Viabilidade econômica da produção de piauçu Leporinus macrocephalus (Garavello & Britski, 1988)

A piscicultura brasileira apresentou um acelerado desenvolvimento nos anos 90, principalmente impulsionada pelo aumento de estabelecimentos pesqueiros conhecidos como "pesque-pagues". Entretanto, o aumento do número de criadores de alevinos e a redução de pesqueiros resultou em um aumento na oferta de peixes e, conseqüente, diminuição do preço de comercialização. O presente estudo analisa os parâmetros zootécnicos, os custos de produção, a rentabilidade e a viabilidade econômica da engorda de piauçu (L. macrocephalus) em tanques escavados. Os custos com insumos somam 47,1% do custo total de produção, representando juntamente com o preço de venda do pescado, o fator decisivo na rentabilidade da atividade. O período de recuperação do capital foi de 8,3 anos, valor presente líquido de US$291,07, taxa interna de retorno de 9$ 291.07, the internal return margin 9%, and the income-outcome ratio was 1.01, which represents an unattractive investment as a projection based on current conditions. The improvement in productive efficiency enhances the economic valuation index, and that the relative magnitude of cost and income are the most important points for the economic viability of the studied farm

Respostas fisiológicas de matrinxã (Brycon cephalus) arraçoadas com diferentes níveis de vitamina C e submetidos à exposição aérea

This work evaluated the participation of vitamin C on physiological responses of matrinxã (Brycon cephalus) submitted to air exposure. In the first experimental phase, 900 fish (70.15g) were random1y distributed in fifteen 500L boxes (60 fish/box) and fed 5• experimental rations (treatments): Control (no addition); TIOO (100 mg); T200 (200 mg); T400 (400 mg) and T800 (800 mg of vitamin C/ kg ration). Each ration was offered to fish from 3 boxes during 60 days and, after that, the second phase began. The experiment was divided in 3 steps, each one was considered a block (repetition) and samplings were carried out in different days. In each sampling, 28 fish of each treatment were transferred to 100 L plastic boxes (4 boxes/treatment, 7 fish/box), where they stayed for 48 hours until the stressful factor application, that consisted in taking out all fish of boxes, with polyethylene nets previously adapted to the boxes, maintaining them out of the water for two minutes. The samplings were carried out 5, 15, 30 and 60 min after they return to the water. Each sampled box was removed of the experiment to avoid additional stress. Blood were collected for glucose, cortisol, total protein, sodium, chloride, calcium determination, hematocrit, hemoglobin and white and red cells count and liver for hepatosomatic index (HSI calculation and glycogen determination. No significant differences in the cortisol, chloride, total protein, hemoglobin, leukocytes, glycogen and HSI values were registered. The blood glucose decreased, in all treatments, at 15 and 30 min at 60 min it surpassed the levels registered in first sampling (5 min.). The TI00fish showed, in all sampling times, blood glucose significantly elevated when compared to fish fed of control, T200- and T800. The serum calcium in T800 fish was larger than those 01' the control and T100 fish and the levels were significantly smaller at 30 and 60 min when compared to those registered at 5 min ..

Suplementação alimentar de pacu (Piaractus mesopotamicus Holmberg, 1887) com β 1,3 glicano: atividade respiratória de leucócitos, lisozima e estresse por captura

O sistema imune é dividido em duas partes que se complementam: o sistema imune inato (não específico) e o adquirido (específico). O sistema imune inato é considerado como a primeira linha de defesa e inclui barreiras físicas (pele e muco) e componentes celulares e moleculares (macrófagos, células killer e fatores solúveis de imunidade, como lisozima, proteínas do sistema complemento, peptídeos antimicrobianos, entre outros). No processo de criação, o sistema imune dos peixes pode ser prejudicado por vários fatores, mas efeitos benéficos podem ser observados com o uso de substâncias conhecidas como imunoestimulantes. Dentre os imunoestimulantes estudados, os glicanos vêm sendo amplamente utilizados como importantes indutores de mecanismos não específicos de defesa. Em algumas espécies de peixes tropicais, como o pacu (Piaractus mesopotamicus) e matrinxã (Brycon amazonicus), estudos observaram o papel da vitamina C como imunoestimulante avaliando a hematologia dos peixes como indicador das alterações imunológicas. O número de leucócitos e de trombócitos é considerado importante indicador de seu estado de saúde. Entretanto, não são conhecidos estudos que avaliem outros parâmetros imunológicos bem como os efeitos do glicano nas respostas imunológicas inatas de peixes tropicais. O pacu, por ser uma espécie onívora, de fácil cultivo e adaptada a ampla variedade de alimentos, tem grande importância na piscicultura brasileira e por esta razão foi escolhido como modelo experimental nesta pesquisa. O objetivo deste trabalho foi testar, inicialmente, técnicas para avaliação de alguns mecanismos inatos de defesa (atividade respiratória de leucócitos e concentração e atividade de lisozima) nesta 37 espécie tropical, cujos resultados são apresentados no capítulo 2 desta tese. Este estudo registrou essas respostas imunes inatas no pacu...The immune system is divided in two parts that complement each other: the specific and non-specific immune system. The non-specific immune system is the primary defence line and includes natural barriers (skin and mucus) and cellular and molecular components (macrophages, natural killer cells, immune soluble factors, like lysozyme, complement, antimicrobials peptides, among others). In all farming, the immune system of fish may be damaged by many factors, but the benefic effects may be observed using immunostimulants. It has been of common knowledge that glucans are the most known of them and are being used like nonspecific defence mechanisms stimulants. In some tropical fish species, such as pacu (Piaractus mesopotamicus) and matrinxã (Brycon amazonicus), studies evaluated vitamin C effect as immunostimulant, considerating the fish hematology as immune alterations indicator. The leucocytes and trombocytes number is considerated an important health indicator. However, there are no studies evaluating different immune parameters and the glucan effect in innate immune response of tropical fish. The pacu is an omnivore specie of great importance to Brazilian fish farming. For this reason, it was chosen as experimental model in this research. The aim of this work was to test some techniques for evaluation of some defence innate mechanisms (burst oxidative and lysozyme) in this tropical specie, whose results are showed in chapter 2 of this work. This research recorded these immune responses of pacu and established adequate methodologies for its determination. After, this study evaluated the effect of glucan, administered to intraperitoneal injection and incorporated in the diet, in stimulation of some immune systems components of pacu. Besides, it was also verified 39 the stress responses after the capture of pacu fed with diets supplemented with glucan ...(Complete abstract, click electronic access below)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Stress in pacu exposed to ammonia in water

The present study evaluated stress indicators in pacu exposed to ammonia in water under the following conditions: without NH4Cl (0.00 g/L); with 0.0078 g NH4Cl/L; and with 0.078 g NH4Cl/L (pH 8.3 and 27 ºC). After the salt dilution the water flow was interrupted and reestablished in 24 hours. Sampling occurred prior to the addition of NH4Cl (control) and after 12, 24 and 48 hours. Glycaemia increased only in fish with the highest salt concentration when compared with group control, regardless of time, and at 24 hours, regardless of treatment. Plasma ammonia, highest in fish exposed to the highest NH4Cl concentration, decreased progressively up to 48 hours. Plasma chloride only decreased in fish not exposed to salt when compared with control and osmolality increased after 24 hours. Hematocrit (Ht), number and volume of erythrocytes and hemoglobin did not change when NH4Cl was added; Ht decrease was reported after 12 hours, but it was not followed by the other blood parameters. The results show tolerance of the pacu to ammonia in the environment

Welfare and meat quality of cattle transported over different distances and in differently designed trucks (truck, trailer and double deck) in the region of Cuiabá/MT/ Brazil

The transport of animals for slaughter is an important step in humane slaughter and factors such as truck design, transport distance and time and weather conditions have a high correlation with  meat and carcass quality and must be adjusted for each producing region. The effect of transport distance (D1 = 180 to 250 km and D2 = 75 to 130 km) and truck design (C1= regular truck, C2= trailer and C3= double deck) were evaluated on welfare, meat and carcass quality of 120 Nellore cattle using a completely randomized design. Differences were observed in the pH values 1h post-mortem (p ≤ 0.05) between treatments, but this was not true for the values of pH 24 post-mortem in the same muscle (L. dorsi). Higher bruising frequency (1.09 and 1.02) and intensity (1.81 and 1.65) were found in the carcasses of animals transported by C3 in relation to other treatments (p ≤ 0.05). High blood cortisol levels were obtained in animals transported by C3 over distance D2, followed by C1 over distance D1. It was concluded that C3 over distance D2 showed poor welfare and carcass quality compared to the other treatments

Efeito do ambiente pós-transporte na recuperação dos indicadores de estresse de pacus juvenis, Piaractus mesopotamicus - DOI: 10.4025/actascianimsci.v28i4.610

The aim of this work was to evaluate the recovery of physiological stress responses after the transport of pacu juveniles in different stocking conditions. After being transported for 2 h30min, fish were transferred to earthen ponds or indoor polyethylene boxes. There was a significant reduction of cortisol values registered at fish arrival , 24 hours after, in both stocking conditions . The glucose concentration reduced significantly 72 hours after in fish stocked in earthen ponds , and 120 hours in fish stocked indoor. Osmolality, sodium, potassium and chloride behavior suggested the re-establishment of the homeostasis during the recovery period, mainly in fish kept in the earthen ponds. Concerning the hematological parameters, only hemoglobin concentration reduced significantly in the recovery period , without effect of stocking condition, which does not characterize feasible indicators. After transport, a management procedure that causes stress in fish, the recovery of the basal condition was fa vored when pacu were stocked in earthen ponds.O objetivo deste trabalho foi avaliar a recuperação das respostas fisiológicas de estresse após transporte de pacus em diferentes condições de es tocagem. Após transporte por 2h30min, os peixes foram transferidos para tanque de terra ou para caixas de polietileno em laboratório. Houve significativa redução dos valores de cortisol observados na chegada 24 horas depois, nas duas condições de estocagem , enquanto a concentração de glicose caiu significativamente 72 horas depois nos peixes estocados no tanque de t 1erra e 120 horas nos peixes estocados no laboratório. A osmolalidade, sódio, potássio e cloreto suger em um retorno à homeostase durante o perío do de recuperação, principalmente nos peixes no tanque de terra. Os parâmetros hematológicos, sem efeito da condição de estocagem, não se caracterizaram indicadores sensíveis. Após o transporte, uma prática de manejo que causa estresse em peixes, o retorno às condições normais foi favorecido quando os pacus foram estocados em tanque de terra