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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
121

Estudo econômico da produção de tilápia do Nilo (Oreochromis niloticus) em tanques-rede / Economic survey of Nile tilapia production (Oreochromis niloticus) in cages

Fritzen, Nalva Alina 27 February 2015 (has links)
Submitted by Marilene Donadel (marilene.donadel@unioeste.br) on 2018-04-20T19:26:59Z No. of bitstreams: 1 Nalva_Fritzen_2015.pdf: 1186463 bytes, checksum: bb35877d759f48f8281dbc14e226c99b (MD5) / Made available in DSpace on 2018-04-20T19:26:59Z (GMT). No. of bitstreams: 1 Nalva_Fritzen_2015.pdf: 1186463 bytes, checksum: bb35877d759f48f8281dbc14e226c99b (MD5) Previous issue date: 2015-02-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The objective of this study was to analyze the productive performance, the physical and chemical composition and the cost benefit of tilapia production (Oreochromis niloticus) in cages, in three different weight classes (500, 700 and 900g) termination. 24.000 fish were used, with initial weight of 150 ± 5,4 g for analysis of cost of production, over thirty cages of 6 m3 of useful volume. A sample of five fish for cage was harvested for yield performance, including 10% of those steaks were used for chemical analysis. To survey costs and profitability, we used the Operating Cost (Effective and Total), Depreciation, Total Cost and Profit. At the end it was observed that the smaller fish (500g) showed a smaller amount of lipids (1,76%) and visceral (3,69%) and a higher content of ash (1,40%) in the fillet. The best fillet yield and main trunk was found in larger fish (900g), 32,48% and 50,82% respectively. The profitability of production, the average fish (700g) stood out (19,77%). / O objetivo neste trabalho foi analisar o desempenho produtivo, a composição físico-química e o custo benefício da produção de tilápias do Nilo (Oreochromis niloticus) em tanques-rede, em três diferentes classes de peso (500, 700 e 900g) de terminação. Foram utilizados 24.000 peixes, com peso inicial de 150±5,4g, para análise de custo da produção, distribuídos em trinta tanques-rede de 6m3 de volume útil. Uma amostra de cinco peixes por tanque foi abatida para o desempenho produtivo, dos quais 10% dos filés obtidos foram utilizados para análise bromatológica. Para o levantamento dos custos e rentabilidade, utilizou-se o Custo Operacional (Efetivo e Total), Depreciação, Custo Total e Lucro. Ao final observou-se que os peixes menores (500g) apresentaram menor quantidade de lipídeos (1,76%) e gordura visceral (3,69%) e, maior teor de matéria mineral (1,40%) no filé. O melhor rendimento de filé e tronco limpo foi encontrado nos peixes maiores (900g), 32,48% e 50,82% respectivamente. Quanto a lucratividade da produção, os peixes médios (700g) se destacaram (19,77%).
122

The effects of DDE on the health of the Mozambique Tilapia (Oreochromis mossambicus)

Bremner, Kieren Jayne 02 May 2012 (has links)
M.Sc. / The organochlorine insecticides were amongst the first pollutants shown to cause adverse population effects. The potential adverse effects of these pollutants on wildlife are a cause for great concern. Severities of their effects were sometimes surprising given the low levels of the compounds in environmental compartments such as surface waters and soils. High lipophilicity combined with chemical stability and very slow biodegradation are characteristic features of these toxic Persistent Organic Pollutants (POPs). Regional declines in fish, bird as well as invertebrate populations resulting from long term exposure to POPs such as 1,1-bis (4-chlorophenyl) -2,2,2-trichloroethane (DDT) and its stable metabolite 1,1-bis (4-chlorophenyl) -2,2-dichloroethene (DDE), could be related to some biochemical, endocrine and physiological effects in individuals. Some POPs have been suggested to have negative effects disrupting physiological processes and resulting in alterations of homeostasis, reproduction, development and behavior. Such adverse effects upon populations may be avoided if the potential of chemicals to cause them is recognized before problems arise. The aim of this study was to determine whether or not the ongoing spraying of DDT in the Limpopo Province is negatively affecting the health of aquatic species found in surface water of the area. Extensive research has shown that biomarkers have been very effective in the trace determination of a number of adverse effects caused by metals, and thus, are also being used for POPs. A battery of biomarkers (EROD, CAT and CEA) were used, both in the field and in a controlled laboratory environment, in order to try and determine the long term effects of exposure to low environmentally relevant levels of DDE in the selected area. DDT levels in the biota, water and sediment samples were also measured to determine the possible levels of exposure. Dose-response relationships were most successfully determined by the EROD and the CEA biomarkers in this study. In a controlled laboratory study, a definite effect was noted on the Mozambique Tilapia with increasing concentrations of DDE. In the natural environment, dose-response relationships to DDE exposure were more difficult to quantify as additional chemicals and natural environmental stressors also affect the results.
123

Desempenho produtivo e efeito da vitamina C na qualidade nutricional e nos níveis de marcadores do estresse oxidativo em alevinos de tilápia-do-nilo (Oreochromis niloticus Linnaeus, 1857) / Performance and effect of vitamin C on nutritional quality and levels of oxidative stress markers in Nile tilapia (Oreochromis niloticus Linnaeus, 1857)

Menezes, Maria Emília da Silva 16 April 2010 (has links)
Vitamin C is used in the diets in order to improve growth, resistance to stress and disease, as well as the survival of fish. It can also be effective in the conservation of fish during processing and storage, inhibiting the degradation of lipids by oxidation. This study evaluated the stocking density and the effects of supplementation of vitamin C in the final quality of the fillet tilapia (Oreochromis nilotius, Linneaus, 1875). We used one hundred and twenty fingerlings for each trial, the study of fish stocking density had an initial weight of 4.0 g and evaluation of supplementation with vitamin C, 11.0 g. Both studies had a randomized design, comprising four treatments of different stocking densities (50, 75, 100 and 125 fish/m3) with five replications. Already working with vitamin C (ascorbic acid 2 - sulfate acid - protected form) was carried out in four treatments with six replicates, characterized by four levels of supplementation of vitamin C in the diets (250, 500 and 750 mg/kg diet) and control group (zero mg/kg diet) with two different stocking densities (50 and 100 fish/m3). The ration given to the first study contained 36% crude protein and 3100 kcal/DE/kg feed and the second was 28% crude protein and 3400 kcal/DE/kg. After ninety days, the fish were slaughtered and evaluated the growth performance parameters for the study of stocking density, chemical composition, cholesterol content, fatty acid profile, quality of lipid fraction in both studies. The liver of fish from the second stage of labor was frozen at - 80°C for lipid peroxidation analysis and determination of enzyme activity of oxidative stress (catalase and superoxide dismutase). It follows that for the study of stoking significant difference ρ <0.05 between the final average weight and total weight gain between the different densities tested, the highest weight was found in the group density of 75 fish/m3. The body composition analysis, differences were observed ρ <0.05 between the densities on moisture, total lipid content, protein, calories and cholesterol. The ratio polyunsaturated / saturated was higher in density of 11.76 for 100 fish/m3, since the density of 50 fish/m3 presented a sum of 6.85 for the levels of EPA + DHA. In assessing the nutritional quality of lipids, the densities studied showed the contents of n-6/n-3, hypocholesterolemic/hypercholesterolemic index of polyunsaturated fatty acids of atherogenicity and index of thrombogenicity as favorable for consumption. Fish reared at a density of 50 fish/m3 can be seen as a good food from a nutritional standpoint, they presented a good level of fatty acids, especially omega-3 fatty acid and its value in hypocholesterolemic/hypercholesterolemic. Regarding the second stage of labor was observed difference ρ<0.05 between the levels of vitamin C supplementation levels in total lipid content, crude protein, calories and cholesterol. The ratio polyunsaturated/saturated was higher in the supplementation level of 250 mg of vitamin C (1.26), since the level of 500 mg of vitamin C showed a sum of 6.48 for the levels of EPA + DHA. In assessing the nutritional quality of lipids, the levels of vitamin C study showed rates of n-6/n-3, hypocholesterolemic / hypercholesterolemic index of atherogenicity and index of thrombogenicity for subsequent food consumption. Fish reared with diets supplemented with 750 mg of vitamin C in the density of 50 fish/m3 can be seen as a good food from a nutritional standpoint, they presented a good level of fatty acids, especially omega-3 fatty acid and its value in hypocholesterolemic/hypercholesterolemic. In the study of redox balance results showed that there was an increase in lipid peroxidation, suggesting that there may have been damage to the liver of animals and the antioxidant defenses were not sufficient to prevent oxidative stress. Density of 50 fish/m3, the dietary supplementation with vitamin C can be pro-oxidant. Since the density 100 fish/m3, vitamin C supplementation may be an antioxidant. The catalase activity of the enzyme showed low activity, suggesting an impairment in hepatic redox balance for this enzyme in animals receiving diets containing different levels of vitamin C. Since superoxide dismutase activity of the enzyme showed high activity, suggesting a redox balance in protecting liver for this enzyme in animals receiving diets containing different levels of vitamin C. / Conselho Nacional de Desenvolvimento Científico e Tecnológico / A vitamina C é usada nas dietas com a finalidade de melhorar o crescimento, a resistência ao estresse e às doenças, assim como a sobrevivência de peixes. Também pode ser eficiente na conservação do pescado durante o processamento e estocagem, inibindo a degradação dos lipídeos pela oxidação. O presente trabalho avaliou a densidade de estocagem e os efeitos da suplementação de vitamina C na qualidade final do filé de Tilápia-do-Nilo (Oreochromis nilotius, Linneaus, 1875). Foram utilizados cento e vinte alevinos para cada estudo, sendo que os peixes do estudo da densidade de estocagem tinham peso inicial de 4,0 g e os da avaliação com a suplementação de vitamina C de 11,0 g. O delineamento inteiramente casualizado foi utilizado em ambos os estudos perfazendo quatro tratamentos de diferentes densidades de estocagem (50, 75, 100 e 125 peixes/m3) com cinco repetições. Já o trabalho com a vitamina C (ácido 2 - sulfato ascórbico - forma protegida) foi realizado em quatro tratamentos com seis repetições, caracterizado pela suplementação de quatro níveis de vitamina C nas rações (250, 500 e 750 mg/kg de ração) e o grupo controle (zero mg/kg de ração) com duas diferentes densidades de estocagem (50 e 100 peixes/m3). A ração fornecida para o primeiro estudo continha 36% de proteína bruta e 3100 kcal/energia digestiva/kg de ração e a segunda tinha 28% de proteína bruta e 3400 kcal/energia digestiva/kg. Após noventa dias, os peixes foram abatidos e foram avaliados os parâmetros de desempenho zootécnico para o estudo de densidade de estocagem, composição centesimal, teor de colesterol, perfil de ácidos graxos, qualidade da fração lipídica para ambos os estudos. O fígado dos peixes da segunda etapa do trabalho foi congelado a – 80ºC para análises de peroxidação lipídica e determinação da atividade das enzimas do estresse oxidativo (catalase e superóxido dismutase). Conclui-se que para o estudo de densidade de estocagem houve diferença significativa ρ<0,05 entre o peso médio final e no ganho de peso total entre as diferentes densidades populacionais testadas; o maior peso foi encontrado no grupo de densidade de 75 peixes/m3. Quanto à análise da composição corporal observou-se diferença ρ<0,05 entre as densidades nos teores de umidade, lipídeos totais, teor de proteína bruta, valor calórico e de colesterol. A relação poliinsaturados/saturados foi mais elevada na densidade de 100 peixes/m3 de 11,76, já a densidade de 50 peixes/m3 apresentou uma somatória de 6,85 para os teores de ácido eicosapentaenóico + ácido docosahexaenóico. Na avaliação da qualidade nutricional dos lipídeos, as densidades estudadas mostraram os índices de n-6/n-3, hipocolesterolêmicos/hipercolesterolêmicos, índice de ácidos graxos poliinsaturados de aterogenicidade e índice de trombogenicidade como favoráveis para consumo alimentar. Os peixes criados na densidade de 50 peixes/m3 podem ser considerados como um bom alimento do ponto de vista nutricional, pois apresentaram um bom teor de ácidos graxos, principalmente de ácido ômega-3 e pelo seu valor em hipocolesterolêmicos/hipercolesterolêmicos. Com relação à segunda etapa do trabalho foi observado diferença ρ<0,05 entre os níveis de suplementação da vitamina C nos teores de lipídeos totais; teor de proteína bruta; valor calórico e de colesterol. A relação poliinsaturados/saturados foi mais elevada no nível de suplementação de 250 mg de vitamina C (1,26), já o nível de 500 mg de vitamina C apresentou um somatório de 6,48 para os teores de ácido eicosapentaenóico + ácido docosahexaenóico. Na avaliação da qualidade nutricional dos lipídeos, os níveis de suplementação de vitamina C estudados mostraram os índices de n-6/n-3, hipocolesterolêmicos/hipercolesterolêmicos, índice de aterogenicidade e índice de trombogenicidade favoráveis quanto ao consumo alimentar. Os peixes criados com ração suplementada com 750 mg de vitamina C na densidade de 50 peixes/m3 podem ser considerados como um bom alimento do ponto de vista nutricional, pois apresentaram um bom teor de ácidos graxos, principalmente de ácido ômega-3 e pelo seu valor em hipocolesterolêmicos/hipercolesterolêmicos. Já no estudo do balanço redox os resultados mostraram que houve aumento na peroxidação lipídica, sugerindo que podem ter existido danos ao fígado dos animais e as defesas antioxidantes não foram suficientes para evitar o estresse oxidativo. Na densidade de 50 peixes/m3, a ração suplementada com vitamina C pode ser pró-oxidante. Já na densidade 100 peixes/m3, a vitamina C suplementada pode ser antioxidante. A atividade da enzima catalase apresentou uma baixa atividade, sugerindo um comprometimento no balanço redox hepático para esta enzima nos animais submetidos à ração com diferentes níveis de suplementação de vitamina C. Já atividade da enzima superóxido dismutase apresentou elevada atividade, sugerindo uma proteção no balanço redox hepático para esta enzima nos animais submetidos à ração com diferentes níveis de suplementação de vitamina C.
124

Testicular apoptotic activity in two bio-sentinel fish species inhabiting an aquatic ecosystem in an area where continual DDT spraying occurs : utility of immunohistochemical assays

Patrick, Sean Mark 08 July 2009 (has links)
Endocrine disrupting chemicals (EDCs) such as DDT have the ability to disrupt hormonally controlled processes, such as spermatogenesis, which is the maturation of germ cells into spermatozoa. During normal spermatogenesis, germ cell apoptosis can occur, but the degree of apoptosis within the testis could possibly be affected by exposure to EDCs. In 2004, a pilot study on the reproductive health of two freshwater fish species, Oreochromis mossambicus and Clarias gariepinus, from three impoundments in the Luvuvhu River, found concerning levels of DDT and its metabolites in both species from the Nandoni Dam, and in O. mossambicus from the Xikundu Weir. This was not surprising as a large part of the Luvuvhu River catchment is located within an area where ongoing DDT-spraying occurs for vector control purposes. Hence, in 2006, a larger WRC-funded project began to further investigate the findings from the pilot study. A subsidiary study, spanning two seasons, was initiated to investigate testicular apoptosis in fish from the polluted systems, the Nandoni Dam (ND) and the Xikundu Weir (XW), as well as a reference site, the Albasini Dam (AD), utilizing caspase-3 and TUNEL immunoexpression as apoptotic markers. In addition, three fixatives, Bouin’s Fluid (BF), Neutrally Buffered Formalin (NBF) and Paraformaldehyde (PFA), were used to determine which would be the optimal fixative for both histological and immunohistochemical assessments. Sampling occurred during season 1, the low-flow season (October 2007), during DDT spraying of the surrounding area, and season 2, the high–flow season (February 2008), two months after the DDT-spraying was completed. The testes of O. mossambicus (n = 19 season 1, n = 25 season 2) and C. gariepinus (n = 19 season 1, n = 20 season 2) were fixed in the above-mentioned fixatives, embedded in paraffin wax, prepared for immunohistochemistry, and exposed to caspase-3 antibodies and TUNEL antibodies individually. The results indicated that the residues of p,p´-DDT - DDD and - DDE were found in the fat samples of both O. mossambicus and C. gariepinus, in AD, ND and XW. Testicular apoptotic assessment using the caspase-3 assay clearly labeled spermatocytes in the process of cellular death in both seasons, in all three fixatives. When comparing the two assays, a significant difference is found between the caspase-3 and TUNEL positive cells. The results further show that, when comparing the three sampling sites, the highest amount of positive cells are found at the XW. The decrease observed in season two, in both the caspase-3 and TUNEL assay may possibly be linked to the stage of spermatogenesis, coinciding with hormonal changes associated with the different sampling seasons (i.e. breeding and non-breeding seasons). The levels of DDT found in the fat tissue, could not be correlated to an up-regulation in apoptotic cells. The results The results indicated that the choice of fixative, could affect the identification of the amount of positive cells. The utility of the caspase-3 and TUNEL assays, in conjunction with all three fixatives, proves a successful tool in assessing and quantifying modulated testicular apoptosis, creating greater research potential in the assessment of the effects of aquatic pollution. Copyright / Dissertation (MSc)--University of Pretoria, 2008. / Physiology / unrestricted
125

Invasive Nile tilapia Oreochromis niloticus (Linnaeus, 1758) in the Limpopo River system, South Africa : conservation implications

Zengeya, Tsungai Alfred 03 September 2012 (has links)
In most tropical river systems there has been a lack of integrated ecological research to investigate the dynamics and impacts of invasive species on recipient river systems. This is in sharp contrast to temperate river systems. This thesis investigated the nature, extent, and impact of Nile tilapia, Oreochromis niloticus (Linnaeus, 1758), on indigenous congenerics within the Limpopo River basin in northern South Africa. An integrated approach was adopted to gain a better understanding of factors that allow Nile tilapia to be a successful invader and also to gain an insight into its invasion rate and conservation implications within South Africa. Morphometric and genetic variation between Nile tilapia, indigenous congenerics and their associated hybrids were determined. Intermediate meristic characters obscured the identification of hybrid specimens from pure morpho-specimens and species identity was only confirmed through mtDNA analysis. Preliminary evidence points to unidirectional hybridization among Oreochromis congeners in the Limpopo River system. The hypothesis that bigger Nile tilapia males may have a competitive advantage over spawning grounds and in female mate choice is proposed. The trophic ecology of Nile tilapia was investigated using both stomach contents and stable isotope analysis. A high similarity in stomach contents was observed but interspecific differences were revealed in the isotopic composition of diets that suggest fine scale patterns of resource partitioning that could be achieved by the ability of fish to selectively feed on what is immediately available and the ability to perceive the dynamics that determine food resource availability. Ecological niche models were used to determine the potential invasive range of Nile tilapia and revealed broad invasive potential over most river systems in southern Africa that overlapped the natural range of endemic congenerics. It was noted that model performance and the degree of niche conservatism varied significantly with variable selection and spatial extent of study area. This implied that the spatial distribution of suitable and unsuitable environmental variables varied between the native and introduced ranges of Nile tilapia and also indicated the ability of Nile tilapia to survive in conditions incongruent with its native range. The extreme hardiness and adaptive life history characteristics of Nile tilapia have probably predisposed it to be a successful invader in novel systems within southern Africa. Lastly, a qualitative risk assessment method was developed as a potential application to determine the risk of establishment and spread of the invasive Nile tilapia. Results showed that in the absence of quantitative data on ecosystem structure and functioning, habitat suitability analysis in terms of known physiological tolerance limits to minimum water temperature, presence or absence of dams, seasonality of river flows and the presence of indigenous fish species of concern could be adequate for identifying vulnerable river systems. The model developed also provides an objective method that is easy to implement, modify and improve on as new data become available. Furthermore, the model can be applied to highlight areas of uncertainty where future research should be directed. / Thesis (PhD)--University of Pretoria, 2012. / Zoology and Entomology / Unrestricted
126

Selektionsexperimente zur Erhöhung des Männchenanteils bei Nilbuntbarschen (Oreochromis niloticus) mittels Temperaturbehandlung / Selection experiments to increase the male proportion in Nile Tilapia (Oreochromis niloticus) by means of temperature treatment

Wessels, Stephan 14 July 2006 (has links)
No description available.
127

Níveis nutricionais de lisina e metionina+cistina digestíveis para juvenis de tilápia-do-nilo (Oreochromis niloticus)

Rampe, Maria Cecília Cabral 26 March 2012 (has links)
Submitted by Maykon Nascimento (maykon.albani@hotmail.com) on 2016-04-27T19:06:09Z No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Dissertacao Maria Cecilia Cabral Rampe.pdf: 3505409 bytes, checksum: f0fa90892ebfa73252ffcc79d0e799b9 (MD5) / Approved for entry into archive by Patricia Barros (patricia.barros@ufes.br) on 2016-06-06T13:01:17Z (GMT) No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Dissertacao Maria Cecilia Cabral Rampe.pdf: 3505409 bytes, checksum: f0fa90892ebfa73252ffcc79d0e799b9 (MD5) / Made available in DSpace on 2016-06-06T13:01:17Z (GMT). No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Dissertacao Maria Cecilia Cabral Rampe.pdf: 3505409 bytes, checksum: f0fa90892ebfa73252ffcc79d0e799b9 (MD5) / CAPES / Objetivando-se determinar as necessidades nutricionais de lisina e metionina+ cistina digestíveis para juvenis de tilápia-do-nilo (Oreochromis niloticus), da linhagem tailandesa, foram realizados dois experimentos no Laboratório de Aquicultura do Departamento de Zootecnia da Universidade Federal do Espírito Santo, com duração de 30 dias cada. No primeiro experimento, objetivou-se avaliar a necessidade nutricional de lisina digestível, para tanto, foram utilizados 720 juvenis de tilápia-do-nilo masculinizados e com peso médio inicial de 7,30 ± 0,11 g, distribuídos em delineamento inteiramente casualizado, com oito tratamentos, seis repetições e quinze peixes por unidade experimental. As tilápias foram distribuídas em 48 aquários de polietileno com volume útil de 60L, com aeração individual e temperatura controlada em sistema de recirculação com renovação mínima da água de 50% ao dia. Os tratamentos constaram de oito rações (26,81% de proteína digestível e 3090 kcal/kg de energia digestível) contendo diferentes teores de lisina digestível (1,24; 1,36; 1,48; 1,60; 1,72; 1,84; 1,96 e 2,08%). Foram avaliadas variáveis de desempenho (ganho de peso, taxa de crescimento específico, taxa de sobrevivência, consumo de ração, consumo de lisina digestível, conversão alimentar aparente, eficiência protéica para ganho, eficiência de lisina para ganho e eficiência de retenção de nitrogênio) e de composição corporal (teores de umidade, gordura, proteína, matéria mineral corporal e as taxas de deposição diária de proteína e gordura corporais). A elevação do teor de lisina digestível na ração não influenciou (P>0,05) o consumo de ração, a taxa de sobrevivência e os teores de umidade e matéria mineral corporal, mas melhorou de forma quadrática (P<0,05) os demais parâmetros avaliados, com exceção do consumo de lisina e da eficiência de lisina para ganho, que aumentou e reduziu, respectivamente, de forma linear (P<0,05). Recomenda-se que rações para juvenis de tilápia-do-nilo devam conter 1,84% de lisina digestível para máximo ganho de peso. No segundo experimento, objetivou-se determinar a necessidade nutricional de metionina+cistina digestível, para tanto foram utilizados 1260 juvenis de tilápia-do-nilo com peso médio inicial de 0,80 ± 0,03g, distribuídos em delineamento inteiramente casualizado, com sete tratamentos, seis repetições e trinta peixes por unidade experimental. As tilápias foram distribuídas em 42 aquários de polietileno com volume útil de 300L, com aeração individual e temperatura controlada em sistema de recirculação com renovação mínima da água de 25% ao dia. Os tratamentos constaram de sete rações (26,80% de proteína digestível e 3090 kcal/kg de energia digestível) contendo diferentes teores de metionina+cistina digestível (0,68; 0,80; 0,92; 1,04; 1,16; 1,28 e 1,40%). Foram avaliadas variáveis de desempenho (ganho de peso, taxa de crescimento específico, taxa de sobrevivência, consumo de ração, consumo de lisina digestível, conversão alimentar aparente, eficiência proteica para ganho, eficiência de lisina para ganho e eficiência de retenção de nitrogênio) e de composição corporal (teores de umidade, gordura, proteína, matéria mineral corporal e as taxas de deposição diária de proteína e gordura corporais). A elevação do teor de metionina+cistina digestível na ração não influenciou (P>0,05) o consumo de ração, a taxa de sobrevivência e os teores de proteína e matéria mineral corporal, mas melhorou de forma quadrática (P<0,05) os demais parâmetros avaliados, com exceção do consumo de metionina e do teor de umidade corporal que aumentaram de forma linear (P<0,05) e, do teor de gordura corporal que reduziu de forma linear (P<0,05). Recomenda-se que rações para juvenis de tilápia-do-nilo devam conter 0,96% de metionina+cistina digestível para máximo ganho de peso. / Aiming to determine the nutritional needs of lysine and methionine+cystine for juvenile Nile tilapia (Oreochromis niloticus), Thai strain, two experiments were conducted at the Laboratory of Aquaculture Department of Animal Science, Federal University of Espirito Santo, with 30 days each. In the first experiment aimed to evaluate the nutritional need of lysine to this, we used 720 juvenile Nile tilapia with initial weight of 7.30 ± 0.11 g, distributed in a completely randomized design with eight treatments, six replications and fifteen fish per experimental unit. The tilapia were divided into 48 polyethylene tanks with a volume of 60L, with individual aeration and temperature controlled recirculation system with minimum water renewal of 50% per day. Treatments consisted of eight diets (26.81% of digestible protein and 3090 kcal/kg digestible energy) containing different levels of digestible lysine (1.24, 1.36, 1.48, 1.60, 1.72; 1.84, 1.96 and 2.08%). We evaluated the performance variables (weight gain, specific growth rate, survival rate, feed intake, digestible lysine intake, feed conversion, protein efficiency for gain, efficiency of lysine for gain and efficiency of retention nitrogen) and body composition (moisture, fat, protein, ash body and deposition rates of daily protein and fat). The high levels of dietary lysine did not affect (P>0.05) feed intake, the survival rate and the moisture and ash body, but improved quadratic (P<0.05) the other parameters, except for lysine intake and efficiency of lysine for gain, which increased and decreased, respectively, linearly (P<0.05). It is recommended that diets for juvenile Nile tilapia should contain 1.84% digestible lysine for maximum weight gain. In the second experiment aimed to evaluate the nutritional requirements of methionine+cystine, were used for both 1260 juvenile Nile tilapia with initial weight of 0.80 ± 0.03 g, distributed in a completely randomized design with seven treatments six replicates and thirty fish per experimental unit. The tilapia were divided into 42 polyethylene tanks with a volume of 300L, with individual aeration and temperature controlled recirculation system with minimum water renewal of 25% per day. Treatments consisted of seven diets (26.80% of digestible protein and 3090 kcal/kg digestible energy) containing different levels of methionine+cystine (0.68, 0.80, 0.92, 1.04, 1, 16, 1.28 and 1.40%). We evaluated the performance variables (weight gain, specific growth rate, survival rate, feed intake, digestible lysine intake, feed conversion, protein efficiency for gain,
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Determina??o da toxicidade aguda e caracteriza??o de risco ambiental do herbicida Roundup (glifosato) sobre tr?s esp?cies de peixes / Determination of acute toxicity and environmental risk characterization of the herbicide Roundup (glyphosate) on three species of fish

Moura, Emerson Eduardo Silva de 27 March 2009 (has links)
Made available in DSpace on 2014-12-17T14:01:59Z (GMT). No. of bitstreams: 1 EmersonESM.pdf: 931852 bytes, checksum: f768665fe7e8aa27e4023b4def16f98d (MD5) Previous issue date: 2009-03-27 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Considering their commercial importance, as these are the species of freshwater fish more commercialized in Brazil, their occurence in different kinds of aquatic environments (lakes, rivers and dams) and for being tolerant to a wide range of variation of various physical parameters and chemical water, the fish species Oreochromis niloticus, Cyprinus carpio and Colossoma macropomum were chosen for this study, furthermore, to test the toxicity we used the herbicide Roundup. The fingerlings of tilapia (Oreochromis niloticus), commun carp (Cyprinus carpio) and tambaqui (Colossoma macropomum) were submitted to the herbicide roundup in the following concentrations: 0.0 (control); 18,06; 19,10; 20,14; 21,18 and 22,22 mg.L-1, 0.0 (control); 13,89; 14,86; 15,83; 16,81 and 17,78 mg.L-1, and 0.0 (control); 18,06; 19,10; 20,14; 21,18 and 22,22 mg.L-1, respectively, three for 96 hours. The LC50 - 96h for O. niloticus, C. carpio and C. macropomum was 21,63, 15,33 and 20,06 mg.L-1 of the herbicide roundup, respectively. The results show that this herbicide is classified as slightly toxic to the three species. The values of dissolved oxygen, pH and temperature recorded in the aquarium control and aquarium experimental of the three fish species have remained without significant variations during the tests, which reduces the possibility of death caused by sudden variations of these parameters during the 96 hours the experiment. The values of LC50 between different species of fish were observed, noting that the species O.niloticus, C. carpio and C. macropomum showed no expressive differences. The values of environmental risk of Roundup were calculated to obtain more stringent parameters in assessing the dangerousness of those on nontargets. The risk of environmental contamination by Roundup for the Nile tilapia, common carp, and tambaqui are low for the lowest application rate (1 L.ha-1) and depths (1.5 and 2.0 m). The dilution of 100%, the highest recommended dose (5 L.ha-1) and depths (1.5 and 2.0 m) the risk is moderate for the three species. The values of the Risk Ratio (QR) were greater than 0,1, indicating that the values of the CAE and LC50 are above acceptable levels and there is a need, this study, a refinement in ecotoxicological tests / Considerando a import?ncia comercial, por se tratarem das esp?cies de ?gua-doce mais comercializadas no Brasil, por ocorrerem em diversos tipos de ambientes aqu?ticos (lagos, rios e a?udes) e ainda por serem tolerantes a um amplo espectro de varia??o de diversos par?metros f?sicos e qu?micos da ?gua, as esp?cies de peixes Oreochromis niloticus, Cyprinus carpio e Colossoma macropomum foram escolhidas para este estudo com a finalidade de testar a toxicidade do herbicida roundup. Diante do exposto, o presente trabalho teve como objetivo determinar a toxicidade aguda e avaliar o risco de contamina??o ambiental dessas tr?s esp?cies de peixes pelo herbicida Roundup. Os alevinos de Til?pia do Nilo (Oreochromis niloticus), Carpa-comum (Cyprinus carpio) e Tambaqui (Colossoma macropomum) foram submetidos ao herbicida roundup nas seguintes concentra??es: 0,0 (controle); 18,06; 19,10; 20,14; 21,18 e 22,22 mg.L-1, 0,0 (controle); 13,89; 14,86; 15,83; 16,81 e 17,78 mg.L-1 e 0,0 (controle); 18,06; 19,10; 20,14; 21,18 e 22,22 mg.L-1, respectivamente, os tr?s por 96 horas. A CL50 96h para O. niloticus, C. carpio e C. macropomum foi de 21,63, 15,33 e 20,06 mg.L-1 do herbicida roundup, respectivamente. Os resultados obtidos demonstram que esse herbicida est? classificado como levemente t?xico para as tr?s esp?cies. Os valores de oxig?nio dissolvido, pH e temperatura registrados no aqu?rio controle e nos aqu?rios experimentais das tr?s esp?cies estudadas mantiveram-se sem varia??es significativas ao longo dos testes, o que reduz a possibilidade de mortalidade causada por varia??es bruscas desses par?metros, durante as 96 horas de experimento. Os valores das CL50 entre as diferentes esp?cies de peixes foram observadas, constatando que as esp?cie Oreochromis niloticus, Colossoma macropomum e Cyprinus carpio n?o apresentaram diferen?as expressivas. Os valores de risco ambiental do Roundup foram calculados para a obten??o de par?metros mais rigorosos na avalia??o da periculosidade desses sobre organismos n?o-alvos. O risco de contamina??o ambiental por roundup para a til?pia do Nilo, carpa-comum e tambaqui s?o baixos para a menor dose de aplica??o (1 L.ha-1) e nas profundidades (1,5 e 2,0 m). Na dilui??o de 100%, na maior dose recomendada (5 L.ha-1) e nas profundidades (1,5 e 2,0 m) o risco ? moderado para as tr?s esp?cies. Os valores de Quociente de Risco (QR) foram maiores que 0,1, indicando que os valores da rela??o CAE e CL50 est?o acima dos n?veis aceit?veis, havendo a necessidade de um refinamento nas an?lises ecotoxicol?gicas
129

Frequencias e formas de fornecimento de ração para tilápia do Nilo criada em sistema raceway / Feed frequency and ratio for Nile tilapia in raceway system

SANTOS, Janaína Gomes Araújo 20 August 2008 (has links)
Made available in DSpace on 2014-07-29T15:07:50Z (GMT). No. of bitstreams: 1 Dissertacao JanainaGomes.pdf: 323977 bytes, checksum: 872ea1e01b711a691d7746d206ac395e (MD5) Previous issue date: 2008-08-20 / The present research was carried out at Sector of Fish of the Goiás Federal University, between December the 2006 and May the 2007, which lasted for 127 days. Nile tilapia juveniles (Oreochromis niloticus), Supreme strain, with starter weight of 31.86 ± 1.75 g were randomly allotted in 32 tanks of 100 L of capacity each one in raceway system. The full water exchange of the tanks occurred in 30 min at the beginning. The fish were fed with extruded diet containing 36% of CP in pellets of 2-4 mm in diameter. By the average weight of 100 g, the fish were fed with extruded diet with 32% of CP in pellets of 4-6 mm in diameter until the end of the experiment. This assessment was performed to evaluate feed frequencies (2, 3, 4 and 5 times/day) and ratio (ad libitum and based on the percentage of the biomass weight - %PVBIO) on the productive performance, chemical composition, biometric indices, carcass and fillet yield and costs and profitability partial of Nile tilapia during the weight gain in the raceway system. The experimental design was composed by a completely randomized design in a factorial (4 x 2), with four repetitions, totalizing 32 experimental units. The performances body weight (BW), weight gain (WG), final biomass (FB), feed intake (FI), index of food intake (IF), apparent feed conversion ratio (AFCR), feed efficiency (FE), survival (S%), protein efficiency ratio (PER), specific growth ratio (SGR) and uniformity of the lot (U%) -; fillet weight (FW), carcass yield (CY), fillet yield(FY), biometric indices, and chemical composition fillet (total dry matter (TDM), moisture (MO), crude protein (CP), crude lipid (CL), ash) were the main evaluated parameters. The performance data were submitted to the analysis of variance and Duncan tests (5%), and the others to Tukey test (5%). Despite the quantity of food provided in the treatments, the main variables of water quality remained within the limit recommended for fish breeding. Better AFCR, FE and PER were reached for fish fed three times a day and greater PVBIO% for those ones fed twice daily ad libitum (P <0.05). The values of FBW, FL, FWG, FB, and FI were higher for fish fed four times a day (P <0.05), with the AFCR and PER values similar to those in fish fed three times a day. S%, SGR, CF and U% suffered no influence by the feeding frequency (P> 0.05). Only in IF differences on how to supply the ration (P <0.05) were observed. Fish fed four, five and three times a day had better average of FY, differing from those fed twice a day (P<0.05). The feeding frequency of less than five times had greater CY and VFI, but it did not differ from the other regimens. Difference in form of supply was observed only for RF, and the best average was reached in fish fed ad libitum. Regarding the chemical composition fillet, no differences in ashes were observed (P>0.05). The highest level of CL was found in three times of feeding frequency, which was statistical relevant (P<0.05) in comparison to the others. Interaction was observed for the variables TDM, MO and CP. The cost incidence (CI) was lower in three times a day of feeding frequency with feed supply based on %BW. The feeding frequency of 3 times per day ad libitum presented the best result concerning performance, and suggested lower cost with labor for juveniles of Nile tilapia cultivated in raceway tanks. / A pesquisa foi realizada no Setor de Piscicultura da Escola de Veterinária da Universidade Federal de Goiás, no período de dezembro de 2006 a maio de 2007, com duração de 127 dias. Foram utilizados juvenis de tilápia do Nilo (Oreochromis niloticus), linhagem Supreme, com peso médio inicial de 31,86 ± 1,75 g, distribuídos aleatoriamente em 32 caixas reguladas para 100 L adaptadas ao sistema raceway. A troca total de água das caixas, no início, ocorreu em 30min. Os peixes foram alimentados com ração extrusada contendo 36% de PB e grânulos com 2 a 4 mm de diâmetro até o peso médio aproximado de 100 g; em seguida, foram alimentados com ração extrusada 32% de PB com grânulos de 4 a 6 mm de diâmetro até o final do experimento. Objetivou-se determinar o efeito das frequências (2, 3, 4 e 5 vezes/dia) e formas de fornecimento da ração (à vontade e com base na porcentagem do peso da biomassa) sobre o desempenho produtivo, a composição bromatológica do filé, os índices biométricos, os rendimentos de carcaça e filé, e custos e rentabilidade parciais da tilápia durante a fase de engorda no sistema raceway, constituindo, assim, um delineamento inteiramente casualizado em esquema fatorial (4 x 2), com quatro repetições, totalizando 32 unidades experimentais. Foram assim avaliados: desempenho produtivo - peso (P), ganho de peso (GP), biomassa final (BF), consumo de ração (CR), índice de consumo alimentar (IA), conversão alimentar aparente (CAA), taxa de eficiência alimentar (TEA), taxa de eficiência protéica (TEP), taxa de crescimento específico (TCE), sobrevivência (S%), uniformidade do lote (U%) -; peso do filé (PF), rendimentos de carcaça (RC) e filé (RF), índice hepatosomático (IHS), índice gordura víscero-somático (IGVS) e composição bromatológica do filé (matéria seca total (MST), umidade (UM), proteína bruta (PB), extrato etéreo (EE), cinzas). Os dados de desempenho produtivo foram submetidos à análise de variância e teste Duncan (5%), e os demais ao teste Tukey (5%). Apesar da quantidade de alimento fornecido por tratamento, as principais variáveis de qualidade da água permaneceram dentro do limite recomendável para os peixes. Os valores de P, GP, BF, e CR foram maiores para os peixes arraçoados quatro, três e cinco vezes ao dia, respectivamente, diferindo de duas vezes ao dia (P<0,05). Foi observada interação significativa para IA, CAA, TEA e TEP. Observou-se melhor CAA, TEA e TEP para os peixes arraçoados três vezes ao dia pela %PVBIO e duas vezes ao dia à vontade (P<0,05). S%, TCE e U% não sofreram influência quanto à frequência alimentar (P>0,05). Os peixes arraçoados três, quatro e cinco vezes ao dia apresentaram melhor média de RF diferindo dos peixes arraçoados duas vezes (P<0,05). A frequência de cinco vezes apresentou menor RC e maior IGVS, porém não diferiu das demais. Foi observada diferença para forma de fornecimento apenas para RF, sendo a melhor média para os peixes arraçoados à vontade. Quanto à composição bromatológica, só não foram observadas diferenças (P>0,05) para Cinzas. O maior teor de EE foi encontrado na frequência de três vezes (P<0,05) diferindo das demais. Foi observada interação (P<0,05) para as variáveis MST, UM e PB. Quanto à avaliação econômica, a incidência de custo (IC) foi menor na frequência de três vezes ao dia com fornecimento de ração baseado na %PVBIO. Recomenda-se a frequência alimentar de 3 vezes/dia para juvenis de tilápia do Nilo até o abate por possibilitar menor gasto com mão de obra, melhores resultados para desempenho, com fornecimento de ração à vontade, até atingirem a saciedade aparente, quando cultivados em tanques raceways
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Desempenho zootécnico de duas linhagens de Tilápia-do-Nilo sob diferentes densidades de estocagem em raceway / Performance of two nile tilapia strains in different stocking densities in raceway system

OLIVEIRA, Raquel Priscila de Castro 30 April 2010 (has links)
Made available in DSpace on 2014-07-29T15:13:43Z (GMT). No. of bitstreams: 1 Tese Raquel Priscila de Castro Oliveira.pdf: 2385507 bytes, checksum: 70f3aa3088e08bd364a210435717e331 (MD5) Previous issue date: 2010-04-30 / This study was developed in order to analyze productive performance, economic evaluation, bromotological composition of fish fillet, body components percentage and glucose level of two of Nile tilapia strains (chitralada and supreme) in three stocking densities (90, 120 and 150 fish/m3) in the raceway system. This work was carried out at the Fish Culture Sector from Universidade Federal de Goias. A total of 1,440 Nile tilapia fingerlings were produced in 24 polyethylene water tanks, adapted to raceway system. Each experimental unit had individual pipe for water supply and flow was regulated to allow total exchange every 30 minutes, regardless of stocking density. The animals were fed three times a day with commercial extruded ration, ad libitum, seven days a week. The design was completely randomized in a 2 x 3 factorial arrangement and four replications. The results were submitted to variance analysis and, in cases of statistical variance, to the Tukey test (5%). After the all variables analysis, it was concluded that both strains presented positive characteristics for production in Goias State in raceway system. Supreme strain, in higher water density, is the one recommended by this study due to greater profitability, and to positive performance aspects. / Esse trabalho foi desenvolvido com o intuito de avaliar o desempenho produtivo, a avaliação econômica, a composição bromatológica do filé, o percentual de componentes do corpo, e a glicemia de duas linhagens comerciais de tilápia-do-Nilo, a chitralada e a supreme submetidas a três densidades de estocagem 90, 120 e 150 peixes/m3 em sistema de alto fluxo de água. O estudo foi realizado no Setor de Piscicultura da Universidade Federal de Goiás. No total, 1440 alevinos de tilápia-do-Nilo foram estocados em 24 caixas d água de polietileno adaptadas ao sistema raceway. Cada unidade experimental era provida de tubulação individual para abastecimento e a vazão foi regulada para troca total a cada 30 minutos, independente da densidade de estocagem. Biometrias mensais foram realizadas e coletados dados para a avaliação. Os animais foram alimentados com ração comercial extrusada, até a saciedade momentânea, sete dias por semana. O delineamento utilizado foi inteiramente ao acaso em esquema fatorial 2x3 e quatro repetições. As médias dos resultados encontrados foram submetidos a análise de variância e, em caso de diferença estatística, ao teste de comparação de médias Tukey (5%). Após a análise de todas as variáveis concluiu-se que ambas as linhagens apresentaram características favoráveis de produção no Estado de Goiás em sistema raceway. A linhagem supreme, na maior densidade de estocagem, foi a recomendada após esse estudo devido a maior rentabilidade e aspectos positivos no desempenho.

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