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Listeria monocytogenes is a foodborne pathogen that contaminates food-processing environments and persists within biofilms on equipment, thus reaching final products by cross-contamination. With the growing demand for clean-label products, the search for natural antimicrobials as biopreservants, such as bacteriocins, has shown promising potential. In this context, this study aimed to evaluate the anti-listerial action of bacteriocins produced by Enterococcus lactis LBM BT2 in an alternative medium containing sugarcane molasses (SCM). Molecular analyses were carried out to characterize the strain, including the presence of bacteriocin-related genes. In the kinetic study on SCM medium E. lactis, LBM BT2 showed biomass and bacteriocin productions similar to those observed on a sucrose-based medium (control), highlighting the potential of the sugarcane molasses as a low-cost substrate. Stability tests revealed that the molecule remained active in wide ranges of pH (4–10) and temperature (60–100 °C). Furthermore, the proteolytic treatment reduced the biomolecule’s antimicrobial activity, highlighting its proteinaceous nature. After primary purification by salting out and tangential flow filtration, the bacteriocin-like inhibitory substance (BLIS) showed bacteriostatic activity on suspended L. monocytogenes cells and against biofilm formation at a concentration of 0.625 mg/mL. These results demonstrate the potential of the produced BLIS as a biopreservative in the food industry.

Streptococcus agalactiae is an important bacterial pathogen in intensive Nile tilapia production, causing high mortality rates and great economic losses. This work aimed to evaluate the Nile tilapia vaccination against S. agalactiae and fed with ration containing probiotic AQUA PHOTO® composed of Bacillus subtilis and Lactobacillus plantarum, on the immune response action and gut microbiota. The experimental design was completely randomized with five treatments (CON = control; ADJ = adjuvant; PRO = probiotic; VAC = vaccine; PRO + VAC = probiotic + vaccine) and five replicates. The vaccine (bacterin + adjuvant) was injected after 21 days (21d) of probiotic feeding and the vaccine was booster 14 days post-vaccination (35d). After 14 days of the booster (49d), the fish were challenged with S. agalactiae and observed for more than 14 days, completing 63 days. The immunized group showed a better survival rate (CON 40%; ADJ 57%; PRO 67%; VAC 87%; PRO + VAC 97%). The treatments VAC and PRO + VAC, after booster produced higher levels of IgM antibodies compared with the control from the same time. The combination of probiotic and vaccination provided better protection against S. agalactiae infection, directly affecting the gut microbiological profile. These results indicated the contribution of probiotic to the adaptive immune response through the modulation of the intestinal microbiota, improving the effect of the vaccination. In conclusion, AQUA PHOTO®, composed of B. subtilis and L. plantarum, orally administered to Nile tilapia vaccinated against and challenged with S. agalactiae increases protection from infection and modifies the intestinal microbiota profile of the host, promoting the microbiota balance and improving adaptive immune response.

A commercial probiotic containing Bacillus subtilis (109 CFU g-1) was evaluated in caged matrinxã, Brycon amazonicus, by measuring hematological parameters and macrophage activity after 42 and 84 days after feeding. The product was added to commercial feed using 2% soybean oil as a protectant. A randomized three-treatment experiment was performed using four replicates per treatment. The groups included: (a) control without probiotic, (b) 5 g kg-1 probiotic, and (c) 10 g kg-1 probiotic. For hematological analysis, eight fish per treatment were used to determine total cell count (RBC); thrombocytes, differential, and total leukocyte count (TLC); hematocrit (Htc); hemoglobin tax; mean corpuscular volume (MCV); and mean corpuscular hemoglobin concentration (MCHC). Furthermore, plasma cortisol and glucose levels were measured in blood samples. Macrophage phagocytic activity was evaluated by injecting Saccharomyces cerevisiae (11,000 cells in a 3 mL volume) into the coelomic cavity incubating for 8 hours. Addition of probiotics to the diet of caged matrinxã altered the Htc, RBC, MCV, MCHC, TLC, lymphocyte, and eosinophil values. We observed increased cortisol and glucose levels and phagocytic activity, but no increase in the phagocytic index. We thus conclude that supplementing caged Brycon amazonicus with probiotics improves their non-specific immunity and alters blood profiles.

The use of probiotics, prebiotics and synbiotics provides better growth rates, improves the innate immune system and protection against several bacterial pathogens. The species Aeromonas hydrophila causes high mortality rate and production loss, provoking an antimicrobial overuse. This study aimed to prove the capacity of commercial probiotic DBA® (Bifidobacterium sp, Lactobacillus acidophilus and Enterococcus faecium), prebiotics MOS and chitosan, combined as synbiotics or not to promote Nile tilapia growth performance, innate immune system modulation and protection against A. hydrophila. One experiment with 24 units, duration of 63 days, and another experiment infection assay with A. hydrophila (18 experimental units, individual recirculation system, duration of 15 days) were performed. The treatments were: control, probiotic DBA (PRO), the prebiotics mannan oligosaccharides (Actigen®) (MOS) and chitosan (CHI), and the synbiotics composed of probiotic and MOS (Actigen®) (PRO + MOS), probiotic and chitosan (PRO + CHI). Growth performance, hematology, intestinal histology and immunology, and relative protection level against A. hydrophila were analyzed. Significant differences were observed in the final biomass for the treatments PRO + CHI and CHI when compared with PRO + MOS, and greater individual weight gain in group PRO + CHI in relation to group PRO + MOS. High concentrations of Lactobacillus spp. in intestinal tract of probiotics, prebiotics and symbiotics groups were observed. The treatments PRO + MOS, PRO + CHI and PRO promoted apparent preservation of the intestinal epithelium and stimulated an increase in goblet cells, blood vessels and mast cells, associated to immune system. The symbiotics MOS and DBA® promoted better relative protection level with percentage of 40%. This study recommends the use of probiotics, prebiotics and synbiotics to improve the protection against A. hydrophila infection without growth reduction. Inclusion of feed additives may reduce the application of antimicrobials in fish farming.

The aim of this study was to evaluate the effect of the probiotic Bacillus subtillis and beta-glucan from the fungus Agaricus blazei on survival, growth and immunological capacity in bullfrogs (Lithobates catesbeianus) cultured in low and high stocking densities. Animals weighing 24.3 ± 2.38 g were randomly distributed into four treatments with four simultaneous replicates: D100: 100 frogs/m2 (control); D236: 236 frogs/m2; D236 + Prob.: 236 frogs/m2 supplemented with probiotic; and D236 + BG: 236 frogs/m2 supplemented with beta-glucan. The parameters evaluated were weight gain, survival, plasma corticosterone (CORT), phagocytic capacity (PC) and phagocytic index (PI), at 24 h and 15 and 30 days. There is significant interaction between treatments and time for CORT levels. At 30 days, these values were very close for the D100 (control) and D236 + BG groups. Meanwhile, no statistical differences were observed between treatments for PC and PI. These results indicate that beta-glucan reduced the effects of stress caused by high density in bullfrogs, but the probiotic did not reduce these effects. Both compounds are not efficient at increasing survival rates, weight gain and neither immune response of animals. Thus, the use of commercial food additives may not have the favorable impact desired by the farmer. Their use in aquaculture should be further studied in experiments involving a longer trial period and taking into account the cost of their use.

The aquaculture industry is in considerable increases. Optimization of husbandary conditions in intensive aquaculture are in continuous interest. Probiotic was proved as promising factors to enhance fish production by remodeling intestinal microbial balance, boosting immune system and reducing antibiotic uses. The efficient strategy of probiotic uses and their protection of fish still making debate. The intake of tilpia fed with basal diet enriched with probiotic (Enterococcus faecium) and its response following to a challenge with pathogenic strain of Aeromonas hydrophila was studied. Four feeding strategies were tested and compared: continuous feeding with only basal diet (CTR), continuous feeding with probiotic-supplemented diet (CON), pulse-administration feeding of 7 days (P7) and 14 days (P14) alternation with probiotic supplemented diet and basal diet. Differences in growth rate, immune system modulation and biochemical parameters were evaluated. P7 strategy showed efficacy in promote fish growth conditions. Body chemical composition and blood biochemical parameters did not show any significative differences between feeding strategies. Burst respiratory analysis showed significant difference in fish fed with P14 strategy. After challenge test, CON strategy showed better fish protection against Aeromonas hydrophila. Enterococcus faecium enhance fish growth, boost imune system if administrated in 14 days period, and efficiently protect fish if it is continuously administrated. Keywords: Enterococcus faecium, Tilapia, Immune system, Feeding strategies, Challenge, Aeromonas hydrophila

This work examines the economic advantages of probiotic use in the diet of Nile tilapia broodstock during the reproductive period. For this purpose, Bacillus subtilis was applied as a feed additive. The experimental design was completely randomized with three treatment groups: the T0 control (without probiotic), the T1 continuous probiotic intake, and the T2 alternate probiotic intake at a dose of 0.50 g kg-1 of feed (1010 CFU g-1) with four replicates. For the reproduction assay, 118 females and 48 males of Nile tilapia (proportion 4 males:9 females. hapa-1) (weight 527.65 g ± 185.98 g and length 30.16 cm ± 3.57 cm) were distributed into 12 hapas (3.5 × 2.0 × 1.5 m). Reproductive variables (spawning female percentage, egg production, and fry production) were used to calculate the economic feasibility indexes (total cost of nutrition [TcN], gross revenue [GR], and total operational profit [ToP]). The results show increasing values for spawning female number, collected eggs, and surviving fry in the probiotic groups. We recommend continuous intake of probiotic (feed with addition of probiotic) at a dose of 0.5 g kg-1 of feed (1010 CFU g-1) during the breeding season of Nile tilapia, due to the suitable reproductive indexes and profitability.

The objective of this work was to evaluate the addition of Bacillus subtilis probiotic to the feed of common snook (Centropomus undecimalis) fingerlings, in alternate and continuous regimens. Six hundred and sixty fish, with average length of 5.90±0.88 cm and weight of 1.92±0.28 g, were stocked in 12 cages of 1.0 m3, with 55 fish each. The experimental design was completely randomized, with three treatments and four replicates. The treatments consisted of diet with the addition of probiotic, provided in alternate regimen for 7 days and in continuous regimen; besides a control without probiotic in the feed. Zootechnical performance, body composition, immune response, and blood parameters were evaluated. No significant differences were observed in zootechnical performance indexes and in body composition of fish treated with probiotic, when compared to the control. Fish from the alternate regimen showed an increment in respiratory burst and a lower total erythrocyte count than fish from the continuous regimen and the control. Fish from the continuous regimen did not differ from those of the control. The addition of Bacillus subtilis does not increase growth rates of common snook fingerlings; however, it has an immunostimulant action when supplied in alternate regimen.

This study aimed to analyze the economic feasibility of supplement probiotics Bacillus subtilis to “matrinxã” Brycon amazonicus, raised in cages. The experiment was conducted at the Polo Regional Vale do Ribeira, in Pariquera-açu municipality, São Paulo State, Brazil, from February to July 2009. A total of 960 juvenile matrinxã were stocked in twelve 2.7 m³-net cages (1.5 x 1.5 x 1.2 m), in ponds with a total area of 600 m2 and an average depth of 1.50 m. The tests were conducted with a control treatment (T1) and two probiotic doses (T2 = 5 g and T3 = 10 g kg-1 of diet) with four replicates. Results showed that T2 produced better economic performance for matrinxã at the juvenile stage in intensive rearing system.Objetivou-se analisar a viabilidade econômica do uso do probiótico Bacillus subtilis na alimentação de matrinxã Brycon amazonicus, em tanques-rede. O experimento foi conduzido no Polo Regional do Vale do Ribeira, no município de Pariquera-Açu, São Paulo, Brasil, entre fevereiro e julho de 2009. Foram avaliados 960 peixes juvenis, divididos em 12 tanques-rede de 2,7 m³ (1,5 x 1,5 x 1,2 m) em uma área total de 600 m2, com profundidade média de 1,50 m. Os testes foram conduzidos com um tratamento testemunha (T1), duas doses de probiótico (T2 = 5 g e T3 = 10 g kg-1 de ração) e quatro repetições. Os resultados mostraram que o T2 proporcionou melhor desempenho zootécnico e econômico da matrinxã na fase de engorda no sistema intensivo de criação.

This study aimed to analyze the economic feasibility of supplement probiotics Bacillus subtilis to “matrinxã” Brycon amazonicus, raised in cages. The experiment was conducted at the Polo Regional Vale do Ribeira, in Pariquera-açu municipality, São Paulo State, Brazil, from February to July 2009. A total of 960 juvenile matrinxã were stocked in twelve 2.7 m³-net cages (1.5 x 1.5 x 1.2 m), in ponds with a total area of 600 m2 and an average depth of 1.50 m. The tests were conducted with a control treatment (T1) and two probiotic doses (T2 = 5 g and T3 = 10 g kg-1 of diet) with four replicates. Results showed that T2 produced better economic performance for matrinxã at the juvenile stage in intensive rearing system.

O objetivo deste trabalho foi avaliar o desempenho zootécnico de larvas de matrinxã, Brycon amazonicus, alimentadas com probiótico composto de Bacillus subtilis bioencapsulado em Artemia salina, em diferentes doses. Foram utilizados seis tratamentos, sendo: T0 = controle (sem adição de probiótico), T2,5 = 2,5 g de probiótico, T5,0 = 5,0 g de probiótico, T7,5 = 7,5 g de probiótico, T10,0 = 10,0 g de probiótico e T12,5 = 12,5 g de probiótico por litro de água quando alimentados com A. salina (4h antes da alimentação das larvas) e por quilo de ração (comercial pó 40% proteína bruta) na fase seguinte. Os resultados mostraram heterogeneidade em relação ao crescimento, indicando que na fase larval o probiótico não influenciou no canibalismo.The aim of this study was to evaluate the growth performance of Brycon amazonicus larvae fed with probiotic consisting of Bacillus subtilis, bioencapsulated in Artemia salina at different doses. Six treatments were used: T0 = control (without probiotic), T2.5 = 2.5 g, T5.0 = 5.0 g, T7.5 = 7.5 g, T10.0 = 10.0 g and T12;5 = 12.5 g per liter of probiotic when fed with A. saline (4h before feeding the larvae); and per kilogram of feed (commercial powder with 40% crude protein) in the next phase. The results showed heterogeneity with regard to growth, indicating that larvae fed with probiotic had no influence on cannibalism.

Brycon amazonicus larvae fed with probiotic consisting of Bacillus subtilis, bioencapsulated in Artemia salina at different doses. Six treatments were used: T0 = control (without probiotic), T2.5 = 2.5 g, T5.0 = 5.0 g, T7.5 = 7.5 g, T10.0 = 10.0 g and T12;5 = 12.5 g per liter of probiotic when fed with A. saline (4h before feeding the larvae); and per kilogram of feed (commercial powder with 40% crude protein) in the next phase. The results showed heterogeneity with regard to growth, indicating that larvae fed with probiotic had no influence on cannibalism.Brycon amazonicus, alimentadas com probiótico composto de Bacillus subtilis bioencapsulado em Artemia salina, em diferentes doses. Foram utilizados seis tratamentos, sendo: T0 = controle (sem adição de probiótico), T2,5 = 2,5 g de probiótico, T5,0 = 5,0 g de probiótico, T7,5 = 7,5 g de probiótico, T10,0 = 10,0 g de probiótico e T12,5 = 12,5 g de probiótico por litro de água quando alimentados com A. salina (4h antes da alimentação das larvas) e por quilo de ração (comercial pó 40% proteína bruta) na fase seguinte. Os resultados mostraram heterogeneidade em relação ao crescimento, indicando que na fase larval o probiótico não influenciou no canibalismo.

Apparent digestibility coefficients (ADC) of starch and calcium (Ca) and phosphorus (P) apparent availability were evaluated in five cereal grain products and byproducts (corn, wheat meal, rice grain, rice bran and sorghum) for Nile tilapia. Chromic oxide was used as anexternal digestibility marker. The highest Ca and P apparent availability, respectively, were obtained for rice grain (43.03 and 64.79%), sorghum (39.89 and 58.09%) and corn (22.18 and 19.48%), while rice bran (-31.49 and 3.25%) and wheat meal (5.80 and 1.18%) showed the lowest values. Starch digestibility varied between 99.45and 95.59% among the evaluated ingredients. This high ADC of starch observed in this study confirms that Nile tilapia is able to efficiently digest and utilize complex carbohydrates.

Na aquicultura são utilizados análises da ativação e incremento da migração de macrófagos, com intuito de verificar a capacidade imunológica inespecífica dos peixes frente a um desafio. Neste sentido, o objetivo deste estudo foi determinar o tempo de migração de monócitos/macrófagos para a cavidade peritoneal em matrinxã, Brycon amazonicus, por meio da técnica de inoculação de leveduras Saccharomyces cerevisiae, e verificar as possíveis alterações dos parâmetros hematológicos após o estímulo. Foram utilizados 30 matrinxãs com peso médio de 101,55 ± 24,50 g e comprimento médio de 19,75 ± 1,72 cm. Os tempos de inoculação utilizados foram 2, 4, 8 e 12 horas, sendo utilizados 6 animais por tempo. Após os períodos de incubação (2, 4, 8 e 12 horas), os exemplares foram anestesiados e alíquotas de sangue foram coletadas por punção do vaso caudal, para a análise: número total de células, contagem diferencial e total dos leucócitos e contagem total de trombócitos, hematócrito, taxa de hemoglobina e índices hematimétricos (VCM, HCM e CHCM). Os resultados mostram que a capacidade fagocítica do macrófago não apresentou diferenças significativas entre os tempos experimentais. Com relação ao índice fagocítico, o tempo de 2 horas representa o tempo em que os macrófagos fagocitaram maior número de leveduras com diferenças significativas em relação aos outros tempos experimentais, indicando que este tempo (2 horas) de incubação foi suficiente para a migração e ativação máxima dos macrófagos da cavidade peritoneal, da espécie estudada. Os valores do número de eritrócitos apresentaram diferenças entre os tempos de incubação. Entretanto, os valores dos outros parâmetros hematológicos não apresentaram diferenças significativas.In aquaculture, analysis of activation and increased macrophages migration are used in order to verify the ability of the nonspecific immune fish exposed to a challenge. This study aimed to determine the time of macrophages migration in matrinxã, Brycon amazonicus, through the technique of yeast Saccharomyces cerevisiae inoculation, verifying possible changes in hematological parameters. Thirty animals with average weight of 101.55 ± 24.50 g and average length of 19.75 ± 1.72 cm were employed. The experimental inoculation periods were 2, 4, 8 and 12 hours. Thereafter, animals were anesthetized and blood was withdrawn through a caudal puncture for the determination of total erythrocytes number, differential and total leukocyte counts and total thrombocytes count, hematocrit, hemoglobin concentration and calculation of the erythrocytes index. The results for the phagocytic capacity were not significantly different between experimental periods. In the phagocytic index, the period of 2 hours presented the highest rate of phagocytized cells, indicating that 2 hours of incubation was sufficient for the macrophages migration in B. amazonicus. The number of erythrocyte was the only parameter that presented significant difference among periods.

Avaliou-se a substituição do milho pelo triticale em dietas para tilápias-do-nilo. Os peixes foram submetidos ao teste de desempenho em sistema de aquários (50 L) com temperatura controlada e recirculação da água. Alevinos de 1,7 ± 0,08 g foram estocados em 30 aquários, em delineamento inteiramente casualizado, com cinco níveis de substituição (0,0; 25,0; 50,0; 75,0 e 100,0%) do milho por triticale e seis repetições. As características zootécnicas avaliadas foram: sobrevivência, ganho de peso, conversão alimentar aparente, consumo alimentar, índice hepato-somático, índice víscero-somático; parâmetros hematológicos: contagem do número de eritrócitos, taxa de hemoglobina, porcentagem de hematócrito, volume corpuscular médio, concentração de hemoglobina corpuscular média. Aos 60 dias de avaliação, houve maior sobrevivência dos peixes que receberam ração com 25% de substituição em relação àqueles alimentados com a ração sem triticale. Aos 100 dias de avaliação, os peixes alimentados com ração com triticale no nível de 50% apresentaram a pior conversão alimentar e o maior consumo de alimento. A inclusão do triticale influenciou os parâmetros hematológicos, aumentando o número de eritrócitos e reduzindo o volume corpuscular médio. A substituição de até 100,0% do milho por triticale na dieta não prejudica o desempenho e o custo da alimentação nem altera as características de carcaça de alevinos de tilápia-do-nilo.Corn replacement with triticale in Nile tilapia diets was assessed. The fish were submitted to a performance test in a system of aquariums (50 L) with controlled temperature and water recirculation. Fingerlings weighing from 1.7 ± 0.08 g were stocked in 30 aquaria in a randomized complete block with five replacement levels (0.0, 25.0, 50.0, 70.0 and 100.0%) of corn with triticale and six replications. The performance parameters analyzed were: survival, weight gain, apparent feed conversion, feed intake, cost, hepato-somatic index, viscero-somatic index; blood parameters: number of erythrocytes, hemoglobin concentration, hematocrits percentage, mean corpuscular volume, mean corpuscular hemoglobin concentration. The data were submitted to variance analysis and compared by Duncan's test. At 60 days of assessment there was greater survival of fish that received diet with 25.0% substitution compared to those fed diet without triticale. At 100 days of assessment the fish fed diet with triticale at the level of 50.0% presented the worst feed conversion rate and highest feed intake. Triticale inclusion influenced the blood parameters, increasing the number of red blood cells and reducing the mean corpuscular volume. Triticale can replace up to 100% corn in Nile tilapia fingerling diets without affecting the fish performance, feed cost and carcass quality.

Este estudo foi realizado para determinar a melhor relação lisina digestível:proteína digestível em rações para juvenis de tilápia-do-nilo. As tilápias (11,0 ± 0,43 g) foram distribuídas em 36 aquários (250 litros) numa densidade de seis peixes/aquário. Foram formuladas 12 rações com 22,0; 26,0 ou 30,0% de proteína digestível, com base na composição em aminoácidos digestíveis, e 4,5; 6,0; 7,5 ou 9,0% de lisina, em relação à proteína digestível, fornecidas à vontade durante 60 dias. Houve interação significativa dos fatores lisina digestível/proteína digestível para o ganho de peso, uma vez que o aumento dos níveis de lisina em rações com 26,0 e 30,0% de proteína digestível promoveu aumento linear desse parâmetro. Os melhores valores de conversão alimentar foram obtidos com os níveis de 26,0 e 30,0% proteína digestível, que determinaram aumento do consumo diário de proteína digestível. O nível de lisina promoveu redução linear da conversão alimentar e aumento linear da taxa de eficiência proteica. O nível de 26,0% de proteína digestível pode ser utilizado em rações para juvenis de tilápiado-nilo, entretanto essas rações devem ser formuladas com aminoácidos digestíveis e relação lisina digestível/proteína digestível de 6,0%. Quando utilizados níveis superiores a 26,0% de proteína digestível, o nível máximo de 7,5% de lisina digestível em relação à proteína digestível melhora o ganho de peso na espécie.This study was carried out to determine the best digestible protein/digestible lysine ratio that should be present in feed fed to Nile tilapias. Two hundred and sixteen tilapias (11.0 ± 0.43g) were distributed in 36 fish tanks (205 L) at a density of 6 fish/tank. Twelve feeds were formulated with three different digestible protein (DP) levels 22.0; 26.0 and 30.0% (based on digestible amino acids) and four different lysine percentages of 4.5; 6.0; 7.5 or 9.0% in relation to digestible protein. The fish were fed ad libtum during a 60-day period. There was significant effect of the digestible protein and digestible lysine ratio on weight gain, because the increase in lysine levels in feeds with 26 and 30% DP promoted linear increase in this parameter. The best values for feed conversion were obtained at the levels 26 and 30% DP that increased the daily consumption of digestible protein. The lysine level caused a linear reduction in feed conversion and linear increase in the protein efficiency rate. The results suggested that the 26% DP level might be used in ration to feed Nile tilapia juveniles; however, these should contain digestible amino acids and the digestible lysine/digestible protein ratio should be 6.0%. However, for levels higher than 26% DP, a maximum digestible lysine level of 7.5% DP improved weight gain for the species.

The objective of this study was to assess the growth performance and the histomorphometric characterization of the middle intestine of GIFT strain Nile tilapia, Oreochromis niloticus juveniles fed probiotics, added either before or after the feed processing. The experimental design was completely randomized, with five treatments and five replications: pelleted feed without any probiotic; pelleted feed with inclusion of probiotic before the processing; pelleted feed with inclusion of probiotic after the processing; extruded feed without any probiotic and extruded feed with inclusion of probiotic after the processing. Two hundred and fifty juveniles were distributed in 25 aquaria (20L) and fed for 63 days. Differences in the mean values of total weight were found at the end of the experiment. After 42 days of feed intake, significant differences in feed conversion were verified for treatments with extruded diets when compared to the pelleted ones. The fishes fed diets supplemented with probiotic presented increase in the thickness of the epithelium of the intestine. The best zootechnical performance was observed in the extruded diet supplemented with probiotic added after the feed processing. The inclusion of 4.0 x 108 CFU g-1 of Bacillus subtilis and 4.0 x 108 CFU g-1 of Bacillus toyoi in both the pelleted and the extruded diets promoted an increase in the thickness of the epithelial layer of the middle intestine.

This study aimed to analyze the economic feasibility of supplement probiotics Bacillus subtilis to “matrinxã” Brycon amazonicus, raised in cages. The experiment was conducted at the Polo Regional Vale do Ribeira, in Pariquera-açu municipality, São Paulo State, Brazil, from February to July 2009. A total of 960 juvenile matrinxã were stocked in twelve 2.7 m³-net cages (1.5 x 1.5 x 1.2 m), in ponds with a total area of 600 m2 and an average depth of 1.50 m. The tests were conducted with a control treatment (T1) and two probiotic doses (T2 = 5 g and T3 = 10 g kg-1 of diet) with four replicates. Results showed that T2 produced better economic performance for matrinxã at the juvenile stage in intensive rearing system.

O coeficiente de digestibilidade aparente (CDA) do amido e a disponibilidade aparente do cálcio (Ca) e fósforo (P) de cinco alimentos energéticos (milho, farelo de trigo, quirera de arroz, farelo de arroz e sorgo) foram avaliados para a tilápia do Nilo. O óxido de crômio-III foi utilizado como indicador inerte das rações. Apresentaram os maiores CDA do Ca e P, respectivamente, a quirera de arroz (43,03 e 64,79%), o sorgo (39,89 e 58,09%) e o milho (22,18 e 19,48%), enquanto o farelo de arroz (-31,49 e 3,25%) e o farelo de trigo (5,80 e 1,18%) apresentaram os menores valores. A digestibilidade do amido apresentou-se entre 99,45 e 95,59% entre os alimentos energéticos avaliados. O alto CDA do amido observado neste estudo confirma a grande capacidade da tilápia do Nilo de utilizar carboidratos nas formas mais complexas. PALAVRAS-CHAVE: carboidratos; CDA; extrusão; minerais; tilápia.

Brycon amazonicus, alimentadas com probiótico composto de Bacillus subtilis bioencapsulado em Artemia salina, em diferentes doses. Foram utilizados seis tratamentos, sendo: T0 = controle (sem adição de probiótico), T2,5 = 2,5 g de probiótico, T5,0 = 5,0 g de probiótico, T7,5 = 7,5 g de probiótico, T10,0 = 10,0 g de probiótico e T12,5 = 12,5 g de probiótico por litro de água quando alimentados com A. salina (4h antes da alimentação das larvas) e por quilo de ração (comercial pó 40% proteína bruta) na fase seguinte. Os resultados mostraram heterogeneidade em relação ao crescimento, indicando que na fase larval o probiótico não influenciou no canibalismo.

O experimento utilizou 4 linhagens de tilápias do Nilo (Oreochromis niloticus) chamadas de CESP, Pernambuco, Santa Catarina e Tailandesa. O objetivo do projeto foi comparar o desempenho e a sobrevivência dessas diferentes linhagens de tilápia do Nilo na fase de reversão sexual. As pós-larvas foram estocadas em aquários de 4,5L em sistema de recirculação e com temperatura constante. Os peixes foram alimentados com ração contendo 60mg/kg de 17 alfa-metiltestosterona, fornecida 6 vezes ao dia, por período de 30 dias. O delineamento foi inteiramente casualizado com 4 tratamentos (linhagens) e 7 repetições. Os parâmetros avaliados foram: comprimento total, ganho de peso, taxa de crescimento específico, taxa de sobrevivência e eficiência de reversão sexual. Os dados foram submetidos à análise de variância e as médias comparadas pelo teste de Tukey. A análise de reversão foi submetida ao teste de qui-quadrado. O resultado demonstra que houve maior eficiência na taxa de reversão sexual nas linhagens Santa Catarina e Pernambuco quando comparados com a CESP e a Tailandesa. As linhagens Tailandesa e Santa Catarina obtiveram maior taxa de sobrevivência e desempenho satisfatório durante a fase de reversão sexual, portanto, apresentam-se como as mais propícias para a criação em sistema de recirculação na fase de reversão sexual.