Dissertations / Theses on the topic 'Stocking density'
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North, Benjamin Paul. "Effects of stocking density on the welfare of farmed rainbow trout (Oncorhynchus mykiss)." Thesis, University of Stirling, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.417679.
Full textCampbell, Mackenzie Andrew. "Interaction Of Stocking Density And The Feeding Environment In Lactating Holstein Dairy Cows." ScholarWorks @ UVM, 2017. http://scholarworks.uvm.edu/graddis/776.
Full textNicholson, Gareth Hurst. "Towards understanding the effects of stocking density on farmed South African abalone, Haliotis Midae." Thesis, Rhodes University, 2014. http://hdl.handle.net/10962/d1015646.
Full textGlenney, Gavin W. "Comparisons of tilapia seed production under various broodstock densities and fry stocking densities." Thesis, This resource online, 1996. http://scholar.lib.vt.edu/theses/available/etd-08292008-063206/.
Full textGarner, Alan Brad. "High-Density Grass Carp Stocking Effects on a Reservoir Invasive Plant, Water Quality, and Native Fishes." NCSU, 2008. http://www.lib.ncsu.edu/theses/available/etd-09132008-145505/.
Full textPence, Kristen Jean. "The effects of dietary forage, social hierarchy, and stocking density on stress in lactating cows during relocation." Thesis, Virginia Tech, 2005. http://hdl.handle.net/10919/33830.
Full textMaster of Science
Johnston, Gavin. "Effect of feeding regimen, temperature and stocking density on growth and survival of juvenile clownfish (Amphiprion percula)." Thesis, Rhodes University, 2001. http://hdl.handle.net/10962/d1005118.
Full textAnderson, Mallory Grace. "Chicken or fish? Do environmental complexity and stocking density impact affective states of broiler chickens and rainbow trout?" Thesis, Virginia Tech, 2021. http://hdl.handle.net/10919/105133.
Full textMaster of Science
Conventional housing of broiler chickens and rainbow trout (both raised for meat) causes concern for their welfare and affective states. Environmental conditions can greatly impact animals' affective states–their long-term emotional state, ranging from positive to negative. In barren environments at high stocking densities, broiler chickens and rainbow trout are prevented from showing normal behaviors and these conditions can compromise their affective state and welfare. By 'asking' chickens and trout whether the glass is half full or half empty, we can determine level of optimism or pessimism, and level of anxiety or calmness, therefore gaining a better understanding of their affective states. This can be done using a judgement bias test and attention bias test, where animal responses (optimism and anxiety) are recorded during ambiguous situations (judgement) and threatening situations (attention). Animals in positive affective states judge ambiguous situations optimistically (glass half full) and pay little attention towards perceived threats, while animals in negative affective states judge the same ambiguous situations pessimistically (glass half empty) and pay more attention towards perceived threats. In Chapter 3, responses to ambiguous situations were used to determine the affective state of broiler chickens housed in either enriched (perches, dust bath, pecking stones, rotating toys) or barren environments at either high or low stocking densities. Broiler chickens housed in enriched environments had an optimistic judgement bias of ambiguous situations (glass half full), suggesting they were in a more positive affective state compared to broilers housed in barren environments. Stocking density did not impact their level of optimism. In Chapter 4, responses to a perceived threat were used to determine level of anxiety and a tonic immobility test was used to determine fear of broilers housed under the same conditions as in Chapter 3. Broilers housed in enriched environments paid less attention to a perceived threat than broilers housed in barren environments, indicating the former were less anxious (glass half full) and in a positive affective state. Fear was not impacted by the tested enrichments, but birds kept under higher stocking densities did show reduced fear compared to birds in low-density environments. In Chapter 5, rainbow trout were housed in either enriched (shelter structure and artificial plants) or barren tanks at either high or low stocking densities. Affective state was evaluated through their responses to ambiguous situations. Trout housed in high stocking density environments had an optimistic judgement bias of ambiguous situations (glass half full), suggesting they were in a more positive affective state than trout housed in low stocking density environments. The enrichments did not impact their responses during the test, suggesting they did not impact fish optimism. These results indicate that an enriched environment improves broiler affective state and welfare compared to conventional housing conditions, the tested densities did not impact their welfare. Although an enriched environment did not positively impact responses of trout during ambiguous situations, our results show that housing rainbow trout in large groups results in a positive affective state and improved welfare status compared to housing trout in small groups. Overall, environmental enrichment, not stocking density, had a positive impact on broiler chicken affective states. Rainbow trout affective states were positively impacted by stocking density, but not environmental enrichment.
Rubio, Zuazo Ana Maria, and anarubio zuazo@gmail com. "Environmental influences on the sustainable production of the Sydney rock oyster Saccostrea glomerata : a study in two southeastern Australian estuaries." The Australian National University. Centre for Resource and Environmental Studies, 2008. http://thesis.anu.edu.au./public/adt-ANU20080618.091057.
Full textTalebi, Aniseh. "The effects of regrouping and stocking density on social behaviour, lying behaviour and locomotor activity of mid and late lactation dairy cows." Thesis, University of British Columbia, 2011. http://hdl.handle.net/2429/35738.
Full textSilva, Liliane Severino da. "Tiller population density and demography dynamics of Convert HD 364 brachiariagrass in response to canopy height and growth rate under continuous stocking." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/11/11139/tde-13112015-110013/.
Full textA pecuária baseada em pastagens é uma das principais atividades econômicas do Brasil. Geralmente, ocorre adoção de novos materiais forrageiros sem que haja informações suficientes sobre suas características produtivas o que compromete seu potencial de uso. Um experimento foi conduzido em Piracicaba (22º42\' S, 47º30\' W, 580 m asl.) durante dois verões agrostológicos tendo por objetivo descrever e explicar a dinâmica de perfilhamento da Brachiaria híbrida Convert HD 364 (Brachiaria hybrid CIAT 36087) sob lotação contínua e taxa de lotação variável. Foram avaliados densidade populacional de perfilhos (DPP), demografia do perfilhamento (taxas de aparecimento - TAP- e sobrevivência de perfilhos - TSP), índice de estabilidade da população de perfilhos (IE), peso médio de perfilhos (PMP), massa de forragem (MF), índice de área foliar (IAF), interceptação luminosa (IL), ângulo de inserção da lâmina foliar (ALF), altura do meristema apical (AMA) e da lígula da última folha expandida (AFE). O delineamento experimental foi em blocos completos casualizados, com arranjo fatorial 3x2, correspondendo às combinações entre alturas de dossel (10, 25 e 40 cm) e taxas de crescimento (50 e 250 kg N ha-1 ano-1), com três repetições. Os dados foram analisados utilizando-se o procedimento de modelos mistos e as médias comparadas utilizando-se o teste \"t\" (P<=0,05). Sob altura de dossel de 10 cm, o capim Convert HD 364 apresentou DPP 10 e 25% superiores àquelas sob 25 e 40 cm, respectivamente. O aumento na taxa de crescimento resultou em aumento de 10% na DPP e decréscimo de 9% no PMP. O PMP foi 80 e 274% maior nos dosséis de 40 cm de altura do que nos de 25 e 10 cm, respectivamente. Dosséis mantidos a 40 cm submetidos à taxa de crescimento baixa e alta, respectivamente, apresentaram incremento de 163 e 233 % na MF do que dosséis de 10 cm. Obtiveram-se respostas similares entre AMA e AFE, nas quais houve um incremento na altura de ambas com o aumento da altura do dossel. Houve diferença entre as taxas de crescimento para AMA e AFE somente em dosséis de 25 cm. Com o aumento da dose de nitrogênio, TAP sofreu aumento de 29%, enquanto, TSP sofreu decréscimo de 13%. TAP e TSP variaram ao longo do período estudado, demonstrando a influência de fatores ambientais nas mesmas. Não houve variação no IE ao longo do período experimental em dosséis sob taxa de crescimento baixa, enquanto na taxa alta o IE foi 20 e 35% maior em Fevereiro do que em Janeiro e Março, respectivamente, para ambos os anos. A determinação da localização do meristema apical é uma importante ferramenta para o planejamento adequado de estratégias de manejo em sistemas de produção animal sob pastejo.
Pontin, Mariana Caroline Furian. "Proteção antioxidante do colostro bovino em células intestinais de juvenis de pacu (Piaractus mesopotamicus) submetidos a estresse." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/11/11139/tde-14082018-102616/.
Full textThe stress causes changes in the intestinal epithelium, such as the increase in the number of goblet cells and on the rate of apoptosis. The use of nutraceutical foods has been an alternative to soften these modifications on the epithelial tissue. Thus, this study aimed to evaluate if the inclusion of bovine colostrum, which is composed of antioxidant, immune and growth factors, would be able to attenuate the consequences of chronic stress on the intestine. For this, pacu juveniles (Piaractus mesopotamicus), stocked at density of 50 kg/m3, were fed twice daily until satiety with pelleted and semi-purified diet without (0% LBC) and with the inclusion of lyophilized bovine colostrum in increasing concentrations (10, 20 and 30% LBC), (n = 4). After 28 days, segments of the middle gut, S1 and S2, and rectum (RT) were collected. The tissues were stained with histological dyes for the quantification of goblet cells containing neutral, acidic (including sialo and sulphomucins) and acid-neutral mucins. The volume (Vv) and surface density (Sv) of the mucosa were also measured by stereological analysis and the thickness of the muscular layer. The ratio between the number of each goblet cell type and subtype and the Vv or Sv was calculated to estimate the density of goblet cells, Dv and Ds, respectively. The apoptotic rate was analyzed qualitatively according to the intensity (high, medium and low) of caspase-3 immunostaining in epithelial cells. The diets did not influence the zootechnical parameters analyzed (P> 0.05). In the rectum, the groups that received 20 and 30% LBC presented lower number of goblet cells containing sulphomucins and lower Ds in relation to 0 and 10% (P = 0.0148 and 0.0198, respectively). In RT, total Dv and Dv of goblet cells containing acid mucins were higher in 0 and 30% LBC in relation to 20% LBC (P = 0.0155 and 0.225, respectively). In S1, 10 and 30% LBC presented higher Dv in relation to 20% LBC (P = 0.0540). Muscle layer thickness, Vv and Sv did not differ between treatments (P> 0.05). In S2 and RT, the rate of apoptosis was inversely related to the concentration of lyophilized bovine colostrum added in the diet. In the three segments, there was higher proportion of goblet cells containing acidic than neutral mucins, most of them being sulphomucins. Thus, the inclusion of lyophilized bovine colostrum in diets of pacu juveniles reduced apoptosis in the intestinal segments S2 and RT and also decreased the number of goblet-containing sulphomucins in the RT, indicating that lyophilized bovine colostrum can be used as a nutraceutical feed for pacus (Piaractus mesopotamicus) under high stocking density to decrease the apoptotic rate and protect the intestine against bacterial enzymes, one of the main functions of sulphomucins.
Marquardt, Svenja. "Activity and plant selection patterns of free-ranging cattle in Southern Bolivian mountain forests, and the impact of cattle stocking density on the woody vegetation /." [S.l.] : [s.n.], 2009. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=18305.
Full textSilva, JÃssica Lucinda Saldanha da. "Optimum rate of juvenile feeding of Nile tilapia (Oreochromis niloticus) grown in artificial substrate based system in different density storage." Universidade Federal do CearÃ, 2014. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=11228.
Full textThe feeding rates practiced in fish cultured directly influence the economic return of activity, because excessive rates result in zootechnical, economic losses and environmental. An alternative for improving the quality of crop water and increase the production of fish is the use of artificial substrates for colonization by periphyton. This study was conducted in two consecutive phases. The first phase of research was aimed at determining, in fish farming system based substrate, the optimal rate of feeding in each track of body weight, that maximizes the weight gain and feed efficiency, and minimizes the concentrations of ammonia and nitrite in pond water. Using seven treatments and a control, with five repetitions each, totaling 40 tanks of 250 L. In the treated groups growing feeding rates were evaluated, beginning with the following values: 3, 6, 9, 12%; 15, 18 and 21% biomass per day. The second phase of the study aimed to determine the best stocking density of juvenile tilapia fed at rates optimized in the cropping system based on substrate. By regression analysis of the results of final weight, specific growth rate and yield as a function of feeding rates employed, these variables observed increase in initial feed rate of about 12% of the biomass day -Â, occurring decreased these variables with increasing feed rate. Variables of water quality for initial feed rate of 12%, as NAT (0,39 mg/L), NH3 (0,026 mg/L) and O2D (5,18 mg/L) were within the acceptable for tilapia levels. With the increase in feed rate, there was worsening in water quality, it was not possible observe the effect of biofilter periphyton. Therefore in the first phase, that the optimal rate of feeding of juvenile Nile tilapia cultured in ponds with submerged substrates for periphyton, in the growing phase (1-30 g), corresponds to the initial rate of 12% biomass day-Â. In the second experimental phase, the rate of feeding and stocking density showed higher final body weight (25 g), yield (14,77 g/ mÂ/day) and TCE (5,16) were equal to 12% biomass day-Â (initial) and 9 fish/tank, respectively. The variables of water quality for this treatment were within the acceptable for growing tilapia tracks.
As taxas de arraÃoamento praticadas em cultivos de peixes influenciam diretamente no retorno econÃmico da atividade, pois taxas excessivas resultam em prejuÃzos zootÃcnicos, econÃmicos e ao meio ambiente. Uma alternativa para melhorar a qualidade da Ãgua de cultivo e aumentar a produÃÃo de pescado à o emprego de substratos artificiais para colonizaÃÃo por perifÃton. O presente trabalho foi realizado em duas fases consecutivas. A primeira fase teve como objetivo geral determinar, em sistema de cultivo de peixes baseado em substrato, a taxa de arraÃoamento Ãtima, em cada faixa de peso corporal, que maximiza o ganho em peso e a eficiÃncia alimentar; e minimiza as concentraÃÃes de amÃnia e nitrito na Ãgua de cultivo. Utilizando sete tratamentos e um controle, com cinco repetiÃÃes cada, totalizando 40 tanques de 250 L. Nos grupos tratados foram avaliadas taxas crescentes de arraÃoamento, iniciando-se com os seguintes valores: 3; 6; 9; 12%; 15, 18 e 21% da biomassa ao dia. A segunda fase do trabalho teve por objetivo determinar a melhor densidade de estocagem de juvenis de tilÃpia alimentados sob taxas otimizadas, em sistema de cultivo baseado em substrato. Pela anÃlise de regressÃo dos resultados de peso final, taxa de crescimento especÃfico e produtividade em funÃÃo das taxas de arraÃoamento empregadas, observou-se aumento dessas variÃveis atà a taxa de arraÃoamento inicial de, aproximadamente, 12% biomassa dia-Â, ocorrendo queda dessas variÃveis com a elevaÃÃo da taxa de alimentaÃÃo. As variÃveis de qualidade de Ãgua para taxa alimentar inicial de 12%, como NAT (0,39 mg/L), NH3 (0,026 mg/L) e O2D (5,18 mg/L) ficaram dentro dos nÃveis aceitÃveis para o cultivo de tilÃpia. Com o aumento da taxa de alimentaÃÃo, houve piora da qualidade de Ãgua, nÃo sendo possÃvel observar o efeito de biofiltro do perifÃton. Concluiu-se, na primeira fase, que a taxa Ãtima de arraÃoamento de juvenis de tilÃpia do Nilo cultivados em tanques com substratos submersos para perifÃton, na fase de recria (1 â 30 g), corresponde à taxa inicial de 12% biomassa dia-Â. Na segunda fase experimental, a taxa de arraÃoamento e a densidade de estocagem que proporcionaram maior peso corporal final (25 g), produtividade (14,77 g/mÂ/dia) e TCE (5,16) foram iguais a 12% da biomassa dia-1 (inicial) e 9 peixes/tanque, respectivamente. As variÃveis de qualidade de Ãgua para esse tratamento se apresentaram dentro das faixas aceitÃveis para o cultivo de tilÃpia do Nilo.
Costa, Beatriz Braun. "Densidade de estocagem de lambari (Astyanax altiparanae) em tanques-rede." Universidade Federal de São Carlos, 2011. https://repositorio.ufscar.br/handle/ufscar/7003.
Full textFinanciadora de Estudos e Projetos
With the increased interest in growing native fish species the tetra has been highlighted nationally in the marketing of fish facing the two niche markets: as a snack in bars and restaurants and other natural bait for sport fishing. Therefore, studies on the stocking density are needed for better understanding in response to performance than can affect the growth, nutrition and animal behavior. This study aimed to evaluate the economic viability and growth performance of the tetra (Astyanax altiparanae) in cages, subjected to different stocking rates. The experiment was conducted on the premises of the UPD Pirassununga, APTA Pole Central East, in cages of 1m3, villages in densities: 250,450 and 600 fish per tank with 4 repetitions. The temperature, water clarity, dissolved oxygen an pH were daily measured. The tetra were fed extruded commercial diet containing 36%of protein. The experiment lasted 57 days and monthly samples were collected to evaluate the development and adjust amount of feed. To verify the significance between treatment means was used Tukey s test at 5% probability. The results showed increasing linear effect for variable total biomass (p<0,05) as opposed to the linear effect (p<0,05) for average consumption of feed as well as weight gain, average final length and final weight medium according to the increase of stocking density. The physic-chemical parameters remained at adequate levels. It is concluded that stocking density affects the development of juveniles of tetra and the density of persons over fishes/m³. Can still be used in the cultivation of 600 fishes/m³ tetra juveniles in cages, resulting in higher total biomass, although they result in smaller populations.
Com o aumento do interesse no cultivo de espécies de peixes nativos, o lambari tem se destacado nacionalmente na comercialização de pescado frente à dois nichos de mercado: um como petiscos em bares e restaurantes e outro como isca natural para a pesca esportiva. Sendo assim, estudos referentes à densidade de estocagem se fazem necessários para um melhor entendimento frente ao desempenho produtivo que pode afetar o crescimento, a alimentação e o comportamento dos animais. Neste estudo, objetivou-se avaliar a viabilidade econômica e o desempenho produtivo do lambari (Astianax altiparanae) em tanquesrede, submetidos à diferentes densidades de estocagem. O experimento foi conduzido nas instalações da UPD de Pirassununga, Pólo APTA Centro-Leste, em tanques-redes de 1m3, povoados nas densidades de: 250, 400 e 600 peixes por tanque com 4 repetições. A temperatura, transparência da água, oxigênio dissolvido e o pH foram aferidos diariamente.Os lambaris foram alimentados com ração comercial extrusada contendo 36% de proteína bruta. O experimento durou 57 dias e mensalmente foram realizadas biometrias para avaliar o desenvolvimento e o ajuste da quantidade de ração. Para verificar a significância entre as médias dos tratamentos foi utilizado o teste de Tukey, ao nível de 5% de probabilidade. Os resultados mostraram efeito linear crescente para variável de biomassa total (p<0,05) em oposição ao efeito linear decrescente (p<0,05) para consumo médio de ração, assim como ganho de peso médio, comprimento final médio e peso final médio conforme aumento da densidade de estocagem. Os parâmetros físicoquímicos permaneceram em níveis adequados. Conclui-se que a densidade de estocagem afeta o desenvolvimento dos juvenis de lambari e que a densidade de 300 peixes/m3proporciona indivíduos maiores. Ainda pode-se utilizar 600 peixes/m3 no cultivo de juvenis de lambari em tanque-rede, resultando em maior biomassa total, apesar de resultarem em populações menores.
Marimon, Bruno Teixeira. "Desempenho de leitões submetidos a diferentes densidades durante a fase de creche." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2018. http://hdl.handle.net/10183/178240.
Full textThe aim of this study was to evaluate the effect of space allowance on performance and behavior of nursery pigs. At weaning 560 pigs (5.75 ± 0.9 kg of body weight and 20.92 ± 0.8 days of age) were randomly assigned in four treatments with different stocking densities: T0.33, T0.28, T0.23 and T0.18 (0.33, 0.28, 0.23 and 0.18 m²/pig respectively). Pens were standardized to have the same group size (20 pigs/pen) and feed was provided ad libitum. Tail and ear biting lesions and the fighting lesions were weekly observed. Sixteen pens were videotaped in three different moments (1st, 4th and 6th housing week) and the frequency of fights and belly nosing were recorded. A linear effect was observed of stocking density on average daily gain (ADG; P=0.049), a quadratic effect and a quadratic tendency of effect were observed on body weight at 42 days after weaning and on average daily feed intake (ADFI) (P=0.030; P=0.075, respectively). There was no effect of stocking density on the gain:feed ratio or weight coefficient of variation (CV) at day 42. Higher graduation of severe ear lesions was observed in pigs from T0.18 when compared to T0.33 (P = 0.0196) and T0.28 (P = 0.056). A higher number of pigs with moderate or severe tail and ear lesions was observed in T0.18 (P > 0.05). Moreover, it was observed a linear effect of density on the frequency of fights, with higher occurrence in groups housed in restricted spaces. However, no effect of stocking density was observed on fight lesions or belly nosing among treatments. In conclusion, increased density negatively affected the performance of piglets and increased the occurrence of unsuitable behaviors.
Woolpert, Melissa Elizabeth. "Management Practices and Communication Strategies to Improve Milk Fat and Protein Content on Dairy Farms." ScholarWorks @ UVM, 2016. http://scholarworks.uvm.edu/graddis/594.
Full textFerreira, Eric Silva. "Efeitos do substrato e da densidade populacional sobre as atividades comportamentais e n?veis de hom?citos em rela??o ? densidade em Litopenaeus vannamei (BOONE, 1931)." Universidade Federal do Rio Grande do Norte, 2006. http://repositorio.ufrn.br:8080/jspui/handle/123456789/17363.
Full textConselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico
Carciniculture in Brazil occupies world-wide prominence due to shrimp culture, and the state of Rio Grande do Norte has presented the best results in the culture of the Litopenaeus vannamei in the last decade. This species has been shown to adapt easily to different environments and is between the five most cultivated penaeids of the world. The ponds are usually constructed in areas close to water courses and estuaries. Stock density and substrate ponds can pollute environment, causing losses in the growth and survival of the shrimps, being considered stress factors. Shrimps in inadequate densities and substrates can result reduced productivity of the farm; and favor diseases. So, it is important to verify how these variables influence the development of the animals in the culture farms. Our objective was to study the influence of the type of substrate and the stock density on the behavior and haemocyte count of the L. vannamei. Individually marked juvenile shrimps were kept in aquaria with 30 L of seawater and continuous aeration, in 12L-12D photoperiod. They were observed through Ad libitum and focal sampling instantaneous methods during thirty days, five times per week, six times per day (8:00 to 18:00) in windows of 15 minutes every two hours. The marking of carapace permitted quantifying molting and the feeding was supplied three times a day. Two experiments were carried out: the first one tested animals in the three different substrates (fine sand, smaller rocks-SPP and biggest rocks-SGR) with 33 shrimp/m2. In the second one, the animals were tested in three stock densities (26, 52 and 66 shrimp/m2) in fine sand substrate. At the end of experiment, biometry (first and second ones) and haemocyte count (second one) were made. The behavior of the L. vannamei seems to have been influenced by substrate and stocking density. In low granulometry of the substrate; the exploratory behavior became more frequent and inactivity of the shrimps was reduced. Burrowing was registered in sand substrate, specially in the initial period of the day. Cleaning was gradually higher along the day, presenting the biggest levels as the dark phase approached. The ingestion of feeding was more frequent in low density, and the animals were bigger and heavier at the end of the experiment. In the fine sand condition, the animals presented better growth, probably associated with the burrowing. The molting was equivalent in all types of substrate, but it was more frequent in high densities. Mortality of the shrimps was more frequent in high densities, and cannibalism and diseases were also registered in that condition. The clinical signals were similar to the ones of infectious mionecrosis (IMNV), generally associated with environment and physical stress. The haemocyte count was low for the hematologic standards of the penaeid, which we attributed for greater dilution of haemolymph in the postmolting phase. Smaller shrimps presented lower levels of haemocytes in relation to the bigger animals, count was also low in 26 shrimp/m2 density. The study demonstrates that stocking density and the granulometry of the substrate can affect the welfare, the health and the behavior of the L. vannamei. The sand substrate and low stocking density can be important tools in the management systems of shrimp production
A carcinicultura brasileira ocupa lugar de destaque mundial devido ? cria??o de camar?o, sendo o Rio Grande do Norte o maior produtor no cultivo de Litopenaeus vannamei. Essa esp?cie apresenta grande adapta??o ambiental e est? entre os cinco pene?deos mais cultivados do mundo. A cria??o ? realizada em viveiros nas ?reas pr?ximas a cursos d ?gua e estu?rios. Altas densidades populacionais e o substrato dos viveiros acarretam o aumento da polui??o e promovem perdas no crescimento e na sobreviv?ncia dos camar?es, sendo considerados fatores estressantes. Esses fatores podem comprometer a produtividade dos viveiros e favorecer doen?as, sendo importante verificar como essas vari?veis influenciam no desenvolvimento dos animais nas fazendas de cultivo. Nosso objetivo foi estudar a influ?ncia do tipo de substrato e da densidade populacional sobre o padr?o de atividades comportamentais e os n?veis de hem?citos (CHT) de L. vannamei. Em aqu?rios com 30 litros de ?gua salgada com aera??o cont?nua e em fotoper?odo 12C 12E (claro das 06:00 ?s 18:00), camar?es juvenis marcados individualmente foram observados pelos m?todos Ad libitum e focal instant?neo durante 30 dias, 5 vezes por semana, 6 observa??es di?rias (iniciando a primeira ?s 8:00 e a ?ltima ?s 18:00) em janelas de 15 minutos a cada duas horas, sendo registrado a cada minuto os seus comportamentos e localiza??o. Tamb?m foi feita a marca??o da carapa?a para quantificar as ecdises e a alimenta??o foi fornecida tr?s vezes ao dia. Dois experimentos foram realizados: tr?s substratos diferenciados (Areia, Seixos Pequenos e Seixos Grandes) com 33 animais/m2; e outro com tr?s densidades populacionais (26, 52 e 66 animais/m2) em substrato arenoso. Ao final dos experimentos, foram feitas a biometria dos camar?es e a contagem de hem?citos (apenas no 2? experimento). O padr?o geral de atividades comportamentais de L. vannamei n?o foi influenciado pelo substrato e densidade populacional. Contudo, ? medida que diminuiu a granulometria do substrato, o comportamento de explora??o tornou-se mais freq?ente e reduziu a inatividade dos camar?es. O enterramento foi registrado em substrato arenoso, sendo maior no per?odo inicial do dia. A limpeza distribuiu-se de forma crescente ? medida que a fase escura se aproximava, sendo maior ? noite. A ingest?o alimentar foi mais freq?ente em densidade baixa; acarretando maior crescimento nos camar?es. Houve maior ganho de peso nos animais em substrato arenoso, podendo estar associado com o enterramento e a taxa de crescimento dos animais. A taxa de ecdise foi igual em todos os substratos testados, mas a taxa de ecdise foi maior em maiores densidades. A mortalidade foi mais elevada em condi??es de maiores densidades, sendo registrados canibalismo e enfermidades nos animais. Os sinais cl?nicos foram semelhantes aos da mionecrose infecciosa (IMNV), geralmente associada ao estresse ambiental. Os n?veis de hem?citos foram baixos para os padr?es dos pene?deos, atribu?da pela maior dilui??o da hemolinfa na fase de p?s-ecdise. Camar?es menores apresentaram n?meros de hem?citos reduzidos em rela??o aos maiores, sendo tamb?m baixos em densidade de 26 camar?es/m2. O estudo demonstrou que os efeitos da densidade populacional elevada e a gramulometria do substrato podem afetar o bem estar, a sa?de e o comportamento de L. vannamei. O uso de substrato arenoso e baixa densidade populacional parecem ser medidas de manejo importantes em um sistema de produ??o de camar?o
Richard, Alexandre. "Régulation densité-dépendante des juvéniles de truites Salmo trutta sous l'effet du rempoissonnement : implications pour la gestion." Phd thesis, Université de Grenoble, 2014. http://tel.archives-ouvertes.fr/tel-01064492.
Full textSilva, Wilton Ladeira da. "Morfogênese, características estruturais e acúmulo de forragem em pastos de capim-Tifton-85 manejados com diferentes IAF residual /." Jaboticabal : [s.n.], 2010. http://hdl.handle.net/11449/96545.
Full textBanca: André Fischer Sbrissia
Banca: Kleber Tomás de Resende
Resumo: A produção de forragem é influenciada pelas estratégias de manejo impostas a ela, desta maneira, as técnicas para identificação do melhor momento para início e término do pastejo, aliadas aos estudos das características morfogênicas e estruturais das plantas, tornam-se úteis para direcionamento do manejo, pois buscam auxiliar no melhor entendimento do crescimento vegetal, e por conseqüência, da produção forrageira. O experimento foi realizado no setor de Forragicultura, em área pertencente à FCAV da UNESP - Jaboticabal no período de dezembro de 2008 a abril de 2009, com o objetivo de avaliar o efeito de índices de área foliar residual (IAFr) sobre as características morfogênicas e estruturais, além do acúmulo de forragem em pastos de Cynodon spp cv Tifton-85 sob regime de lotação rotacionada com ovinos. Os tratamentos foram constituídos por três IAFr, 2,4, 1,6 e 0,8, mantidos por regime de lotação rotacionada com ovinos. O delineamento experimental utilizado foi o de blocos completos casualizados em arranjo de parcelas subdivididas no tempo com sete repetições, totalizando 21 unidades experimentais. Foram avaliadas nas condições de pré e pós-pastejo, as alturas do dossel, os IAF e a massa de forragem, além da taxa de acúmulo de forragem e as características morfogênicas e estruturais dos pastos. No pré e pós-pastejo as alturas médias e o IAF do dossel se comportaram de forma análoga, decrescendo com a diminuição dos IAFr. O maior valor de interceptação luminosa no pós-pastejo (68,19%), foi verificado para o IAFr 2,4 e o menor valor (35,57%) para o IAFr 0,8. A taxa de aparecimento de folhas foi maior para o dossel mantido sob IAFr 0,8 em função da sua menor taxa de alongamento de colmos (0,51 cm/perfilho.dia). Os pastos mantidos sob IAFr 0,8 apresentaram maior densidade populacional de perfilhos. A massa de forragem seca... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The production of forage is influenced by handling strategies imposed on the techniques to identify the best moment for the beginning and ending of grazing, linked to the studies of morphogenetic and structural characteristics of plants, become useful tools for the directing of management for they aim to aid the best understanding of vegetal growth, and as consequence, forage plants. The experiment was conducted at Setor de Forragicultura at Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal, at UNESP - Jaboticabal from December 2008 to April 2009, and aimed to evaluate the effect of residual leaf area index (LAIr) about the morphogenical and structural characteristics, and forage accumulation in pastures of Cynodon spp cv Tifton-85 in a rotational stocking system with sheep. The treatments were constituted by three LAIr, 2,4, 1,6 e 0,8, maintained by rotational stocking with sheep. A complete randomized block design was used arranged in sub-divided parcels with seven replications, totaling 21 experimental units. They were evaluated in pre and post-grazing conditions, the height of the sward, LAI and forage mass, besides the accumulation of forage rate and the morphogenetic and structural characteristics. In the pre and post-grazing, the average height and the LAI of sward, decreasing with the diminishing of LAIr. The biggest value of light interception in post-grazing (68,19%), was verified by LAIr 2,4 and the smallest value (35,57%) for LAIr 0,8. The stem elongation rate (0,51 cm/tiller.day). The grazing maintained by LAIr 0,8 had higher tiller population density. The total dry forage mass was 27,1% superior for LAIr 2,4 regarding to LAIr 0,8 in pre-grazing conditions, being this total production, 72,0% was composed by stem fractions and dead material. The biggest rates of dry matter accumulation were observed with LAIr 2.4, in the second and third grazing cycles... (Complete abstract click electronic access below)
Mestre
Lorenz, Evandro Kleber. "Densidade de estocagem de piracanjuba (Brycon orbigniannus) em tanques-rede de pequeno volume." Universidade Estadual do Oeste do Paraná, 2010. http://tede.unioeste.br:8080/tede/handle/tede/1611.
Full textCoordenação de Aperfeiçoamento de Pessoal de Nível Superior
The density of stocking (DS) is a factor that can affect the development of fish. The aim of this current study was to analyze the effect of DS over the survival, weight, growth, and biomass hematology and chemical composition of juveniles Brycon orbignyannus farmed in cages. The experiment was realized in the area of transition of the tank of Itaipu Binational in the center of research development to fish farm in cages located in the Biological Refuge in the city of Santa Helena-PR, for a period of five months. It was used 750 juveniles with an initial average weight and length of 26.72+-5,99 g and 13.45+-0,99cm, respectively distributed in twelve cages of 1,00m3 randomly in a design completely casualized and three repetitions. The animals received commercial food extruded containing 36% of rough protein and they were feed three times a day until the visible satiety. At the end of the experimental period, the fish were kept in fasting for a period of 24 hours. Subsequently, they were realized the proceeding of blood collection assessment of the parameters of performance, income and chemical composition of the animals carcass. The survival and the final biomass increased straightly with the increase number of animals stocked for unit productive. The values of income of carcass as gutted weight, clean barrel, fillet, head and grease visceral didn t present significant difference (p>0.05) between the treatment. However, the total length and pattern, gain weight, total weight and hipathossomatic indices presented significant difference (p<0.05) and effect quadratic of the treatment. The chemical analyzes of the animals carcass didn t differ, statistically (p>0.05) to the variable dry material, protein and mineral material, so that, the higher lipic deposition was watched at fish produced in density 50 fish per m3. The varieties erythrocitics as hemoglobin and hematocrito didn t present difference statistics (p>0.05) to the treatment used, however, the total erythrocitics and the glucose differed significantly (p<0.01 and p<0.05, respectively) between the densities. It was concluded that the best density to the farm of piracanjuba in cages is between 58and 75 fish per m3
A densidade de estocagem (DE) é um fator que pode afetar o desenvolvimento dos peixes. O objetivo do trabalho foi avaliar a densidade de estocagem de juvenis de Brycon orbignyanus cultivados em tanques-rede sobre a sobrevivência, peso, crescimento, biomassa, hematologia e composição química. O experimento foi realizado durante cinco meses na área de transição do reservatório da Itaipu Binacional no Centro de Desenvolvimento de Pesquisa para Piscicultura em Tanques-rede localizado no Refúgio Biológico do município de Santa Helena PR. Foram utilizados 750 juvenis com peso e comprimento médio inicial de 26,72±5,99g e 13,45±0,99cm, respectivamente, distribuídos em 12 tanques-rede de 1,00 m3 em um delineamento inteiramente casualizado. Foram utilizados quatro tratamentos (25, 50, 75 e 100 peixes/m3) e três repetições. Os animais receberam ração comercial extrusada contendo 36% de proteína bruta e foram alimentados três vezes ao dia até a saciedade aparente. Ao final do período experimental, os peixes permaneceram em jejum por um período de 24 horas para, posteriormente, serem realizados os procedimentos de coletas de sangue e avaliações dos parâmetros de desempenho, rendimento e composição química da carcaça dos animais. A sobrevivência e a biomassa final aumentaram linearmente com o aumento do número de animais estocados por unidade produtiva. Os valores de rendimento de carcaça como peso eviscerado, tronco limpo, filé, cabeça e gordura visceral não apresentaram diferenças significativas (p>0,05), entre os tratamentos. Entretanto, o comprimento total e padrão, ganho de peso, peso total e índice hepatossomático apresentaram diferenças significativas (p<0,05) e efeito quadrático para os tratamentos. A análise química da carcaça não diferiu estatísticamente (P>0,05) para as variáveis matéria seca, proteína e matéria mineral, no entanto, a maior deposição lipídica foi observada nos peixes produzidos na densidade de 50 peixes/m3. As variáveis eritrocitárias como hemoglobina e hematócrito não apresentaram diferenças estatísticas (P>0,05) para os tratamentos utilizados, porém, o eritrócito total e a glicose diferiram significativamente (P<0,01 e P<0,05, respectivamente) entre as densidades. Concluiu-se que a densidade ótima para o cultivo de piracanjuba em tanques-rede fica entre 58 e 75 peixes/m3
Dahlström, Anna. "Betesmarker, djurantal och betestryck 1620-1850 : naturvårdsaspekter på historisk beteshävd i Syd- och Mellansverige /." Uppsala : Department of Economics, Swedish University of Agricultural Sciences, 2006. http://epsilon.slu.se/200695.pdf.
Full textMiljan, Veljić. "Svetlosni program, gustina naseljenosti i sastav obroka u funkciji proizvodnih parametara,kvaliteta mesa i dobrobiti brojlerskih pilića." Phd thesis, Univerzitet u Novom Sadu, Poljoprivredni fakultet u Novom Sadu, 2016. https://www.cris.uns.ac.rs/record.jsf?recordId=101567&source=NDLTD&language=en.
Full textThe purpose of the research was to investigate the effect of the lighting program (constant – KS and intermittent – ORS), feed density and stocking density and their interaction with production and slaughterhouse characteristics of broiler chicken, meat quality and feet pad damage.The research was conducted on a chicken farm Donji Crnci in the vicinity of Podgorica, in three trials: the first trial focused on effects of the lighting program and feed density, the second on the lighting program and stocking density and the third on the lighting program and the feed density (mixes with standard and increased content of energy and protein, with a constant energy:protein ratio). Each of the trials included 320 chicken of the Cobb 500 hybrid line, mixed sexes; trials lasted for 42 days. In all three trials, four groups were formed with four repetitions and each group included 80 one-day chickens.Production parameters (weight, feed consumption and deaths) were monitored in all trials and feed conversion ratio and production index were calculated. Weight was measured when broilers were 1; 7; 14; 21; 28; 35 and 42 days old. Feed consumption was determined at the end of the use of specific mixes, as follows: 14th day the quantity of starter mix consumed, 35th day the quantity of grower mix consumed and 42nd day quantity of the finisher mix. Mortality rate was determined by recording the number of chicken that died during the trial. Production indices were calculated based on weight, food conversion ratio and mortality.At the end of all trials, at 6 weeks of age, the chickens were measured individually, group averages were calculated and then by random sampling, 20 chicken were taken from each group (10 males and 10 females) in order to analyse slaughter characteristics. Pre-slaughter fasting lasted for 12 hours. After slaughter and cleaning, the carcasses were cooled to 40C over 24 hours and then processed as: “classical processing”, “ready to grill” and “barbecue ready”.In carcass processing, abdominal fat was taken out, weight of processed carcases measured and carcass yield values were obtained. In order to determine the yield and share of the main and secondary parts of the carcass, cooled carcasses were cut out. Evaluation of carcass conformation was done on the basis of absolute measures of the following: metatarsus length, keel length, breast depth and drumsticks circumference. Index representing the ratio of live weight before slaughter and measure observed was used (g/mm).In Trial II, physical examination of bones was done, on femur, upon separation from the broiler skeleton, and in Trial III moisture content, total fat content, total ash content and total protein of white and red meat was determined on samples of muscle tissue of breasts and thighs of 5 male and 5 female carcasses in each of the treatments (20 in total).The results show that lighting program had no statistically significant effect on final body weight in Trials I and II, while in Trial III, higher weights were recorded in chicken fattened under KS. ORS resulted in slowing down of the growth rate in the first fattening period, and as a result of compensatory growth it had no effect on final weights, except in the third trial. Better food conversion ratio in the period of finisher mix diet was achieved by chicken in Trial I under ORS than those under KS, as well as in starter mix diet in Trial III. Lighting program in Trial II had no effect on food conversion ratio and mortality of chicken. Feed density did not have an effect on final weights, feed conversion, mortality and production index. In chicken fed with meals with higher protein and energy content, higher weight was recorded at the end of the fattening period (P<0.01). Feed density in Trials I and III did not have an effect on feed conversion ratio, mortality and production index. Significantly higher weight was recorded in chicken fattened at the stocking density of 12 animals/m2 (2667.08 g) than at the density of 17 animals/m2 (2435.768g) and differences had statistically high significance. No effect of stocking density was identified in terms of feed conversion, mortality and production index.Factors analysed (light, feed density and stocking population) did not have an effect on carcass yield, but interactions of some of them did. In all the trials, a smaller share of abdominal fat was established under ORS than under KS, but it was not statistically significant. Feed density and stocking density had no effect on abdominal fat content. Higher abdominal fat content in all trials was found in female than in male chicken. The share of breasts is larger under KS than under ORS, but differences are statistically significant only in the Trial III. Feed density and stocking density had no effect on the share of breasts in the carcass. The share of drumsticks was higher in chicken fattened under ORS than those under KS, but differences were statistically significant only in the Trial I. The share of thighs in Trials I and II did not differ significantly between lighting programs, while in the Trial III it was higher under ORS than under KS (P<0.01). Effect of stocking density and feed density on the share of drumsticks and thighs was not determined. Higher share of drumsticks was determined in male chicken while in female, the share of thighs was higher.Relative values of conformation measures were not influenced by the light programs and feed density, except that in lower stocking density the relative value of the breast depth was higher (P<0.05). Effect of light and feed density on feet pads damage was not determined, but chicken in higher stocking density, as of 28th day, had significantly higher feet pad damage than those in lower stocking density.Light program and stocking density did not have an effect on physical properties of femur: cross-sectional area, breaking force and specific breaking force. Male chicken had larger cross-sectional area and femur breaking force, differences in cross-sectional area were statistically significant, but this was not the case with the breaking force.Percentage of fat in dark meat was higher and that of proteins lower under ORS than under KS. Other parameters of the chemical analysis of dark and white meat were not under the influence of the light programs. Feed density had no effect on chemical composition of breasts and thighs meat.Based on all stated above, it can be concluded that all three factors (light program, feed density and stocking density) as well as their interactions had effect on numerous production parameters and quality of broiler meat, including on their welfare in different fattening phases. Taking into account enormous differences in effects that may be achieved in different combinations of these factors, the results of these and similar researches should make easier the selection of the technology that would yield the best economic effects in chicken fattening. Furthermore, where results are unclear or contradictory, further research should be conducted on a larger number of animals and focus on economically more significant production and slaughterhouse characteristics of chicken.
Vaz, Luciano Jensen. "Produção e transporte do camarão rosa Farfantepenaeus brasiliensis para a pesca amadora: uma alternativa sustentável?" Universidade Federal de São Carlos, 2012. https://repositorio.ufscar.br/handle/ufscar/1785.
Full textFinanciadora de Estudos e Projetos
As well as being popular and growing worldwide, sport fisheries are considered an important recreational, economic and social activity that propels a wide production chain and generates employment and income. The major species of marine shrimp used as live bait in the Brazilian coast used as live bait in sport fishing are: white shrimp Litopenaeus schmitti and pink shrimp Farfantepenaeus brasiliensis and Farfantepenaeus paulensis, all of them included in the list of overexploited species. Although the shrimp are caught in estuaries throughout the year, the main period of capture occurs in the summer months. This fact produces significant fluctuations in the catch throughout the year, occurring in situations that greatly reduced catches. In view of these facts, the cultivation of shrimps for bait production could become an important tool for conservation and regulation of the market for live bait. Thus, the studies that comprise this thesis were directed to the production of pink shrimp F. brasiliensis in biofloc system and management studies related to transportation of shrimp as live bait. From the results observed in thesis, it was observed that there is already a well established method for the production of post-larvae of F. brasiliensis this phase is not an obstacle for the production of live bait. Furthermore, the results show that F. brasiliensis has a potential for the cultivation in biofloc system and can be reared in a stocking density of up to 100 shrimp/m² during the nursery stage and in a density of up to 75 shrimp/m² during the grow-out phase. Finally, it was observed that for the transport of F. brasiliensis the water temperature should be between 16 and 19 °C and stocking density should not exceed 3 shrimp / L or (16.5 g / L), the transport is recommended for a maximum of 10 hours to prevent mortality. Therefore, according to all data obtained in this thesis, post-larvae production, cultivation in biofloc system and transportation of F. brasiliensis to be used as live bait proved to be technically viable solutions to meet the needs of sport fisheries.
Além de popular e crescente no mundo todo, a pesca amadora é considerada uma importante atividade recreativa, econômica e social que movimenta uma ampla cadeia produtiva gerando emprego e renda. As principais espécies de camarões marinhos nativos da costa brasileira utilizados como isca viva na pesca amadora são: o camarão-branco Litopenaeus schmitti e os camarões-rosa Farfantepenaeus brasiliensis e Farfantepenaeus paulensis, todas incluídas na lista de espécies sobre-explotadas. Embora os camarões sejam capturados em estuários ao longo de todo o ano, o principal período de captura ocorre nos meses de verão. Este fato produz flutuações significativas na captura ao longo do ano, ocorrendo situações em que as capturas diminuem muito. Em vista destes fatos, o cultivo de camarões para produção de iscas vivas pode vir a ser um importante instrumento para a conservação e para regulação do mercado de isca viva. Portanto, os estudos que compõem esta tese foram direcionados para a produção do camarão-rosa F. brasiliensis em sistema de bioflocos e para estudos de manejo relacionados ao transporte destes camarões como isca viva. A partir dos resultados observados na tese, pode se verificar que já existe uma metodologia bem estabelecida para a produção de pós-larvas de F. brasiliensis não sendo esta fase um obstáculo para a produção de isca viva. Além disso, os resultados mostraram que F. brasiliensis apresenta um potencial para o cultivo em sistema de bioflocos podendo ser cultivado na densidade de estocagem de até 100 camarões/m2 durante a fase de berçário e até 75 camarões/m2 durante a fase de engorda. Por último, observou-se que para o transporte de F. brasiliensis a temperatura da água deve estar entre 16 e 19 °C e a densidade de estocagem não deve ultrapassar os 3 camarões/L ou (16,5 g/L), sendo recomendado o transporte por no máximo 10 horas para evitar mortalidades. Portanto, de acordo com os dados obtidos na presente tese, a produção de pós-larvas, o cultivo em sistema de bioflocos e o transporte de F. brasiliensis para a comercialização na forma de isca viva para suprir as necessidades da pesca amadora demonstrou ser tecnicamente viável.
Queiroz, Livia Maria Soares. "Análise de densidades de alojamento nos sistemas convencional e cage-free de produção de ovos comerciais." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/10/10135/tde-13042018-105108/.
Full textInnovation in animal production has been increasingly demanded by consumers. In the field of egg production, the greatest demand is for eggs coming from alternative systems to traditional cages, mostly from the trends observed in Europe, and thus, research highlighting the Brazilian reality is being carried out. The objective of this study was to evaluate productive and welfare parameters in two contexts of productive systems, under different stocking densities. For this purpose, 250 Lohmann Brown® birds were distributed in a completely randomized design with treatments arranged in a 2 x 4 factorial scheme, with 2 housing systems (conventional and cage-free) and 4 densities (375.00; 450.00, 562.50 and 750.00 cm2 / bird), with 6 replicates. The experimental period was 21 to 36 weeks of age, totalling 4 cycles of 28 days each. (Egg weight, feed intake, feed conversion per kg of egg), egg quality (weight, yolk color, yolk index, % yolk,% albumen,% shell, shell thickness and resistance to breakage, and Haugh unit) and indicators of welfare (respiratory rate and heart rate, body temperature, body lesion score, IgY concentration in the yolk). The interaction between production system and housing density was observed for: % laying, feed intake , feed conversion per kg of eggs, egg weight, % yolk, % albumen, shell thickness. The increase in density had a significant effect on % laying, feed intake, cloacal temperature, keel and foot injury. The type of production system affected feed intake, feed conversion per kg of egg, egg weight, yolk color, yolk index, breaking strength, cloacal temperature, keel and foot lesions, and IgY concentration in the yolk. The results of this study demonstrate that both the production system and housing density are linked to productive effects, egg quality, and animal welfare.
Silva, Wilton Ladeira da [UNESP]. "Morfogênese, características estruturais e acúmulo de forragem em pastos de capim-Tifton-85 manejados com diferentes IAF residual." Universidade Estadual Paulista (UNESP), 2010. http://hdl.handle.net/11449/96545.
Full textConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
A produção de forragem é influenciada pelas estratégias de manejo impostas a ela, desta maneira, as técnicas para identificação do melhor momento para início e término do pastejo, aliadas aos estudos das características morfogênicas e estruturais das plantas, tornam-se úteis para direcionamento do manejo, pois buscam auxiliar no melhor entendimento do crescimento vegetal, e por conseqüência, da produção forrageira. O experimento foi realizado no setor de Forragicultura, em área pertencente à FCAV da UNESP – Jaboticabal no período de dezembro de 2008 a abril de 2009, com o objetivo de avaliar o efeito de índices de área foliar residual (IAFr) sobre as características morfogênicas e estruturais, além do acúmulo de forragem em pastos de Cynodon spp cv Tifton-85 sob regime de lotação rotacionada com ovinos. Os tratamentos foram constituídos por três IAFr, 2,4, 1,6 e 0,8, mantidos por regime de lotação rotacionada com ovinos. O delineamento experimental utilizado foi o de blocos completos casualizados em arranjo de parcelas subdivididas no tempo com sete repetições, totalizando 21 unidades experimentais. Foram avaliadas nas condições de pré e pós-pastejo, as alturas do dossel, os IAF e a massa de forragem, além da taxa de acúmulo de forragem e as características morfogênicas e estruturais dos pastos. No pré e pós-pastejo as alturas médias e o IAF do dossel se comportaram de forma análoga, decrescendo com a diminuição dos IAFr. O maior valor de interceptação luminosa no pós-pastejo (68,19%), foi verificado para o IAFr 2,4 e o menor valor (35,57%) para o IAFr 0,8. A taxa de aparecimento de folhas foi maior para o dossel mantido sob IAFr 0,8 em função da sua menor taxa de alongamento de colmos (0,51 cm/perfilho.dia). Os pastos mantidos sob IAFr 0,8 apresentaram maior densidade populacional de perfilhos. A massa de forragem seca...
The production of forage is influenced by handling strategies imposed on the techniques to identify the best moment for the beginning and ending of grazing, linked to the studies of morphogenetic and structural characteristics of plants, become useful tools for the directing of management for they aim to aid the best understanding of vegetal growth, and as consequence, forage plants. The experiment was conducted at Setor de Forragicultura at Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal, at UNESP – Jaboticabal from December 2008 to April 2009, and aimed to evaluate the effect of residual leaf area index (LAIr) about the morphogenical and structural characteristics, and forage accumulation in pastures of Cynodon spp cv Tifton-85 in a rotational stocking system with sheep. The treatments were constituted by three LAIr, 2,4, 1,6 e 0,8, maintained by rotational stocking with sheep. A complete randomized block design was used arranged in sub-divided parcels with seven replications, totaling 21 experimental units. They were evaluated in pre and post-grazing conditions, the height of the sward, LAI and forage mass, besides the accumulation of forage rate and the morphogenetic and structural characteristics. In the pre and post-grazing, the average height and the LAI of sward, decreasing with the diminishing of LAIr. The biggest value of light interception in post-grazing (68,19%), was verified by LAIr 2,4 and the smallest value (35,57%) for LAIr 0,8. The stem elongation rate (0,51 cm/tiller.day). The grazing maintained by LAIr 0,8 had higher tiller population density. The total dry forage mass was 27,1% superior for LAIr 2,4 regarding to LAIr 0,8 in pre-grazing conditions, being this total production, 72,0% was composed by stem fractions and dead material. The biggest rates of dry matter accumulation were observed with LAIr 2.4, in the second and third grazing cycles... (Complete abstract click electronic access below)
Hansen, Per. "Potentiell koppling mellan elektrolys och landbaseradfiskodling : En analys av behov och tillgång på syrgas och värme." Thesis, Högskolan i Gävle, Miljövetenskap, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-36512.
Full textThere will be a major expansion of electrolysis for production of hydrogen in Sweden and the rest of the world. To reduce production costs and thus make hydrogencheaper, this report analyzes how much oxygen and heat a fish farm consumes andtherefore would need to buy from an electrolyser. The analysis shows that the species used in the study - tilapia (Oreochromis, Oreochromis, Alcolapia), rainbow(Oncorhynchus mykiss) and salmon (Salmo salar) - in a farm that produces 40 tonsof fish per year would consume 1.16 percent of the oxygen and 0,35 percent of theheat produced from a 3 MW PEM electrolyzer. The value of the oxygen and theheat from a 3 MW electrolyser is calculated at SEK 694,939/year for the oxygenand SEK 1,829,813/year for the heat. The average cost for the species in the studyin a 40 tonne/year fish farm is calculated at SEK 8,900/year for the oxygen and SEK6,400/year for the heat in a land-based fish farm.
Reis, L?gia Garcia. "Efeito da salinidade, densidade de estocagem e da infec??o hipodermal e necrose hematopoi?tica (IHHN) na imunidade do camar?o Litopenaeus vannamei cultivados em fazendas do Rio Grande do Norte." Universidade Federal do Rio Grande do Norte, 2008. http://repositorio.ufrn.br:8080/jspui/handle/123456789/13044.
Full textThe main problem faced by the shrimp industry are the infectious diseases. The hypodermal and hematopoietic necrosis infection (IHHN) is one of the major cause of disease in the cultured shrimp, Litopenaeus vannamei. Environmental changes involving water quality, oxygen concentration, salinity, temperature, stocking density, presence of pathogens, among others, triggering a stressing condition for the cultured shrimp, weakening them and allowing the outbreak of diseases. The stress on the animal leads to a change in the molecules immune response components, which can be used as indicators of shrimp health. Thus, the objective of the present study was to evaluate the effect of salinity, stocking density and IHHNV infection on the L. vannamei shrimp. The immune parameters used to check the shrimp health were the total hemocytes counts (THC), the agglutinating activity (AA) and the clotting time (CT) of the serum of shrimp. These parameters were analyzed in healthy and IHHNV-infected shrimp, grown in low (0-0.5 ), medium (19-24 ) and high (> 38 ) salinity, and extensive (7-12 cam.m-2), semi-intensive (15-25 cam.m-2) and intensive (33-45 cam.m -2) stocking density. The IHHNV infection rate was significantly higher in low salinity (P<0.005) and intensive density (P<0.005), both stressful conditions for L. vannamei. Low salinity significantly increased THC (P<0.05) and decreased and CT (P<0.05) in healthy and infected shrimp, but AA (P<0.05) significantly decreased in healthy shrimp at medium salinity. Culture intensification did not affect the THC, AA and CT of healthy and infected shrimp (P>0.05). The IHHNV infection did not affect any immune parameters of shrimp cultured at different salinities and stocking densities. It is necessary to emphasize that this study was conducted in shrimp grown in ponds, where several environmental factors are acting simultaneously. Thus, further studies are needed about the influence of other environmental factors on the immune parameters of shrimp cultured in pond
O principal problema enfrentado pela ind?stria do camar?o s?o as enfermidades de origem infecciosa. A Infec??o Hipodermal e Necrose Hematopoi?tica (IHHN) ? uma das principais causas de doen?as no camar?o de cultivo Litopenaeus vannamei. Altera??es do ambiente de cultivo envolvendo qualidade da ?gua, concentra??o de oxig?nio, salinidade, temperatura, densidade de estocagem, presen?a de pat?genos, entre outros, desencadeiam uma situa??o de estresse nos camar?es cultivados, debilitando-os e permitindo a instala??o de enfermidades. O estresse desencadeia no animal a altera??o de mol?culas componentes da resposta imune, que podem ser usadas como indicadores de sa?de do camar?o. Desta forma, o objetivo do presente trabalho foi avaliar o efeito da salinidade, densidade de estocagem e infec??o pelo IHHNV na imunidade do camar?o de cultivo L. vannamei. Os par?metros imunes utilizados para monitorar as condi??es de sa?de dos camar?es foram o n?mero total de hem?citos (THC), a atividade aglutinante (AA) e o tempo de coagula??o (TC) dos soros dos camar?es. Estes par?metros foram analisados em camar?es saud?veis e infectados pelo IHHNV, cultivados em baixa (0-0,5 ), m?dia (19-24 ) e alta (>38 ) salinidades e em extensiva (7-12 cam.m-2 ), semi-intensiva (15-25 cam.m-2) e intensiva (33-45 cam.m-2) densidades de estocagem. A taxa de infec??o pelo IHHNV foi significativamente maior em baixa salinidade (P<0,005) e na densidade intensiva (P<0,005), ambas condi??es estressantes para o L. vannamei. Baixa salinidade significativamente aumentou THC (P<0,05) e diminuiu TC (P<0,05) de camar?es saud?veis e infectados, mas AA (P<0,05) de camar?es saud?veis diminui significativamente na m?dia salinidade. A intensifica??o do cultivo n?o afetou THC, AA e TC de camar?es saud?veis e infectados (P>0,05). A infec??o pelo IHHNV n?o afetou nenhum dos par?metros imunes dos camar?es cultivados nas diferentes salinidades e densidades de estocagem. ? necess?rio enfatizar que o presente estudo foi realizado em camar?es cultivados em viveiros, onde v?rios fatores ambientais est?o atuando simultaneamente. Desta forma, s?o necess?rios estudos adicionais sobre a influ?ncia de outros fatores ambientais nos par?metros imunes de camar?es nas condi??es de cultivo
Franco, Sofia Cota. "Effects of stocking density on A. tonsa (Copepoda: Calanoida) culture." Master's thesis, 2009. http://hdl.handle.net/10400.1/435.
Full textA nutrição é um elemento chave na larvicultura marinha e pesquisas recentes têm demonstrado as vantagens do uso de copépodes como alimento vivo. Acartia tonsa é uma espécie de copépode calanóide com elevado potencial de cultivo, mas cuja densidade de cultivo permanece como uma das principais restrições à sua futura produção comercial. Como tal, este estudo recorreu a uma abordagem integrada com vista a avaliar os efeitos da densidade de cultivo no crescimento, produção de ovos e sucesso de eclosão em A. tonsa. Verificou-se que o uso de densidades elevadas (6000 cop l-1) não apresenta efeitos deletérios no crescimento e desenvolvimento de copépodes, embora a mortalidade aumente significativamente, de ≤2.5 % d-1 a densidades de ≤1000 cop l-1 para 3.5-4.0 % d-1 a 3000-6000 cop l-1. A produção individual de ovos também diminuiu com o aumento da densidade, registando-se uma produção de 28.4±1.43 ovos fêmea-1 d-1 a densidades de 100 cop l-1 e de 7.13±0.61 ovos fêmea-1 d-1 a 2500 cop l-1. Para mais, registou-se um atraso na eclosão de ovos produzidos por adultos criados em culturas densas (500-2500 cop l-1), bem como ovos incubados a densidades elevadas (1.000.000 eggs l-1). Apesar dos efeitos negativos da densidade na sobrevivência, produção de ovos e sucesso de eclosão, a magnitude destes efeitos não compromete a produção a altas densidades. Pesquisas futuras deverão focar-se no melhoramento de sistemas de produção e metodologia de armazenamento de ovos, bem como nos processos que controlam a diapausa, já que a capacidade de produzir copépodes calanóides em larga escala representaria um avanço significativo no cultivo larvar de espécies marinhas.
Nutrition is a key element in marine larviculture and the use of copepods as live feed for marine fish larvae has been shown to have several advantages over traditional live preys. Acartia tonsa is a calanoid copepod with high culture potential, although culture stocking density remains a bottleneck to its future commercial production. Considering this, the present study took an integrated approach to provide further insight on the effects of A. tonsa stocking density on growth, egg production and hatching success. Increased stocking densities (6000 cop l-1) were shown to have no unfavorable effect on copepod growth and development. Nevertheless copepod mortality significantly increased with density, from ≤2.5 % d-1 at densities of ≤1000 cop l-1 to 3.5-4.0 % d-1 at 3000-6000 cop l-1. Individual egg production rate also decreased at higher stocking densities, with an egg production of 28.4±1.43 eggs female-1 d-1 at 100 cop l-1 and of 7.13±0.61 eggs female-1 d-1 at 2500 cop l-1. Delayed hatching was observed for eggs produced by adults grown in dense cultures (500-2500 cop l-1) and for eggs incubated at increased hatching densities (1.000.000 eggs l-1). In spite of the negative effect of stocking density on survival, egg production and hatching success, the magnitude of these effects does not compromise the profitable use of high density cultures. Future research should focus on the improvement of production systems and egg storage, as well as investigating the processes controlling egg diapause, since the ability to rear calanoid copepod species at large scale would present a major advancement in larviculture of marine fish species.
Lu, Wen Jie, and 盧文杰. "Effects of stocking density on kuruma prawn, penaeus japonicus, growout ecosystem." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/33044547119841972532.
Full textCHEN, QIU-JIN, and 陳秋錦. "The effects of stocking density on tiger prawn (Penaeus monodon) growout systen." Thesis, 1990. http://ndltd.ncl.edu.tw/handle/47423486168736101226.
Full text"INTERACTION OF ALCALINITY AND STOCKING DENSITY FOR SILVER CATFISH Rhamdia quelen JUVENILES (HEPTAPTERIDAE)." Tese, Biblioteca Digital de Teses e Dissertações da UFSM, 2005. http://coralx.ufsm.br/tede/tde_busca/arquivo.php?codArquivo=25.
Full textWu, Chen-Yu, and 吳鎮宇. "Farming and Economics of Chinese mitten crab (Eriocheir sinensis) in Stocking Density in Taiwan." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/9pt72j.
Full text國立臺灣海洋大學
水產養殖學系
105
This research will focus on the Chinese Mitten Crab industry in Taiwan and take a closer look at the issues to search the key factor of the development. As a reference for industry development. Study the biological and economic information for the farming process by questionnaire survey, and apply a statistical theory to analysis. The results show that the average stocking density of the Chinese mitten crabs in Taiwan was 1,996 crabs/ha. The average culture cycle was 7.9 month and the average surival rate was 28.2%. According to the view of productice economics, the average cost about NTD 145,529 per ha, and NTD 208,495 per ha in stocking density≧2,500 crabs per ha as the cost highest and stocking density <1,500 crabs per ha as the cost lowest about NTD 107,931 per ha. The labor costs( NTD 92,279 per ha) was the major production in the unit costs of input and the feed cost( NTD 26,407 per ha) followed. Based on the profitability, the average total revenue was NTD 233,526 per ha, and NTD 87,997 per ha in net revenue. The benefit-cost ratio was 2.00. Overall, the profitability was highest at the stocking density 1,500~2,499 per ha (2.40) and the stocking density≧2,500 per ha 1.72 was lowest. The Chinese Mitten Crab industry in Taiwan development main problem is poor survival rate and poor management of farming costs. Decision on optimal stocking densities, improvements in farming technology, effective management of farming costs and establishmet of standard operating procedures for the Chinese mitten crabs farming. As the development to enhance the competitiveness of the Chinese Mitten Crab industry in Taiwan.
Ssu, Kuo-Wei, and 斯國威. "Effect of Stocking Density on the Hog Performance and Validation of a Pig Growth Model." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/09377690521007262916.
Full textTSAI, JIN-FENG, and 蔡金峯. "The effects of Stocking Density and Feeding Frequency on Cannibalism in Epinephelus lanceolatus×Epinephelus fuscoguttatus." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/k578g5.
Full text國立高雄海洋科技大學
水產養殖研究所
106
The study aims to develop the techniques for larvae rearing of Brindle Grouper (Epinephelus lanceolatus × Epinephelus fuscoguttatus) and investigate the effects of stocking density and feeding frequency on cannibalism. In experiment one, the effects of stocking density on survival, percent weight gain, feed intake, size heterogeity and cannibalism were examined. Six experiment groups were cultured for one week at different densities: 5 fish/L, 10 fish/L, 20 fish/L, 30 fish/L, 40 fish/L and 50 fish/L. The fishes were fed four times daily (6:00,10:00,15:00,19:00) to satiation. In experiment two, the effects of feeding frequency on survival, percent weight gain, feed intake, size heterogeity and cannibalism were examined. Four experiment groups were cultured for one week at same 40 fish/L density and were fed at different frequencies to satiation: 2 meals per day (6:00, 15:00), 4 meals per day (6:00,10:00,15:00,19:00), 6 meals per day (6:00, 9:00, 12:00, 15:00, 18:00, 21:00) and 8 meals per day (6:00, 8:00, 10:00, 12:00, 14:00, 16:00, 18:00, 20:00). The result suggests that rearing the larvae at 40 fish/L stocking density and 4~6 meals feeding frequency with a standard rearing operating procedure will reduce the cannibalism and increase the survival. It could improve the operating efficiency and facilitate the long term sustainability of the industry.
Huang, Wen-Bin, and 黃文彬. "The Effect of Stocking Density on Growth, Survival, and Size Variation of Fry: Common Carp and Tilapia." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/66826755745944340059.
Full textShiau, Jyh-Yeuan, and 蕭智遠. "Effects of stocking density and feeding pattern on growth and survival of the hard clam, Meretrix lusoria." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/94874133119860487323.
Full text國立臺灣海洋大學
環境生物與漁業科學學系
101
In this study, two data-collection methods were used to examine the effects of different stocking density and feeding pattern on the growth and survival rate of the hard clam, Meretrix lusoria. The first method is artificial feeding, and the second is questionnaire. Two artificial feeding experiments were conducted. Experiment one is to examine the effects of three different stocking densities (80, 120 and 200 clam/m2) and two different feeding methods (artificial feed and algae water). Experiment two is to examine the effect of five different stocking densities (80,120, 200, 280 and 360 clam/m2) in fed water algae. The questionnaire was divided into three parts. The first part contains the farming experience, breeding pool age, breeding pool size, stocking size, sediment concentration, stocking density, feeding time, and the bottom sand layers drainage system. The second part contains the mixed breeding species and density mixed breeding. The third part contains the feeding category and feeding amount. The Multiple Regression Model was used to examine the effects of various factors on the growth and survival of the hard clam. According to the experimental results of artificial feeding, stocking density effect on growth rates was not significant (p>0.05). The first experimental results of two feeding modes, the AGR (shell length and weight) and the survival rate has significant difference, showed a better effect of feeding algae water for the hard clams. The results of multiple regression analyses indicated that the feeding with algae water, bottom sand layers drainage system were positively correlated to the growth rate. While, farming experience was negatively correlated to the growth rate. The species mixed breeding had no significant effect on growth. In addition, the pond size was positively correlated to the mortality rate but feeding with algal water was negatively correlated to the mortality rate. Both experiments and questionnaire indicated that stocking density had no significant effect on the growth rate of the hard clams, but feeding with algae water can promote the growth of the hard clams.
Suabulu, Andrew Gray, and 安德魯. "The effect of stocking density and feeding frequency on the growth performance of juvenile white shrimp (Litopenaeus vannamei)." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/57400957409599888758.
Full textLigaraba, Tshililo Joyce. "Effects of strain, stocking density and limited-time feeding on growth performance and carcass characteristics of broiler chickens." Diss., 2016. http://hdl.handle.net/11602/389.
Full textManriquez-Hernandez, Juan A. "INTERACTION OF IRRADIANCE AND STOCKING DENSITY ON NUTRIENT UPTAKE BY RED MACROALGAE. IMPLICATIONS FOR BIOREMEDIATION OF FISH FARM EFFLUENTS." 2013. http://hdl.handle.net/10222/38441.
Full text"Maximizing net income for pork producers by determining the interaction between dietary energy concentration and stocking density on finishing pig performance, welfare, and carcass composition." Thesis, 2014. http://hdl.handle.net/10388/ETD-2014-11-1846.
Full textSiaga, Rudzani. "Effects of stocking density, genotype and sex on the growth performance and carcass characteristics of Ross and Cobb broilers chickens." Diss., 2015. http://hdl.handle.net/11602/819.
Full textHengsawat, Khwuanjai. "The effect of stocking density on production, growth and mortality of African catfish (Clarias gariepinus Burchell 1822) cultured in cages." 1993. http://hdl.handle.net/1993/29381.
Full textLin, Hsiao-Lun, and 林孝倫. "The Effect of Body Size and Stocking Density on Ammonia Excretion Rate and Oxygen Consumption Rate of Haliotis diversicolor supertexta." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/85531177935740893406.
Full text國立臺灣海洋大學
水產養殖學系
93
The experiment was undertaken to study the effect of body size and stocking density on ammonia excretion rate and oxygen consumption rate for Haliotis diversicolor supertexta. Three size of abalone (mean shell lengths: 3.5、5、7 cm) combined with different stocking density were reared in a small recirculating culture system maintained at 24-25℃. Ammonia excretion rate (MB (NH4)) and oxygen consumption rate (MB(DO)) were measured for three days continuously in order to found the relationship between specific ammonia excretion rate (S(TAN)), specific oxygen consumption rate (S(OUR)), BW (g) and D (abalone/m3). Abalone showed a diurnal cycle regular pattern in S(TAN) and S(OUR). Ammonia-N concentration was found varied in a range of 1.3~34.8 μg/L. S(TAN) of diurnal change varied in a range of 136.3~567.1 %. The oxygen concentration ranged 4.35~6.13 mg/L and S(OUR) of diurnal change ranged 128.0~363.5 %. Average S(TAN) by shell lengths (3.5、5、7 cm) were 4.16±0.8、2.7±0.3 and 2.4±0.3 mg/kg/hr. Means of S(OUR) were 284.5±55.4、247.8±14.7 and 212.0±8.9 mg/Kg/hr. The result concluded that the highest S (OUR) (S (H-OUR)) (mg/kg/hr), lowest S (OUR) (S (L-OUR)), means of S (OUR) (S (M-OUR)), density (D) (abalone/m3) and BW (g) is as following : S (H-OUR)= 624.9671-0.7503D-10.8926BW+0.0201BW×D R2 = 0.9177 S (L-OUR) =140.8128+0.0057BW×D R2 = 0.3504 S (M-OUR)= 415.9542-0.5095D-7.0676BW+0.0189BW×D R2 = 0.7214 On the other hand, the highest S (TAN) (S (H- TAN) ) (mg/kg/hr), the lowest S (TAN) (S (L-TAN)), the means of S (TAN) (S (M- TAN)), density (D) (abalone/m3) and BW (g) is as following : S (H-TAN)= 7.9748-0.000016D2-0.2814BW +0.0028BW2+0.0003BW×D R2= 0.8217 S (L-TAN4)= 1.2507+0.0272D-0.00008D2-0.1822BW+0.0006BW×D R2= 0.5781 S (M-TAN)= 5.5495-0.00002D2-0.1841BW+0.0004BW×D R2= 0.7114
Meng-Fang, Tsai, and 蔡孟芳. "The effects of different dietary seaweed sources and different stocking density on the growth and survival of juvenile Litopeaneus vannamei." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/38824647899784898842.
Full text國立臺灣海洋大學
水產養殖學系
94
Abstract This study investigated the effects of different stocking density and dietary seaweed sources on the growth and survival of juvenile Litopeaneus vannamei. Experiment I was conducted to evaluate the effects of stocking density on the growth and survival of juvenile Litopeaneus vannamei. Six different stocking densities (27.77 PL/m2 、55.55 PL/m2、88.33 PL/m2、111.11 PL/m2、138.88 PL/m2 and 166.66 PL/m2) of white shrimp were fed semi-purified diet (35% C.P and 6% crude lipid) for six weeks and detected ammonia every other day. After six weeks, the weight gain of white shrimps stocked with 27.77 PL/m2 was significantly higher than those of stocked with other densities. Survival of all treatments were above 80%. Experiment II was conducted to evaluate the effects of sources and levels of seaweed meal of hot-water extract on the dietary water stability and growth and survival of juvenile Litopeaneus vannamei. The semi-purified diets contained 3%、6% and 9% hot-water extract of dry powder of Ulva and Gracilaria, respectively. Diet, without hot water extract of dry powder of Ulva and Gracilaria was used as control. White shrimp fed control diet had the highest weight gain (805.6±48.7%), followed by shrimp fed with diet containg 6% Gracilaria (798.6±176.6%), and the lower weight gain of shrimp fed diet with 3% Ulva (721.9±99.2%). Survival of all treatments were above 93%. After four hours of water stability test, the control diet had the highest water stability 89.0% and diet with 6% Ulva had the lowest water stability. Experiment III was conducted to evaluate the effects of dietary seaweed on the dietary water stability and growth and survival of juvenile Litopeaneus vannamei. The semi-purified diet (35% C.P and 6% crude lipid) contained 6% of Ulva meal、Gracilaria meal、alginate、agar and carrageenan, respectively. The shrimps fed diets containing alginate and Ulva meal had the highest weight gain and those fed diet containg agar had the lowest weight gain. The diet containing Gracilaria meal had lower survival 50%. The water stabilities of diets containg agar and alginate were 92.6% and 92.2%, respectively.
Rubio, Zuazo Ana Maria. "Environmental influences on the sustainable production of the Sydney rock oyster Saccostrea glomerata : a study in two southeastern Australian estuaries." Phd thesis, 2007. http://hdl.handle.net/1885/49349.
Full textLY, Mouhamadou Amadou, and 李茂達. "The effects of feeding frequency, stocking density and fish size on growth, feedingbehavior and body composition of juveniles grouper, Epinephelus coioides." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/14538633155300653783.
Full text國立臺灣海洋大學
水產養殖學系
93
Two experiments were conducted on juvenile grouper Epinephelus coioides. Experiment 1 deal with the effects of feeding frequency, stocking density and fish size on growth and feeding behavior. The effect of feeding frequency, stocking density and fish size on body composition, growth, ammonia excretion, digestibility and feeding behavior were examined in experiment 2. Feeding frequency had positive effects on food consumption, growth and final size variation. Fish fed three times per day in both experiments showed better food consumption, but fed one meal per day in the 2nd experiment had better food conversion rate. In both experiments, fish size variation decreased with increasing feeding frequency and fish fed fewer meals per day tend to eat more per meal. Fish fed once daily had heavier stomach than from other groups. Fish fed three times daily had the highest body lipid content. Feeding frequency had no effect on apparent digestibility coefficient on grouper. Our result showed that a peak of ammonia excretion occurs 4 hours after the first feeding session. Increased feeding frequency to two or three lead to a cumulative effect of ammonia excretion. The low-density group had the highest food consumption as compared to medium and high densities in experiment 1. Fish stocked at high density had higher moisture content, stomachosomatic index, gut relative weight and condition factor. In experiment 1, the small size fish had higher size variation index compared to big size fish and had lower survival rate than medium and big fish. Our result indicated that fed three-time/ day for grouper grown from 10 to 30 g and one meal a day for the fish grown from 31 to 88 g, respectively and stocked at high density is recommended. Keywords: feeding frequency; stocking density; fish size; growth; body composition; feeding behavior; grouper.
Cai, Qiao-Xin, and 蔡喬欣. "Effects of stocking density, water exchange rate, photosynthetic bacteria (Rhodobium orientis) and algal addition on growth, survival and water quality of giant freshwater prawn ( Macrobrachium rosenbergii)." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/sj29rd.
Full text國立東華大學
海洋生物多樣性及演化研究所
100
Macrobrachium rosenbergiis the world's breeding the highest amount of one of three prawns, but still need to improve the environment in shrimp nurturing and strengthening the management. To determine the optimal condition for larval culture of this speices, the effects of stocking density, water exchange rate, photosynthetic bacteria and algal addition on growth, survival and water guality of juveniles were assessed. Photosynthetic strains used the 16SrDNA sequence analysis and results confirm for Rhodobium sp. First, the effects of the photosynthetic bacteria (Rhodobium sp.) at concentrations of 0, 103, 104, 105, 106and 107cells mL-1 on the M. rosenbergii juvenile survival rate is recorded using a control tank with unchanged water and lacking photosynthetic bacteria and algae. The effect on the juvenile freshwater prawn is then calculated with variables such as density of prawn present at 7, 10, 13 and 16 juveniles L-1 and variations of photosynthetic bacteria. 0 juveniles L-1 is control. The effect on the juvenile freshwater prawn is calculated with different treatments are zero-exchange ,change water and gain photosynthetic bacteria. The results indicate that Rhodobium sp. had significantly higher survival rates in tanks with concentrations the other groups than those in the 0 and 103 cells mL-1 tanks (p<0.05); the growth rates in the103 cells mL-1 tanks had significant (p<0.05). The seven groups in NH3-N, NO2-N, NO3 -N, PO4-P had no significant differences (p>0.05). The 7 juveniles L-1 also had significantly higher survival rates in the tanks with 13 and 16 juveniles L-1 tanks (p<0.05); the growth rates had no significant differences (p>0.05). The water quality present in the 0 tanks had lower levels of NH3-N, NO2-N, NO3 –N and PO4-P (p<0.05). The survival rates in the zero-exchange and change water were not significant (p>0.05); the growth rates in the treatments had no significant differences (p>0.05). The water quality present in the NH3-N had no significant differences (p>0.05); PO4-P and NO3 -N in the change water had lower significant(p<0.05)and NO2 -N in the zero-exchange had higher significant(p<0.05). This report indicates that the tanks prosper best with a concentration of R. orientis at 104 ~ 107 cells mL-1and juvenile prawns densities of 7 juveniles L-1; zero water exchange in the tank with photosynthetic bacteria and algal can maintain a stable.
Wang, Ying-Wei, and 王英偉. "The Treatment and Rense of Culture Pound Water-The Specific Ammonia-N Production Rate and Specific Oxygen Consumption Rate for Eel Culture with Various Size and Stocking Density." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/26210342554516031949.
Full textYip-Hoi, Trevor Andrew. "An investigation of effects of dissolved oxygen level, sediment type, stocking density and predation on the growth rate, survivorship, and burrowing behavior of juvenile brown and white shrimp." 2003. http://www.lib.ncsu.edu/theses/available/etd-05262003-125224/unrestricted/etd.pdf.
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