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This work evaluated the effects of food frequencies and self-feeding on the behavior, performance, and blood biochemistry of Colossoma macropomum. Juveniles weighing 3.63 ± 0.05 g were distributed in 27 aquariums (40 L), with six fish per aquarium, to evaluate nine treatments in three replications in a 12L:12D photoperiod. The treatments were 24-h self-feeding (SF); daytime self-feeding at will (SFD); nighttime self-feeding at will (SFN); and feeding at fixed frequencies of two (2D), four (4D), and six times (6D) daytime and twice (2 N), four (4 N), and six times (6 N) nightly. The treatments were offered in automatic feeders, with fixed frequencies programmed. Extruded commercial feed, with 46% protein, was used. The experimental period was 40 days. In the SF treatment, the animals exhibited 95.7% nocturnal and 4.3% diurnal feeding activity (p

This study aimed to evaluate the influence of increasing concentrations of dietary dry oregano leaves (DOL), ranging from 0 to 0.15%, on different performance parameters of Nile tilapia. Hence, two separate experimental trials testing growth factors (Trial 1) and innate immunity and disease resistance against Streptococcus agalactiae infection (Trial 2) were conducted with a total of 464 tilapia juveniles and two to four replicates. As a result, dietary inclusion of DOL did not induce significant effects on growth performance, hematological parameters, and fillet composition. However, there were significant differences in lysozyme activity between groups of DOL at 0.075% and the control (0%). Moreover, the bactericidal index of the positive control and groups supplemented with DOL were significantly higher than baseline treatment groups. For disease resistance, there was a reduction of 15% in the relative risk of streptococcosis in fish juveniles after dietary inclusion of oregano at 0.15%. In conclusion, the inclusion of DOL in tilapia diets resulted in no significant gains in terms of growth; nevertheless, the immune system and resistance of tilapia against S. agalactiae infection were significantly improved.

This work evaluated the blood parameters of Lophiosilurus alexandri juveniles submitted to doses of 80, 160, 320, and 640 mg L−1 eugenol (n = 60, 171.59 ± 37.87 g) and 60, 120, 240, and 480 mg L−1 benzocaine (n = 60, 214.87 ± 75.83 g) were tested. For each anesthetic, there was a control group. Thus, anesthesia time and recovery of the analgesia condition were evaluated. Of the 12 animals from each treatment, six went through blood collection after sedation and the other six, 24 h after anesthesia. The survival index for the use of both anesthetics, after 24 h after anesthesia, was 100%. The induction times for eugenol and benzocaine presented an inversely proportional ratio, while the recovery time, a ratio directly proportional to the increase in anesthetic concentrations. Glucose was higher after sedating the animals, regardless of the concentrations tested. The hematocrit had lower values after 24 h after anesthesia at the doses of 320 and 640 mg L−1, while the total protein was not affected during the observations. With the use of benzocaine, glucose was higher at concentrations of 240 and 480 mg L−1. In relation to time, glucose was higher after anesthesia. Total protein had higher values in the doses of 240 and 480 mg L−1. The hematocrit was not affected in the experiment. Concentrations between 80 and 160 mg L−1 eugenol and between 60 and 120 mg L−1 benzocaine may be used in anesthetic procedures of L. alexandri juveniles.

O objetivo deste trabalho foi avaliar o efeito do eugenol como anestésico para juvenis de pacamã (Lophiosilurus alexandri). Os animais foram divididos em dois grupos, denominados juvenil I (0,72 g) e juvenil II (7,44 g), e submetidos a seis tratamentos de eugenol (20, 40, 60, 80, 100 e 120 mg L-1), em dez repetições. Durante o experimento, foram realizadas biometrias e cronometragens dos tempos de indução e recuperação. Com o aumento das doses, o tempo de anestesia foi reduzido de 69 para 27 s, em juvenis I, e de 93,8 para 37,3 s em juvenis II. A sobrevivência foi de 100%.

The experiment carried out at National Center for Research in Tropical Fish Pirassununga, SP, aiming to determine the effect of the ration processing on the apparent digestibility coefficients of the ingredients for the piau (L. elongatus). A total of 600 males of piau were utilized, allotted into six ponds of 300L. The applied treatments were: grinder processed ration, pelleting ration and extruded ration, utilizing rations with 32% crude protein and 3400 Kcal DE.Kg-1. The experiment was in a randomized blocks design with three treatments, three blocks and two replicates. The data were submitted to variance analysis by the SAEG computational package and the means of the treatments compared by SNK test (5% of significance). The results showed that there were significant differences among the digestibility coefficients of both protein and energy for the pelleted and extrused rations (P0.05).

O objetivo deste trabalho foi avaliar parâmetros metabólicos de pacus (Piaractus mesopotamicus) alimentados com dietas com diferentes óleos. O experimento foi conduzido em laboratório, em maio de 2009, durante 28 dias. Foram utilizados 64 pacus com peso inicial de 61 g, mantidos em tanques de 250 L. Os tratamentos foram: dieta controle mais óleo de oliva; dieta controle mais óleo de milho; dieta controle mais óleo de peixe; e dieta controle mais óleo de milho e de peixe. Utilizou-se o delineamento inteiramente casualizado, com quatro repetições, em arranjo fatorial 4x4 (quatro dietas e quatro tempos de coleta: 7, 14, 21 e 28 dias). Foram avaliados: níveis sanguíneos de colesterol e lipoproteínas, composição química muscular, e atividade de glicose-6-fosfato desidrogenase (G6PD) e enzima málica (EM). Os dados foram submetidos à análise de variância, à comparação das médias pelo teste de Tukey, e à análise de regressão. Não houve diferença nos teores musculares de umidade e cinzas, mas foram observadas alterações na deposição lipídica e proteica, conforme os tempos de coleta, em todos os tratamentos. As dietas interferiram nos parâmetros sanguíneos avaliados. A atividade de G6PD é superior à da EM, sendo maior nos animais alimentados com óleo de oliva e milho, o que sugere maior deposição lipídica muscular nestes peixes. Portanto, o metabolismo lipídico do pacu é influenciado pela composição do lipídio da dieta. The objective of this work was to evaluate the metabolic parameters of pacu (Piaractus mesopotamicus) fed diets with different oils. The experiment was conducted in the laboratory, on May 2009, during 28 days. Sixty four fish with initial weight of 61 g, kept in 250 L tanks, were used. The treatments were: control diet plus olive oil; control diet plus corn oil; control diet plus fish oil; and control diet plus corn oil and fish oil. A completely randomized design was used, with four replicates and a 4x4 factorial arrangement (four diets and four sampling times: 7, 14, 21, and 28 days). The following were evaluated: cholesterol and lipoprotein blood levels, muscle chemical composition, and activity of glucose-6-phosphate dehydrogenase (G6PD) and malic enzyme (ME). The data were subjected to analysis of variance, comparisons of means using the Tukey test, and to regression analysis. There were no differences in muscle levels of moisture or ash, but changes were observed in lipid and protein deposition, depending on collection time, for all treatments. The diets interfered in the evaluated blood parameters. G6PD activity is higher than that of ME, being higher in animals fed with olive and corn oil, suggesting more lipid deposition in the muscles of these fish. Therefore, the lipid metabolism of pacu is influenced by the lipid composition of the diet.

Com este experimento objetivou-se avaliar o rendimento de carcaça de matrinxã (Brycon cephalus) nos diferentes cortes de cabeça, sendo o mesmo conduzido na Estação de Piscicultura da Universidade Federal de Lavras, no mês de maio de 2001. O delineamento foi inteiramente casualizado com 2 tratamentos (corte reto da cabeça e corte oblíquo da cabeça) e 20 repetições. Os peixes foram retirados dos tanques com peso médio de 840 gramas e abatidos por choque térmico em água com gelo. Foram analisados o rendimento de filé, rendimento de tronco limpo e a relação entre o comprimento do filé e o comprimento padrão. Concluiu-se que o corte oblíquo da cabeça proporcionou melhores rendimentos de tronco limpo (65,67%) em relação ao corte reto da cabeça (61,28%). Quanto à relação comprimento do filé e comprimento padrão, o corte oblíquo da cabeça também mostrou resultados superiores quando comparado ao corte reto da cabeça The objective of this study was to determine the carcass yielding of Brycon cephalus in different cuts of its head. The experiment was conducted in the Fish Farmer at the Federal University of Lavras, in may 2001. The experiment was in a randomized design with two treatments (head rightly cut and head obliquely cut) and twenty replications. The fish were removed from the tank with an average weigh of 840 g and were killed by temperature shock with water and ice. It was concluded that the head obliquely cut rendered the best barrel clean yielding (66%) compared to the head rightly cut (61%). In the same way, the ratio fillet/standard length also showed better results for the oblique cut compared to the right cut