Natação sustentada atenua o estresse em juvenis de Brycon amazonicus criados em alta densidade de estocagem

The objective of this work was to evaluate the effect of stocking density associated with the swimming exercise on the stress responses of Brycon amazonicus. During 70 days, fish were subjected to three stocking densities: LD, low density of 88 fish per cubic meter; ID, intermediary density of 176 fish per cubic meter; and HD, high density of 353 fish per cubic meter. These densities were combined with static water (non-exercised group) or moderate-speed water (exercised group). Chronic stress was observed in HD, and plasma cortisol and glucose increased with the stocking densities. In HD, levels of plasma cortisol were significantly lower in exercised fish (135 ng mL-1) than in non-exercised ones (153 ng mL-1). The greatest hepatic glycogen bulks occurred in fish kept in ID and sustained swimming. Hepatic free amino acids (FAA) increased with the stocking density, particularly in non-exercised fish. The contents of FAA in the liver and of free fatty acids (FFA) in the liver and muscle were mobilized to meet the metabolic demands imposed by exercise and stocking density. The hematological parameters remained stable. The results show that Brycon amazonicus is more resistant to stress when subjected to sustained swimming and high stocking density than to static water.O objetivo deste trabalho foi avaliar o efeito da densidade de estocagem associada ao exercício de natação nas respostas ao estresse de matrinxã (Brycon amazonicus). Durante 70 dias, os peixes foram submetidos a três densidades de estocagem: BD, baixa densidade de 88 peixes por metro cúbico; DI, densidade intermediária de 176 peixes por metro cúbico; e AD, alta densidade de 353 peixes por metro cúbico. Estas densidades foram combinadas com água parada (grupo não exercitado) ou com água em velocidade moderada (grupo exercitado). O estresse crônico foi observado em AD, e o cortisol e a glicose plasmática aumentaram com a densidade de estocagem. Em AD, os níveis plasmáticos de cortisol foram significativamente menores nos peixes exercitados (135 ng mL-1) do que nos não exercitados (153 ng mL-1). Os maiores acúmulos de glicogênio hepático ocorreram em peixes mantidos em DI e em natação sustentada. Os aminoácidos livres (AAL) hepáticos aumentaram com a densidade de estocagem, particularmente nos peixes não exercitados. As reservas de AAL hepáticos e de ácidos graxos livres hepáticos e musculares foram mobilizados para atender às demandas metabólicas impostas pelo exercício e pela densidade de estocagem. Os parâmetros hematológicos mantiveram-se estáveis. Os resultados são indicativos de que o matrinxã é mais resistente ao estresse quando submetido à natação sustentada e à alta densidade de estocagem que à água parada

Crescimento e hematologia de pacu submetido a natação sustentada e alimentado com diferentes níveis proteicos

The objective of this work was to evaluate the effect of sustained swimming and dietary protein levels on growth and hematological responses of juvenile pacu (Piaractus mesopotamicus). A completely randomized design was used in a 3x2 factorial arrangement, with three levels of dietary protein (24, 28, and 32% crude protein), two rearing conditions (sustained swimming or motionless water), and 15 replicates. Fish were subjected to sustained swimming at the velocity of two body lengths per second (2 BL s-1), for 45 days. The level of dietary protein and the swimming conditions affected the performance, growth, and hematological profile of pacu. Swimming conditions influenced nutritional factors, increasing daily weight gain, specific growth rate, number of erythrocytes, mean corpuscular volume, and mean corpuscular hemoglobin. Fish under sustained swimming and fed with 24% crude protein showed better growth performance, with higher specific growth rate (4.11±0.88) and higher daily weight gain (2.19±0.47 g per day). Sustained swimming can increase the productive performance of pacu and simultaneously reduce dietary protein levels.O objetivo deste trabalho foi avaliar o efeito da natação sustentada e de níveis de proteína na dieta sobre o crescimento e a resposta hematológica de juvenis de pacu (Piaractus mesopotamicus). Utilizou-se o delineamento inteiramente casualizado, em arranjo fatorial 3x2, com três níveis de proteína na dieta (24, 28 e 32% de proteína bruta), duas condições de criação (natação sustentada ou água imóvel) e 15 repetições. Os peixes foram submetidos à natação sustentada na velocidade de duas vezes o comprimento corporal por segundo (2 CC s-1), por 45 dias. O nível de proteína da dieta e as condições de nado afetaram o desempenho, o crescimento e o perfil hematológico do pacu. As condições de nado influenciaram os fatores nutricionais, com aumento de ganho de peso diário, taxa de crescimento específico, número de eritrócitos, volume corpuscular médio e hemoglobina corpuscular média. Peixes sob natação sustentada e alimentados com 24% de proteína bruta apresentaram melhor desempenho de crescimento, com maior taxa de crescimento específico (4,11±0,88) e maior ganho em peso diário (2,19±0,47 g por dia). A natação sustentada pode aumentar o desempenho produtivo de pacus e ao mesmo tempo reduzir os níveis de proteína na dieta

Trânsito gastrintestinal de dietas extrusadas ou peletizadas em pacu alimentado com níveis distintos de inclusão de lipídios e carboidratos

The objective of this work was to evaluate the effect of pelletized or extruded diets, with different levels of carbohydrate and lipid, on the gastrointestinal transit time (GITT) and its modulation in pacu (Piaractus mesopotamicus). One hundred and eighty pacu juveniles were fed with eight isonitrogenous diets containing two carbohydrate levels (40 and 50%) and two lipid levels (4 and 8%). Four diets were pelletized and four were extruded. Carbohydrate and lipid experimental levels caused no changes to the bolus transit time. However, the bolus permanence time was related to diet processing. Fish fed pelletized diets exhibited the highest gastrointestinal transit time. Regression analysis of bolus behavior for pelletized and extruded diets with 4% lipid depicted different fits. GITT regression analysis of fish fed 8% lipid was fitted to a cubic equation and displayed adjustments of food permanence, with enhanced utilization of the diets, either with extruded or pelletized diets. GITT of fish fed extruded diets with 4% lipid was adjusted to a linear equation. The GITT of pacu depends on the diet processing and is affected by dietary levels of lipid and carbohydrate.O objetivo deste trabalho foi avaliar o efeito de dietas peletizadas ou extrusadas, com diferentes níveis de carboidrato e lipídio, sobre o tempo de trânsito gastrointestinal e sua modulação em pacu (Piaractus mesopotamicus). Cento e oitenta juvenis de pacu foram alimentados com oito dietas isoproteicas com dois níveis de carboidratos (40 e 50%) e dois níveis de lipídeos (4 e 8%). Quatro dietas foram peletizadas e quatro extrusadas. Os níveis experimentais de carboidrato e lipídeo não alteraram o tempo de passagem do bolo alimentar. Entretanto, o tempo de permanência do bolo alimentar foi dependente do processamento aplicado à dieta. Os peixes alimentados com dietas peletizadas apresentaram o maior tempo de trânsito gastrointestinal (TTGI). A análise de regressão do comportamento do bolo alimentar para dietas peletizadas e extrusadas com 4% de lipídeo mostraram diferentes ajustes. A análise de regressão do TTGI de peixes alimentados com 8% de lipídios ajustou-se a uma equação cúbica e mostrou ajustes na permanência do alimento, com maior aproveitamento das dietas, quer com dietas extrusadas ou peletizadas. O TTGI dos peixes que receberam dietas extrusadas com 4% de lipídeos ajustou-se a uma equação linear. O TTGI de pacu depende do processamento da dieta e é afetado pelos níveis de lipídios e carboidratos na dieta

Desempenho de produção e enriquecimento em ácidos graxos de pacu (Piaractus mesopotamicus) com diferentes fontes lipídicas nas dietas

Fontes lipídicas de origem animal e vegetal foram usadas em dietas de juvenis de pacu para avaliar o desempenho de produção, composição corporal, perfil de ácidos graxos corporais e digestibilidade. O experimento foi realizado no Laboratório de Nutrição de Organismos Aquáticos do Centro de Aqüicultura da UNESP - CAUNESP, em Jaboticabal - SP. Cinco dietas isoprotéicas (26 % proteína bruta) constituíram os tratamentos (SS - sem adição de óleo; SJ - óleo de soja degomado; SA - óleo de salmão; GI- óleo de girassol; LI- óleo de linhaça) estudados. Foi realizado um ensaio de crescimento, no qual foram coletadas amostras teciduais para composição corporal e perfil de ácidos graxos, assim como um ensaio de digestibilidade. Não houve diferença significativa (P > 0,05) entre os parâmetros de crescimento, exceto para consumo de ração diário (P 0,05). No entanto, encontrou-se diferença (P 0.05) was observed in the growth parameters, except for food consumption (P < 0.01), which was higher for SA diet. Protein digestibility was higher for CS while lipids were better digestible with LI diet. No significant differences (P < 0.05) were found for body composition (moisture, crude protein and lipids) or nutrients retention. However, significant differences (P < 0.05) were observed in fatty acids (FA) profile of fillet and carcass samples, in which satisfactory results indicated by the presence of essential FA were achieved by supplementing the diets with salmon and linseed oils.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Crescimento, hematologia e metabolismo de pacu (Piaractus mesopotamicus) submetido ao exercício aeróbico e alimentado com níveis crescentes de proteínas

The composition of the diet, the metabolic adaptations and variations in the activity of the fish are the main factors responsible for seasonal changes in physiological variables. It is known that aerobic exercise can improve the fish growth due to: the enhancement of feed conversion, reduced dominance, increased protein synthesis and lipid and glucose catabolism. The diet must satisfy the nutritional requirements of each species. Knowledge of the appropriate protein level is critical because maximizes feed conversion efficiency, lowers costs and reduces the load of nutrients released to the aquatic ecosystem. In Brazil, the pacu, Piaractus mesopotamicus, is an important fish in aquaculture, especially for hardiness, fast growth, excellent meat quality. This species may respond to exercise with lower levels of protein catabolism and for directing them to growth. Thus, a balanced diet and a well established aerobic exercise protocol could promote better growth for pacu. This study aimed to evaluate the effects of the combination of different levels of crude protein in the diet and sustained exercise in pacu through growth performance, hepatosomatic and viscerosomatic indexes, metabolic and hematological parameters. The experiment followed a completely randomized 2 x 3 factorial arrangement, consisting of two swimming activities (exercised-E, non-exercising) and three levels of dietary protein percentage (24, 28 and 32). The pacu exercised and fed 24 % crude protein (CP) showed better growth. The hematologic variables were responsive to nutritional status and exercise. When comparing the exercised groups all together, it was observed that the high levels of CP in the diet increased protein catabolism and lipogenesis in the liver and white muscle and lipid catabolism in red muscle. High levels of CP in the diet of non-exercised pacu increased protein catabolism in white muscle and lipogenesis in the liver. Sustained swimming activity increased the use of liver glycogen at all levels of protein studied, and protein anabolism and lipogenesis in pacu fed higher-protein diet. Based on the responses obtained in this study we can infer that for exercised pacu, the appropriate level of protein in the diet is 24 % of crude protein and levels above that promote the use of protein as an energy source.Universidade Federal de Sao CarlosA dieta deve atender as necessidades de cada especie. O conhecimento do teor de proteina adequado e fundamental, pois maximiza a eficiencia da conversao alimentar, reduz os custos e a carga de nutrientes lancados para o ecossistema aquatico. Sabe-se que o exercicio aerobico pode contribuir para a criacao mais eficiente de peixes aumento as taxas de crescimento devido a aumento da eficiencia alimentar, diminuicao da dominancia, aumento da sintese proteica e catabolismo lipidico e glicidico. No Brasil, o pacu, Piaractus mesopotamicus, destaca-se pela rusticidade, crescimento rapido, carne de excelente qualidade. Essa especie pode responder ao exercicio utilizando menores niveis de proteinas para o catabolismo e direcionando-as para o crescimento. Assim, uma dieta balanceada e o exercicio aerobico bem estabelecido poderiam promover maior crescimento para o pacu. Esse estudo teve como objetivo avaliar os efeitos da associacao de teores diferentes de proteina bruta da dieta e exercicio aerobico em pacu atraves das respostas de crescimento, indices hepatosomatico e viscerosomatico, variaveis hematologicas e metabolicas. O experimento obedeceu a um delineamento inteiramente casualizado em esquema fatorial 2 x 3, constituido de duas atividades natatorias (exercitado- E; nao-exercitado- SE), e tres niveis percentuais de proteina na dieta (24, 28 e 32). Os pacus exercitados e alimentados com 24 % proteina bruta (PB) apresentaram melhor crescimento. As variaveis hematologicas foram responsivas a condicao nutricional e ao exercicio. Quando comparados os pacus exercitados entre si, observou-se que os altos teores de PB na dieta aumentaram o catabolismo proteico e lipogenese no figado e musculo branco e o catabolismo lipidico no musculo vermelho. Altos niveis de PB na dieta de pacus nao-exercitados aumentaram o catabolismo proteico no musculo branco e a lipogenese no figado. A atividade natatoria sustentada aumentou o uso de glicogenio hepatico em todos os niveis de proteina avaliados e o anabolismo proteico e lipogenese nos pacus que receberam o maior teor de proteina na dieta. Com base nas respostas obtidas neste estudo podemos inferir que para pacus exercitados, o nivel adequado de proteina na dieta foi 24 % PB e que niveis acima promovem o uso da proteina como fonte energetica

EFEITO DO PROCESSAMENTO DE DIETAS COM DIFERENTES NÍVEIS DE CARBOIDRATOS E LIPIDEOS SOBRE A COMPOSIÇÃO CORPORAL E PERFIL DE ÁCIDOS GRAXOS DO FILÉ DO PACU (Piaractus mesopotamicus)

The objective of this study was to evaluate the effect of extruded or pelletized diets on the condition factor, body composition and fatty acid composition of Piaractus mesopotamicus. Eight isoproteic diets (220 gkg-1 digestible protein) were supplied for 90 days ad libtum. The following parameters were evaluated: condition factor, body composition, and fatty acid composition. The condition factor showed different responses according to the type of processing. The body composition of the fish submitted to different diets showed no statistical difference. The pellet diets with 40% carbohydrate consistently showed the highest ratio compared to n3/n6 extruded diets. The fatty acid composition of the fillet showed an interaction of carbohydrate, lipids and processing. The increase in carbohydrate in the extruded diets produced Piaractus mesopotamicus with higher levels of omega-3

Growth and hematology of pacu subjected to sustained swimming and fed different protein levels

The objective of this work was to evaluate the effect of sustained swimming and dietary protein levels on growth and hematological responses of juvenile pacu (Piaractus mesopotamicus). A completely randomized design was used in a 3x2 factorial arrangement, with three levels of dietary protein (24, 28, and 32% crude protein), two rearing conditions (sustained swimming or motionless water), and 15 replicates. Fish were subjected to sustained swimming at the velocity of two body lengths per second (2 BL s-1), for 45 days. The level of dietary protein and the swimming conditions affected the performance, growth, and hematological profile of pacu. Swimming conditions influenced nutritional factors, increasing daily weight gain, specific growth rate, number of erythrocytes, mean corpuscular volume, and mean corpuscular hemoglobin. Fish under sustained swimming and fed with 24% crude protein showed better growth performance, with higher specific growth rate (4.11±0.88) and higher daily weight gain (2.19±0.47 g per day). Sustained swimming can increase the productive performance of pacu and simultaneously reduce dietary protein levels

Gastrointestinal transit of extruded or pelletized diets in pacu fed distinct inclusion levels of lipid and carbohydrate

The objective of this work was to evaluate the effect of pelletized or extruded diets, with different levels of carbohydrate and lipid, on the gastrointestinal transit time (GITT) and its modulation in pacu (Piaractus mesopotamicus). One hundred and eighty pacu juveniles were fed with eight isonitrogenous diets containing two carbohydrate levels (40 and 50%) and two lipid levels (4 and 8%). Four diets were pelletized and four were extruded. Carbohydrate and lipid experimental levels caused no changes to the bolus transit time. However, the bolus permanence time was related to diet processing. Fish fed pelletized diets exhibited the highest gastrointestinal transit time. Regression analysis of bolus behavior for pelletized and extruded diets with 4% lipid depicted different fits. GITT regression analysis of fish fed 8% lipid was fitted to a cubic equation and displayed adjustments of food permanence, with enhanced utilization of the diets, either with extruded or pelletized diets. GITT of fish fed extruded diets with 4% lipid was adjusted to a linear equation. The GITT of pacu depends on the diet processing and is affected by dietary levels of lipid and carbohydrate

Genetic variability among the wild boars (Sus scrofa scrofa), crossbred animals and pigs using microsatellite markers (STRs)

The aim of this work was to study the genetic variability among the wild boars, crossbred animals and pigs using microsatellite markers. Five genetic groups were studied. The fragments of three microsatellites developed for Sus scrofa domestica - IGF1, ACTG2 and TNFB - were amplified through PCR technique to evaluate the expected intra populacion variability (He) and observed (Ho) heterozygosity, and endogamy coefficient (F IS ) within each population and inter population variability F IS , testing relationship among five genetic groups to establish the genetic distance among them. The high level of observed heterozygosity values varied between 0.537 and 0.7871. Generally, F IS was low, suggesting that the endogamy did not exist between the tested animals