasibility of life table studies of grass grub populations under Canterbury conditions. Study plots were established in four areas, two on non-irrigated pastureland at Lincoln and Weka Pass and two on irrigated pastureland at Winchmore. A third study plot was established at Winchmore in the second year of field work.
133

Espaços individuais para novilhos confinados / Individual space for feedlot steers

Cattelam, Jonatas 28 February 2012 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The objective, of this study, was evaluated, different individual spaces for steers feedlot finished in group pens and yours effects on patterns behavioral and performance. Forty eight steers, with average initial of twenty months and 243.4 kg, were used. Animals were feedlot, four for pen, allocated in treatments accorded the individual space, 2.5, 5.0 and 10 m2, with four pens for treatment. The animals were feedlot until reaching estimated cold carcass weight of 220 kg. The diet, with 115 g of crude protein and 705 g of total digestible nutrient by kg of diet in dry matter (DM), contained roughage: concentrate relation of 39:61 (DM basis). The complete randomized block experimental design was used. The dry matter intake, with intakes of 8.21; 8.29 and 8.41 kg, for steers with individual spaces of 2.5; 5.0 and 10 m2, respectively, as well the average daily gain was simulated between the different spaces, with means of 1.32; 1.41 and 1.47 kg, in the same order. The steers feed efficiency was not influenced by space allowance. The individual space not influenced the time spent to feeding, idle and rumination, which showed mean of 244.1; 790.3 and 405.6 minutes/day, respectively. Likewise, the number of times that animals showed each of the behaviours, as well the changes in posture during idle and rumination were similar between the different spaces evaluated. The total time that the animals remained standing or lying was not influenced by individual space, with average duration of 610.0 and 830.0 minutes/day, respectively, and the realization of activities in synchronism, not difference between the different spaces, the average time that the animals fed, standing or lay down in synchrony was 85.8, 308.0 and 468.4 minutes/ day, in the same order. The total number of disputes, with 21.9, 21.5 and 19.7 events between animals kept in spaces, 2.5, 5.0 and 10 m2, in the same order, and the number of non-agonistic interaction was not influenced by individual space available. Confined steers with 5.0 and 10 m2, extended their members 8.8 and 9.7 times per day, respectively, superior to animals maintained on individual spaces of 2.5 m2, this behavior made 4.3 times per day. The cleanliness differed between the spaces, with values of 3.2, 2.4 and 1.1 for steers with individual spaces of 2.5, 5.0 and 10 m2 respectively, as well as respiratory rate, with 27.1, 24.8 and 22.7 breaths / minute, in the same order. The hot and cold carcass weight, 226.0 and 222.0, respectively, and hot and cold carcass dressing, 58.5 and 57.0 kg/ 100 kg by live weight, in the same order, were not influenced by individual space. For all spaces evaluated, the carcass required minimum fat thickness, 3 mm. The weights and percentage of commercial cuts, also the weight and participation tissues in carcass were similar between different spaces. Color, texture, marbling, sensorial characteristics and shear force, were not influenced by individual space. / Objetivou-se, com este estudo, avaliar a disponibilidade de diferentes espaços individuais para novilhos confinados coletivamente em fase de terminação e seus reflexos sobre parâmetros comportamentais e produtivos. Foram utilizados 48 novilhos, com idade e pesos médios iniciais de 20 meses e 243,4 kg, respectivamente. Os animais foram mantidos em baias coletivas, com quatro animais cada, distribuídos nos tratamentos conforme o espaço individual disponível, 2,5; 5,0 ou 10 m2, sendo utilizadas quatro baias por tratamento. Os novilhos permaneceram confinados até atingir, por estimativa, peso de carcaça fria de 220 kg. A dieta, com 115 g de proteína bruta e 705 g de nutrientes digestíveis totais por kg de matéria seca (MS) da dieta, a qual continha relação volumoso concentrado de 39: 61 (base na MS). O delineamento experimental utilizado foi blocos ao acaso. O consumo diário de matéria seca, com ingestões de 8,21; 8,29 e 8,41 kg, para novilhos mantidos com espaços individuais de 2,5; 5,0 e 10 m2, foi similar entre os diferentes espaçamentos, assim como o ganho médio diário de peso, com valores de 1,32; 1,41 e 1,47 kg, citados na mesma ordem. As eficiências alimentares dos novilhos não foram influenciadas pelo espaçamento. O espaço individual não influenciou os tempos de alimentação, ócio e ruminação, os quais apresentaram valores médios de 244,1; 790,3 e 405,6 minutos/dia, respectivamente, e as mudanças de postura durante ócios e ruminações. O tempo total que os animais permaneceram em pé ou deitados ao longo do dia, médias de 610,0 e 830,0 minutos, respectivamente, e o tempo médio que os animais se alimentaram, permaneceram em pé ou deitaram-se sincronizadamente foi de 85,8; 308,0 e 468,4 minutos/dia, citados na mesma ordem, não foram influenciados pelo espaço disponível. O número total de disputas, com 21,9; 21,5 e 19,7 ocorrências diárias nos novilhos em espaços de 2,5; 5,0 e 10 m2, respectivamente, e o número de interação não-agonísticas foram similares entre os diferentes espaçamentos avaliados. Novilhos confinados com 5,0 e 10 m2 estenderam seus membros 8,8 e 9,7 vezes por dia, respectivamente, superiores aos animais mantidos com disponibilidade individual de 2,5 m2, que realizaram esse comportamento 4,3 vezes ao dia. O escore de limpeza diferiu entre os espaçamentos, com valores de 3,2; 2,4 e 1,1 para novilhos com espaços individuais de 2,5; 5,0 e 10 m2, respectivamente, assim como a frequência respiratória, com 27,1; 24,8 e 22,7 movimentos/ minuto, citados na mesma ordem. Os pesos de carcaça quente e fria, médias de 226,0 e 220,0 kg, respectivamente, bem como seus rendimentos, 58,5 e 57,0 kg/ por 100 kg de peso vivo, citados na mesma ordem, não foram influenciados pelo espaçamento, tendo as carcaças apresentado espessura de gordura mínima exigida, 3 mm. O peso e o rendimento dos cortes comerciais da carcaça, como também o peso absoluto e a participação dos tecidos que compõem a carcaça foram similares entre os diferentes espaçamentos. Cor, textura, marmoreio, características organolépticas e força de cisalhamento da carne não foram influenciadas pelos espaçamentos utilizados.
134

Behavioural circadian rhythms : a novel approach to monitor sheep in extensive systems and study the differences between beef steers for methane emission, feed efficiency and growth / Ritmos circadianos comportamentais : um novo modo de monitorar ovinos em sistemas extensivos e estudar a emissão de metano, eficiência alimentar e crescimento de bovinos de corte

Sarout, Bruna Nunes Marsiglio January 2017 (has links)
As tecnologias baseadas em sensores estão cada vez mais disponíveis e podem ser usadas para coletar informações detalhadas sobre o comportamento animal. Com esta informação é possível avaliar o ritmo circadiano de variáveis comportamentais e monitorar sua resposta. A identificação de variações na resposta deste ritmo tem o potencial de detectar problemas de saúde e questões de bem-estar animal. O objetivo deste trabalho foi estudar os ritmos circadianos comportamentais como uma nova abordagem para monitorar ovelhas em sistemas extensivos e estudar a emissão de metano, eficiência alimentar e crescimento de novilhos de corte. Este trabalho foi composto por dois experimentos (ovinos e bovinos). Foram utilizados cochos automatizados e sensores de atividade baseados em acelerômetro para coletar informações detalhadas do comportamento ingestivo (bovinos) e do comportamento de atividade (ovinos e bovinos), juntamente com as características de desempenho animal. Estes dados foram utilizados para calcular a percentagem de comportamento cíclico harmônico/sincronizado a cada período de 24 h. Essa porcentagem é chamada de grau de acoplamento funcional (DFC) e é calculada com uso de um período móvel de sete dias. No experimento com ovinos, um total de 29 ovelhas Scottish Blackface foram monitoradas por quatro semanas em cada estação do ano, em sistema extensivo nas terras altas da Escócia. Dados meteorológicos foram coletados diariamente. Modelos estatísticos de regressão com efeito aleatório foram utilizados para avaliar a variação da resposta entre indivíduos. Houve uma forte dinâmica criada pelas estações do ano e pelo ciclo produtivo/fisiológico das ovelhas. Durante a primavera e o verão, o desvio padrão do DFC foi um melhor estimador do ganho de peso quando comparado ao índice de moção. A combinação da análise do DFC e o agrupamento de indivíduos com base em sua resposta às variáveis ambientais oferece potencial para obter informações relevantes para o manejo do rebanho. O experimento de bovinos foi conduzido com duas dietas contrastantes (volumoso: concentrado 8:92 e 50:50) e duas raças (40 mestiços Charolês e 40 Luing). Os padrões diurnos de ingestão e atividade foram altamente sincronizados. O ritmo circadiano da atividade foi importante para explicar as diferentes emissões de metano entre indivíduos, independente da raça ou dieta, e também teve ligação com a eficiência alimentar e o crescimento dos novilhos. Este trabalho mostra a importância dos ritmos circadianos comportamentais e como essas abordagens podem melhorar a qualidade e o significado dos dados provenientes de sensores automatizados. / Sensor-based technologies are becoming increasingly available and can be used to gather detailed information about animal behaviour. With this information it is possible to assess animal behavioural circadian rhythm and monitor its response. Identifying breakdowns of this rhythm has the potential to detect health problems and animal welfare issues. The aim of this work was to study the behavioural circadian rhythms as a novel approach to monitor sheep in extensive systems and to study the differences between beef steers production traits, in methane emission, feed efficiency and growth. This work consisted of two experiments, one dealing with sheep in an extensive system and the other with housed beef steers. Automated feed intake equipment and accelerometer-based activity sensors were used to collect detailed information on feed intake (for cattle) and activity behaviour (for sheep and cattle), alongside animal performance characteristics. These data were used to calculate the percentage of cyclic behaviour that is harmonic/synchronized to each 24 h period as Degree of Functional Coupling (DFC) shown within rolling seven day periods. In the sheep experiment, in total twenty-nine Scottish Blackface ewes were monitored for four consecutive weeks in each season across a full year, in an extensive system on Scottish upland pastures. Weather data were collected daily. Random regression statistical models were used to assess between-individual variation in response to the weather. There was a strong dynamic created by the seasons and by the production and physiological cycle in sheep in these high latitude systems. Over the spring and summer period, the variation in the response of DFC was a better estimator of BWG (Body Weight Gain) than the use of a simple motion index. The combination of circadian rhythm analysis and the clustering of individuals into groups based around their regression response to environmental variables provides considerable potential to glean information relevant for group and individual animal management. The cattle experiment was conducted with two contrasting diets (concentrate-based and mixed diet) and two breeds (40 crossbred Charolais and 40 purebred Luing). The diurnal patterns of feeding and activity behaviours were strong and highly synchronised. Activity rhythmicity was well suited to show up differences between individual methane emissions independent of breed or diet, and it was also well related to important production traits as feed efficiency and growth of beef steers. This work shows the importance of the behavioural circadian rhythms and that these approaches may enhance the quality and meaningfulness of data coming from automated sensors.
135

Behavioural circadian rhythms : a novel approach to monitor sheep in extensive systems and study the differences between beef steers for methane emission, feed efficiency and growth / Ritmos circadianos comportamentais : um novo modo de monitorar ovinos em sistemas extensivos e estudar a emissão de metano, eficiência alimentar e crescimento de bovinos de corte

Sarout, Bruna Nunes Marsiglio January 2017 (has links)
As tecnologias baseadas em sensores estão cada vez mais disponíveis e podem ser usadas para coletar informações detalhadas sobre o comportamento animal. Com esta informação é possível avaliar o ritmo circadiano de variáveis comportamentais e monitorar sua resposta. A identificação de variações na resposta deste ritmo tem o potencial de detectar problemas de saúde e questões de bem-estar animal. O objetivo deste trabalho foi estudar os ritmos circadianos comportamentais como uma nova abordagem para monitorar ovelhas em sistemas extensivos e estudar a emissão de metano, eficiência alimentar e crescimento de novilhos de corte. Este trabalho foi composto por dois experimentos (ovinos e bovinos). Foram utilizados cochos automatizados e sensores de atividade baseados em acelerômetro para coletar informações detalhadas do comportamento ingestivo (bovinos) e do comportamento de atividade (ovinos e bovinos), juntamente com as características de desempenho animal. Estes dados foram utilizados para calcular a percentagem de comportamento cíclico harmônico/sincronizado a cada período de 24 h. Essa porcentagem é chamada de grau de acoplamento funcional (DFC) e é calculada com uso de um período móvel de sete dias. No experimento com ovinos, um total de 29 ovelhas Scottish Blackface foram monitoradas por quatro semanas em cada estação do ano, em sistema extensivo nas terras altas da Escócia. Dados meteorológicos foram coletados diariamente. Modelos estatísticos de regressão com efeito aleatório foram utilizados para avaliar a variação da resposta entre indivíduos. Houve uma forte dinâmica criada pelas estações do ano e pelo ciclo produtivo/fisiológico das ovelhas. Durante a primavera e o verão, o desvio padrão do DFC foi um melhor estimador do ganho de peso quando comparado ao índice de moção. A combinação da análise do DFC e o agrupamento de indivíduos com base em sua resposta às variáveis ambientais oferece potencial para obter informações relevantes para o manejo do rebanho. O experimento de bovinos foi conduzido com duas dietas contrastantes (volumoso: concentrado 8:92 e 50:50) e duas raças (40 mestiços Charolês e 40 Luing). Os padrões diurnos de ingestão e atividade foram altamente sincronizados. O ritmo circadiano da atividade foi importante para explicar as diferentes emissões de metano entre indivíduos, independente da raça ou dieta, e também teve ligação com a eficiência alimentar e o crescimento dos novilhos. Este trabalho mostra a importância dos ritmos circadianos comportamentais e como essas abordagens podem melhorar a qualidade e o significado dos dados provenientes de sensores automatizados. / Sensor-based technologies are becoming increasingly available and can be used to gather detailed information about animal behaviour. With this information it is possible to assess animal behavioural circadian rhythm and monitor its response. Identifying breakdowns of this rhythm has the potential to detect health problems and animal welfare issues. The aim of this work was to study the behavioural circadian rhythms as a novel approach to monitor sheep in extensive systems and to study the differences between beef steers production traits, in methane emission, feed efficiency and growth. This work consisted of two experiments, one dealing with sheep in an extensive system and the other with housed beef steers. Automated feed intake equipment and accelerometer-based activity sensors were used to collect detailed information on feed intake (for cattle) and activity behaviour (for sheep and cattle), alongside animal performance characteristics. These data were used to calculate the percentage of cyclic behaviour that is harmonic/synchronized to each 24 h period as Degree of Functional Coupling (DFC) shown within rolling seven day periods. In the sheep experiment, in total twenty-nine Scottish Blackface ewes were monitored for four consecutive weeks in each season across a full year, in an extensive system on Scottish upland pastures. Weather data were collected daily. Random regression statistical models were used to assess between-individual variation in response to the weather. There was a strong dynamic created by the seasons and by the production and physiological cycle in sheep in these high latitude systems. Over the spring and summer period, the variation in the response of DFC was a better estimator of BWG (Body Weight Gain) than the use of a simple motion index. The combination of circadian rhythm analysis and the clustering of individuals into groups based around their regression response to environmental variables provides considerable potential to glean information relevant for group and individual animal management. The cattle experiment was conducted with two contrasting diets (concentrate-based and mixed diet) and two breeds (40 crossbred Charolais and 40 purebred Luing). The diurnal patterns of feeding and activity behaviours were strong and highly synchronised. Activity rhythmicity was well suited to show up differences between individual methane emissions independent of breed or diet, and it was also well related to important production traits as feed efficiency and growth of beef steers. This work shows the importance of the behavioural circadian rhythms and that these approaches may enhance the quality and meaningfulness of data coming from automated sensors.
136

Modificação na estrutua do pasto e no comportamento ingestivo de bovinos durante o rebaixamento do capim-marandu submetido a estratégias de pastejo rotacionado / Modifications in sward structure and ingestive behaviour of cattle during the grazing down process of marandu palisadegrass subjected to rotational grazing strategies

Júlio Kuhn da Trindade 07 March 2007 (has links)
Práticas de manejo afetam a estrutura do dossel forrageiro, podendo afetar os padrões de deslocamento, procura e ingestão de forragem pelos animais em pastejo. O objetivo deste trabalho foi avaliar o efeito de estratégias de pastejo rotacionado sobre o comportamento animal e padrões de ingestão de forragem de bovinos de corte em pastos de Brachiaria brizantha cv. Marandu. O experimento foi realizado no Departamento de Zootecnia da USP/ESALQ, de novembro de 2005 a abril de 2006. Os tratamentos experimentais compreenderam a combinação entre duas intensidades (altura pós-pastejo de 10 e 15 cm) e dois intervalos entre pastejos (período de tempo necessário para se atingir 95 e 100% de interceptação luminosa pelo dossel durante a rebrotação - IL), e foram alocados às unidades experimentais (piquetes de 1.200 m²) segundo um delineamento inteiramente casualizado e arranjo fatorial 2 x 2, com 3 repetições. As avaliações foram realizadas de forma repetida em duas épocas do ano: (1) primavera (novembro e dezembro de 2005), e (2) verão (janeiro a abril de 2006). A densidade de lotação foi dimensionada para que a duração do período de ocupação fosse de 10 a 12 horas. Foram avaliadas as seguintes variáveis-resposta: distribuição vertical dos componentes morfológicos da massa de forragem, dinâmica do rebaixamento dos pastos, padrões de ingestão (massa do bocado, taxa de bocados e taxa de consumo), comportamento (pastejo, ruminação e outras atividades), composição morfológica da forragem consumida; padrões de deslocamento e busca por alimento (número de estações alimentares por unidade de tempo e número de passos entre estações alimentares), e padrões de desfolhação de perfilhos individuais (profundidade de desfolhação e freqüência e intensidade de desfolhação de folhas em geral e nas categorias folhas em expansão e expandidas). As maiores taxas de rebaixamento foram registradas para os tratamentos 100/10 e 100/15, enquanto as menores para o tratamento 95/15. De modo geral, à medida que os animais permaneceram nos piquetes e ocorria depleção do estrato pastejável, a taxa de rebaixamento diminuiu em virtude da diminuição da altura do dossel e do aumento da presença de colmos e de material morto no horizonte de pastejo. Apesar de a intensidade de pastejo menos severa (altura pós-pastejo de 15 cm) resultar, no início do pastejo, em menor bocado, taxa de consumo e intensidade de desfolhação de folhas em expansão e expandidas, os animais acabaram consumindo uma forragem com maior proporção de folhas. Ao longo do rebaixamento, os tratamentos de 100% IL resultaram em bocados maiores, mas, no entanto, a taxa de consumo e a proporção de folhas na forragem consumida foram menores em relação aos tratamentos de 95% de IL. Os tratamentos 95/10 e 95/15 estiveram associados com maior atividade de pastejo e maior taxa de consumo, sugerindo maior consumo diário. Entretanto, o tratamento 95/15 foi o que resultou na maior proporção de folhas na forragem consumida, e foi o tratamento em que a intensidade e freqüência de desfolhação de folhas foram mais baixas, condicionadas pelas menores densidades de lotação empregadas. Esse padrão de desfolhação resultou em uma maior área foliar remanescente, favorecendo a rebrota seguinte e o rápido retorno dos pastos à utilização. A estratégia de pastejo que resultou em melhor utilização da forragem produzida, foi aquela em que os pastejos foram realizados com 95% de IL até uma altura pós-pastejo de 15 cm. / Management practices affect sward structure and may affect patterns of animal movement, search and forage ingestion during grazing. The objective of this study was to evaluate the effect of rotational grazing practices on animal behaviour and patterns of forage ingestion of beef cattle on Brachiaria brizantha cv. Marandu. The experiment was carried out at Departamento de Zootecnia, USP/ESALQ, from November 2005 to April 2006. Treatments corresponded to combinations between two grazing intensities (post-grazing residues of 10 and 15 cm) and two grazing frequencies (equivalent to the period of time necessary for swards to reach 95 and 100% interception of the incident light during regrowth ? LI), and were allocated to experimental units (1200 m2 paddocks) according to a completely randomised design and a 2 x 2 factorial arrangement, with 3 replications. Measurements were performed in two seasons of the year: (1) spring (November and December 2005), and (2) summer (January to April 2006). Stocking density was calculated aiming at an occupation period of paddocks of 10 to 12 hours. The following response variables were analysed: vertical distribution of morphological components of sward herbage mass, dynamics of the grazing down process, patterns of ingestion (bite mass, bite rate, and intake rate), animal behaviour (grazing, rumination and other activities), morphological composition of the consumed herbage, patterns of animal movement and search for forage (number of feeding stations per unit of time and number of steps between feeding stations), and patterns of defoliation of individual tillers (defoliation depth, frequency and intensity of defoliation of leaves ? expanding and expanded leaves). The highest rates of decrease in sward height were recorded for treatments 100/10 and 100/15, and the lowest for treatment 95/15. In general, as the occupation period progressed, the grazing stratum was depleted and there was a decrease in the rate swards were lowered, a result of lower sward heights and increased presence of stems and dead material in the stratum used by the animals for grazing. In spite of the lower grazing intensity (post-grazing height of 15 cm) has resulted, at the beginning of grazing, in smaller bites, intake rate and defoliation intensity of expanding and expanded leaves, the ingested herbage had a higher proportion of leaves compared to grazings at 10 cm residue. During the grazing down process, the 100% LI treatments resulted in heavier bites, but lower intake rate and proportion of leaves in the herbage consumed than the 95% LI treatments. Treatments 95/10 and 95/15 were associated with the largest grazing activity and highest intake rate, suggesting higher daily intake. However, 95/15 was the treatment that resulted in the largest proportion of leaves in the herbage consumed, and in the lowest values of frequency and intensity of defoliation of leaves, due to the lowest stocking density used. This pattern of defoliation resulted in a high residual leaf area after grazing, favouring regrowth and quick return of swards to grazing. The grazing strategy that allowed more efficient harvest of herbage was that where grazings were initiated with 95% LI and finished with a 15 cm post-grazing height.
137

Aspectos neuroimunes de camundongos tratados com morfina. / Neuroimmune aspects of morphine-treated mice.

Elaine Cristina Rodrigues da Costa 17 June 2010 (has links)
Injeções repetidas de psicoestimulantes e/ou compostos opióides desencadeiam respostas comportamentais, bioquímicas, endócrinas e celulares diferentes daquelas induzidas pela exposição aguda. Em particular, a morfina, considerada como o protótipo do estimulante opioidérgico, tem despertado grande interesse devido a seus efeitos múltiplos. Assim, no presente estudo avaliaram-se as consequências dos tratamentos agudo e repetido com morfina (20mg/kg) em camundongos sobre os seguintes aspectos: atividade geral; níveis séricos de corticosterona; concentrações corticais, estriatais e hipotalâmicas de noradrenalina, dopamina e serotonina, de seus metabólitos e as taxas de renovação destes neurotransmissores; atividade funcional ex vivo de neutrófilos sanguíneos e de macrófagos peritoneais, sendo estes desafios realizados in vivo com diferentes estímulos imunológicos, infecciosos ou não; crescimento tumoral e a sobrevida de camundongos portadores de um tumor ascítico de Ehrlich. Os resultados obtidos mostraram que os tratamentos agudo e repetido com morfina modulam diferentemente as repostas comportamental e neuroendócrina, dependendo do tempo de observação pós-desafio. Portanto, conclui-se que camundongos tratados repetidamente com morfina (20mg/kg) apresentam alterações comportamentais e neuroendócrinas que, no entanto, não foram acompanhadas por diferenças nas avaliações de atividade imune inata. / Repeated administrations of psychostimulant and/or opioid compounds trigger different behavioral, biochemical, endocrine and cellular responses as compared with those induced by acute exposure. Morphine, has attracted great interest due to its multiple effects. Thus, this study evaluated the effects of acute and repeated treatment with morphine (20mg/kg) in mice on the following: locomotor activity; serum levels of corticosterone; cortical, striatal and hypothalamic concentration of dopamine, noradrenaline and serotonin, as well as their metabolites and turnover; blood neutrophils and peritoneal macrophage activity ex vivo, which were challenged with different immunological stimulants; tumor growth and survival of mice with Erlich ascitic tumor. The results showed that acute and repeated morphine treatment differently modulated behavioral and neuroendocrine responses, depending on the these period after the injection challenge. Thus, it is concluded that mice repeatedly treated with morphine (20mg/kg) present behavioral and neuroendocrine changes; however, this changes were not accompanied by variation in innate immune activity.
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Morfometria geométrica, dimorfismo sexual e avaliação da atratividade de Cratosomus flavofasciatus (Coleoptera: Curculionidae) ao feromônio sintético

Campos, Philippe Correia Souza 24 February 2017 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Knowledge about biology and animal behavior is critical to understanding how a particular organism interacts with its environment. Identifying the sex of individuals is an essential step in conducting behavioral studies. An integral part of animal behavior is communication, which can be intermediated by pheromones. Within different groups, insects are the animals use pheromones the most in order to carry out their fundamental activities. Cratosomus flavofasciatus, a Coleoptera of the Curculionidae family, popularly called the Orange-tree-borer, is considered one of the main citrus pests, occurring in Sergipan orchards. The objective of this work was to evaluate the morphological characteristics that allow the sexual differentiation of C. flavosfaciatus and to evaluate the attractiveness of C. flavosfaciatus to the synthetic compounds that make up the pheromone of this species. To verify the sexual dimorphism of C. flavofasciatus, a geometric morphometry analysis was first made using 80 adult individuals of each sex. There were 27 landmarks in the ventral region in each individual. The anatomical landmarks 2, 9, 10, 11, 18, 21 were the ones that contributed most to the distinction between males and females, which represent the region of the rostrum, the final portion of the abdomen and the end of the thorax. For sex confirmation, a withdrawal of the genitalia of both sexes was also performed. In females it was possible to recognize the following structures: sternite VIII and bursa copulatrix. In males, it was possible to observe the gastric spicule and the aedeagus with a pair of parammero. The Procrustes Anova showed significant differences between the sexes (P<0.001) and the size (centroid) in relation to sex (P <0.001), but there was no difference in shape in relation to size (P = 0.229) and the form in relation to sex in conjunction with the size (P = 0.707). Principal component analysis demonstrated an evident differentiation between the genders based on the ventral region of the species. The first two main components explained 51.909% (PC1 + PC2: 39.563% + 12.346%) of the shape variation. The discriminant analysis indicated a significant difference (permutation test = 10,000 permutations; P < 0.001) for the sexual dimorphism of the ventral region. The determination of the adult sex of C. flavofasciatus through the last abdominal sternum is as accurate as the dissection of the genitalia. The behavioral response of C. flavofasciatus to synthetic pheromonal compounds (a mixture of 2-((1R, 2S)-1-methyl-2-(prop-1-en-2-yl)cyclobutil)ethanol (grandisol), (E)-2-(3,3-dimethyl-cyclohexylidene)ethanol (alcohol E) and (Z)-2-(3,3-dimethyl-cyclohexylidene)ethanol (alcohol Z)) and for their host plants Cordia curassavica (Maria-Preta) and Citrus sinensis (Orange Tree) were evaluated by olfactory tests performed on a Y-tube olfactometer. Both sexes were significantly more attracted to C. sinensis stalks (P <0.05) than to filtered air. Tests with C. curassavica stalk attracted only males (P = 0.02). When the insects had the opportunity to choose between C. curassavica stalks and C. sinensis stalks, males preferred those from C. curassavica (P = 0.01), whereas females showed no significant preference (P> 0.05). The combination of the C. curassavica and C. sinensis volatiles associated with the synthetic pheromone at 100ppm concentration was more attractive for both sexes (P <0.05) than for the control (hexane together with the host plant). On the other hand, at the concentration of 10ppm, only the association with C. curassavica attracted males (P = 0.009). These results can be used as a basis for field testing, contributing to the development of an environmentally safe and effective method for monitoring orange tree borer. / O conhecimento sobre a biologia e o comportamento animal é fundamental para compreensão de como determinado organismo interage com o seu ambiente. A identificação do sexo dos indivíduos é um passo essencial na execução de estudos comportamentais. Um ponto integrante do comportamento animal é a comunicação, a qual pode ser intermediada por feromônios. Dentre os vários grupos, os insetos são os animais que mais utilizam os feromônios para desempenhar suas atividades fundamentais. Cratosomus flavofasciatus, um coleóptero da família Curculionidae, popularmente chamado de broca-da-laranjeira, é considerado uma das principais pragas do citros, apresentando grande ocorrência em pomares sergipanos. O presente trabalho teve como objetivo avaliar características morfológicas que permitam a diferenciação sexual de C. flavosfaciatus e avaliar a atratividade de C. flavosfaciatus aos compostos sintéticos que compõem o feromônio de agregação dessa espécie e à suas plantas hospedeiras. Para verificar o dimorfismo sexual de C. flavofasciatus, primeiramente foi feito uma análise de morfometria geométrica utilizando 80 indivíduos adultos de cada sexo. Foram feitos 27 marcos anatômicos (landmarks) na região ventral em cada indivíduo. Os marcos anatômicos 2, 9, 10, 11, 18 e 21 foram os que mais contribuíram para a distinção entre machos e fêmeas, os quais representam a região do rostro, a porção final do abdômen e o final do tórax. Para confirmação do sexo, foi realizada também a retirada da genitália de ambos os sexos. Nas fêmeas foi possível o reconhecimento das seguintes estruturas: esternito VIII e bursa copulatrix. Já nos machos foi possível observar a espícula gastral e o edeago com par de parâmeros. A Anova de Procrustes demonstrou diferença significativa da forma (P < 0,001) e do tamanho (centróide) (P < 0,001) entre os sexos, porém não houve diferença da forma em relação ao tamanho (P = 0,229) bem como da forma em relação ao sexo em conjunto com o tamanho (P = 0,707). A análise de componentes principais demonstrou uma evidente diferenciação entre os sexos com base na região ventral da espécie. Os dois primeiros componentes principais explicaram 51,91% (PC1 + PC2: 39,56% + 12,35%) da variação da forma. A análise de discriminantes indicou diferença significativa (teste de permutação = 10000 permutações; P < 0,001) quanto ao dimorfismo sexual da forma da região ventral. A determinação do sexo em adultos de C. flavofasciatus através do último esternito abdominal é tão precisa quanto à dissecação da genitália. A resposta comportamental de C. flavofasciatus aos compostos feromonais sintéticos (mistura de 2-((1R, 2S)-1-metil-2-(prop-1-en-2-il)ciclobutil)etanol (grandisol), (E)-2-(3,3-dimetilciclohexilideno)etanol (álcool E) e (Z)-2-(3,3-dimetilciclohexilideno)etanol (álcool Z)) e para suas plantas hospedeiras Cordia curassavica (Maria-Preta) e Citrus sinensis (Laranjeira) foi avaliada por meio de testes olfativos realizados em um olfatômetro em “Y”. Ambos os sexos foram significativamente mais atraídos para os caules de C. sinensis (P < 0,05) que para o ar filtrado. Já os testes com caules de C. curassavica atraíram significativamente somente os machos (P = 0,02). Quando os insetos tiveram a oportunidade de escolher entre caules de C. curassavica e caules de C. sinensis, os machos preferiram os de C. curassavica (P = 0,01), já as fêmeas não apresentaram preferência significativa (P > 0,05). A combinação dos voláteis de C. curassavica e C. sinensis associadas ao feromônio sintético na concentração de 100ppm foi mais atrativa para ambos os sexos (P < 0,05) que para o controle (hexano juntamente com a planta hospedeira). Por outro lado, na concentração de 10ppm, somente a associação com C. curassavica atraiu apenas os machos (P = 0,009). Tais resultados podem ser utilizados como base para testes de campo, contribuindo para o desenvolvimento de um método ambientalmente seguro e eficaz para o monitoramento da broca-da-laranjeira.
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The evolutionary ecology of animal information use and social dominance

Lee, Alexander January 2015 (has links)
Organisms are frequently faced with uncertainty regarding how best to exploit vital resources, and may benefit from collecting information about their distribution through space and time. However, the ways in which competition over resources might systematically facilitate or constrain an individual's ability to use information has been largely overlooked. In this thesis, I develop a conceptual framework for considering how the distribution of limited resources might underpin interdependencies between competition and information use. I focus on the evolutionary ecology of relationships between social dominance and social information use. I begin with an observational study of wild chacma baboons (Papio ursinus) suggesting that, when resources can be monopolised, individuals with low competitive ability are limited in their ability to use social information. Building on these findings, I then develop a general model exploring selection on social information use in a competitive context across three axes of 'resource ecology' (scarcity, depletion rate, monopolisability). This study makes predictions regarding the resource conditions under which competitive ability might constrain social information use, and the potential importance of social information use in the evolution of social dominance. I go on to test these predictions in chacma baboons using a field experiment. This experiment also explores whether the predictability of resource distribution might facilitate the decoupling of social information use from the competitive context in which it was collected. Taken together, these findings provide general insights into the combinations of ecological conditions and behavioural mechanisms that should underpin the benefits of social dominance. I end by building a simple population matrix model to study social dominance using an eco-evolutionary approach, in which feedback loops between ecological and evolutionary processes are considered. By modelling relationships between dominance rank and survival, reproduction, inheritance, and development, I am able to derive estimates of long-term fitness associated with dominance. Using these estimates, I generate predictions regarding how dominance hierarchies should impact the dynamics of group stability, viability, and fission.
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Déplacements collectifs auto-organisés : décision individuelle et transfert d'information / Self-organized collective movements : individual decision and information transfer

Toulet, Sylvain 13 November 2015 (has links)
Les déplacements collectifs se manifestent souvent de façon spectaculaire et intriguent tant les amateurs de la nature que les chercheurs. Comment émergent ces formes spectaculaires et comment la cohésion des groupes est elle assurée ? Si de nombreux travaux ont été consacrés à l'identification des règles permettant la cohésion dans les groupes en mouvement, plus rares sont ceux consacrés aux transitions entre les états d'arrêt et de déplacement. Cette thèse traite des mécanismes comportementaux impliqués dans les prises de décisions collectives et la dynamique de transition de tels évènements chez le mouton Merinos (Ovis aries). Nous proposons de nouvelles hypothèses sur la modulation des interactions entre individus par des effets spatiaux dans des groupes de grande taille. Nous proposons un modèle spatio-temporel reproduisant nos résultats expérimentaux sur les départs, les déplacements collectifs et les arrêts de groupes de taille croissante et permettant d'explorer les décisions collectives dans des conditions nouvelles. Les résultats expérimentaux et théoriques per- mettent d'améliorer la compréhension des mécanismes individuels à l'origine des décision collectives permettant de maintenir ou non la cohésion des groupes. / Collective movements often involve very spectacular displays that fascinate nature lovers and researchers. How do such amazing patterns appear and how group cohesion can be maintained ? If many studies were carried out to decipher the rules underlying cohesion for groups in movement, there is a lack of works adressing the transitions involved in collective movements : departures and stops. This thesis adresses the behavioural mechanisms involved in the collective decision-making processes oc- curing in such transitions in Merino sheep (Ovis aries) groups. We propose some new kinds of spatial hypotheses that can account for the way interactions between individuals are locally modulated in large groups where individuals cannot have an access to the global information of all individuals. We developed a novel spatiotemporal model of sheep collective motion that reproduces the experimental observations and allows to explore the outcomes of collective decisions in various conditions. The experimental and theoretical results increase the understanding of the individual mechanisms that produce collective decisions allowing to maintain group cohesion.

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