Male Fischer rats (n=43) were used in a diet-diet/ exercise design to investigate the apparent protein sparing effects of exercise. The animals were divided into five groups: INITIAL (baseline), SEDENTARY (control), DIET, DIET/EXERCISE, and EXERCISE. Carcasses were analyzed for body composition, the blood for plasma alanine concentration and the urine for urea nitrogen concentration. The results showed no significant differences between groups in urinary urea nitrogen, plasma alanine, body weight, or carcass weights. The EXERCISE group had a significant increase in percent protein and a significant decrease in percent fat and grams of fat when compared to all other groups (p <.05).

In recent years, there has been a growing interest in feeding phytogenic products to poultry for their growth and health benefits. The objective of this experiment was to determine the effects of a phytogenic feed additive on turkey poult performance and digestive physiology over a 6-week brooding period. In total, 864 male Hybrid Converter turkey poults were obtained from a local commercial hatchery on day-of-hatch and placed into floor pens with clean pine shavings. The treatments were randomly assigned including an industry-type corn-soybean meal positive control (PC), a similar diet with a 1.5% reduction in crude protein and key amino acids (NC), or the NC with the addition of Digestarom® (PFA) included at a rate of 1 g/kg. Body weight gain (BWG), feed intake (FI), feed efficiency (FE), and mortality were recorded throughout the experiment. On day 14 poults fed the PFA had significantly higher BWG compared to the PC and NC fed birds. By day 42 birds fed the PC and PFA diets had significantly higher BWG compared to the NC, and the PC had significantly higher FE compared to the NC and PFA fed birds. No differences in FI or mortality were observed throughout the experiment. There were no significant differences in AMEn, crude protein digestibility, or nutrient transporter or pancreatic enzyme mRNA expression among treatments. However, aminopeptidase activity tended to be lower in the ileum of poults fed the PC or PFA diets compared to the NC, suggesting that the PFA may be improving protein utilization. / Master of Science / Recent regulations and customer demand have severely restricted the use of antibiotics in poultry production. Historically, antibiotics have been included in poultry diets at sub-therapeutic concentrations to improve performance and reduce disease incidence. Since this restriction, producers have experienced increased feed conversion ratio, decreased body weights, and increases in morbidity and mortality. Not only does this present an animal welfare issue, but producers experience decreased profits due to the decrease in performance associated with restricted antibiotic use. Many researchers are investigating the ability of alternative feed additives to help mitigate the lost performance this restriction has caused. One such alternative is a class of compounds known generally as phytogenic feed additives. These are herbs, spices, and associated products which can be included into the diet at relatively low concentrations. Previous research has demonstrated the ability of phytogenic feed additives to positively influence performance and gastrointestinal tract health, primarily in broiler chickens. Therefore, the objective of this thesis is to investigate the effect of a commercially available phytogenic feed additive on the performance, nutrient digestibility, and absorption in turkey poults over the first six weeks of feeding. Previous indications with this product seem to indicate that it also increases protein utilization so this product was evaluated using a reduced protein diet. By day 14, poults fed the feed additive had significantly higher body weights compared to both the positive and negative control. At the conclusion of the experiment on day 42, the birds fed the feed additive had significantly higher body weight compared to the negative control and were similar to the positive control. This suggests the ability of the feed additive to improve performance when dietary protein is reduced. Data from aminopeptidase activity in the ileum suggest a potential improvement in the efficiency of protein utilization, which may explain the performance improvements when poults were fed the phytogenic feed additive.

Current treatments for obesity have been unsuccessful. It is essential that a patient-centred approach for obesity management is developed and for this to be successful other diet and lifestyle approaches need to be considered. A systematic review comparing low carbohydrate vs. low fat diets for the treatment of obesity was carried out. It found that low carbohydrate/high protein diets are as effective as, if not better, for treating obesity and cardiovascular disease risk factors. A randomised controlled trial investigating dietary approaches for the treatment of obesity and its co morbidities was carried out. Variables including weight and body composition, cardiovascular risk factors, adipokines, liver and kidney function, and health and lifestyle factors were measured. Those with metabolic syndrome were also examined. It was hypothesised that there are alternative ways of treating obese subjects depending on their phenotype. Those with a higher BMI tend to have a higher carbohydrate intake rather that a higher fat intake so may be better suited to a low carbohydrate/high protein diet rather than the conventional low fat/energy reduced diet. Subjects were initially treated with the standard dietary approach for obesity (health eating, HE) and if not successful after 3 months were randomised to either a very low calorie diet (Lighterlife, LL) or a protein sparing modified fast (PSMF). All three groups showed a significant weight loss and reduced risk for CVD at 12 months. Significant improvements were seen for plasminogen-activated receptor-1, adiponectin, leptin and IL-6 on HE and LL, but only adiponectin significantly improved on the PSMF. Neither diet showed any detrimental effects for those with a healthy liver and kidney function. Quality of life and levels of depression improved at 12 months. Of the 54 subjects with metabolic syndrome at baseline, 12 remained on HE and 32 were randomised to LL and PSMF. This indicates that most subjects did not suit a low fat dietary approach. They were successful at losing weight on LL and PSMF and showed improvement in MS risk factors, and adipokine levels at 12 months. In conclusion, the study demonstrates that a low fat diet may not necessarily be the first line of approach to treat obese subjects with a BMI over 35 kg/m2, including those with MS. A very low calorie diet such as LL or a PSMF may be better suited to the subject.

Made available in DSpace on 2016-05-02T13:55:33Z (GMT). No. of bitstreams: 1 CelioLuizBernardes-Dissertacao.pdf: 591497 bytes, checksum: 3c6604ea02d2ceebbbe446b5f072e787 (MD5) Previous issue date: 2012-03-05 / This study evaluated the influence of different carbohydrate/lipid ratios (CHO:L) in the diet of hybrid catfishes, carnivorous Pseudoplastitoma reticulatum x omnivorous Leiarius marmoratus, on the performance, body composition and nutrient utilization. Four isoproteic diets were formulated containing 43% crude protein, with increasing levels of lipids with CHO: diet I, 1.3; diet II, 1.1; diet III, 0.9; diet IV, 0.8. The fishes were fed at 5% of the living body weight (LBW) for the triplicate groups of 6 fishes (18 ± 1.5 g) during 8 weeks. Although the final weight and the absolute weight gain decreased with the increase of lipids in the diet, no significant difference was found in the ration daily consumption (DC) between the treatments. In addition, the viscerosomatic index (VSI) and the hepatosomatic index (HIS) showed no statistic difference between the dietary treatments. Protein efficiency retention (PER), lipid efficiency retention (LER) and protein gain (PG) were higher in the 1.3 CHO:L group, but no significant difference was found between the 0.9 and 0.8 CHO:L groups. In conclusion, high CHO:L ratios around 1.3 produced great benefit due to the best growth performance in the studied hybrid model. / Avaliou-se a influência de diferentes níveis de carboidratos / lipídios na dieta de peixes (CHO/ L) sobre o desempenho , composição corporal e utilização de nutrientes de híbrido, carnívoros (Pseudoplastistoma reticulatum ) x onívoros (Leiarius marmoratus) . Quatro dietas isoproteicas foram formuladas contendo proteína bruta a 43%, com aumento dos níveis de lipídios na dieta, usando-se o CHO com os seguintes índices: L: dieta 1, 1,3; dieta 2, 1,1; dieta 3, 0,9. e dieta 4, 0,8. Os peixes foram alimentados a 5% do peso vivo (PV) para os grupos triplicados, de 6 peixes (18 ± 1,5 g) durante 8 semanas. Apesar do peso final e do ganho em peso absoluto ter diminuído com o aumento de lipídios na dieta, não houve diferença significativa no consumo diário de ração (CD) entre os tratamentos. Além disso, o índice viscerossomático (IVS) e índice hepatossomático (IHS) não apresentaram nenhuma diferença estatística entre os tratamentos dietéticos. O teor de proteína muscular foi alto e significativo para os peixes alimentados com a dieta 1. Contudo, houve a diminuição de umidade e lipídios nos peixes alimentados com a dieta 4. A retenção de eficiência protéica (ERP), a retenção de eficiência lipídica (ERL) e o ganho de proteína (GP) foram superiores no grupo 1,3 CHO/L, mas nenhuma diferença significante foi encontrada entre os grupos 0.9 e 0.8 CHO:L. Em conclusão, CHO alta: cerca de 1,3 L relações apresentaram grande benefício, pelo melhor crescimento no modelo estudado no híbrido.

Traditionally, fish meal (FM) and fish oil (FO) have been used extensively in aquafeeds, mainly due to their excellent nutritional properties. However, various reasons dictate the use of sustainable alternatives and the reduction of the dependence on these commodities in fish feeds. Hence, the aim of the present thesis was to investigate the effects of the replacement of FM and FO with two vegetable oils (VO) and an oilseed meal on the growth performance, feed utilization, nutrient and fatty acids (FA) digestibility and tissue FA composition and metabolism in three commercially important European fish species. Specifically, in Experiment I crude palm oil (PO) was used to replace FO in diets for rainbow trout. In Experiments II and III FO was replaced with rapeseed oil (RO) in diets for Atlantic salmon at various dietary protein/lipid levels aiming also at further reductions of FM by using low protein (high lipid) diet formulations. In Experiments II and III the fish were reared at low and high water temperatures, respectively, in order to elucidate, also, the potential effects of temperature. Lastly, the effects of the replacement of FM with full fat soya meal (FFS) in Atlantic cod were investigated in Experiment IV. The results of the present thesis showed no negative effects on growth performance and feed utilization in rainbow trout when FO was replaced with PO. The dietary inclusion of RO improved the growth of Atlantic salmon, possibly, due to changes in the nutrient and FA digestibilities and FA catabolism while, the growth and feed utilization were unaffected by the dietary protein/lipid level. However, the growth of Atlantic cod was affected negatively by the replacement of FM with FFS. The proximate composition of the fish whole body was in most cases unaffected by dietary treatments. The changes in dietary formulations affected the dietary FA compositions and resulted in significant changes in the fish tissue FA compositions. It was clearly shown that the fish tissue total lipid FA composition reflects the FA composition of the diet, although specific FA were selectively utilized or retained in the tissues by the fish. These may have serious implications not only for fish metabolism and growth but also for the quality of the final product, especially in terms of possible reductions of n-3 HUFA.