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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.
11

Proteção antioxidante do colostro bovino em células intestinais de juvenis de pacu (Piaractus mesopotamicus) submetidos a estresse / Antioxidant protection of bovine colostrum on intestinal cells of juvenile pacu (Piaractus mesopotamicus) submitted to stress

Mariana Caroline Furian Pontin 11 May 2018 (has links)
O estresse causa modificações no epitélio intestinal, tais como o aumento de células caliciformes e da taxa de apoptose. O uso de alimentos nutracêuticos tem sido uma alternativa para amenizar essas modificações sobre o tecido epitelial. Desta forma, este trabalho teve como objetivo avaliar se a inclusão de colostro bovino, o qual é constituído de fatores antioxidantes, imunes e de crescimento, seria capaz de amenizar as consequências do estresse crônico sob o intestino. Para isso, juvenis de pacu (Piaractus mesopotamicus) adensados a 50 kg/m3 foram alimentados duas vezes ao dia até a saciedade com ração peletizada e semi-purificada sem (0%CBL) e com a inclusão de colostro bovino liofilizado em concentrações crescentes (10, 20 e 30%CBL), (n=4). Após 28 dias, foram coletados segmentos do intestino médio, S1 e S2, e reto. Os tecidos foram marcados com corantes histológicos para a quantificação de células caliciformes contendo mucinas neutras, ácidas (incluindo sialo e sulfomucinas) e ácidas-neutras. Também foram mensurados o volume (Vv) e a densidade da superfície (Sv) da mucosa, por análise estereológica, e a espessura da camada muscular. A razão do número de cada tipo e subtipo de célula caliciforme sobre o Vv e Sv foi calculada para estimar a densidade de células caliciformes, Dv e Ds, respectivamente. A taxa apoptótica foi analisada qualitativamente através da intensidade (alta, média e baixa) da imunomarcação da caspase-3 nas células epiteliais. As dietas não influenciaram os parâmetros zootécnicos analisados (P>0,05). No reto, os grupos que receberam 20 e 30%CBL apresentaram menor número de células caliciformes contendo sulfomucinas e menor Ds em relação a 0 e 10% (P=0,0148 e 0,0198, respectivamente). No RT, Dv total e Dv de células caliciformes contendo mucinas ácidas foi maior em 0 e 30%CBL em relação a 20%CBL (P=0,0155 e 0,225, respectivamente). No S1, 10 e 30%CBL apresentaram maior Dv em relação a 20%CBL (P=0,0540). A espessura da camada muscular, o Vv e a Sv não diferiram entre os tratamentos (P>0,05). No S2 e RT, a taxa de apoptose teve relação inversa à concentração de colostro bovino liofilizado adicionado na ração. Nos três segmentos, houve maior proporção de células caliciformes contendo mucinas ácidas do que neutras, sendo a maioria representada por sulfomucinas. Assim, a inclusão de colostro bovino liofilizado nas rações de juvenis de pacu adensados diminuiu a apoptose nos segmentos intestinais S2 e RT e também diminuiu o número de células caliciformes contendo sulfomucinas no RT, indicando que o colostro bovino liofilizado pode ser utilizado como alimento nutracêutico para pacus (Piaractus mesopotamicus) adensados, a fim de diminuir a taxa apoptótica e proteger o intestino contra enzimas bacterianas, uma das principais funções das sulfomucinas. / The 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.
12

<strong>The Impacts of Stocking Density on Behavior of Pullets Reared in Cage-free Housing Systems</strong>

Torey Jean Fischer (16641804) 27 July 2023 (has links)
<p>  </p> <p>There is a clear need for more research detailing how to manage birds in cage-free housing systems. Although management guides for birds in cage-free systems focus on adult hens, previous research has established that the pullet phase is important to success later in life. Past research regarding the effects of stocking density on behavior has focused on caged adult hens, and often deals with confounding factors such as group size, limiting its interpretation. The goal of this project was to investigate the impacts of stocking density on behaviors of pullets in cage-free housing systems. </p> <p>A 2x2 randomized complete block design with two strains (Lohmann LB-Lite (Brown) and Lohmann LSL-Lite (White)) and two stocking densities (619.1 (high stocking density; HSD) and 1,248.9 (low stocking density, LSD) cm2/bird) was utilized. Videos of 6 pens for each strain by stocking density combination (59 birds/pen, n = 1416) were recorded for 2 consecutive days at 12 and 16 weeks of age (WOA). Behaviors of interest were recorded every 10 minutes for 1 hour in the morning, afternoon, and evening. Most behavior data were analyzed using a mixed model, PROC GLIMMIX, in SAS 9.4 with main effects of stocking density (SD), strain, age and time of day (TOD). Behaviors that were infrequent or that could not be transformed to meet normality assumptions were analyzed as binomial data (occurred or did not occur) and odds ratios were calculated using PROC LOGISTIC.</p> <p>Stocking density influenced every behavior examined. The LSD had fewer birds that performed eating and drinking behaviors, but more birds performed inactive, locomotion, exploratory and comfort behaviors compared to the HSD. Additionally, birds in the HSD were more likely to participate in pecking and piling behaviors compared to LSD. These results suggest that LSD may provide welfare benefits to the pullets. However, producers may face economic barriers when attempting to decrease stocking densities. Further research is needed in this area, but these results could help to achieve a stocking density that maximizes the range of behaviors pullets are able to perform within the scope of a producer’s resources. Future directions may consider collecting behavior data across the life cycle in addition to examining the relationships among behavior and welfare parameters such as feather quality, foot condition and keel bone fractures.</p>
13

Stocking Density Affects Welfare Indicators in Horses Reared for Meat Production

Raspa, Federica, Tarantola, Martina, Bergero, Domenico, Bellino, Claudio, Mastrazzo, Chiara Maria, Visconti, Alice, Valvassori, Ermenegildo, Vervuert, Ingrid, Valle, Emanuela 13 April 2023 (has links)
Horses kept for meat production are reared in intensive breeding farms. We employed a checklist adapted from the Animal Welfare Indicators (AWIN) assessment protocol. Our evaluation aims to assess whether welfare indicators are influenced by stocking densities (m2/horse) and feeding strategies applied. An analysis was carried out on the data obtained from 7 surveys conducted at a single horse farm designed for meat production. In each survey, the same 12 pens were assessed, but on each occasion, the horses in the pens had been changed as had the stocking densities. Briefly, 561 horses aged 16 ± 8 months (mean ± standard deviation) were evaluated. Two stocking density cut-off values (median and 75th percentile: 3.95 and 4.75 m2/horse, respectively) were applied to investigate the effect of stocking density on horse welfare. Data were analysed using Mann–Whitney U and Fisher’s exact tests (p < 0.05). When cut-off was set as the median percentile, lower stocking density was associated with improvements in body condition score (BCS), coat cleanliness and bedding quantity, less coughing, less resting in a standing position, and less feeding related to the greater space available at the feed bunk. When the 75th percentile cut-off was used, indicators that improved were coat cleanliness, bedding quantity and mane and tail condition, as well as less resting in standing position and less feeding related to the greater space available at the feed bunk. Accordingly, the use of two different stocking density cut-off values showed that the increase of space allowance affected specific welfare indicators. Further increment of space and/or changes in management regimes should be investigated to improve all the indicators. Moreover, results related to feeding indicated the need to intervene as starch intakes exceeded recommended safe levels, negatively affecting horse welfare.
14

Chicken or fish? Do environmental complexity and stocking density impact affective states of broiler chickens and rainbow trout?

Anderson, Mallory G. 30 September 2021 (has links)
In commercial settings, broiler chickens and rainbow trout are housed in barren environments under high stocking densities, due to an emphasis on production efficiency. These monotonous housing conditions do not provide broilers or trout with the ability to perform functional, highly-motivated behaviors and increase their susceptibility to excessive anxiety and fear, resulting in negative affective states and poor animal welfare. Affective state (or emotional state) is a cumulative product of short-term life experiences, ranging from positive to negative. Because affective states are largely influenced by environmental condition, determining animal affective state can provide useful information on how to improve housing conditions in order to ensure positive experiences and good animal welfare. Cognitive processes are closely associated with affective state; a "cognitive bias" occurs when affective state influences aspects of cognition, such as judgement and attention. Animals in positive affective states make optimistically-biased decisions during ambiguous situations, judging the situation as if it will produce a positive outcome, and show less bias towards a perceived threat, responding in a less anxious and calm manner. Animals in negative affective states make pessimistically-biased decisions during ambiguous situations, judging the situation as if it will result in a negative outcome. Additionally, animals in negative affective states will bias their attention towards a perceived threat rather than alternative stimuli, responding in an anxious manner. Therefore, judgement and attention bias tests can be used to determine animal affective states. In Chapter 3, a judgement bias test was used to determine affective state of broiler chickens housed in either complex (perches, dust bath, pecking stones, and rotating enrichment objects) or barren (no enrichment) environments under either high or low stocking densities. Broilers housed in complex environments responded more optimistically during the judgement bias test than broilers from barren environments, indicating the former were in a positive affective state. Stocking density did not impact their responses in the judgement bias test, indicating that affective states were not impacted by that treatment. In Chapter 4, an attention bias test was used to determine level of anxiety and a tonic immobility test was used to determine fear in order to investigate affective state of broilers housed in the same conditions as described for Chapter 3. Broilers housed in complex environments were less anxious during the attention bias test than broilers from barren environments, indicating environmental complexity reduced anxiety in broilers. Stocking density did not impact anxiety. Broilers from high stocking density environments had shorter tonic immobility durations than broilers from low stocking density environments, suggesting the former were less fearful. Environmental complexity did not impact fearfulness. In Chapter 5, a judgement bias test was used to determine affective state of rainbow trout housed in either complex (shelter structure and artificial plants) or barren (no enrichment) tanks under either low or high stocking densities. Trout housed in high stocking density tanks responded optimistically during the judgement bias test, indicating they were in a more positive affective state compared to trout housed in low stocking density tanks. Environmental complexity did not impact their responses in the judgement bias test, indicating no effect of enrichments on affective states was found. These results indicate a beneficial relationship of a complex environment on broiler chicken affective state, observed through an optimistic judgement bias and reduced attention bias (anxiety) towards a perceived threat. Thus, providing a complex housing environment for broilers can improve their welfare and result in a positive affective state. Rainbow trout reared at the tested high density resulted in a positive affective state, although complexity did not benefit their welfare. Our results contribute much needed information on stocking densities to ensure fish welfare. Overall, environmental complexity, 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 complexity. / Master 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.
15

Využití samokrmítkových systémů pro okounovité ryby

HOMOLA, Ondřej January 2018 (has links)
This diploma thesis researched the use of self-feeding systems in intensive aquaculture of pikeperch and perch, serving to optimize the production of these fish species. In the experiment with the pikeperch, there was studied the effect of the various types of feeding methods including self-feeders on the production indicators and feeding behavior. In the experiment with the perch, there was studied the influence of the stocking density on the production indicators and feeding behavior using self-feeding.
16

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)

Ferreira, Eric Silva 28 June 2006 (has links)
Made available in DSpace on 2014-12-17T15:37:19Z (GMT). No. of bitstreams: 1 EricSF.pdf: 350001 bytes, checksum: 9fc8363dd4359a5ba205b8e441f4895c (MD5) Previous issue date: 2006-06-28 / Conselho 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
17

Densidade de estocagem de piracanjuba (Brycon orbigniannus) em tanques-rede de pequeno volume / Density of stocking of piracanjuba (Brycon orbignyannus), in cages of small volume

Lorenz, Evandro Kleber 23 February 2010 (has links)
Made available in DSpace on 2017-07-10T17:48:19Z (GMT). No. of bitstreams: 1 Evandro_Kleber_Lorenz.pdf: 2851299 bytes, checksum: e8177ab9b556d239d3038a5b4241bdca (MD5) Previous issue date: 2010-02-23 / Coordenação 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
18

Great Eggs-pectations: Understanding Markers of Stress and Welfare in Pullets Using Feeder Space and Stocking Density Stressors

Meagan E Abraham (14206337) 09 December 2022 (has links)
<p>  </p> <p>Little is known about pullet stress and welfare and even less is known about pullets in cage-free housing. The studies included in this dissertation evaluated bird responses to stocking density, feeder space, and ACTH stressors in pullets. The project and procedures were reviewed and approved by the Purdue University Animal Care and Use Committee (Protocol#:2001002002 and # 1908001938).  </p> <p>Two studies of external stressors and one study of an internal stressor were applied to Lohmann LB-Lite (Brown) and Lohmann LSL-Lite (White) pullets. For both studies of an external stressor, bird-based welfare parameters included evaluation of bird appearance through feather coverage, foot condition, and keel condition; blood parameters, i.e., cholesterol, corticosterone, cortisol, NDV/IBV IgG/IgY titer, and differential WBC (%) and heterophil to lymphocyte ratio; measurements of the spleen, bursa, thymus, and liver; and production values measured through body weight, body weight uniformity, shank length, feed consumption, and feed conversion ratio (FCR). Birds were followed from 2-16 weeks of age (WOA) for the external stressors and were housed on the floor.</p> <p>The first external stressor was applied through a 2 x 2 factorial randomized complete block design (RCBD) using Brown and White strains and two stocking densities- high (HSD) and low (LSD). Stocking densities were adjusted over time, with the ending density of 670 cm2/bird for HSD and 1352 cm2/bird for LSD at 16 WOA. Density alone affected relative bursal weight (%), with LSD generating heavier bursas. LSD also generated lower, better FCR for both white and brown strains though this difference was not statistically significant. Within a density, opposing strain effects were seen for body weight uniformity and feather coverage. White was improved at HSD while Brown was improved for LSD. </p> <p>The second external stressor study was a 2 x 2 x 3 factorial RCBD with Brown and White, 2 feeder space allocations (3.5 or 7 cm/bird), and 3 stocking densities. The ending stocking densities were 154.45, 518.76, and 1,247.38 cm2 for the high (HSD), medium (MSD), and low (LSD) stocking density treatments, respectively, at 16 WOA. In this study, less space per bird was associated with poorer feather condition but improved FCR. Reduced feeder space was associated with elevated or worse FCR.</p> <p>In a study of internal stressors, ten each of Lohmann LSL-Lite hens received either a saline-mannitol or synthetic human ACTH injection at 6, 17, and 26 weeks of age. Blood was collected prior to injection and 1- and 2-hours post-injection. H:L ratio, WBC differential counts, corticosterone, and cortisol were measured in blood. Albumen samples were collected to measure corticosterone and cortisol at 26 WOA only but were unaffected by treatment. Serum corticosterone and H:L ratio were also unaffected by treatment. Serum cortisol was increased 1 hour after ACTH injection at 17 and 26 WOA and percent heterophils and lymphocytes were affected by ACTH at 26 WOA indicating potential utility as a measure of stress for adult birds only. </p> <p>The results of these studies show that pullets are resilient and resistant to several stressors. Both acute and chronic as well as internal and external stressors were tested in these studies with limited effects on the birds’ physiology, immunity, condition, or production. Feather coverage and bursal size were improved at lower stocking densities and FCR was improved at greater feeder space but the implications of these differences are unclear. Further research is needed to identify why there are reduced stress responses in pullets; it is possible that domestication or preserved evolutionary pathways explain some of the differences between pullet and adult stress responses. And while the majority of parameters were unaffected by the stressors used, the results of this study presented baseline values for Lohmann LB-Lite and Lohmann LSL-Lite pullets that will help guide future research. Additionally, the results of these studies left perhaps more questions than answers but illustrate perfectly that more research will be critical to an understanding of pullet stress and welfare.</p>
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Análise de densidades de alojamento nos sistemas convencional e cage-free de produção de ovos comerciais / Analysis of housing densities in conventional and cage free commercial egg production systems

Queiroz, Livia Maria Soares 01 December 2017 (has links)
Inovação em produção animal tem sido cada vez mais exigido pelos consumidores. No ambito de produção de postura, a maior demanda é por ovos provenientes de sistemas alternativos às gaiolas tradicionais, majoritariamente pelas tendencias observadas na Europa, e dessa forma, pesquisas ressaltando a realidade brasileira estão sendo realizadas. O objetivo deste estudo foi avaliar parametros produtivos e de bem-estar em dois contextos de sistemas produtivos, sob variadas densidades de alojamento. Para isso 250 aves Lohmann Brown&reg; foram distribuídas em delineamento inteiramente casualizado (DIC) com os tratamentos organizados em esquema fatorial 2 x 4, sendo 2 sistemas de alojamento (convencional e cage-free) e 4 densidades (375,00; 450,00; 562,50 e 750,00 cm2/ave), com 6 repetições. O período experimental foi de 21 a 36 semanas de idade das poedeiras, totalizando 4 ciclos de 28 dias cada. Foram avaliados desempenho produtivo (produção de ovos, consumo de ração, conversão alimentar por kg de ovos), qualidade de ovos (peso, coloração de gema, índice gema, % de gema, % albumen, % casca, espessura e resistência a quebra, e unidade Haugh) e indicadores de bem-estar (frequência respiratória e cardíaca, temperatura clocal, escore de lesão corporal, concentração d eIgY na gema) Observou-se interação entre sistema de produção e densidade de alojamento para: % postura, consumo de ração, conversão alimentar por kg de ovos, peso do ovo, % de gema, % albúmen, espessura de casca. O aumento de densidade promoveu efeito significativo para % postura, consumo de ração, temperatura cloacal, lesão em quilha e em pés. O tipo de sistema de produção afetou consumo de ração, conversão alimentar por kg de ovos, peso do ovo, coloração de gema, índice gema, resistência à quebra, frequência cardíaca temperatura cloacal, lesões de quilha e pés e concentração de IgY na gema. Os resultados deste estudo demonstram que tanto o sistema de produção quanto a densidade de alojamento estão ligados a efeitos produtivos, de qualidade de ovos, e de bem-estar animal. / Innovation 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&reg; 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.
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CONTROL OF REPRODUCTION IN NILE TILAPIA (OREOCHROMIS NILOTICUS) BY MANIPULATION OF ENVIRONMENTAL FACTORS

de Lapeyre, Boris Adrien 01 February 2008 (has links)
No description available.

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