Fábio Meurer

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,

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.

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.

Utilização de Saccharomyces cerevisiae como probiótico para tilápias-do-nilo durante o período de reversão sexual submetidas a um desafio sanitário

A 29-d experiment was carried out to evaluate the Saccharomyces cerevisiae (SC) as probiotic in diets for Nile tilapia (Oreochromis niloticus) during the sexual reversion phase, under a sanitary challenge. Three hundred 2-d larvae averaging 8.9 ± 1.02 mg and 0.71 ± 0.09 cm were allotted to a completely randomized design with two treatments and six replicates in twelve 50 L-aquaria. Sanitary challenge consisted of a daily supply of 0.5 mL of fresh swine manure. Treatments consisted of a commercial diet for the sexual reversion of tilapia, with (TP) or without (TT) 0.1% of S. cerevisiae. The larvae were fed ad libitum five times a day. At the end of experiment, the fries were counted, measured and weighed. Two fries of each treatment were randomly chosen for gu removal and counting of the number of bacteria and total coliforms. No treatment effect on performance and survival was observed. Only the intestine of TP fries was colonized by SC. No significant differences were observed for bacteria and total coliforms per g of intestinal content and aquarium water. The use of Saccharomyces cerevisiae as probiotic in diets for Nile tilapia (Oreochromis niloticus) during the sexual reversion period resulted in intestine settling with no effect on performance and survival, in a system of culture with sanitary challenge.

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.

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.

Fontes protéicas suplementadas com aminoácidos e minerais para a tilápia do Nilo durante a reversão sexual

This work aimed to evaluate the effect of protein source origin and lysine and methionine or phosphorus and calcium supplementation to Nile tilapia during sex reversal phase. Two hundred fries were assigned to a completely randomized design with four treatments and five replications, in twenty 12 L aquarium. One aquarium with 10 Nile tilapia fry was considered an experimental unit. Morning and afternoon temperatures, dissolved oxygen, pH and electric conductivity was 22.6 ± 0.1oC, 24.1± 0.4oC; 6.77 ± 0.38 mg/L, 7.75 ± 0.16 e 173.4 ± 2 µS/m, respectively. The treatments were diets, one only with protein source of animal origin (FA), other only with protein source plant origin (FV), another with protein source plant origin but supplemented with lysine and methionine (FAA) and other with protein source plant origin but supplemented with calcium and phosphorus (FP). Means of end values of weight and length fry submitted to FA diet was greater than others treatments, followed to FP and FV diets, who had same value that the FAA diet. FA diet showed higher values of final biomass, followed by FP and FAA, that showed the same value of FV diet. Fry condiction of FA diet was greater than FAA and FV, but similar to FP diet. The survival of FA, FV, and FP diets was same and greater than FAA. Diets with animal protein ingredients were more efficient than vegetal protein ingredients with lysine and methionine or calcium and phosphorus supplementation, for Nile tilapia during sex reversion phase.

Farelo de soja na alimentação de tilápias-do-nilo durante o período de reversão sexual

Eight hundred Nile tilapia larvae with two days old were used to evaluate the inclusion of soybean meal in diets fed Nile tilapia during the sex reversion period (30 days). The experiment was analyzed as a completely randomized blocks, with four treatments and four replications. A net tank with 50 larvae was considered an experimental unit. The treatments were formulated to be isoprotein and isonitrogenous (38.6% of digestible protein and 3,800 kcal/kg of digestible energy), with increasing levels of soybean meal inclusion 0, 16, 34 and 42%. Average final weight and length linearly increased as the dietary soybean meal levels increased. No treatment effect on survival and body condition was observed. It is recommend to include up to 42% of soybean meal in Nile tilapia diets in the sexual reversion phase.

Sensibilidade antimicrobiana de bactérias isoladas de Jundiá (Rhamdia quelen)

Aiming the evaluation of sensitivity profiles of pathogen bacteria responsible for fish diseases, 51 bacterial isolates from Jundia (Rhamdia quelen) belonging to the genus Acinetobacter spp. (8), Aeromonas spp. (15), Edwardsiella spp. (2), Enterobacter spp. (2), Klebsiella spp. (1), Plesiomonas spp. (5), Pseudomonas spp. (1), Staphylococcus spp. (11), and Vibrio spp. (6), were tested against antimicrobial agents used for treatment of bacterial fish diseases. All samples were processed at the Laboratory of Bacteriology, Department of Preventive Veterinary Medicine, UFSM. From 51 bacteria isolated from jundia fishes (Rhamdia quelen) 51 (100%) were sensitive to gentamycin, 49 (96,08%) to sulphazotrin, 47(92,16%) to chloramphenicol, 43 (84,31%) to tetracylin, 43 (84,31%) to naldixic acid, 31 (60,78%) to nitrofurantoin, 22 (43,14%) to erytromycin, 22 (43,14%) to ampicillin, 15 (29,41%) spiramycin, 13 (25,50%) to cholystin, and 5 (3%) to penicillin G. With exception of an isolate of Staphylococcus spp., the bacteria analyzed in the present study were resistant to one or more antimicrobial agents tested. Knowledge of the sensitivity profile of bacteria involved in infectious processes in fish will allow rational antimicrobial treatment that will contribute to the control of fish diseases in Rhamdia quelen without causing great risks to public health and the environment.