Wilson Rogério Boscolo

Digestibilidade aparente de alguns alimentos protéicos pela tilápia do Nilo (Oreochromis niloticus)

ABSTRACT - A digestibility trial was carried out to determine the dry matter (MS), gross energy (EB) and crude protein (PB)apparent digestibility coefficients (CD) for fish meal (FP), poultry by-products meal (FV), gluten meal (GM) and alchool spray driedyeast (LV) for Thai Nile tilapia fingerlings. A hundred sexually reverted fishes (average weight 37.6 ± 5.0 g) were assigned to two500-L feeding tanks and two 150-L cylindrical tanks with conical bottom, to feces collection . CD analysis was performed by the indirectmethod, using 0.1% chromic oxide (Cr 2 O 3 ), as marker. Average water temperature, dissolved oxygen, pH and conductivity were 25.8± 1.0 o C; 3.2 ± 1.4 mg/L; 6.8 ± 0.1; and 205.7 ± 16.5 µS/cm, respectively. CD of PB, EB and MS were 90.66, 89.53 and 87.63 for FP;82.03, 72.09 and 62.21 for FV; 97.61, 93.52 and 91.01 for GM; 77.39, 62.77 and 58.68 for LS, respectively. The digestible values ofprotein (%) and energy (kcal/kg), as fed basis, were 53.01 and 3568.0 for FP; 47.65 and 3650.9 for FV; 65.34 and 5036.7 for GM; and32.19 and 2706.9 for LS.Key Words: digestibility, foods,

Lipídeos na Alimentação de Alevinos Revertidos de Tilápia do Nilo (Oreochromis niloticus, L.)

Aiming to evaluate the effect of increasing levels of fat in the ration on performance, speed of food pass, consummates of ration and corporal fat, it were used 168 Nile tilapia fingerlings, reverted, with average weight of 1.24 ± 0,03g and average size of 4.10 ± 0.30 cm, allotted to 24 aquariums, of 50 L of useful volume, in a completely randomized design with six treatments and four replicates, where the aquarium with seven animals was considered experimental unit, for a period of 40 days. The temperature was kept in 27.2 ± 0.6oC for heaters of 100W with thermostat and constant aeration. Diets were formulated to be isonitrogen, isoenergy and isoamino acidic for lysine and cystine + methionine, varying how much to the level of fat (3.0, 4.8, 6.6, 8.4, 10.2, and 12.0%). They had been evaluated the effect of the level of fat on the averages of the weight gain (GP), feed conversion (CA), tax of protein efficiency (TE), consumption of ration (CR), speed of food pass (VP) and corporal fat (GC). The GP, TE, CA had decreased linearly as the dietary level of fat increased, while GC increased, the CR did not present difference between the treatments, the VP presented a quadratic effect with point of minimum in 6.0% of fat in the ration. To reverted Nile tilapia fingerlings it is recommend 3.0% as fat level in the diet and was show a better starch utilization like energy source than fat in this specie.

Exigência de proteína digestível para larvas de tilápia do Nilo (Oreochromis niloticus), durante a reversão sexual

ABSTRACT - The aim of the work was to determine the digestible protein requirement (PD) for Nile tilapia in the sexual reversionphase, where 1250 larvae were assigned to 25 aquariums (60 L), with five treatments and five replicates in a completly randomiz ed design.The larvae were fed ad libitum , five times a day, with isoenergy, isocalcium, isophophorus rations, with 30, 34, 38, 42 and 46% of PD,and 30 mg/kg of a-metil hormone testosterone. The animals of each experimental unit were counted and weighed at each 15 and 28 daysof experiment for evaluation of the survival and average weight. For the average weight of the animals quadratic effect was obs erved,with point of maximum of 39.06 and 38.56% of PD at 15 and 28 days, respectively. The survival rate linearly decreased as the P D levelsincreased, at 15 and 28 days. Water temperature, pH, conductivity and dissolved oxygen level presented average values of 24.60 of ±2.02 o C; 7.34 ± 0.22; 218.47 ± 16.29 µS/cm; and 6.38 ± 1,18 mg/L respectively. The PD requirement of for Nile tilapia in the sexual reversionphase was of 38.6%.Key Words: protein requirement, larval phase, Nile tilapia,

Influência do processamento da ração no desempenho e sobrevivência da tilápia do Nilo durante a reversão sexual

This work was carried out at Aquicultura Laboratory of Maringa State University, to evaluate the different processing form of diets on Nile tilapia fry performance and survive, during sexual revert phase. Was utilized 540 fry distributed, on completely randomized design with three treatments and six replications, in eighteen 54 L aquarium and one aquarium with 30 Nile tilapia fry was considered an experimental unit. The experimental period was 28 days with average temperatures of 21.9 ± 0.1oC in the morning and 22.7 ± 0.3oC in the afternoon. The diet was formulated (38.6% of digestible protein and 3800 kcal/kg digestible energy) differing only about processing form (crumble [MD], meal [ND] and pasty [PD]). No difference was observe to final weight and body condition, but to biomass production, the fry submitted of ND treatment was higher than MD and PD treatments, that were equal. To survive ND and PD were equal and higher than MD treatment. It was concluded that, with 0.5 mm of mealling degree, the meal diets was most adequate to Nile tilapia fry, during sex revert phase.

Desenvolvimento de girinos de rã-touro (Rana catesbeiana, Shaw, 1802) cultivados em diferentes densidades de estocagem em tanques-rede

Objetivou-se, nesta pesquisa, avaliar o efeito da densidade de estocagem sobre o desenvolvimento de girinos de ra-touro em tanques-rede. Foram utilizados 360 girinos com peso medio inicial 0,01g e comprimento inicial medio de 0,92±0,06 cm, distribuidos em um delineamento em blocos ao acaso com cinco tratamentos (0,50; 1,00; 1,50; 2,00 e 2,50 individuos/L) e quatro repeticoes, em 20 tanques-rede experimentais (12 L). Foi fornecida dieta com 40,00% de proteina bruta, na proporcao de 8,00% do peso vivo, duas vezes ao dia. Observou-se aumento linear da biomassa por tanque, em funcao da densidade de estocagem. O peso final medio e a taxa de sobrevivencia apresentaram reducao linear, com o aumento da densidade. Observaram-se lotes mais uniformes dos girinos cultivados em menores densidades. A conversao alimentar nao foi influenciada pelas diferentes densidades de estocagem. As variaveis fisico-quimicas da agua estiveram em niveis adequados. Concluiu-se que, com menores densidades, obtem-se girinos maiores e lotes mais uniformes com melhor taxa de sobrevivencia.

Digestibilidade aparente da energia e proteína das farinhas de resíduo da filetagem da tilápia do Nilo (Oreochromis niloticus) e da corvina (Plagioscion squamosissimus) e farinha integral do camarão canela (Macrobrachium amazonicum) para a tilápia do Nilo

The trial was conducted to evaluate the apparent digestibility coefficients (CDa) of gross energy (EB) and crude protein (PB) of tilapia (FT) and corvina (FC) processing by-product meal, and canela crayfish (Macrobrachium amazonicum) meal (FM), for Nile tilapia fingerlings. Forty sexual reverted fishes, with average weight of 40 g, were allotted to 500 L feeding tanks. Feces collection was performed at two 150 L conical tanks. CDa was evaluated by an indirect method, with 0.1% chromic oxide (Cr2O3) as the indicator. Average temperature, dissolved oxygen, pH and conductivity were 8.5 ± 0.5oC, 3.57 ± 0.12 mg/L, 7.21 ± 0.03, e 0.18 ± 0.01 mS/cm, respectively. Digestibility coefficients of PB, EB and MS was 70.67 and 54.45 for FC, 67.09 and 48.52 for FT, 88.79 and 68.38 for FM, respectively; the digestible values of protein (%) and energy (kcal/kg) as fed basis were, 37.50 and 2107.46 for FC, 28.72 and 1927.18 for FT, 53.74 and 2763.23 for FM. The evaluated feedstuffs have potential for utilization on tilapia nutrition, however, it is necessary to determine its inclusion levels in diets for the different rearing phases of this species.

Desenvolvimento de larvas de surubim-do-iguaçu (Steindachneridion melanodermatum) submetidas a diferentes dietas

An assay was conducted to evaluate the development of Iguacu surubim (Steindachneridion melanodermatum) larvae fed different diets. The experiment was analyzed as a complete randomized design with five treatments and four replicates, in 35 L-aquaria, each one with 15 larvae (8.35±0.85 mm and 6.75±0.64 mg). The treatments consisted of five feeding programs: Artemia (A); diet (D); zooplankton (Z); Artemia with diet (A+D); and zooplankton with diet (Z+D). Larvae development was evaluated in illuminated environment during 29 days. For larvae feeding evaluation, three larvae were collected every three days, in five additional aquaria for stomach content analysis. In the A+D and Z+D treatments, the larvae average weight (659 and 571 mg) was significantly higher than the other treatments. The combinations of feeds resulted in better results and, in treatment R, it was observed survival rate of 1.7, that differs from the other treatments. Cannibalism rate was higher in D and Z treatments, with values of 60 and 25%, respectively. The A+D treatment provided the best development and the highest survival rate for Steindachneridion sp larvae.

Fibra Bruta para Alevinos de Tilápia do Nilo (Oreochromis niloticus, L)

This work aimed to evaluate different crude fiber levels on reverted Nile tilapia (Oreochromis niloticus, L) fingerlings performance and time of retention of food. One hundred and twenty-five fingerlings of Thai strain, 1.39 ± 0.03 g of initial weight were allotted to twenty-five 54 L aquarium, at five treatments and five replications on completely randomized design. Five isoenergy (3000 kcal/kg of digestible energy) and isoprotein (30% of crude protein) diets were formulated with five different crude fiber levels (3.65, 4.75, 6.00, 7.25 and 8.50%), for ranging cellulose and inert material addition. The experimental period was 64 days with 26.5oC ± 0.8 in the morning and 27.5oC ± 0.7 in the afternoon temperatures. No difference was observed to fingerlings performance (food conversion, final weight, weight gain), but a linear decrease to time of retention of food with crude fiber addition.

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.

Farinha de resíduos da filetagem de tilápias na alimentação de tilápia-do-nilo (Oreochromis niloticus) na fase de reversão sexual

Este trabalho foi realizado com o objetivo de avaliar a inclusao da farinha de residuos da industria de filetagem de tilapias (FT) na alimentacao da tilapia-do-nilo na fase de reversao sexual. Foram utilizadas 375 larvas com dois a tres dias de idade, distribuidas em 25 aquarios com capacidade para 30 L, em delineamento inteiramente casualisado, com cinco tratamentos e cinco repeticoes, sendo a unidade experimental constituida por um aquario com 15 larvas. Foram elaboradas cinco racoes isoproteicas e isoenergeticas com 38,6% de proteina digestivel e 3.800 kcal de ED/kg, com niveis de 0, 5, 10, 15 e 20% de inclusao de FT. Os valores de temperatura, oxigenio dissolvido, pH e condutividade eletrica da agua dos aquarios durante o periodo experimental foram de 24,53 ± 1,60oC; 4,81 ± 0,68 mg/L; 7,70 ± 0,25; e 175,97 ± 108,46 µS/cm, respectivamente. Ao final do experimento, nao foram observadas diferencas no peso e comprimento final, no fator de condicao, na sobrevivencia e no indice de reversao sexual das larvas alimentadas com a FT. A inclusao de ate 20% de FT em racoes para tilapia do Nilo na fase de reversao sexual nao causa prejuizo ao desempenho dos peixes.