Submitted in fulfillment of the requirements for the degree of Masters of Applied Science in Food and Nutrition, Durban University of Technology, Durban, South Africa, 2016. / Introduction: Food and Agriculture Organisation (FAO 2015a) estimated that 220 million people (23.2%) in Sub-Saharan Africa were undernourished. Parallel to hunger, obesity rates have more than doubled globally since 1980; in 2014, 1.9 billion adults in the world were overweight and 600 million were obese (FAO 2015a). Obesity is a serious concern facing the world today and a major contributor to chronic disease such as diabetes and cardiovascular disease, which are often fatal (Bray, Frühbeck, Ryan and Wilding 2016: 1947). In South Africa, overweight and obesity have reached unacceptable numbers as over 60% of South Africans are overweight or obese. Furthermore, in 2015 South Africa was declared the fattest nation in Sub-Saharan Africa, adding another burden to the HIV epidemic (Ng, Fleming, Robinson, Thomson, Graetz, Margono, Mullany, Biryukov, Abbafati and Abera 2014: 777). Unemployment is one of the major factors that drive household food insecurity due to the fact that most people access food commercially. Therefore, income is a significant factor in ensuring that a healthy and nutritious diet is consumed regularly. The study community was at Umbilo, Durban, KwaZulu-Natal in a government owned estate called Kenneth Gardens. The estate has 286 units and accommodates approximately 1500–1800 residents. It formed part of an extensive network of cluster housing schemes developed by the apartheid government as a protectionist strategy to provide safe and affordable housing for poor and working class whites. Kenneth Gardens is currently managed by KwaZulu-Natal (KZN) Province and offers subsidized housing to residents from diverse background. Residents are low income bracket earners and many rely on state disability and pension grants for survival. Kenneth Gardens faces a wide range of social problems such as alcohol, drug abuse, domestic violence, unemployment and limited access to education (Marks 2013:26). Aim: The aim of the study was to determine the food security status, coping strategies, food intake and the nutritional status of the Kenneth Gardens community, which is situated in an urban area in KwaZulu-Natal. Methodology: One hundred and fifty (n=150) randomly selected caregivers participated in the study. The sample size was calculated using a power calculation indicating that 150 participants represent a reliable sample. The sampling procedure was simply random sampling. This study was quantitative and partly qualitative and descriptive in nature therefore, different measuring instruments were used to collect relevant data. The research tools for various variables measurements included; food security questionnaire, anthropometric measurements, a socio-demographic questionnaire, a food frequency questionnaire, and 24-hour recall questionnaires conducted in triplicate. Food security coping strategies were documented through a focus group interview with the Kenneth Gardens community members to determine strategies used to address food scarcity. All participants were weighed and measured to determine body mass index (BMI), classified according to the World Health Organisation (WHO) cut-off points. Data for socio demographic, FFQ, anthropometric measurements, and coping strategies was captured by the researcher on Excel® Spread sheets and analysed by a statistician for descriptive statistics using the Statistical Package for the Social Science (SPSS) version 17.0. Data for the 24-hour recall was captured and analysed by a nutrition professional using the MRC Food Finder® version 3.0 software, based on the South African composition tables. Results: The study population consisted of 150 households, including women (n=122) and men (n=28). The results revealed that the majority of households (52.7%, n=79) were headed by a mother, and only 40% (n=60) of households were headed by a father. Majority (47.3%, n=71) of the participants had completed matric and 7.3% (n=11) had tertiary education. English, (52%, n=78), was the most spoken home language, followed closely by Zulu, (43.3%, n=65). Thirty six percent (n=54) of the participants were unemployed and 26.7% (n=40) were employed; however over, 50% (n=40) of the employed participants were temporary. Twenty eight percent (n=42) of the participants earned less than R3000.00 per month and 31.3% (n=47) earned between R3000.00 and R6000.00 per month. Pensioners were 17.3% (n=26), who therefore received a government grant that ranges between R1500 and R1520 per month depending on the claimant’s age. The average household income was reported as R4429.20. The average number of people in the household was five, which equates to R6.00 per person per day. The results also revealed that 38% (n=57) of the household had a sole contributor to the household income; other households had two contributors (42.7, n=64) and 11.3% (n=17) had three contributors. Urban South Africans tend to purchase food as opposed to growing their own food. A lack of purchasing power results in food insecurity that eventually leads to malnutrition. The majority (56.6%, n=85) of the participants indicated a shortage of money to buy food and this inevitably leads and drive utilisation of coping strategies with high severity rate during periods of food scarcity. Bulk food was purchased once a month by the majority (68%, n=102) of the participants. The most commonly used coping strategy during periods of food scarcity was “Rely on less expensive and preferred food” with the mean score of 4.56 (±SD 2.772). The second used coping strategy was “Reduce the number of meals eaten in a day” with a mean score of 3.85 (±8.163), followed by “Contribute to a food stokvel in order to ensure food over a scarce period” (3.31, ±7.505) and “Restrict consumption by adults in order for small children to eat” (2.24, ±5.333). Utilisation of these food coping indicate a degree of food insecurity. The Body Mass Index (BMI) classification indicated that women had a higher (31.46 ±8.474) BMI than men (26.00±5.445). A total of 26.2% (n =32) women were overweight and 51.7% were obese category I, II and III. The mean BMI for the whole group was (30.44±8.261) which clearly demonstrated obesity. Nonetheless, men were not overweight; however 25% (n=7) were obese category I. Collectively, underweight was prevalent in women (3.3%, n=4) and men (3.6%, n= 1). The Food Variety Score was medium (31.91, ±10.573), which indicated a consumption of 30- 60 individual foods from four to five food groups during the seven day period; however the top 20 foods consumed from the 24-hour recall revealed that the diet was energy dense and the most consumed foods were primarily from the carbohydrate and fat group and a low consumption of fruits and vegetables was reported; hence the nutrient analysis showed a deficient intake of several nutrients, such as: calcium, vitamin A, zinc, vitamin D, vitamin E, vitamin K, zinc, magnesium, phosphorus, selenium and thiamine by both men and women. According to the WHO dietary factor goals, the acceptable macronutrient distribution ranges (AMDRs) and fruit and vegetable intake based on the 24-hour recalls, fat and protein intake exceeded the recommended 15-30 percent goal. Fruit and vegetable intake was very low in comparison to the minimum recommended intake of >400g. Carbohydrates intake for women were within the recommended 55-75 percent; however, men aged 19-50 years (50.70%) and >50 years (53.74%) did not meet the recommended intake. Conclusion: The results of this study reveal that the nutrition status of this community was compromised. The top 20 food intake indicated inadequate eating patterns and that diets comprised of energy dense foods, such as carbohydrates and fats, which could directly be responsible for the high obesity levels of >50% in women and >25% in men. Furthermore, there was low income and a high unemployment rate that proliferates the prevalence of food insecurity, hence the coping strategies reported. Malnutrition exists in communities as a result of food and nutrition insecurity which is affected by a significant number of factors that need to be considered and addressed. Nutrition interventions and nutrition education on a balanced diet, healthier methods of preparing food, and physical activity are required to ensure and improve health status, quality of life and better and sustainable coping strategies for our communities. / M

Nesta tese, determinou-se o consumo alimentar e consumo de álcool de 2972 participantes de pesquisa do Estudo Longitudinal de Saúde do Adulto (ELSA-Brasil). Posteriormente foi identificada a relação da dieta e álcool com as subfrações de colesterol medidas por ultracentrifugação vertical, denominada Vertical Auto Profile (VAP). Foi identificada baixa associação dos ácidos graxos dietéticos e as subfrações de colesterol. Quanto ao consumo de álcool, independentemente do tipo de bebida alcóolica consumida, o álcool resultou em melhor perfil lipídico, com níveis significativamente maiores de HDL-colesterol, HDL2-colesterol e HDL3-colesterol, tanto em homens quanto mulheres. Também foi discutida a parte ética de pesquisas com seres humanos, contextualizando o caso do ELSA-Brasil. / In this thesis, food and alcohol consumption of 2972 research participants from the Estudo Longitudinal de Saúde do Adulto (ELSA-Brazil) were determined. Subsequently, the relationship between diet and alcohol with cholesterol subfractions measured by vertical ultracentrifugation, called Vertical Auto Profile (VAP), was identified. Low association of dietary fatty acids and cholesterol subfractions has been seen. Regarding alcohol consumption, regardless of the type of alcohol consumed, alcohol resulted in a better lipid profile, with significantly higher levels of HDL-cholesterol, HDL2-cholesterol and HDL3-cholesterol, in both men and women. The ethical part of research with human beings was also discussed, contextualizing the case of ELSA-Brazil.

As aflatoxinas são substâncias naturais que apresentam efeitos tóxicos aos humanos e são reconhecidamente carcinogênicas. Estas substâncias podem estar presentes na dieta humana ou, em casos específicos, no ar respirado. Desta maneira, a exposição humana às aflatoxinas é objeto de muita preocupação. Uma das maneiras mais eficazes de avaliar a exposição humana as aflatoxinas é através da mensuração da presença de biomarcadores da exposição a estas substâncias em fluidos biológicos. Dentre as possibilidades de biomarcadores de exposição às aflatoxinas tem-se que aflatoxina M1 (AFM1), presente na urina e leite humano, é considerada um biomarcador válido. Assim sendo, o objetivo deste trabalho de pesquisa foi avaliar a presença de AFM1 em amostras de urina provenientes de indivíduos residentes na região urbana e rural da cidade de Piracicaba-SP, assim como, de leite de gestantes de Piracicaba e cidades da região. Nos indivíduos doadores de amostras de urina foi levantado também o padrão de ingestão de alimentos com alto risco de conter aflatoxinas, através da aplicação de inquéritos de freqüência alimentar e recordatórios 24 horas. A análise de AFM1 em urina e leite foi realizada por cromatografia liquida de alta eficiência (CLAE) com detecção por fluorescência. A extração e purificação do extrato foram realizadas com auxílio de colunas de imunoafinidade. No total 69 amostras de urina e 18 de leite foram analisadas. Entre as amostras de urina detectou-se a presença de AFM1 em 54 (78%) das amostras, com concentrações variando de 1,8 até 39,9 pg/mL. Não foi observada diferença estatística entre as concentrações médias detectadas entre urinas de indivíduos da zona urbana e rural, bem como no nível de consumo de produtos de risco. Apesar das concentrações de AFM1 detectadas serem inferiores as concentrações médias reportadas em outros países a freqüência de amostras positivas foi bastante elevada mostrando que as populações estudadas estão sendo expostas às aflatoxinas. Assim, melhores avaliações dos níveis de exposição necessitam ser realizados considerando que a amostragem utilizada foi pontual, pode existir variação de contaminação sazonal com aflatoxinas na dieta e a contaminação é heterogênea dentro no alimento. Não foi observada uma correlação entre o nível do consumo de produtos de risco e as concentrações detectadas em amostras de urina. Apenas uma amostra de leite apresentou contaminação detectada; entretanto, o nível de contaminação estava entre o limite de detecção (LD) e o limite de quantificação (LQ). / Aflatoxins are natural substances that present toxic and carcinogenic effects to humans. These substances may be present in human diet or, in specific cases, in the breathing air. Thus, the human exposition to aflatoxins is object of concern. One of the most effective ways to evaluate human exposition to aflatoxins is to measure the presence of biomarkers in biological fluids. Among the possibilities of aflatoxin presence biomarkers, the aflatoxin M1 (AFM1), present in human urine and milk, is considered a valid biomarker. The objective of this work was to evaluate the presence of AFM1 in urine samples from individuals who live in urban and rural areas in the county of Piracicaba, state of São Paulo, Brazil, and in milk of pregnant women from Piracicaba and neighbor cities. Urine-donor individuals were researched in relation to the ingestion of food with high risk of containing aflatoxins through the application of a food frequency questionnaire and 24-hour recall. The analysis of AFM1 in urine and milk was performed through high-performance liquid chromatography (HPLC) with fluorescence detection. The extract purification and extraction were performed with the aid of immunoaffinity columns. Overall, 69 urine and 18 human breast milk samples were analyzed. Among urine samples, the presence of AFM1 was detected in 54 (78%), with concentrations ranging from 1.8 to 39.9 pg/mL. No statistical difference was observed between average concentrations detected in the urine of individuals from urban and rural areas, as well as the consumption of aflatoxin risky food. Although the AFM1 concentrations detected are lower than those reported for other countries, the frequency of positive samples was quite high, showing that the populations studied are exposed to aflatoxins. Thus, further evaluations on the exposition levels should be performed, and considering that the sampling used in this work was punctual, there may be seasonal contamination variations in diet and the contamination level is heterogeneous within a food. No correlation between the consumption of risky food and concentrations detected in urine samples was observed. Only one milk sample presented detected contamination; however, the contamination level was between the limit of detection (LOD) and the limit of quantification (LOQ).

Les caractéristiques de la ressource occupent une place prépondérante à toutes les étapes des processus d'ingestion et de sélection alimentaire par les herbivores, à court et à long terme. Par une approche expérimentale, nous avons contribué à une meilleure compréhension des adaptations mises en place par les chevaux confrontés à des variations de la qualité et de la hauteur de la végétation offerte.<br> A partir de l'analyse de données individuelles d'ingestion mesurées à l'auge pour une large gamme de fourrages, nous avons montré que les chevaux pouvaient compenser dans une certaine mesure une faible valeur nutritive du fourrage par une augmentation du niveau d'ingestion. Tous les individus n'ont pourtant pas exprimé la même réponse face à la diminution de la qualité de leur ressource. A partir de deux expériences conduites au pâturage, nous avons montré que lorsque les chevaux avaient le choix d'ajuster leur temps d'alimentation entre deux couverts variant uniquement en hauteur, ou simultanément en hauteur et en qualité, ils pouvaient maintenir un niveau d'ingestion de MSD relativement constant. Bien que la vitesse d'ingestion instantanée de MS digestible ait été plus élevée sur les couverts les plus accessibles, la déplétion des couverts au cours de la journée a probablement nivelé les vitesses d'ingestion moyennes réalisées sur l'ensemble des couverts, ce qui pourrait expliquer, au moins en partie, la constance des quantités ingérées journalières de MS digestible. Les résultats obtenus au pâturage et à l'auge s'inscrivent dans une relation générale montrant que lorsque la concentration en énergie et en azote de la ressource diminue, les chevaux peuvent maintenir leur niveau d'ingestion de façon à couvrir leurs besoins alimentaires.<br> En situation de choix binaire entre des sites d'alimentation dont la qualité était proche, les chevaux ont pâturé préférentiellement les couverts les plus hauts sur lesquels ils ont maximisé leurs vitesse d'ingestion de MS et de MS digestible (en accord avec les théories d'optimisation). À mesure que le couvert le plus haut est devenu mature, et donc que le compromis entre la qualité et la hauteur de la ressource est devenu important, les chevaux ont reporté leur temps d'alimentation sur les couverts les plus courts de meilleure qualité, bien que la vitesse d'ingestion de MS digestible soit restée plus élevée sur le couvert le plus haut. Nous avons montré que ce comportement est en relation avec la nécessité de satisfaire les besoins azotés, le choix des sites sélectionnés par les animaux pouvant s'expliquer par la vitesse d'ingestion instantanée de matières azotées digestibles permise par les couverts végétaux. Au cours de la journée, les chevaux n'ont pour autant pas exprimé des choix strictement optimaux, ne pâturant pas exclusivement le couvert le plus profitable. Dans l'étude où hauteur et qualité de l'herbe ont varié simultanément, le partage du temps d'alimentation entre les différents sites a probablement permis d'équilibrer leur régime sur la base de l'azote et de l'énergie.<br> Par la modulation de leur temps de pâturage sur les différents sites d'alimentation, les chevaux ont été capables d'adapter leur comportement à l'hétérogénéité de leur environnement, afin de maintenir un régime de bonne qualité et de satisfaire leurs besoins nutritionnels. Quelques perspectives de recherche sont proposées afin d'aboutir à des recommandations en terme de gestion de l'alimentation de ces herbivores et des prairies pâturées. Enfin, nous concluons sur la contribution de cette thèse à la compréhension des relations entre grands herbivores et ressources végétales.

Presented in this thesis is the development of a high-fidelity aerothermal model for GE T700 turboshaft engine. The model was constructed using thermodynamic relations governing change of flow properties across engine components, and by applying real component maps for the compressor and turbines as well as empirical relations for specific heats. Included in the model were bleed flows, turbine cooling and heat sink effects. Transient dynamics were modeled using inter-component volumes method in which mass imbalance between two engine components was used to calculate the inter-component pressure. This method allowed fast, high-accuracy and iteration-free calculation of engine states. Developed simulation model was successfully validated against previously published simulation results, and was applied in the simulation of inlet distortion and engine deterioration. Former included simulation of steady state and transient hot gas ingestion as well as transient decrease in the inlet total pressure. Engine deterioration simulations were performed for four different cases of component deterioration with parameters defining engine degradation taken from the literature. Real time capability of the model was achieved by applying time scaling of plenum volumes which allowed for larger simulation time steps at very little cost of numerical accuracy. Finally, T700 model was used to develop a generic model by replacing empirical relations for specific heats with temperature and FAR dependent curve fits, and scaling T700 turbine maps. Developed generic aerothermal model was applied to simulate steady state performance of the Lycoming T53 turboshaft engine.

Feeding disorders are common in disabled children, and family reactions are critical factors influencing the severity and course of this problem. This study hypothesized that feeding disorders in disabled children would be significantly more stressful to parents than other childhood disabilities; that pediatric feeding disorders would be more stressful in single parent families than two parent families; and that childhood feeding disorders would be less stressful to fathers than to mothers.Two copies each of the Friedrich Questionnaire on Resources and Stress (QRS-F) and a demographic data survey were sent to 79 families of disabled children. Responses were received from 47 subjects representing 31 households. Analysis of Variance of the QRS-F scores indicated significantly greater stress levels in families of disabled children who received tube feedings, but not in families whose disabled children required special assistance with oral feeding. There was an inadequate number of responses from single parent families to statistically compare their stress levels to two parent families with feeding disordered children. The comparison of fathers and mothers of disabled children with feeding disorders did not yield a statistically significant difference in stress levels.The greater stress levels found in parents of disabled children who received tube feedings shows a need to provide improved education and training programs, as well as support after hospital discharge, to families with tube fed children. / Department of Family and Consumer Sciences

The inadvertent ingestion of contaminated soil is the dominant exposure route of non-volatile and semi-volatile contaminants such as polycyclic aromatic hydrocarbons (PAHs). Quantitative mass balance soil ingestion studies have been used to determine soil ingestion rates for use in human health risk assessments (HHRA) that can be used to predict the likelihood of adverse effects in individuals exposed to hazardous contaminants such as PAHs in contaminated soil. The Cold Lake region of Alberta is one of the three major oil sands regions of Alberta, and PAH concentrations in this oil sand region may be elevated in the atmosphere and the soil, resulting in increased exposures to PAHs. The area is home to Cold Lake First Nation who practice traditional activities and lifestyles that may put them in greater contact with soil than previous soil ingestion studies suggest. The primary objective of this research was to assess the soil ingestion rate in a group of First Nations subjects inhabiting the Cold lake region, and assess the carcinogenic risk posed by exposures to PAHs in air and soil. The study employed a quantitative mass balance tracer approach to estimate soil ingestion rates, and followed 9 subjects over a 13 day period. Soil and air samples were simultaneously collected to assess PAH contamination. The mean soil ingestion rate using Al and Si elemental tracers was 52 mg d-1, with a 90th percentile of 220 mg d-1, and a median soil ingestion rate of 37 mg d-1. These values are greater than the soil ingestion rates for HHRA recommended by Health Canada. The mean increase in excess lifetime cancer risk posed by inadvertent ingestion of soil to a First Nations’ individuals following traditional activities was 0.02 cases per 100,000 people with a 95% risk level of 0.067 cases per 100,000 people. Exposure to PAHs through inhalation posed a maximum lifetime cancer risk below 0.1 cases per 100,000, people. Thus, this study found no appreciable increase in excess lifetime associated with PAH exposure of First Nations’ people in the Cold Lake region.

The impact of nutritional intervention on affective states has largely been ignored in the exercise-affect literature. For decades the impact of such interventions on perceptions of exertion has been well documented. However, Hardy and Rejeski (1989) assert that `what' a person feels, as measured by the rating of perceived exertion (RPE) scale, may be very different from `how' they feel, and that on its own the RPE provides limited information about the subjective experiences of individuals during exercise. This thesis describes a series of studies that assess the influence of various fluid ingestion regimes on both `how' and `what' a person feels. Seven studies were undertaken, incorporating a variety of exercise modes, including prolonged running (Study 1,3 & 7), prolonged cycling (Study 2& 4) and prolonged intermittent, high intensity exercise (Study 5,6 & 7). The relationship between fluid ingestion during exercise and affective states during and following exercise proved to be a complex one. The initial investigation (Study 1) showed that the ingestion of water during prolonged running resulted in an overall improvement in valence during the recovery period. A significant increase in activation was also noted in the water trial only, from pre to post exercise. Furthermore, subjective ratings of energy post-exercise were higher in the water trial, compared to the no water trial. In study 2 the beneficial effects observed in study 1 were not so apparent. In this instance the only significant change of interest was in energetic arousal, which was found to be higher 5 min post exercise in the water trial compared to the no water trial. When the ingestion of a CHO solution during exercise was compared to a placebo or flavoured water solution (Studies 3-7) the findings also varied. However, the observation of an enhanced affective profile following CHO ingestion in Study 4 and Study 5 highlights the importance of considering nutritional status and intervention when investigating the exercise-affect relationship. These studies have highlighted some important aspects in our understanding of the exercise-affect relationship alone. Firstly, a robust finding across all the studies was the observation of an almost uniformly positive shift in valence from the final within-exercise assessment to the post exercise assessments. Thus emphasising the dynamic nature of affect and the importance of repeated within exercise assessments. Secondly, moderate intensity exercise of a fixed duration was marked by highly variable inter-individual differences in the response of participants to the valence and activation dimensions. However, exercise to fatigue elicited a homogenous valence response as participants came closer to reaching their exercise capacity.

Thesis (Ed. D.)--Illinois State University, 2002. / Title from title page screen, viewed February 9, 2006. Dissertation Committee: Maureen E. Angell (chair), James R. Thompson, C. Al Bowman, Stacey Jones Bock, Emily H. Watts. Includes bibliographical references (leaves 203-216) and abstract. Also available in print.

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.