Determining the physical and biological habitat variables that influence the abundance of juvenile salmonids in British Columbia streams will improve management practices. Habitat models are tools that provide insight into organisms’ habitat needs and provide a more efficient mechanism for estimating population abundance than direct measurement. Models have been developed for salmonids in other jurisdictions, but very few have included invertebrate drift (a primary food source for juvenile salmonids) as a predictive variable. This is because temporal and spatial variation of drift abundance are widely assumed to be so high that drift cannot be reliably estimated without unreasonable effort. This thesis investigates the temporal and spatial variability of invertebrate drift and the impact of its inclusion in habitat models for juvenile salmonid abundance in two chapters. The first objective of the first chapter was to evaluate the temporal variability of invertebrate drift by comparing the seasonal and day-to-day variation in drift abundance to spatial variation within and between sites. The second objective was to develop predictive models for invertebrate drift abundance. Aquatic, terrestrial and total invertebrate drift abundances varied primarily between sites and very little between days or months at the same site, indicating that a single day of sampling is sufficient to assess drift abundance for comparison among sites. The abundance of invertebrate drift was related to productivity- and flow-related habitat variables. The objectives of the second chapter were to develop predictive models for juvenile salmonid abundance in southwestern BC using physical and biological habitat variables, to determine whether habitat variables differ between the Coast and Interior regions of BC, to determine the contribution of invertebrate drift to the relative predictive ability of the models, and to determine cost:benefit ratios for the predictive models and their component variables. The final models for predicting abundance of all young-of-year salmonids combined, and rainbow trout (Oncorhynchus mykiss) and coho salmon (O. kisutch) individually, included variables related to stream structure and productivity, and the models for rainbow and coho showed regional differences. Invertebrate drift did not improve model fit.

A method has been developed for the continuous automated monitoring of cardiac output in adult rainbow trout. Average cardiac output measured under control conditions and varied environmental conditions of hypoxia and post-hypoxia was significantly higher (P≤ 0.05) in male than female trout. The cardiac output of trout in spawning condition was significantly higher (P≤ 0.05) than that of trout not in spawning condition. Measurements of pulsatile cardiac output were made simultaneously with trout ventilation, and revealed ventilatory interactions with blood flow that varied depending on environmental oxygen condition. The method for monitoring gill blood flow was used with methods for automated measurement of gill water flow, oxygen uptake, and chemical flux in vivo. An experimental protocol was developed in which environmental oxygen was varied to obtain maximum increases in water flow over the gills without blood flow changes, and subsequent attainment of maximum increases in blood flow through the gills with decreasing water flow. The protocol was used as a probe to study variations in chemical flux with varied blood or water flow. The changes in gill flux of butanol (Log octanol/water partition coefficient (P) = 0.88) measured during control, hypoxia, and post-hypoxia correlated with observed changes in blood flow. A 70% increase in butanol flux was noted with a 50% increase in cardiac output, but there was no increase in butanol flux with a 100% increase in ventilation volume. Changes observed in the gill flux of decanol (Log P = 4.57) measured under varied environmental oxygen conditions correlated with observed changes in ventilation volume. A 100% increase in decanol flux was noted with a 160% increase in ventilation volume. The observed blood flow limitations to uptake of the low Log P butanol, and the water flow limitations to uptake of the high Log P decanol helped to verify assumptions made in recently proposed flow-limited models for prediction of chemical flux across fish gills. / Graduation date: 1991

In this study, the nutritional value of wheat distillers grains and the effect of further processing of these products on their nutritional value for rainbow trout were investigated in five experiments. In experiments 1 and 2, wheat distillers grains with solubles (WDDGS) was fractionated using grinding, sieving and elutriation sequentially. Apparent digestibility coefficients (ADC) of dry matter (DM), gross energy (GE), acid ether extract (AEE), ash and amino acids (AA) did not differ between the original WDDGS and the WDDGS protein concentrate (P > 0.05). However, the ADC of crude protein (CP) was significantly higher for WDDGS protein concentrate (88.0 %) than the original WDDGS (84.9 %) (P < 0.05). In experiments 3 and 4, the effect of aqueous fractionation on nutritional composition of wheat wet distillers grains (WWDG) from two local ethanol plants (plant 1 and plant 2) was evaluated. Aqueous fractionation increased levels of CP and GE in the processed WWDG from both plants. Fractionation significantly increased the ADC of DM, GE and AEE (P < 0.05). In contrast, protein digestibility was not influenced by the plant or the processing method (P > 0.10). In experiment 5, a 56 d growth trial was performed to determine the effect feeding the aqueous fractionated WWDG to rainbow trout on growth performance. Rainbow trout (n=22/ tank; body weight 136 g and 3 tanks/ treatment) were fed diets containing 0, 75, 150, 225 and 300 g kg-1 of the processed WWDG from plant 2. There were no significant linear or quadratic relationships between inclusion rate and specific growth rate (SGR), average daily gain (ADG) or feed to gain ratios (feed:gain). However, there was a significant negative linear relationship between inclusion rate and average daily feed intake (ADFI) (P < 0.05). The results of these studies suggest that both dry and aqueous fractionation are suitable methods to produce protein concentrates from wheat distillers grains but that the aqueous fractionation process was more effective in improving nutrient composition and increasing digestibility.

Chemokines are cytokines with chemoattractant ability, and comprise one of the major groups of molecules in immune system. These are small, secreted proteins cause the migration of leukocytes to the sites of injury. Over 40 mammalian chemokines have been identified to date, and they have been implicated in a number of immune mediated processes, including regulation of inflammation, antigen presentation, blood cell development, metastasis, viral infection and wound healing. In rainbow trout, there have been fewer chemokines reported and only one functional study has been published. Rainbow trout chemokine 2 (CK-2) is the only known CC chemokine with a mucin stalk, which has the potential for extensive <em>O</em>-glycosylation. However, no functional characterization has been performed on this molecule yet. CK-2 shares the presence of a mucin stalk with the mammalian chemokines, fractalkine (CX₃CL1), lymphotactin (XCL1), and CXCL16. Another related trout CC chemokine sequence, CK-2. 1, has been discovered recently, which has 98% nucleotide sequence identity with CK-2. CK-2. 1 was believed to be a separate gene due to its apparent differential regulation in challenged rainbow trout. The question remained, however, whether or not CK-2. 1 was a separate gene or an allele of CK-2. The goal of this project was to further characterize both CK-2 and CK-2. 1. <br /><br /> Through genomic PCR on several outbred individuals it was shown that CK-2. 1 is an allele of CK-2 but not a separate gene. Reverse transcriptase (RT) PCR analysis revealed an increased level of transcript both CK-2 and CK-2. 1 in response to phytohaemagglutinin (PHA) stimulation of head kidney leukocytes (HKL) and peripheral blood leukocytes (PBL) collected from fish with different allelic distributions. Similar results were also observed in the rainbow trout macrophage/monocyte cell line, RTS11. Moreover, an anti-CK-2 antiserum was developed in rabbits, which cross-reacted with CK-2. 1. This newly produced antibody was used to determine the protein expression levels in PHA stimulated rainbow trout tissues. RT-PCR was also performed on the same tissues in order to examine the transcript expression. Rainbow trout with both CK-2 and CK-2. 1 were used for this experiment. An overall decreasing pattern of transcript (both CK-2 and CK-2. 1) was observed in brain and HK over 24 hours, while protein was still detected at 24 hours post stimulation. However, in spleen the CK-2 transcript showed a slight upregulation at 4 hours post stimulation along with a very little or no CK-2. 1 expression, although no protein was detected in spleen. Liver showed a very low level of CK-2 and CK-2. 1 transcript at 8 hours post stimulation; while protein was again detected at 24 hours post stimulation. In addition, the sizes of the proteins found in different tissues were larger than expected (&le;30 kDa for CK-2 or &le;35 for CK-2. 1), perhaps due to the presence of extensive <em>O</em>-glycosylation at the mucin stalk of the protein. <br /><br /> A chemotaxis assay was carried out, which is the definitive assay for chemokine activity. This assay showed migration of peripheral blood leukocytes across a membrane with 5µm pores toward CK-2 at an optimal concentration of 500ng/ml (17nm). Moreover, by pre-treating the recombinant chemokine with the polyclonal antisera, it was shown that the chemokine was actually causing the chemotactic activity. Pre-treatment of the cells with pertussis toxin, an inhibitor of G-protein signalling inhibited the migration of PBLs, established the fact that CK-2 caused chemotaxis by binding to a 7 transmembrane, G-coupled receptor just like all other known chemokines. Interestingly, CK-2 was also shown to attract RTS-11 cells. <br /><br /> Overall, the above findings indicate that CK-2 is functionally a chemokine with two very different alleles in rainbow trout. It is probably heavily <em>O</em>-glycosylated and different tissues express different sizes of the protein. This is only the second functional study of a fish chemokine.

In this study, the nutritional value of wheat distillers grains and the effect of further processing of these products on their nutritional value for rainbow trout were investigated in five experiments. In experiments 1 and 2, wheat distillers grains with solubles (WDDGS) was fractionated using grinding, sieving and elutriation sequentially. Apparent digestibility coefficients (ADC) of dry matter (DM), gross energy (GE), acid ether extract (AEE), ash and amino acids (AA) did not differ between the original WDDGS and the WDDGS protein concentrate (P > 0.05). However, the ADC of crude protein (CP) was significantly higher for WDDGS protein concentrate (88.0 %) than the original WDDGS (84.9 %) (P < 0.05). In experiments 3 and 4, the effect of aqueous fractionation on nutritional composition of wheat wet distillers grains (WWDG) from two local ethanol plants (plant 1 and plant 2) was evaluated. Aqueous fractionation increased levels of CP and GE in the processed WWDG from both plants. Fractionation significantly increased the ADC of DM, GE and AEE (P < 0.05). In contrast, protein digestibility was not influenced by the plant or the processing method (P > 0.10). In experiment 5, a 56 d growth trial was performed to determine the effect feeding the aqueous fractionated WWDG to rainbow trout on growth performance. Rainbow trout (n=22/ tank; body weight 136 g and 3 tanks/ treatment) were fed diets containing 0, 75, 150, 225 and 300 g kg-1 of the processed WWDG from plant 2. There were no significant linear or quadratic relationships between inclusion rate and specific growth rate (SGR), average daily gain (ADG) or feed to gain ratios (feed:gain). However, there was a significant negative linear relationship between inclusion rate and average daily feed intake (ADFI) (P < 0.05). The results of these studies suggest that both dry and aqueous fractionation are suitable methods to produce protein concentrates from wheat distillers grains but that the aqueous fractionation process was more effective in improving nutrient composition and increasing digestibility.

Thesis (Ph. D.)--University of Wisconsin, Madison, 2001. / Includes bibliographical references. Also available on the Internet.

Thesis (Ph.D.), Memorial University of Newfoundland, 2000. / Restricted until June 2001. Bibliography: leaves 153-162.

Thesis (M.S.)--West Virginia University, 2002. / Title from document title page. Document formatted into pages; contains viii, 84 p. : ill. (some col.), col. map. Includes abstract. Includes bibliographical references (p. 65-69).

Thesis (Ph. D.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains viii, 198 p. : ill., maps. Vita. Includes abstract. Includes bibliographical references.

Thesis (M.S.)--West Virginia University, 2009. / Title from document title page. Document formatted into pages; contains vii, 51 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 46-51).