A menor capacidade de consumo voluntário de alimentos das fêmeas atuais pode ser evidenciada na fase de lactação. As fêmeas são mais exigentes nutricionalmente, pois o consumo de ração durante o período de lactação pode se tornar insuficiente para atender às exigências de mantença e máxima produção de leite das porcas. Com isso, o consumo voluntário de ração deve ser estimulado para evitar mínima mobilização de reservas corporais das fêmeas, garantindo assim, maior produção de leite e menor perda de peso das fêmeas até o desmame. O uso de substâncias flavorizantes, edulcorantes e do butirato de sódio estão sendo estudados com o objetivo de estimular o consumo voluntário. O experimento foi conduzido com o objetivo de determinar o consumo voluntário e a performance de 14 fêmeas suínas de primeiro parto em lactação, alimentadas com ração de lactação sem o uso de aditivo (T1) e ração de lactação contendo butirato de sódio (T2), edulcorante (T3) e flavorizante (T4), além do desempenho da leitegada de cada fêmea. As dietas experimentais foram administradas a partir do dia seguinte ao parto, até o dia do desmame. Os parâmetros avaliados nas porcas foram: consumo alimentar voluntário, perda de peso durante a lactação, variação na espessura de toucinho, produção de leite e intervalo desmama-estro subseqüente. O ganho de peso dos leitões foi também analisado. Foi observado maior consumo (P<0,05), pelas fêmeas do tratamento controle (T1) quando comparado com os demais tratamentos (T2, T3, T4). Já em relação à produção de leite, não foi evidenciado efeito significativo para nenhum dos tratamentos (P>0,05), porém observa-se uma diferença numérica entre os tratamentos, favorável ao T2. Quando observado peso e espessura de toucinho na entrada da maternidade e no desmame e o intervalo desmama estro, também não foram observadas diferenças significativas (P<0,05). Quanto ao peso dos leitões não foram evidenciadas diferenças significativas. Assim, a adição de substâncias flavorizantes, edulcorante e butirato de sódio em fêmeas primíparas, nas concentrações utilizadas nesse estudo, não apresentou efeito para nenhuma das variáveis, exceto para o consumo voluntário das fêmeas, de modo que são necessários novos estudos para averiguar a interferência desta suplementação sobre o consumo voluntário de alimentos, levando em consideração as linhagens híbridas existentes no mercado. / Sows of modern genotypes have a lower feed intake, whereas nutritional requirements have increased, especially due to higher number of piglets born per sow and thus to higher milk yield. Especially during lactation, if nutritional demands of sows are not met, a high milk production can lead to a negative energy balance, and thus to both a decrease in body fat reserves and a lower body weight at weaning. An alternative to avoid excessive body reserves depletion is feed supplementation with substances which can increase voluntary feed intake, among them flavors, sweeteners and butyric acid. The aim of this study was to assess the effects of such substances towards voluntary feed intake, milk production and performance of sows, and on litters weight gain, after supplementation of sows feeding during lactation. Fourteen first-parturition sows were allocated in one of the following treatments: feeding without any supplement (T1); supplementation with either butyric acid (T2), sweeteners (T3) or flavors (T4). Experimental diets were given from the day after parturition until the weaning. The following parameters were evaluated in sows: feed intake, loss of weight during lactation, variation of backfat thickness, milk production and weaning-estrus interval. Weight gain of piglets was also recorded. Feed intake of sows allocated at T1 group was higher (P<0.05), in comparison with T2, T3 and T4 groups. There was a trend towards a higher milk production of T2 group, although results were not statistically significant (P>0.05). In conclusion, supplementation of primiparous sows diet with flavours, sweeteners and butyric acid, at least at levels utilized in this study, did not produced any changes on the evaluated parameters, except for the voluntary feed intake of sows. Thus, futher investigations on the effects of those additives on voluntary feed intake and satiety mechanisms of new lineages pigs must be conducted.

BACKGROUND & AIMS: Psychological stress in early childhood has been implicated in the pathophysiology of functional dyspepsia but the mechanism is unclear. This study investigates the effect of early psychological stress on the regulation of satiety function in adulthood using an animal model of neonatal maternal separation stress (NMSS). / CONCLUSIONS: Psychological stress in early life leads to aberrant ghrelin profile and dysregulation of feeding behavior in response to acute psychological or physiological stress in adulthood. / METHODS: Sprague-Dawley (SD) rats underwent 3-hour daily maternal separation (MS) from postnatal day 2 to 22 and were weaned. The rats with no MS served as non-handling controls. Three experiments were conducted on these rats on day 60: (1) Water avoidance stress (WAS); (2): Feeding after overnight fasting and (3) Feeding after overnight fasting and WAS. Serial blood samples were collected for acylated ghrelin (AG) assay. In experiments (1) and (2), tissues from the stomach and hypothalamus were harvested additionally for evaluation of ghrelin expression. In experiments (2) and (3), calorie intake was also monitored at regular time intervals. / RESULTS: Experiment (1): MS rats had significantly higher mRNA ghrelin in hypothalamus (1.012 +/- 0.098 vs 0.618 +/- 0.071, P = 0.009) and plasma AG level (141.6 +/- 28.92 pg/mL vs 97.69 +/- 38.21 pg/mL, P = 0.014) in baseline non-stressed conditions. After WAS, MS rats had further increase in plasma AG level and gastric ghrelin expression. Experiment (2): After overnight fasting, the initial calorie intake was significantly higher in MS rats (at 3 mins: 1.303 +/- 0.293 kcal vs 0.319 +/- 0.159 kcal, P= .011; at 8 mins: 2.578 +/- 0.207 kcal vs 1.299 +/- 0.416 kcal, p = 0.019) but it dropped abruptly afterward and no difference in overall calorie intake over 28 minutes was found. The postprandial plasma AG level and gastric mRNA ghrelin were significantly lower in MS rats (95.92 +/- 12.71 pg/mL vs 154.01 +/- 14.53 pg/mL, p = 0.010). Experiment (3): After both fasting and WAS, the MS rats had significantly higher calorie intake in the first hour (17.24 +/- 1.10 kcal vs 11.95 +/- 1.20 kcal, P= 0.006) but it dropped substantially afterward with significantly lower cumulative calorie intake at 3 hours (at 3 hr: 19.44 +/- 1.50 kcal vs 26.49 +/- 2.25 kcal, P = 0.023). The calorie intake in MS rats remained significantly lower than that of controls up to 48 hours (168.1 +/- 4.76 kcal vs 220.8 +/- 8.27 kcal, P&lt; 0.001). / Cheung, Kwan Yui Cynthia. / Adviser: Justin C.Y. Wu. / Source: Dissertation Abstracts International, Volume: 73-06, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 138-154). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

Obesity is a growing problem in the United States. Research into the causes, treatment, and prevention of obesity is vital. One past study examined four eating behaviors in relation to obesity: eating beyond satiety, snacking, night eating, and feeling hungry within three hours of eating. Only eating beyond satiety was associated with obesity. The present study examined these same eating behaviors while correcting some of the flaws of the previous study. Using a cross-sectional design, university undergraduates reported on the frequency of the above-named eating behaviors. Current weight and height were collected. Multiple regression analyses determined that eating beyond satiety and hunger predicted body mass index (BMI). Race/ethnicity moderated the relationship between hunger and BMI. These findings have important implications for obesity treatment as well as suggesting important avenues for future research.

-Glucan is a soluble fibre shown to help regulate blood sugar and lower cholesterol. Incorporation into food, particularly bread, may affect -glucans physicochemical properties and health benefits. The journey of -glucan through the mixing, fermenting, baking, and storage of bread was evaluated, in terms of its solubility and viscosity under in vitro physiological conditions, at levels most likely to be presented to consumers (0.75, 1.0, 1.5 g -glucan/serving). Satiety and glycemic response measures, in addition to the quality and consumer acceptability of the bread, were also investigated. In dough, viscosity of the physiological extract was impacted by -glucan level, fermentation time, and endogenous flour enzymes. Fermentation decreased -glucan solubility indicating that the reduction in viscosity depends on both molecular degradation and solubility reduction. Dough rheological properties and microstructure, characterized using an oscillatory rheometer and fluorescence microscopy, respectively, showed that -glucan may interfere with the gluten network, though gluten addition may help improve this. The breads physical properties supported these observations, as -glucan decreased loaf volume and height, while gluten addition corrected this. Baking increased -glucan solubilization to 58-60%, compared to 9% in dough. Gluten addition increased solubility further (67-68%). Similar trends were seen for extract viscosity and were supported by fluorescence microscopy images. Storage at ambient, refrigeration and frozen conditions showed that bread with -glucan should be consumed fresh to maintain highest bread quality and -glucan solubility and viscosity. Bread with -glucan kept panelists full, longer. Reducing sugar release values implied that satiety may depend on digesta viscosity and/or rate of sugar release from the bread. Bread with -glucan produced the most leveled glucose curve; though areas under the 2 hr plasma glucose curves were similar. Consumers liked the 0.75 g -glucan/serving bread and the control more than the 1.5 g -glucan/serving bread, though provision of health information improved bread liking to similar values. The findings demonstrate that low solubility -glucan concentrate that gets solubilized upon baking is well suited for bakery applications and that a successful -glucan-fortified bread product is possible. Commercialization of bread fortified with -glucan would provide consumers an additional source of dietary fibre to assist them in coming closer to recommended daily intakes. / Food Science and Technology

No description available.

The current study sought to test the existence of a phenomenon known as sensory-specific satiety, in which attentional bias for food cues is specifically diminished for a consumed food, and the role of gender in such biases. In order to do so, the experiment used a version of the Flanker Task in which participants were shown image groups containing a target image and congruent or incongruent distracting flanker images. Participants (17 males, 22 females) were randomly assigned to consume one of two foods depicted in the flanker task (Ritz Bitz sandwiches or miniature Golden Oreos). Results did not support the idea of sensory-specific satiety, as we found a general reduction in reaction time rather than interactions in target/flanker congruency, suggesting that task performance was not driven by attentional bias to the food cues. However, there was an interesting interaction effect for session, consumption, and gender, such that women were faster than men for the consumed food post-satiety. Results may be explained by differences in motivation potentially caused by dissimilarities in dopamine levels. Additionally, results of the current experiment in combination with previous research could provide insight on gender differences in obesity.

The effect of meal-time exposure to food advertisements (FA) on food intake, subjective appetite and caloric compensation was investigated in overweight/obese (OW/OB) and normal weight (NW) boys (study 1) and girls (study 2). In random order, each participant watched either FA or non-food advertisements (NFA) 30 min after consumption of either a non-caloric sweetened control (CON) or a glucose (GLU) drink. Food advertisements increased food intake only in OW/OB girls. The GLU drink reduced food intake in both girls and boys despite no changes in subjective appetite. Food advertisements did not modify the response to the GLU drink in girls and contrary to the hypothesis they magnified the reduction in energy intake following the GLU drink in boys. In conclusion, FA in a TV program during consumption of a pizza meal by NW and OW/OB boys and girls increased food intake only in OW/OB girls and increased caloric compensation for the GLU drink at meal time in boys but not in girls.

The effect of meal-time exposure to food advertisements (FA) on food intake, subjective appetite and caloric compensation was investigated in overweight/obese (OW/OB) and normal weight (NW) boys (study 1) and girls (study 2). In random order, each participant watched either FA or non-food advertisements (NFA) 30 min after consumption of either a non-caloric sweetened control (CON) or a glucose (GLU) drink. Food advertisements increased food intake only in OW/OB girls. The GLU drink reduced food intake in both girls and boys despite no changes in subjective appetite. Food advertisements did not modify the response to the GLU drink in girls and contrary to the hypothesis they magnified the reduction in energy intake following the GLU drink in boys. In conclusion, FA in a TV program during consumption of a pizza meal by NW and OW/OB boys and girls increased food intake only in OW/OB girls and increased caloric compensation for the GLU drink at meal time in boys but not in girls.

Heavily-selected livestock production traits rarely come without compromise; altered physiology arising from intensive selection often gives rise to concern of a welfare trade-off. A particularly clear example of welfare challenge caused by genetic selection in chickens is the ‘broiler-breeder paradox’, wherein breeding populations of broiler-type birds selected for fast growth are feed-restricted in order to reduce growth and maintain reproductive viability at sexual maturity. In order to better-inform management and breeding strategies for alleviating reproductive problems resulting from genetic selection for growth, it is essential to develop a better understanding of the physiological processes underpinning growth. Whereas the molecular mechanisms governing energy balance in mammals have been relatively welldescribed, analogous avian systems have not received as much research attention and remain somewhat poorly understood. The broad aim of this doctoral project was to contribute to understanding of avian energy balance, particularly in the context of selection for high growth. Using an advanced broiler-layer intercross chicken line (AIL), high- and low-growth haplotypes at the locus encoding the cholecystokinin A receptor (CCKAR), underlying the most significant QTL for growth in chickens, were characterised. Of over 300 variations detected, a select panel spaced across the CCKAR locus were tested for prediction of bodyweight in a diverse cohort of chicken populations. One intronic SNP was found to be significant (p < 0.05) and proximal to transcription factor binding sites. The effect of this locus on gross bodyweight remained significant into the 20th AIL generation (~20% at 10wk, p < 0.05). In this otherwise effectively genetically homogeneous population, several specific physiological traits were predicted by CCKAR haplotype alone, yielding some clues as to the significance of perturbed cholecystokinin (CCK) signalling in broiler strains. While birds with high-growth CCKAR haplotype (HG) did not appear to consume more, feed conversion efficiency (FCE) was improved, at least for males, compared to low-growth (LG) (p < 0.05). Visceral organ anatomies were morphologically disparate, with HG individuals exhibiting ~1/3 less gallbladder mass (p < 0.01), and ~10% shorter GI tract (p < 0.01) and metatarsal bone (p < 0.05). Further gaps in knowledge of the expression of peripheral satiety hormones in chicken are addressed in this thesis. Tissue distributions for expression of CCK, gastrin, pancreatic polypeptide (PPY) and peptide YY (PYY), were mapped and their respective dynamic responses to nutritive state examined. CCK was found to be most highly expressed in the brain, whereas PYY, PPY and gastrin were far more abundant in distinct regions of the periphery. Interestingly, peripheral CCK was not responsive to short-term (< 10h) satiety in experimental populations where PYY and gastrin were. PYY expression was found to be greatest in the pancreas and consistently upregulated within hours after feeding (p < 0.01), whereas gastrin expression was confined to the gastric antrum and paradoxically highest in fasting birds (p < 0.01). PPY expression is strictly limited to the pancreas and appears dependent on longerterm energy state. These results highlight similarities and differences to mammalian systems; notably, the avian pancreas seems to fulfil an exceptional role as a site of signal integration, perhaps unsurprising considering its disproportionate size compared to mammals. Indeed, pancreatic PYY appears to act as a primary peripheral short-term satiety hormone in birds. This body of work contributes to the understanding of avian energy balance and growth. An invaluable foundation for future research is formed by the identification of the major locations of production, and basic nutrient-responsive trends, for several peripheral avian hormones. Information on the growth role of CCKAR is consolidated and expanded upon, demonstrating a clear genetic contribution to maintenance organ morphology and overall growth. Such knowledge can be used to reliably assess and advise on selection and management of chickens to stem welfare concerns without compromising production. Comparisons between avian and other vertebrate endocrine systems make for interesting insight into the adaptive role of energy homeostatic mechanisms in divergent evolution of mammals and non-mammalian vertebrates. In some aspects, birds might better represent the ancestral phenotype from which each vertebrate clade arose.

abstract: Dietary protein is known to increase postprandial thermogenesis more so than carbohydrates or fats, probably related to the fact that amino acids have no immediate form of storage in the body and can become toxic if not readily incorporated into body tissues or excreted. It is also well documented that subjects report greater satiety on high- versus low-protein diets and that subject compliance tends to be greater on high-protein diets, thus contributing to their popularity. What is not as well known is how a high-protein diet affects resting metabolic rate over time, and what is even less well known is if resting metabolic rate changes significantly when a person consuming an omnivorous diet suddenly adopts a vegetarian one. This pilot study sought to determine whether subjects adopting a vegetarian diet would report decreased satiety or demonstrate a decreased metabolic rate due to a change in protein intake and possible increase in carbohydrates. Further, this study sought to validate a new device called the SenseWear Armband (SWA) to determine if it might be sensitive enough to detect subtle changes in metabolic rate related to diet. Subjects were tested twice on all variables, at baseline and post-test. Independent and related samples tests revealed no significant differences between or within groups for any variable at any time point in the study. The SWA had a strong positive correlation to the Oxycon Mobile metabolic cart but due to a lack of change in metabolic rate, its sensitivity was undetermined. These data do not support the theory that adopting a vegetarian diet results in a long-term change in metabolic rate. / Dissertation/Thesis / M.S. Nutrition 2012