Arcangelo Augusto Signor

Proteína e energia na alimentação de pacus criados em tanques-rede

The aim of this study was to evaluate the performance of pacu (Piaractus mesopotamicus) raised in cages and fed diets containing levels of crude protein (CP) and digestible energy (DE). It was used 3.960 fish with an average initial weight of 293.38 ± 5.67 g, distributed in 18 net-ponds with 5 m3, with 220 fish per experimental unit (44 fish/m3) in a 3 × 2 factorial scheme composed of three levels of crude protein (25, 30 and 35%) and two levels of digestible energy (3,250 and 3,500 kcal/kg). Feeding was performed four times a day (9:00 a.m., 11:30 a.m., 2:00 p.m. and 5:00 p.m.) until apparent satiety of the animals. No differences were observed for weight gain, survival rate, apparent feed conversion and specific growing rate. Nevertheless, there was a difference on visceral fat deposition which was higher for animals fed ration with higher energy level. It was not observed influence of levels of protein and energy of the diet in contents of moisture, crude protein, mineral matter and lipids in the fish fillets, either. Rations containing 25% of crude protein and 3,250 kcal/kg of digestible energy promote better performance results.

Densidade de estocagem e parâmetros eritrocitários de pacus criados em tanques-rede

O objetivo neste trabalho foi avaliar o manejo, as caracteristicas eritrocitarias e o nivel de glicose sanguinea de pacus (Piaractus mesopotamicus) estocados em diferentes densidades em tanques-rede. Foram utilizados 2.700 peixes com peso inicial de 142,11 ± 10,54 g, distribuidos em nove tanques-rede de 5 m3 de volume util durante 240 dias. O delineamento utilizado foi o inteiramente casualizado, com tres densidades (200, 300 e 400 peixes por tanque), cada uma com tres repeticoes. Somente o peso final e o ganho de peso diminuiram com o aumento da densidade de estocagem. A biomassa final aumenta de acordo com o numero de animais estocados por unidade produtiva. As densidades de criacao nao influenciaram o rendimento de carcaca, mas afetaram o comprimento total, que foi maior nos peixes criados em baixa densidade, que nao diferiram daqueles cultivados em densidade intermediaria. Os peixes criados em menor densidade apresentaram maior deposicao lipidica, mas nao diferiram significativamente daqueles estocados em densidade intermediaria. As variaveis eritrocitarias, como eritrocitos totais, hemoglobina, hematocrito, volume corpuscular medio e concentracoes de hemoglobina corpuscular media e de hemoglobina corpuscular media, nao apresentaram diferencas estatisticas entre as densidades utilizadas e permaneceram na faixa normal para a especie. Os niveis de glicose no sangue nao diferiram significativamente entre as densidades trabalhadas. A densidade de estocagem nao influencia os parâmetros eritrocitarios, o nivel de glicose nem o rendimento de carcaca de pacus. A densidade de 200 peixes/tanque resulta em maior peso final e ganho de peso, porem reduz a produtividade por area e aumenta a deposicao lipidica dos peixes.

Desempenho de juvenis de tilápia-do-nilo alimentados com rações contendo complexo enzimático

The aim of this study was to evaluate the inclusion of an enzimatic complex in diets for Nile tilapia (Oreochromis niloticus) on performance, carcass chemical composition as well as water quality. The experiment was performed in 62 days. It was used two hundred reverted fingerlings (14.57 ± 1.24 g) distributed in a complete randomized design in 20 500 L-tanks with four treatments and five replicates, considering a box with 10 fish as a experimental unit. The fish were fed diets containing 0; 0.033; 0.066 and 0.099% of enzimatic complex. The diets were processed in peletized way and supplied four times a day (8:00 a.m., 11:00 a.m., 2:00 p.m. and 5:00 p.m.) The pH average values, electric conductivity, dissolved oxygen, temperature, total phosphorus, ammonia and water nitrate of the cultivation were not influenced by the inclusion of the enzimatic complexin the diet. The inclusion of enzymatic complex in the diet did not affect weight gain, survival, and specific growing rate; however, it affected diet consumption and food conversion, whose values were greater for fish fed 0.066% of enzimatic complex diet. No differences were observed on dry matter, humidity, crude protein, mineral matter, calcium and phosphorus in the fish carcass, nevertheless, the ether extract decreased linearly as the level of enzymatic complex increased. The utilization of enzimatic complex (amylase, protease, cellulase, lipase, pectinase, xylanase, β-glucanase and phytase) at the level of 0.066% for juvenile Nile tilapia (Oreochromis niloticus) worsens food conversion but does not influence performance and body composition of the fish.

Catfish (jundia) body yield and chemical composition fed different protein and energy level in the diet, reared in net-tanks

Objetivou-se analisar o rendimento corporal e a composicao quimica de jundias, Rhamdia quelen, alimentados com racoes contendo diferentes niveis de proteina e energia e criados em sistema de tanques-rede. Utilizou-se a densidade inicial de 70 peixes/m3, em 18 tanques-rede (5,0 m3), durante 324 dias. O delineamento experimental foi inteiramente casualizado com dois fatores - niveis de proteina bruta (PB), 25, 30 ou 35%; e niveis de energia digestivel (ED): 3.250 e 3.500 kcal - e tres repeticoes. A dieta foi fornecida a vontade, mas mensurada diariamente. No inicio, um lote de peixes foi sacrificado para determinacao dos parâmetros corporais e quimicos. A cada 28 dias, dois peixes de cada unidade experimental foram abatidos para determinacao dos comprimentos total e padrao, do peso total e dos pesos de figado, gonadas, cabeca, tronco limpo e gordura visceral, respectivamente. Posteriormente, foram realizados calculos dos indices hepatossomatico e gonadossomatico, da porcentagem de cabeca e do rendimento de carcaca e do rendimento de tronco limpo. A partir do mes de junho de 2006, tambem foram registrados o rendimento de file e o sexo dos individuos. Para determinacao da composicao da carne do jundia, foram realizadas as analises quimicas de umidade, proteina bruta, lipidios e materia mineral. O fornecimento da racao com 30% de PB resultou em maior rendimento de tronco limpo. A composicao do musculo nao foi influenciada pelas dietas testadas. Os melhores resultados foram obtidos com a utilizacao de dietas contendo 30% de PB e 3.250 kcal de energia digestivel/kg.

Farinha de vísceras de aves na alimentação de alevinos de piavuçu (Leporinus macrocephalus)

The present research aimed at evaluating the inclusion poultry by products of birds viscera flour (FV) in the feeding of piavucu (Leporinus macrocephalus) fingerlings. 125 fingerlings with weight and medium initial length of 0.26±0.01g and 2.37±0.28cm, respectively were used, distributed in 25 aquariums (30 liters water capacity each) in an entirely casualized delineation with five treatments and five repetitions. The rations were formulated in way to contain 0; 5; 10; 15 and 20% of FV, being the same isoenergetics and isoproteics. The feed giving was realized four times at 8, 11, 14 and 17 hours, with base in 10% of the total biomass. The zootechnics parameters evaluated were the final weight (PF), final length (CF), weight gain (GP), apparent alimentary conversion (CA) and survival (SO). There were observed an increase in the lineal differences (P 0.05) among the treatments. The increase in the inclusion of FV in rations up to 20%, improves the piavucu fingerlings performance.

Energia Digestível para Larvas de Tilápia-do-Nilo (Oreochromis niloticus) na Fase de Reversão Sexual

This experiment was conducted to evaluate different levels of digestible energy on the performance of Nile tilapia larvae (Oreochromis niloticus) during the sexual reversion phase. Three hundred and seventy-five larvae with initial average length and weight of 21.0±4.0 mg and 1.19±0.72 cm, respectively, were allotted to 25 30L-aquarium. A completely randomized design with five treatments and five replicates was used. The aquarium with 15 larvae was the experimental unit. The diets were formulated to contain levels of 3,300, 3,525, 3,750, 3,975, and 4,200 kcal/kg of digestible energy and to be isoprotein (38.6% digestible protein). The animals were fed ad libitum five times a day. At the end of the experiment, the averages of weight (PF), survival rate (SO), condition factor (FC) and length (CF) were analyzed. Linear reduction of fishes PF and CF, as the dietary digestible energy levels increased, was observed. No differences on fish SO and FC of different treatments were observed. Deleterious effects on performance due to the increasing dietary digestible energy levels were noticed for Nile tilapia larvae during the sexual reversion.

Energia digestível para alevinos de tilápia-do-nilo (Oreochromis niloticus)

The different levels of digestible energy on the performance of Nile tilapia (Oreochromis niloticus) fingerlings were evaluated. One hundred and twenty-five fingerlings averaging initial length and weight of 0.62±0.12 and 3.25±0.25 cm were allotted to 25 30L-aquariums, as a completely randomized design with five treatments and five replicates (an aquarium with five fingerlings was considered the experimental unit). The diets, formulated to be isonitrogenous (30% of digestible protein), isophosphorous and isocalcium, contained 3,300, 3,525, 3,750, 3,975, and 4,200 kcal/kg of digestible energy. The amount of diet was fed of 10% of biomass four times a day. The abiotic parameters (pH, dissolved oxigen - DO, and electric condutivity - EC) were weekly measured at afternoon and the temperature was was daily mensured. The following values were observed: pH of 7.91±0.19, DO of 8.00±0.05 mg/L, EC of 92.11±2.27 µS/cm, and temperature of 25.61±0.90oC. At the end of experiment, means of final weight, weight gain, final length, apparent feeding conversion, survival rate and condition factor were analyzed. No significant differences on fingerling perfomance were found across the treatments. It can be included from 2,900 to 3,400 kcal of ED/kg in the diet of Nile tilapia fingerlings.

Inclusão de amido em dietas para larvas de tilápia-do-nilo

The experiment was carried out to evaluate the different levels of starch inclusion in Nile tilapia (Oreochromis niloticus) larvae diets. Three hundred and seventy-five larvae averaging initial weight of 8.02 ± 2.11 mg were allotted to 25 30 L-aquariums, as a completely experimental randomized design, with five treatments and five replications. The diets were formulated to contain the inclusion levels of 0: 2.5: 5: 7.5 and 10% of starch, with 3,500 kcal DE/kg and 38.6% digestible protein. The fishes were fed ad libitum, five times a day. No differences were observed on final weight, weight gain, condition factor and the fishes survival fed diets with starch and control treatment. Starch can be included up to 10% for Nile tilapia larvae as energy source, without effect on fish performance.

Farinha de Resíduos da Filetagem de Tilápia em Rações para Alevinos de Piauçu (Leporinus macrocephalus)

This trial was carried out to evaluate the effects of feeding Tilapia fillet by-products meal (TF) for piaucu (Leporinus macrocephalus) fingerlings. One hundred and twenty-five fingerlings averaging weight of 0.19 ± 0.004 g and length of 2.37 ± 0.28 cm were assigned to a completely randomized design with five treatments of five replicates. The diets were formulated to contain levels of 0, 5, 10, and 15% of TF and 0% of TF plus methionine. Diets were fed at 10% of biomass four times a day (8 a.m., 11 a.m., 2 p.m. and 5 p.m.). The means of water abiotic parameters were 7.89 ± 0.05, 89.93 ± 0.42, 7.15 ± 0.10 and 27.10 ± 0.95 for pH and electric conductivity (μS.cm - 1 ) and dissolved oxygen (mg.L -1 ) and temperature (oC), respectively. At the end of the experiment, the means of survival (SO), final weight (FW), final length (FL), weight gain (WG), condiction factor (CF), and apparent feeding conversion (FC) were measured and calculated. Significant effects of treatments on CF, CA, and FC were detected. The better results were observed with the increasing levels of FT and supplementation of methionine. FL increased and FC decreased linearly with the increasing levels of TC, where the LRP model better adjusted to data when 8.56 and 8.19% of TF levels were estimated. The crude protein (PB) in the carcass presented better results for the treatments with more than 5% of FT and 0% of FT with methionine supplementation. It is recommended to include up to 15% of FT in the diets for piaucu fingerlings to obtain better results of performance and CP deposition in the carcass, that becomes the FT an alternative protein source.

Composição química e digestibilidade aparente da energia e nutrientes da farinha de resíduos da indústria de filetagem de tilápias, para a tilápia do Nilo (Oreochromis niloticus)

Coefficients of apparent digestibility (CD) of dry matter (DM), crude protein (CP), crude energy (CE) and the availability of amino-acids (AA), phosphorus (P) and calcium (Ca) of meals from tilapia filleting industrial waste (FT) for the Nile tilapia were determined. Sixty tilapias, mean weight and length 80.69±15.97g and 15.97±1.87cm respectively, underwent feces collection by sedimentation in cone-bottom tanks. DM, CP and BE of FT had a CD of 83.55; 88.13 and 84.74% respectively, with digestible protein and energy rates equivalent to 44.39% and 3799.02 Kcal of ED kg-1. FT had average CD of AA of 91.60%, with CD varying from 67.90% for Fen up to 100% for Arg and Cis. Whereas CD of P was 70.44% with 1.94% of available P, CD of Ca of FT amounts to 51.10% with 4.02% of Ca available. FT is a protein feed with a good index of apparent availability of its nutrients and may be used in feed of tilapia. Above indexes will produce low cost feeds that also meet the requirements of the fish.