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Physic nut Jatropha curcas cake/meal obtained after oil extraction has a high protein content, however, the presence of antinutrients (trypsin inhibitor, lectin and phytate) and toxic compounds (phorbol esters) limit their use as an alternative feedstuff. Thus, the detoxification process in cake/meal is necessary to allow their inclusion in fish diets. The present study aimed to evaluate the effects of solvent and extrusion-treated jatropha cake (SETJC) in Nile tilapia (Oreochromis niloticus) diets on growth, body composition, nutrient utilization, metabolic and hematological responses, and digestibility of experimental diets. Five experimental diets were formulated to be isonitrogenous (28.50% digestible protein) and isoenergetic (13.39 MJ/kg digestible energy) with graded levels of SETJC (0, 3, 6, 9, and 12%). The experimental design was completely randomized with five treatments and four replicates. The detoxification treatments reduced the phorbol esters (PE) of jatropha cake by 96% (0.58 mg/g of PE before and 0.023 mg/g of PE after treatments). Increased levels of SETJC depressed growth, feed efficiency, and protein digestibility. A similar trend was observed for hematological and biochemistry parameters. Aspartate and alanine aminotransferase, as well as phosphorus and magnesium concentrations in the fillets, increased at the highest levels of SETJC. Thus, the data of the present study suggests that the residual content, different structural forms of phorbol ester and its biological activity, as well as some antinutritional factors, can influence negatively the growth, metabolism and digestibility of experimental diets for Nile tilapia.

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Since studies on the reproductive consequences after the exposure to environmentally relevant doses of Benzo(a)pyrene (BaP) during critical stages of development are scarce, this study evaluated female reproductive parameters of adult rats exposed to a low dose of BaP during the juvenile phase. Female rats (Post-natal 21) were treated with BaP (0 or 0.1 µg/kg/day; gavage) for 21 consecutive days. During the treatment, no clinical signs of toxicity were observed. Nevertheless, the ages of vaginal opening and first estrus were anticipated by the BaP-exposure. At the sexual maturity, the juvenile exposure compromised the sexual behavior, as well as the placental efficiency, follicle stimulating hormone levels, placenta histological analysis, and ovarian follicle count. A decrease in erythrocyte, platelet, and lymphocyte counts also was observed in the exposed-females. Moreover, the dose of BaP used in this study was not able to produce estrogenic activity in vivo. These data showed that juvenile BaP-exposure, at environmentally relevant dose, compromised the female reproductive system, possibly by an endocrine deregulation; however, this requires further investigation.

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A variety of plant protein sources have been evaluated in aquafeeds. Crambe meal (CM) has potential for inclusion in fish diets because of its nutritional composition. This study evaluated the apparent digestibility coefficient (ADC) of crambe meal and its potential to partially replace soybean meal (SM) protein in Nile tilapia Oreochromis niloticus diets. The ADC for dry matter, crude protein, ether extract, energy, amino acids, calcium and phosphorus of CM were assessed in fish (n = 80; 65.30 ± 5.32 g). Subsequently, an 80-day feeding trial was conducted with Nile tilapia (n = 140; 6.04 ± 0.25 g) randomly distributed in 20 experimental cages (70 L; seven fish cage-1) allocated in five circular tanks (1000 L) in a recirculation water system, to evaluate the effects of replacement of SM by CM (0, 6, 12, 18 and 24% in isonitrogenous and isoenergetic diets) on growth, blood parameters, fillet yield and proximal composition. The CM shows good digestibility of protein (0.824) and amino acids (0.844) by Nile tilapia and its inclusion in the diet does not affect carcass and fillet yield or proximal composition. Fish fed diets with 24.0% of the SM replaced by CM showed the worst weight gain and feed conversion rate. The protein efficiency ratio decreased in fish fed diets with 12.0, 18.0 and 24.0% of the SM replaced by CM. Hemoglobin, mean corpuscular hemoglobin concentration, total plasma protein, glucose and alanine aminotransferase enzyme activity trend to increase at highest levels of CM in the diet. In conclusion, CM has high digestibility of protein and amino acids for Nile tilapia. However, anti-nutritional factors present in untreated CM interfere on the growth and nutrient utilization of Nile tilapia.

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The objectives of this study were to test an artificial substrate sampler method for aquaculture ponds and assess the water quality based on the benthic macroinvertebrate community living in fishpond sediment at four farms with tilapia production in the Baixa Mogiana region of São Paulo State, Brazil. Benthic macroinvertebrates were monitored every 15 days for 3 months. Approximately 500,000 organisms distributed in 47 taxa were collected. Chironomidae, Glossiphonidae, Hirudinidae, Libelullidae, Oligochaeta, and Polycentropodidae were present in all collected samples, with the dominance of Chironomidae in the benthic community. Polycentropodidae, a sensitive family to organic pollution, had a greater abundance in fish farms with better environmental conditions. Significant differences in dissolved oxygen and pH were observed among fishponds at different fish farms. Biomonitoring with artificial substrate is a simple and low-cost alternative to monitoring water quality of tilapia culture in fishponds. The artificial substrate sampling method was effective, but the evaluation of more critical conditions of water quality would improve the method and enhance the knowledge of taxa and ecology of macrobenthic organisms in fishponds.

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The present study was conducted to compare the growth performance, feed efficiency, nitrogen retention, water quality, biofloc nutritional composition, and hematological profile of Nile tilapia Oreochromis niloticus fingerlings cultured in biofloc technology (BFT) and recirculating aquaculture systems (RAS) over a period of 60 days. This randomized study was designed with two treatments (BFT and RAS) and four replicates. Fish (n = 64; 7.29 ± 0.67) were allocated in eight 150 L aquaria kept at 26.72 ± 0.35 °C and fed until apparent satiation three times daily. Weight gain, apparent feed conversion ratio, and protein efficiency of fish in BFT were statistically superior than in RAS. There were no differences (p > 0.05) for temperature, dissolved oxygen, and nitrogen compounds, indicating similarity in the water quality between BFT and RAS. Furthermore, hematological parameters did not show differences (p > 0.05) between the systems. The chemical composition of biofloc differed (p < 0.05) over the experimental period for crude protein and mineral matter. The best responses of growth performance and feed efficiency of Nile tilapia fingerlings in BFT highlight the importance of bioflocs as a high biological value complementary feed.

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The present study aimed to evaluate the risk assessment, median lethal concentration LC50-96h, development, and mortality of Nile tilapia Oreochromis niloticus larvae exposed to atrazine after stress management. An LC50-96h trial was carried out using fish (n = 147; 8.5 ± 1.0 mg; seven larvae/aquarium), which were allocated randomly in 21 aquaria (1 L) and exposed to five concentrations of atrazine: 2, 4, 8, 16, and 32 mg L-1 plus one control (without herbicide) and a control with a solubility adjuvant (acetone). Temperature, pH, dissolved oxygen, conductivity, and total ammonia were measured daily. In addition, a stress test was performed with fish (n = 150; 17.9 ± 1.7 mg; 10 larvae/aquarium) submitted to air exposition (five minutes) and posteriorly distributed randomly in 15 aquaria (1 L), and exposed to atrazine at 0.18, 6, 12, and 18 mg L-1. The LC50-96h of atrazine for Nile tilapia larvae was 17.87 mg L-1. Significant differences (P < 0.05) were found for weight and final length, pH, and dissolved oxygen that was responsive to the increased levels of herbicide. Larvae mortality post-stress was registered to 6, 12, and 18 mg L-1 of atrazine, and was more critical at 24 h. The increased doses of atrazine used in LC50-96h test depressed the development of Nile tilapia larvae. Fish submitted to stress (air exposition) and exposed to sub-lethal doses of atrazine showed significant mortality, indicating that stressors may increase the toxic effect of atrazine for Nile tilapia larvae. On the other hand, based on risk assessment atrazine can be classified as herbicide with low toxicity for Nile tilapia larvae and low toxicological risk.

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Benzo(a)pyrene (BaP) is a persistent organic pollutant and endocrine disruptor that can compromise the steroidogenesis process by interacting with the StAR protein, causing adverse effects on male reproduction. However, consequences of prepubertal BaP exposure and its impacts on adult life are yet unknown. This study investigated the effects of BaP exposure from the juvenile period to peripubertal on reproductive parameters in adult male rats. Males were exposed to 0; 0.1; 1 or 10 µg/kg/day of BaP from post-natal (PND) 23 to PND 53 (by gavage). The lowest dose of BaP was able to compromise the male copulatory behavior, as evidenced by the delay in the first mount, intromission and ejaculation. Furthermore, BaP-treated groups showed lower sperm quality (disrupted motility and morphology) and quantity, reduced relative weights of the thyroid and seminal gland. Serum testosterone levels and the Leydig cells nuclei volume were decreased by BaP exposure whereas the StAR expression was increased. Histopathological changes in the testis also were detected in the males exposed to BaP. These results showed that prepubertal BaP-exposure adversely influenced the male reproductive system in the adult life, indicating that a comprehensive risk assessment of BaP-exposure on prepubertal period is necessary.

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Studies have demonstrated that Benzo(a)Pyrene (BaP), a polycyclic aromatic hydrocarbon ubiquituous in the environment, can cause teratogenic effects. Since the majority of studies used in vitro models or high doses of BaP, this study evaluated the teratogenicity, reproductive and developmental performance of low doses of BaP through maternal and fetus examination after daily oral administration of BaP (0; 0.1; 1.0 or 10 µg/kg) to pregnant Wistar rats from Gestational day (GD) 6 to GD 15 (the organogenesis period). Pregnant rats did not exhibit clinical signs of toxicity during the exposure period. However, dams exposed to the lowest dose of BaP showed a reduction in the erythrocytes number and in the creatinine levels. The groups exposed to 0.1 and 1.0 µg/kg presented a decrease in placental efficiency, as well as an increase in placental weight. After fetal examination, the treated group with the lowest dose showed a reduced relative anogenital distance, while the curve of normal distribution of weight was changed in the highest dose group. In addition, anomalies evidenced by changes in the renal size and degree of fetal ossification were observed in treated-fetus. In conclusion, treatment with BaP during organogenesis at this dose level is detrimental to the normal development of fetuses.

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The aim of this study was to determine the median lethal concentration (LC50-96h), effective concentration (EC50-96h), risk assessment, and development of Nile tilapia Oreochromis niloticus larvae submitted to florfenicol (FF) exposure. Fish (n = 147; 8.6 ± 0.6 mg; 7 fish/aquarium) were randomly distributed in 21 aquaria (1 L) and exposed to five concentrations of FF 58.73; 131.31; 198.96; 241.88 and 381.81 mg L-1 plus one control and a control with solvent, totalizing seven treatments and three replicates. The estimated median LC50-96h of FF for Nile tilapia larvae was 349.94 mg L-1. The EC50-96h of FF was 500 mg L-1 for weight reduction and was 1040 mg L-1 for length reduction. After the exposure period, final weight and length differed (p < 0.05) among treatments, showing the lowest biometric values ​​with the highest concentrations of FF. The pH and dissolved oxygen were altered (p < 0.05) during the experimental period. The FF high doses used to determine the LC 50 after 96 h negatively affected the development of the larvae. On the other hand, through risk assessment analysis this antibiotic can be classified as low toxicity to Nile tilapia larvae and show low environmental risk.

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The apparent digestibility coefficients (ADC's) of dry matter (DM), crude protein (CP), and gross energy (GE) of conventional feedstuffs (cottonseed meal-CSM, soybean meal-SBM, wheat bran-WHB, corn-COR) and regional alternative feedstuffs (common bean residue meal-CBR, mesquite meal-MES, pasta by-product meal-PBM) were determined for hybrid juvenile tambacu Colossoma macropomum × Piaractus mesopotamicus. The apparent DM and GE digestibility of feedstuffs decreased (p<0.05) as fiber content of the ingredients increased. No differences (p>0.05) were found among ADC's of PBM and COR. The lowest CP ADC among energy sources was observed in MES; the lowest CP ADC among plant protein sources was observed in CBR. Information about the ADC's of conventional and alternative feedstuffs for tambacu is essential to formulate low-cost diets and can contribute to regional development.

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ABSTRACT The apparent digestibility coefficients (ADC's) of dry matter (DM), crude protein (CP), and gross energy (GE) of conventional feedstuffs (cottonseed meal-CSM, soybean meal-SBM, wheat bran-WHB, corn-COR) and regional alternative feedstuffs (common bean residue meal-CBR, mesquite meal-MES, pasta by-product meal-PBM) were determined for hybrid juvenile tambacu Colossoma macropomum × Piaractus mesopotamicus. The apparent DM and GE digestibility of feedstuffs decreased (p<0.05) as fiber content of the ingredients increased. No differences (p>0.05) were found among ADC's of PBM and COR. The lowest CP ADC among energy sources was observed in MES; the lowest CP ADC among plant protein sources was observed in CBR. Information about the ADC's of conventional and alternative feedstuffs for tambacu is essential to formulate low-cost diets and can contribute to regional development.

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This study aimed to evaluate increasing levels (0, 4, 8 and 12%) of acid silage viscera of surubimcatfish as an alternative protein source on growth performance and apparent digestibility coefficients (ADC) for Nile tilapia. Weight gain (WG), feed intake (FI), feed conversion ratio (FCR), and protein efficiency ratio (PER)were evaluated. The digestibility for dry matter (DM), crude protein (CP), ether extract (EE), gross energy (GE)and availability of phosphorus (P) were also assessed. The experimental design was completely randomized with four treatments and four repetitions. The results indicated no difference (p > 0.05) for growth performance parameters. The ADC of CP of treatment containing 8% of silage was lower (p < 0.05) when compared to the others. On the other hand, for the GE, the same level provided a higher ADC (p < 0.05). In conclusion, acid silage viscera of surubim catfish can be included in diets for Nile tilapia up to 12%, with no negative effects on growth performance and digestibility as well as to reduce feed cost.

Níveis crescentes (0%, 4%, 8% e 12%) de inclusão de silagem ácida de vísceras de surubim na alimentação de tilápia-do-nilo foram avaliados sobre o desempenho e coeficiente de digestibilidade aparente(CDA). Os parâmetros de desempenho analisados foram: ganho de peso (GP), consumo de ração (CR),conversão alimentar (CA) e taxa de eficiência proteica (TEP). Avaliou-se o CDA da matéria seca (MS), proteínabruta (PB), extrato etéreo (EE), energia bruta (EB) e disponibilidade de fósforo (P). O delineamento utilizado foi o inteiramente casualizado, com quatro tratamentos e quatro repetições. Os resultados obtidos não demonstraram diferença (p > 0,05) para os parâmetros de desempenho avaliados. O CDA da PB para o tratamento contendo 8% de silagem foi menor (p < 0,05), quando comparado aos demais. Por outro lado, para a EB, este mesmo nível de inclusão proporcionou melhor CDA (p < 0,05). Conclui-se que a silagem ácida de vísceras de surubim pode ser incluída em rações para tilápia-do-nilo em até 12%, sem que haja interferência negativa no desempenho e na digestibilidade, além de reduzir o custo da ração.

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RESUMO

This study aimed to evaluate increasing levels (0, 4, 8 and 12%) of acid silage viscera of surubim catfish as an alternative protein source on growth performance and apparent digestibility coefficients (ADC) for Nile tilapia. Weight gain (WG), feed intake (FI), feed conversion ratio (FCR), and protein efficiency ratio (PER) were evaluated. The digestibility for dry matter (DM), crude protein (CP), ether extract (EE), gross energy (GE) and availability of phosphorus (P) were also assessed. The experimental design was completely randomized with four treatments and four repetitions. The results indicated no difference (p > 0.05) for growth performance parameters. The ADC of CP of treatment containing 8% of silage was lower (p < 0.05) when compared to the others. On the other hand, for the GE, the same level provided a higher ADC (p < 0.05). In conclusion, acid silage viscera of surubim catfish can be included in diets for Nile tilapia up to 12%, with no negative effects on growth performance and digestibility as well as to reduce feed cost.

RESUMO

This study aimed to evaluate increasing levels (0, 4, 8 and 12%) of acid silage viscera of surubimcatfish as an alternative protein source on growth performance and apparent digestibility coefficients (ADC) for Nile tilapia. Weight gain (WG), feed intake (FI), feed conversion ratio (FCR), and protein efficiency ratio (PER)were evaluated. The digestibility for dry matter (DM), crude protein (CP), ether extract (EE), gross energy (GE)and availability of phosphorus (P) were also assessed. The experimental design was completely randomized with four treatments and four repetitions. The results indicated no difference (p > 0.05) for growth performance parameters. The ADC of CP of treatment containing 8% of silage was lower (p < 0.05) when compared to the others. On the other hand, for the GE, the same level provided a higher ADC (p < 0.05). In conclusion, acid silage viscera of surubim catfish can be included in diets for Nile tilapia up to 12%, with no negative effects on growth performance and digestibility as well as to reduce feed cost.(AU)

Níveis crescentes (0%, 4%, 8% e 12%) de inclusão de silagem ácida de vísceras de surubim na alimentação de tilápia-do-nilo foram avaliados sobre o desempenho e coeficiente de digestibilidade aparente(CDA). Os parâmetros de desempenho analisados foram: ganho de peso (GP), consumo de ração (CR),conversão alimentar (CA) e taxa de eficiência proteica (TEP). Avaliou-se o CDA da matéria seca (MS), proteínabruta (PB), extrato etéreo (EE), energia bruta (EB) e disponibilidade de fósforo (P). O delineamento utilizado foi o inteiramente casualizado, com quatro tratamentos e quatro repetições. Os resultados obtidos não demonstraram diferença (p > 0,05) para os parâmetros de desempenho avaliados. O CDA da PB para o tratamento contendo 8% de silagem foi menor (p < 0,05), quando comparado aos demais. Por outro lado, para a EB, este mesmo nível de inclusão proporcionou melhor CDA (p < 0,05). Conclui-se que a silagem ácida de vísceras de surubim pode ser incluída em rações para tilápia-do-nilo em até 12%, sem que haja interferência negativa no desempenho e na digestibilidade, além de reduzir o custo da ração.(AU)

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RESUMO

This study aimed to evaluate increasing levels (0, 4, 8 and 12%) of acid silage viscera of surubim catfish as an alternative protein source on growth performance and apparent digestibility coefficients (ADC) for Nile tilapia. Weight gain (WG), feed intake (FI), feed conversion ratio (FCR), and protein efficiency ratio (PER) were evaluated. The digestibility for dry matter (DM), crude protein (CP), ether extract (EE), gross energy (GE) and availability of phosphorus (P) were also assessed. The experimental design was completely randomized with four treatments and four repetitions. The results indicated no difference (p > 0.05) for growth performance parameters. The ADC of CP of treatment containing 8% of silage was lower (p < 0.05) when compared to the others. On the other hand, for the GE, the same level provided a higher ADC (p < 0.05). In conclusion, acid silage viscera of surubim catfish can be included in diets for Nile tilapia up to 12%, with no negative effects on growth performance and digestibility as well as to reduce feed cost.  

RESUMO

The current study evaluated the growth performance and the haematological profile of barred sorubim fed with levels of hybrid sorubim viscera protein concentrate (0.0; 5.0; 10.0 e 15.0%) in isoprotein and isoenergetic diets. Eighty fish with an average initial weight of 39.8 ± 0.28 g and an average initial length of 19.92 ± 0.25 cm were distributed in 16 aquaria of 60 L, with recirculation system and temperature control, during 35 days. The experimental design was completely randomized with four treatments and four replications. For the growth performance assay were analyzed the follows variables: weight gain (WG), feed consumption (FC), apparent feed conversion ratio (AFCR) and protein efficiency ratio (PER). Furthermore, the hemogram were assessed on the treated fish with levels of protein concentrate. It was observed no significant difference (P>0.05) for all the parameters evaluated. It was concluded that the protein concentrate from hybrid sorubim viscera can be included up to 15% in diets for barred sorubim juveniles without negative response on the performance and health.

O presente trabalho avaliou o desempenho produtivo e a influência nos parâmetros hematológicos de cacharas alimentadas com diferentes níveis de inclusão de concentrado proteico de vísceras de surubim híbrido na dieta (0,0; 5,0; 10,0 e 15,0%) em rações isoproteicas e isoenergéticas. Foram utilizados 80 peixes com peso médio inicial de 39,8 ± 0,28 g e comprimento médio inicial de 19,92 ± 0,25 cm, os quais foram distribuídos em 16 aquários de 60 L, em sistema de recirculação com biofiltro e controle de temperatura, durante 35 dias. O delineamento experimental foi inteiramente casualizado com quatro tratamentos e quatro repetições. Para avaliação do desempenho zootécnico foram analisadas as seguintes variáveis: ganho de peso (GP), consumo de ração (CR), conversão alimentar aparente (CAA) e taxa de eficiência proteica (TEP). Além disso, procedeu-se o hemograma completo dos peixes alimentados com as diferentes concentrações de concentrado proteico. Observou-se que nenhuma das variáveis analisadas diferiu estatisticamente (P>0,05). Pode-se concluir que o concentrado proteico de vísceras de surubim híbrido pode ser incluído em até 15% em rações para juvenis de cacharas, sem que haja interferência negativa no desempenho e saúde dos animais.

RESUMO

The current study evaluated the growth performance and the haematological profileof barred sorubim fed with levels of hybrid sorubim viscera protein concentrate (0.0; 5.0; 10.0 e 15.0%) in isoprotein and isoenergetic diets. Eighty fishwith an average initial weight of 39.8 ± 0.28 g and an average initial length of 19.92 ± 0.25 cm were distributed in 16 aquaria of 60 L,with recirculation system and temperature control, during 35 days. The experimental design was completely randomized with four treatments and four replications. For the growth performance assay were analyzed the follows variables: weight gain (WG), feed consumption (FC), apparentfeed conversion ratio (AFCR) and protein efficiency ratio (PER). Furthermore, the hemogram wereassessed on the treated fish with levels of protein concentrate. It was observed no significant difference (P>0.05) for all the parameters evaluated. It was concluded thatthe protein concentrate from hybrid sorubim viscera can be included up to 15% in diets for barred sorubim juveniles withoutnegative responseon the performance and health.(AU)

O presente trabalho avaliou o desempenho produtivo e a influência nos parâmetros hematológicos de cacharas alimentadas com diferentes níveis de inclusão de concentrado proteico de vísceras de surubim híbrido na dieta (0,0; 5,0; 10,0 e 15,0%) em rações isoproteicas e isoenergéticas. Foram utilizados 80 peixes com peso médio inicial de 39,8 ± 0,28 g e comprimento médio inicial de 19,92 ± 0,25 cm, os quais foram distribuídos em 16 aquários de 60 L,em sistema de recirculação com biofiltro e controle de temperatura, durante 35 dias. O delineamento experimental foi inteiramente casualizado com quatro tratamentos e quatro repetições. Para avaliação do desempenho zootécnico foram analisadas as seguintes variáveis: ganho de peso (GP), consumo de ração (CR), conversão alimentar aparente (CAA) e taxa de eficiência proteica (TEP). Além disso, procedeu-se o hemograma completo dos peixes alimentados com as diferentes concentrações de concentrado proteico. Observou-se que nenhuma das variáveis analisadas diferiu estatisticamente(P>0,05). Pode-se concluir que o concentrado proteico de vísceras de surubimhíbridopode ser incluído em até 15% em rações para juvenis de cacharas, sem que haja interferência negativa no desempenho e saúde dos animais.(AU)

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Objetivou-se avaliar a utilização de diferentes proporções de ácido fórmico e ácido cítrico para confecção da silagem de vísceras de surubim. Além disso almejou-se determinar a composição químico-bromatológica e o coeficiente de digestibilidade aparente da matéria seca, proteína bruta, extrato etéreo, energia bruta e disponibilidade de cálcio e fósforo para tilápia-do-nilo. Para a elaboração das silagens, o ácido fórmico e ácido cítrico foram utilizados nas seguintes proporções: 1:0,75; 0,75:1; 1:1,25 e 1,25:1, além do antioxidante (BHT) 0,02%. Após 30 dias, observou-se que todas as proporções dos ácidos promoveram a obtenção de material estável (pH abaixo de 4), sem diferirem entre si. Dessa forma, optou-se por utilizar a silagem preparada com 1,0:0,75 de ácido fórmico:ácido cítrico, que apresentou a seguinte composição com base na matéria seca: 25,7% de proteína bruta, 7330kcal/kg de energia bruta, 42,4% de extrato etéreo, 0,06% de cálcio e 0,27% de fósforo. Os coeficientes de digestibilidade aparente para matéria seca, proteína bruta, extrato etéreo, energia bruta e disponibilidade de cálcio e fósforo do composto ensilado apresentaram as seguintes porcentagens (%): 83,52; 93,30; 80,18; 87,20; 83,11 e 74,28, respectivamente. Os resultados deste estudo permitem concluir que é viável a produção de silagem de vísceras de surubim com ácido cítrico e ácido fórmico e que esse ingrediente pode ser considerado uma fonte proteica alternativa, com alto valor biológico para tilápia-do-nilo.(AU)

Different proportions of formic acid and citric acid to produce surubim catfish viscera silage and to determine the chemical-bromatological composition and apparent digestibility of dry matter, crude protein, ether extract, crude energy and availability of calcium and phosphorus for Nile tilapia were evaluated in this study. It was used: 0.75; 0.75:1; 1:1.25 and 1.25:1 of formic acid and citric acid respectively, plus antioxidant (BHT) 0.02% for silage production. After 30 days different proportions of acids provided stable content (pH below 4) that not differed among treatments. Silage prepared with 1.0:0.75 formic acid:citric acid was selected and showed the following results expressed on dry matter: 25.7% of crude protein, 7330kcal/kg of gross energy, 42.4% of ether extract, 0.06% of calcium Ca and 0.27% of phosphorus. The apparent digestibility coefficients for dry matter, crude protein, ether extract, gross energy, calcium and phosphorus in ensiled compound showed the following percentages: 83.52; 93.30; 80.18; 87.20; 83.11 and 74.28%. Production of surubim catfish viscera silage is feasible with citric acid and formic acid and this ingredient may be considered an alternative protein source with high biological value for Nile tilapia.(AU)

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RESUMO

Objetivou-se avaliar a utilização de diferentes proporções de ácido fórmico e ácido cítrico para confecção da silagem de vísceras de surubim. Além disso almejou-se determinar a composição químico-bromatológica e o coeficiente de digestibilidade aparente da matéria seca, proteína bruta, extrato etéreo, energia bruta e disponibilidade de cálcio e fósforo para tilápia-do-nilo. Para a elaboração das silagens, o ácido fórmico e ácido cítrico foram utilizados nas seguintes proporções: 1:0,75; 0,75:1; 1:1,25 e 1,25:1, além do antioxidante (BHT) 0,02%. Após 30 dias, observou-se que todas as proporções dos ácidos promoveram a obtenção de material estável (pH abaixo de 4), sem diferirem entre si. Dessa forma, optou-se por utilizar a silagem preparada com 1,0:0,75 de ácido fórmico:ácido cítrico, que apresentou a seguinte composição com base na matéria seca: 25,7% de proteína bruta, 7330kcal/kg de energia bruta, 42,4% de extrato etéreo, 0,06% de cálcio e 0,27% de fósforo. Os coeficientes de digestibilidade aparente para matéria seca, proteína bruta, extrato etéreo, energia bruta e disponibilidade de cálcio e fósforo do composto ensilado apresentaram as seguintes porcentagens (%): 83,52; 93,30; 80,18; 87,20; 83,11 e 74,28, respectivamente. Os resultados deste estudo permitem concluir que é viável a produção de silagem de vísceras de surubim com ácido cítrico e ácido fórmico e que esse ingrediente pode ser considerado uma fonte proteica alternativa, com alto valor biológico para tilápia-do-nilo.

Different proportions of formic acid and citric acid to produce surubim catfish viscera silage and to determine the chemical-bromatological composition and apparent digestibility of dry matter, crude protein, ether extract, crude energy and availability of calcium and phosphorus for Nile tilapia were evaluated in this study. It was used: 0.75; 0.75:1; 1:1.25 and 1.25:1 of formic acid and citric acid respectively, plus antioxidant (BHT) 0.02% for silage production. After 30 days different proportions of acids provided stable content (pH below 4) that not differed among treatments. Silage prepared with 1.0:0.75 formic acid:citric acid was selected and showed the following results expressed on dry matter: 25.7% of crude protein, 7330kcal/kg of gross energy, 42.4% of ether extract, 0.06% of calcium Ca and 0.27% of phosphorus. The apparent digestibility coefficients for dry matter, crude protein, ether extract, gross energy, calcium and phosphorus in ensiled compound showed the following percentages: 83.52; 93.30; 80.18; 87.20; 83.11 and 74.28%. Production of surubim catfish viscera silage is feasible with citric acid and formic acid and this ingredient may be considered an alternative protein source with high biological value for Nile tilapia.

Assuntos

RESUMO

The aim of the present study was to assess the effect of diets supplemented with shrimp-head silage on the incorporation of n-3 in the Nile tilapia fillets. EPA (eicosapentaenoic), DHA (docosahexanoic) and total lipids were determined by chromatography in feeds and the muscles of tilapia specimens were submitted to diets supplemented with a varying degree of silage (0, 4, 8, 12, 16%). The total lipid content ranged from 6.70 to 10.30% in the diets and from 0.79 to 1.37% in the tilapia fillets. In diet with high concentration of silage, it was observed an increase in the level of omega-3 (r=0.92). There was an incorporation of 0.59% (1.34mg 100g-1) and 9.5% (40.50mg 100g-1) of EPA and DHA, respectively, when the addition of silage to the diet was 16%. The results implication states that the inclusion of 16% of the shrimp head silage in the diet for tilapias increases the levels of incorporation of EPA and DHA in the filet.

O objetivo deste estudo foi avaliar a incorporação de ômega-3 EPA (eicosapentaenóico) e DHA (docosahexanóico) no tecido muscular de tilápias do Nilo alimentadas com dietas suplementadas com diferentes níveis de silagem de cabeça de camarão Litopenaeus vannamei (0, 4, 8, 12, 16%). Foram analisados os teores de EPA, DHA e lipídios totais das dietas e dos tecidos musculares das tilápias. Os teores de lipídios totais variaram entre 6,70 a 10,30% nas dietas e 0,79 a 1,37% no tecido muscular. Através da análise de regressão, houve um aumento nos teores de ômega-3 (r=0,92) com a inclusão da silagem na dieta. Foi observada incorporação de 0,59% (1,34mg 100g-1) e 9,5% (40,50mg 100g-1) de EPA e DHA, respectivamente, no tratamento com 16% de silagem na dieta. A inclusão de 16% da silagem ácida de cabeça de camarão na dieta das tilápias aumentou significativamente os níveis de incorporação de EPA e DHA no filé.