RESÍDUOS SÓLIDOS URBANOS (RSU): UMA ANÁLISE DO SETOR ENERGÉTICO EM ASCENSÃO COM BASE NO IMPACTO AMBIENTAL E NA QUALIDADE DE VIDA

Esse artigo é uma revisão de literatura abordando a utilização de RSU (Resíduo Sólido Urbano) na produção  do biogás como fonte energética. Foi utilizada como base bibliográfica, literatura especializada, incluindo levantamento sobre a legislação vigente e artigos científicos selecionados por meio de busca nos bancos de dados do Scielo e Google acadêmico. Temas relevantes foram considerados na pesquisa, como: produção e coleta de lixo no Brasil, descarte inadequado, sustentabilidade, potencial energético. Mostrando assim a necessidade de investir nesse setor, através de novas tecnologias e técnicas, além da necessidade de se fechar lixões e aterros controlados que são locais de descarte inapropriados e apresentam concorrência direta com aterros sanitários para a captação de rejeitos. A pesquisa destaca que a energia é um direito de todos, conforme preconizado pela Organização das Nações Unidas (ONU) e a exploração do biometano como fonte energética contribuiria para a soberania da matriz energética brasileira. Além de possibilitar a diminuição da emissão dos gases do efeito estufa a melhoria da viabilidade econômica, recuperação dos materiais descartados e   na redução de práticas de destinação inadequadas, assim como dos impactos negativos à saúde de milhões de brasileiros

Zootechnical performance of bullfrog tadpoles under different levels of digestible protein and energy

A partir dos valores de digestibilidade de alguns ingredientes foram propostas dietas, com diferentes níveis de proteína e energia digestíveis, em esquema fatorial 3 x 3, destinadas a girinos de rã-touro para avaliar o desempenho zootécnico. O experimento, com duração de 60 dias, foi conduzido com 810 girinos, oriundos da mesma desova, distribuídos em 27 caixas de polipropileno, em uma densidade de 1girino/L. O delineamento experimental foi um esquema fatorial com três níveis de proteína digestível (27; 31 e 35%) e três níveis de energia digestível (2.700; 2.800 e 2.900kcal/kg) com três réplicas. Os parâmetros avaliados aos 60 dias foram ganho de peso, consumo da dieta, consumo em proteína da dieta, conversão alimentar, taxa de eficiência proteica e índice de sobrevivência. Os resultados foram submetidos à análise de variância e ao teste de Duncan (95% de precisão). Os resultados encontrados não apresentaram interação entre proteína e energia digestível para nenhum parâmetro avaliado. Em relação à proteína digestível, foram verificadas diferenças nos parâmetros consumo em proteína da dieta e taxa de eficiência proteica (TEP), o que demonstra ineficiência das dietas com altos valores proteicos. Deve-se oferecer aos girinos de rã-touro dietas com 27% de proteína digestível, por apresentarem melhor resultado para taxa de eficiência proteica e para consumo em proteína da dieta.From the digestibility values of some ingredients, it was proposed diets with different levels of digestible protein and energy, in a 3x3 factorial design for bullfrog tadpoles, aiming at evaluate the zootechnical performance. The experiment was conducted during 60 days with 810 tadpoles from the same spawning distributed into 27 polypropylene boxes at a density of 1 tadpole/L. The experimental design consisted of a factorial arrangement with three levels of digestible protein (27; 31 and 35%) and three levels of digestible energy (2700; 2800 and 2900kcal/kg) with three repetitions. Parameters evaluated at 60 days were weight gain, feed intake, dietary protein intake, feed conversion, protein efficiency rate and survival rate. Results were subjected to analysis of variance and Duncan test (95% accuracy), and presented no interaction between digestible protein and digestible energy for any parameter evaluated. As for the digestible protein, significant differences were detected in the dietary protein intake, and protein efficiency rate, evidencing inefficiency of diets with high protein values. Bullfrog tadpoles should be given diets with 27% digestible protein by having the best result for the protein efficiency rate and for the dietary protein intake, with the lowest value and similar to other levels among evaluated parameters

Influence of the number of feeding environments on the performance of bullfrog tadpoles - doi: 10.4025/actascibiolsci.v36i1.16757

Feeding is one of the major factors that influences the growth and development of animals, justifying thus the present experiment that analyzed the effect of the number of feeding environments on the performance of bullfrog tadpoles through the growth (weight and length) and performance (food remains, average feed intake, average weight gain, and feed conversion). The treatments consisted of subunits of two, four, and eight feeding environments in the experimental units at disposal for the tadpole population, and one without subdivisions, comprising a single environment, during 60 experimental days. The design was completely randomized, with four treatments and three replications. The values were tested using an analysis of variance and Duncan test (α = 0.05). The growth in weight and length and the indices of animal performance were influenced by the number of feeding environments, with the best results found for the treatments with four and eight environments, and the worst, for the treatment with a single environment. The increased number of feeding environments may be an alternative to improve the performance of bullfrog tadpoles.Feeding is one of the major factors that influences the growth and development of animals, justifying thus the present experiment that analyzed the effect of the number of feeding environments on the performance of bullfrog tadpoles through the growth (weight and length) and performance (food remains, average feed intake, average weight gain, and feed conversion). The treatments consisted of subunits of two, four, and eight feeding environments in the experimental units at disposal for the tadpole population, and one without subdivisions, comprising a single environment, during 60 experimental days. The design was completely randomized, with four treatments and three replications. The values were tested using an analysis of variance and Duncan test (α = 0.05). The growth in weight and length and the indices of animal performance were influenced by the number of feeding environments, with the best results found for the treatments with four and eight environments, and the worst, for the treatment with a single environment. The increased number of feeding environments may be an alternative to improve the performance of bullfrog tadpoles.

Development of a water recirculating system for bullfrog production: technological innovation for small farmers

ABSTRACT Despite the technological progress in frog farming, issues related to the environment, biosafety, and the use of technologies that minimise environmental impacts are frequently neglected by farmers. With the goal of developing a low-cost technology for reuse and preservation of water quality, an anaerobic filtering system combined with an aerobic filtering system was implemented in the grow-out sector in the Frog Culture Research Unit at Fundação Instituto de Pesca do Estado do Rio de Janeiro (FIPERJ). The filtering system received the effluent from six pens of frogs that were populated with 362 frogs in different development phases. The efficiency of the filtering system was evaluated by an analysis of the water before and after passing through the filters. In addition to the standards of water quality, the animals' performance was also observed through monitoring rates of survival, weight gain and feed conversion ratio. The results showed the effectiveness of the filtering system by removing organic matter, on average 87%. The values of total ammonia and non-ionisable reached 1.04 and 0.004 mg/L, respectively. Also, frogs subjected to the system presented satisfactory rates of weight gain and a high survival rate (97%)

Desempenho zootécnico de girinos de rã-touro com diferentes níveis de proteína e energia digestíveis

A partir dos valores de digestibilidade de alguns ingredientes foram propostas dietas, com diferentes níveis de proteína e energia digestíveis, em esquema fatorial 3 x 3, destinadas a girinos de rã-touro para avaliar o desempenho zootécnico. O experimento, com duração de 60 dias, foi conduzido com 810 girinos, oriundos da mesma desova, distribuídos em 27 caixas de polipropileno, em uma densidade de 1girino/L. O delineamento experimental foi um esquema fatorial com três níveis de proteína digestível (27; 31 e 35%) e três níveis de energia digestível (2.700; 2.800 e 2.900kcal/kg) com três réplicas. Os parâmetros avaliados aos 60 dias foram ganho de peso, consumo da dieta, consumo em proteína da dieta, conversão alimentar, taxa de eficiência proteica e índice de sobrevivência. Os resultados foram submetidos à análise de variância e ao teste de Duncan (95% de precisão). Os resultados encontrados não apresentaram interação entre proteína e energia digestível para nenhum parâmetro avaliado. em relação à proteína digestível, foram verificadas diferenças nos parâmetros consumo em proteína da dieta e taxa de eficiência proteica (TEP), o que demonstra ineficiência das dietas com altos valores proteicos. Deve-se oferecer aos girinos de rã-touro dietas com 27% de proteína digestível, por apresentarem melhor resultado para taxa de eficiência proteica e para consumo em proteína da dieta.From the digestibility values of some ingredients, it was proposed diets with different levels of digestible protein and energy, in a 3x3 factorial design for bullfrog tadpoles, aiming at evaluate the zootechnical performance. The experiment was conducted during 60 days with 810 tadpoles from the same spawning distributed into 27 polypropylene boxes at a density of 1 tadpole/L. The experimental design consisted of a factorial arrangement with three levels of digestible protein (27; 31 and 35%) and three levels of digestible energy (2700; 2800 and 2900kcal/kg) with three repetitions. Parameters evaluated at 60 days were weight gain, feed intake, dietary protein intake, feed conversion, protein efficiency rate and survival rate. Results were subjected to analysis of variance and Duncan test (95% accuracy), and presented no interaction between digestible protein and digestible energy for any parameter evaluated. As for the digestible protein, significant differences were detected in the dietary protein intake, and protein efficiency rate, evidencing inefficiency of diets with high protein values. Bullfrog tadpoles should be given diets with 27% digestible protein by having the best result for the protein efficiency rate and for the dietary protein intake, with the lowest value and similar to other levels among evaluated parameters

Histopathological aspects of the liver of free-living and farmed bullfrogs (Lithobates catesbeianus)

The objective of this study was to compare the histopathological aspects of the liver of free-living and farmed bullfrogs (Lithobates catesbeianus). Thirty liver samples were collected from young and adult bullfrogs in the states of Minas Gerais and Rio de Janeiro, Brazil. Marked blood congestion and even hemorrhage and a large number of melanomacrophages were observed in most of the livers from free-living bullfrogs. Additionally, hepatocytes showed cytoplasmic eosinophilia and some showed nuclear hypertrophy and presence of microvesicular steatosis; small foci of infiltrates of mononuclear cells were observed in some samples, as well as a thicker capsule. In the farmed bullfrogs, cytoplasmic rarefaction was normal. Morphologically, unlike the livers of animals reared on farms, the livers of free-living animals did not show any evidence of protein-mineral deficiency, characterized by cytoplasmic vacuolation and a larger number of melanomacrophages, suggesting greater aggression to the liver parenchyma, probably due to environmental toxicity. Free-living bullfrogs feed on proteins of better biological value, derived from animals preyed in the natural environment

Histopathological aspects of the liver of free-living and farmed bullfrogs (Lithobates catesbeianus)

ABSTRACT The objective of this study was to compare the histopathological aspects of the liver of free-living and farmed bullfrogs (Lithobates catesbeianus). Thirty liver samples were collected from young and adult bullfrogs in the states of Minas Gerais and Rio de Janeiro, Brazil. Marked blood congestion and even hemorrhage and a large number of melanomacrophages were observed in most of the livers from free-living bullfrogs. Additionally, hepatocytes showed cytoplasmic eosinophilia and some showed nuclear hypertrophy and presence of microvesicular steatosis; small foci of infiltrates of mononuclear cells were observed in some samples, as well as a thicker capsule. In the farmed bullfrogs, cytoplasmic rarefaction was normal. Morphologically, unlike the livers of animals reared on farms, the livers of free-living animals did not show any evidence of protein-mineral deficiency, characterized by cytoplasmic vacuolation and a larger number of melanomacrophages, suggesting greater aggression to the liver parenchyma, probably due to environmental toxicity. Free-living bullfrogs feed on proteins of better biological value, derived from animals preyed in the natural environment