<b>Digestibilidade aparente de alimentos pelo piavuçu, <em>Leporinus macrocephalus</em></b> - DOI: 10.4025/actascianimsci.v26i2.1861 <b>Apparent digestibility of feedstuffs by piavuçu, <em>Leporinus macrocephalus</em></b> - DOI: 10.4025/actascianimsci.v26i2.1861

Este estudo teve por objetivo avaliar o coeficiente de digestibilidade aparente da matéria seca, da proteína bruta e a energia bruta de alimentos (farelo de soja, farelo de canola, farinha de peixe e milho), para juvenis de piavuçu, <em>Leporinus macrocephalus</em> (Anostomidae). 60 peixes (60g) foram alimentados com uma ração referência (purificada) marcada com 0,10% de óxido de crômio III. Os peixes foram mantidos em aquários de alimentação (500L), das 8h às 17h. Após esse período, foram transferidos para aquários (250L) apropriados para a coleta de fezes. Pode-se concluir que alimentos de origem vegetal (farelo de soja e milho) apresentam maiores coeficientes de digestibilidade aparente para a proteína bruta e a energia digestível.<br>This study aimed to evaluate the apparent digestibility coefficients of dry matter, crude protein and digestible energy of feedstuffs (soybean meal, canola meal, fish meal and corn) for piavuçu juveniles, <em>Leporinus macrocephalusn</em> (Anostomidae). Sixty fish (60.0g) were fed control diet (purified) marked with 0.10% chromic oxide III. Fish were maintained in aquaria (500L) for feeding, between 0800-1700h. After this period they were transferred for aquaria (250L) appropriate for fecal collection. The apparent digestibility coefficients of nutrient were determined by assessing the difference between the feed and fecal concentrations of the marker. It was concluded that vegetable feedstuffs (soybean meal and corn) showed high apparent digestible coefficients for protein crude and digestible energy

<b>Teores de cálcio em rações para o escargot francês <em>Helix aspersa máxima</em> em fase de crescimento</b> - DOI: 10.4025/actascibiolsci.v27i1.1361 <b>Calcium levels in escargot <em>Helix aspersa maxima</em> diets in growth phase</b> - DOI: 10.4025/actascibiolsci.v27i1.1361

Com o objetivo de avaliar o efeito de diferentes teores de cálcio em rações para o escargot francês <em>Helix aspersa máxima</em> na fase de crescimento foram utilizados 160 animais, com peso vivo inicial médio de 6,00 g, distribuídos em um delineamento inteiramente casualizado com quatro tratamentos (2,00; 3,00; 4,00 e 5,00 % de cálcio) e quatro repetições. Foram observados efeito linear positivo (p < 0,05) dos teores de cálcio sobre o peso final médio, percentagem de ganho de peso, conversão alimentar, efeito quadrático sobre rendimento de carcaça e consumo médio de ração, entretanto a sobrevivência não foi afetada. Concluiu-se que o aumento do teor de cálcio promove a melhora nas características de desempenho de <em>Helix aspersa máxima</em> na fase de crescimento, e que dentre as rações estudadas a mais indicada é a com 5% de cálcio<br>The experiment was carried out to evaluate the effects of different calcium levels in diets for <em>Helix aspersa maxima</em> in growth phase. One hundred and sixty animals were used with initial mean weight of 6.00 g distributed in a completely randomized design with four treatments (2.00, 3.00, 4.00 and 5.00% of calcium) and four replicates. Linear improve (p < 0.05) of calcium level was observed concerning the final weight medium, percentage of weight gain and food conversion as well as quadratic effect on carcass yield and feed intake. Nevertheless the survival rate was not affected. Results show that the calcium increase promotes a better performance of <em>Helix aspersa maxima</em> in growth phase and that the diet with 5.00% of calcium is highly recommende

<center>Antioxidant capacity of meagre (<i>Argyrossomus regius</i>) fed different lipid content and source, with and without selenium</center>

Selenium, an essential micromineral, is a co-factor of the antioxidant enzyme glutathione peroxidase. This enzyme is involved in cell membrane protection against oxidative damage resulting from reactive oxygen species production. Besides the importance of preservation of unsaturated fatty acids in fish, world aquaculture has been seeking for alternative oil sources in diet of fish. Thus, the main goal of this research work was to study the antioxidant capacity of meagre (Argyrossomus regius) fed with different levels of vegetable blend oil with and without selenium in replacement of traditional diets containing fish oil. Meagre (600 animals) were kept in 24 tanks (80 L) with constant renovation and aeration and maintained at 20.7 ± 0.7ºC and oxygen 8.8 ± 1.7 mg L-1. Fish were fed twice per day, six days per week, with eight different experimental diets for 60 days. Diets were formulated to have two different oil sources (fish or vegetable blend oils with 45% of linseed, 35% of rapeseed and 20% of soybean oil), two lipid levels (12 and 17%) and two selenium supplementation (0 and 1 mg/kg diet). Lipid peroxidation (LPO), glutathione reductase (GR), glutathione peroxidase (GPx), total glutathione (TG) and catalase (CAT) were analyzed in liver of fish. CAT, GPx and GR activities were not significantly altered in fish fed with diets with different oil sources. However, TG in fish fed with fish oil diet was higher than the levels observed in fish fed with vegetable blend oil. Furthermore, fish fed with fish oil diet showed lower lipid peroxidation when compared with fish fed vegetable blend oil diet (Table 1). Concerning the oil level in diet, it was observed that fish fed with a diet of 17% lipids had a higher level of total glutathione when compared to fish fed with a diet of 12% lipids. On the other hand, the fish fed with a diet with 12% lipids showed lower levels of lipid peroxidation when compared to fish fed with a diet of 17% lipids. Fish fed with diets supplemented with selenium showed a significantly increased activity of GPx when compared with fish fed without selenium. Three-way ANOVA analysis showed that dietary lipid level and the presence of selenium have a significant interaction on the activities of CAT and GR, as well as, levels of TG and LPO. A significant interaction between the source of oil and the presence of selenium on GR activities was observed. Interaction on source and level was observed to CAT. In conclusion, the antioxidant capacity of meagre is influenced by the source of oil, the level of lipids and the presence of selenium in their diet.</p