Accurate measurements of energy content and body composition are essential to effectively assess the well-being of fish. Bomb calorimetry and proximate analysis are currently the most dependable and accurate methods to estimate energy content and body composition. However, bioenergetic studies that employ the traditional methodology necessitate the killing of fish to determine physiological composition and energy content in a target tissue. The killing of the individual negates the ability for repeated measures on the same individual, and also suppresses compositional studies involving endangered or threatened species. Recent research has shown Bioelectrical Impedance Analysis (BIA), a quick, easy-to-use, non-invasive, and most importantly, non lethal technique to be an effective method for estimating the proximate composition and energy content of fish. The focus of this research is to evaluate the capability of BIA to accurately assess the bioenergetics of juvenile rainbow trout (Oncorhynchus mykiss), and to develop species-specific indices to predict energy content, total body water and dry mass. To do this, juvenile rainbow trout were subjected to one of three ration regimes: maintenance (0.4 % bw/day), optimum (1.9 % bw/day) and satiation (3.4 % bw/day) for 90 days. Subsamples from each treatment were taken every 30 days to be subjected to BIA testing. Tissue samples were collected from the subsampled trout for future caloric and compositional analysis via bomb calorimetry and proximate analysis. It was found that BIA demonstrated a strong predictive relationship with regard to energy content (r2 = 0.90), total body water (r2 = 0.89) and dry mass (r2 = 0.80). BIA was also able to successfully reflect a notable statistical difference between treatments with regard to total energy content, energy density, total body water, dry mass. These results, along with much of the existing literature, indicate that BIA may be an accurate and reliable tool to estimate the bioenergetics and proximate composition of fish. / UOIT

John Bongaarts' proximate determinants model of fertility has accounted for over 90 percent of variation in the total fertility rate (TFR) of primarily developing nations and historical populations. Recently, dramatically low fertility rates across the globe have raised questions regarding whether this model could be applied to exclusively below-replacement nations. This study follows Knodel, Chamratrithirong, and Debavalya's 1987 analysis of fertility decline in Thailand by conducting in-depth case studies of the proximate determinants in two low fertility countries over time: South Korea, where fertility is well below the level of replacement, and the United States, where fertility has hovered around replacement level for many years. Then, the fertility-inhibiting effect of the proximate determinants is assessed by comparing the quantitative index representing each determinant measured in the 1960s/1970s with its measurement in the 2000s. For both years, I consider the fertility level that would prevail in the determinant's presence as well as the level that would exist in its absence. Finally, I use each of the indices to calculate the TFR and assess how the strength of the model varies over time in the two countries. Ultimately, results indicate that the proximate determinants model does not offer a clean picture of the fertility level in either South Korea or the United States; when trends uncovered by the case studies are compared to the results of the quantitative analysis, a number of inconsistencies are revealed. This suggests that certain components in the model may need to be respecified for more effective application in low-fertility contexts. However, that is not to say that it offers no insight into fertility at all or that it is no longer a useful tool. On the contrary, it is shown that the proximate determinants model holds a lot of potential for analysis in low-fertility nations. The implications of these results, as well as the need for improvements in international data collection efforts, are also discussed.

Wheat distillers dried grain with solubles (DDGS) is a co-product of ethanol production, primarily utilized as an animal feed ingredient. Reduced protein quality, a highly energy-intensive drying process, and product variability are some of the challenges that currently confront its production in western Canada. The main focus of this research undertaking was to examine, on a laboratory-scale, the effect of condensed distillers solubles (CDS) : wet distillers grain (WDG) blending ratio and drying conditions on the protein quality and physico-chemical characteristics of wheat DDGS. The potential of microwave-based drying methods in minimizing protein damage and energy consumption was investigated. An auxiliary case study was also conducted in the Philippines to apply the knowledge and skills acquired from the PhD research undertaking to a related problem situation in a developing country. It aimed to provide more information about brewers spent grain (BSG) supply and utilization in Misamis Oriental, Philippines and enhanced the efficiency and safety of BSG utilization as an animal feed ingredient. Laboratory-scale investigations used samples produced at three CDS:WDG blending ratios (by mass): 15:85 (15% CDS), 30:70 (30% CDS), and 45:55 (45% CDS) and dried under forced air convection (40-120C), and under microwave (420 – 805 W) and microwave convection (nominal settings of 130C-30% power to 190C-30% power) methods using a domestic microwave oven. Freeze-dried samples were used as standards in evaluating chemical composition and color of wheat DDGS. As CDS level in the blend was increased, protein and ash content of freeze-dried samples increased while fat, acid detergent fiber (ADF) and neutral detergent fiber (NDF) content decreased. These trends were attributed to proximate composition differences between CDS and WDG fractions. The CDS fraction had higher protein and ash and lower fat, ADF, and NDF contents compared to WDG. Variation in the CDS:WDG blending ratio employed in the source ethanol plant could be one of the factors contributing to the observed proximate composition differences between two ethanol plant-sourced wheat DDGS samples. This was verified through proximate analyses of: (i) plant-sourced wheat DDGS samples from two production batches; (ii) CDS and WDG samples obtained on the same production date; and (iii) laboratory-produced wheat DDGS samples at varying CDS:WDG blending ratios. Protein, ash, and NDF contents of forced-air convection-, microwave-, and microwave convection-dried samples also showed strong linear relationships with CDS level. Fat and ADF content, however, did not exhibit similar strong relationships with CDS level, indicating the influence of drying conditions. Maximum lysine and minimum acid detergent insoluble crude protein (ADICP) contents were achieved in blends with the highest CDS level (45% CDS) and dried under lower drying temperature (80C), microwave power (676 W), and microwave convection (150C-30% power) settings. Microwave- and microwave convection drying achieved desirable protein quality associated with lower temperature drying under much shorter times. Laboratory-scale drying of ethanol plant-sourced wet distillers grain with solubles (WDGS) under forced air convection produced DDGS samples with decreased lysine content as drying air temperature was increased. In terms of physical properties, dried samples with higher CDS level were significantly finer, denser, less flowable, less dispersible, have lower thermal diffusivity and higher internal friction coefficients, and produced denser and stronger pellets. Color parameters of freeze-dried samples were significantly affected by CDS level. As CDS level increased, lightness (Hunter L) decreased while redness (Hunter a) increased. The color parameters of forced-air convection-, microwave-, and microwave convection-dried DDGS samples did not, however, exhibit similar linear trends with CDS level as these were also affected by drying conditions, such as drying air temperature and microwave power level. Effective moisture diffusivity values, estimated from the drying data, were also significantly affected by drying conditions (drying air temperature and microwave power levels), CDS level, and interaction between drying air temperature and CDS level. Effective moisture diffusivity decreased as CDS level was increased. Physical properties of two commercial (ethanol plant-sourced) wheat DDGS samples, as affected by moisture content, were also assessed. Techno-economic evaluation results indicated that complete replacement of the conventional hot air drying with microwave drying technology was not yet economically feasible. Although energy consumption during drying was substantially reduced with the use of microwave energy, the cost of electricity to generate microwave energy was high. Incorporating microwave drying toward the end of the hot air drying process was seen as the more economically viable alternative. Drying of BSG was not commonly practiced in Misamis Oriental, Philippines. The material was typically stored in open concrete bins and commonly fed to dairy cattle in its wet form. A prototype batch dryer, powered either by solar or biomass energy, was developed to improve shelf life and safe use of BSG. Initial tests showed that drying spent grain using a biomass furnace was feasible. Operating the dryer using solar energy was not an attractive option because of the long drying time. Basic physical attributes, proximate composition, and moisture sorption characteristics of the dried BSG were also determined. Practical implications of the results of these two studies to their respective local contexts were discussed. Recommendations to further improve understanding of wheat DDGS protein quality and physico-chemical characteristics, BSG dryer performance, backyard farmers’ sustainable access and safe use of BSG were also presented.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2002. / Härtill 4 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv. / Härtill 5 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2003. / Härtill 5 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2007. / Härtill 4 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2008. / Härtill 5 uppsatser.

Made available in DSpace on 2016-08-15T20:30:57Z (GMT). No. of bitstreams: 1 PolyannaDFSFB_DISSERT.pdf: 473477 bytes, checksum: 697c9e37a3a564d799921bed252579ca (MD5) Previous issue date: 2010-08-27 / Eight samples of peccary meat (Tayassu tajacu) and thirteen samples of agouti meat (Dasyprocta agouti) were collected and analysed using physicochemical and microbiological parameter. In the analysis were used 08 peccaries and 13 agoutis, all intensive farming. The meats were tested for moisture, dry matter and minerals; in microbiological analysis searched for the presence of enterobacteria, Staphylococcus and mesophilic bacteria. In the determination of dry matter, the average performance was 26.87 ± 1.1% for agoutis and 29.17 ± 1.54% for peccaries. In the analysis of minerals, we obtained an average of 4.84 ± 0.87 for peccaries and 4.72 ± 0.37 for agoutis. For the determination of moisture, peccary samples showed 70.83% and agouti samples showed 73.13%. In the analysis of enterobacteria, peccary samples had an average of 1.57 log10 UFC/g, and agouti samples had an average of 1.5 log10 UFC/g. In the determination of Staphylococcus, the samples showed an average of 1.57 log10 UFC/g and 1.55 log10 UFC/g for peccaries and agoutis, respectively. For mesophilic bacteria, peccary samples showed an average of 1.72 log10 UFC/g and agouti samples showed an average of 1.77 log10 UFC/g. Therefore, the physicochemical results were satisfactory compared with other animals of the same order. The microbiological results showed low levels of contamination. / Foram coletadas e avaliadas físico-quimica e microbiologicamente oito amostras de carne de catetos (Tayassu tajacu) e treze de cutias (Dasyprocta aguti). Nas análises foram utilizados 08 carcaças de catetos e 13 de cutias todos criados em cativeiro de forma intensiva. As carnes foram testadas quanto à umidade, matéria seca e minerais; nas analises microbiológicas pesquisou-se a presença de enterobactérias, Staphylococcus e bactérias mesófilas. Na determinação de matéria seca a média dos resultados foi de 26,87±1,1% para cutias e 29,17±1,54% para catetos. Na análise de minerais obteve-se uma média de 4,84±0,87 para catetos e 4,72±0,37 para cutias. Para a determinação da umidade as amostras de cateto apresentaram 70,83% e de cutia 73,13%. Na análise de enterobactérias as amostras de cateto apresentaram média de 1,57 log 10 UFC/g e as de cutia 1,5 log10 UFC/g. Na determinação de Staphylococcus coagulase positivos as amostras apresentaram média de 1,57 log10 UFC/g e 1,55 log10 UFC/g para catetos e cutias respectivamente. Para as bactérias mesófilas as amostras de cateto apresentaram média de 1,72 log10 UFC/g, e as de cutia apresentaram uma média de 1,77 log10 UFC/g. Portanto os resultados físicos químicos foram satisfatórios quando comparados com animais da mesma ordem e no microbiológico houve baixa contaminação indicando que o produto apresenta boa qualidade.

Les thons tropicaux (thon jaune, thon obèse et bonite à ventre rayé) sont des espèces largement exploitées dont un quart des prises mondiales provient de l'océan Indien. Capturés en bancs mixtes à la senne, ces prédateurs de haut niveau trophique présentent une physiologie particulière (e.g. thermorégulation partielle, nage obligatoire) mais différents traits de vie (e.g. taille maximale, stratégie de reproduction). L’objectif est ici de contribuer à une meilleure compréhension de l'allocation d'énergie chez ces espèces. Pour cela un échantillonnage mensuel a été mis en place en 2013 aux Seychelles, de manière à collecter des thons sur une large gamme de taille et de conditions environnementales. Un premier travail méthodologique nous a conduit à étudier l'effet de la teneur en lipides sur les valeurs isotopiques, et nous avons montré que l'utilisation d'équation de correction du taux de lipides lors des analyses isotopiques nécessite un ajustement spécifique. Au travers de traceurs écologiques (isotopes stables du carbone et de l'azote et acides gras), une comparaison trophique des trois espèces a montré qu'elles n'exploitent pas exactement les mêmes ressources énergétiques, notamment grâce à un changement alimentaire au cours de l'ontogénie. Ce changement se traduit par l'assimilation de proies plus riches en acides gras mono-insaturés pour les individus supérieurs à 100 cm FL. L'étude des contenus en lipides et protéines de quatre tissus aux fonctions physiologiques différentes (muscles blanc et rouge, foie et gonades) a montré que ces espèces font peu de réserves énergétiques et uniquement dans le foie et le muscle rouge. Les mâles consacrent également moins d'énergie que les femelles à la synthèse de cellules germinales. D'autre part, seul l'indice gonado-somatique permet de rendre compte de variations énergétiques, les autres indices testés (facteur de condition de Le Cren, indice hépato-somatique et circonférence) sont de mauvais proxies du contenu énergétique des tissus. Enfin, l'étude des acides gras membranaires indique une incorporation particulière du 20:4n-6 et du 22:6n-3, dont le niveau varie avec l'ontogénie et selon les tissus. Une grande variabilité intra-spécifique est cependant observée et suggère une certaine plasticité physiologique chez ces espèces. / Tropical tunas (yellowfin, bigeye and skipjack tuna) are exploited worldwide with a quarter of the catches coming from Indian Ocean. Caught by purse seine in mixed schools, these top predators displayed a specific physiology (e.g. partial endothermy, ram-ventilators) but various life history traits (e.g. maximal size, reproduction batches). The objective of this work is to contribute to a better understanding of energy allocation in these species. For this purpose, a monthly sampling was carry out throughout 2013 in Seychelles, to collect tunas on a large range size and environmental conditions. In a first methodological step, we studied the lipids influence on isotopic values in tropical tunas and showed that using mathematical correction of lipids content requires a specific adjustment. Then, using ecological tracers (stable isotope of carbon and nitrogen and fatty acids), a trophic comparison of the three species showed that they do not exploited exactly the same energetic resources, especially due to an ontogenic diet shift. This shift was illustrated by an increasing assimilation of mono-unsaturated fatty acids over 100 cm FL. Study of lipid and protein content in four tissues presenting different physiological function (white and red muscles, liver, gonads) showed these species make little energetic reserves, only in liver and red muscle. In addition, males invest less energy for germinal cells production than females. Furthermore, only the gonado-somatic index brought information concerning energetic variations, the others tested indices (Le Cren condition factor, hepato-somatic index, girth) were bad proxies of energetic content in tissues. Finally, study of membrane fatty acids indicates a specific incorporation of 20:4n-6 and 22:6n-3 that varies with ontogeny. A great intra-specific variability was also observed and could suggest a specific physiological plasticity in these species.