Desenvolvimento de microrganismos e valor nutritivo de silagens de capim-Tifton 85
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Data
2002-11-27
Autores
Silva, Jussimara Manoela Nascimento [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Objetivou-se estudar o valor nutritivo e desenvolvimento de fungos e de Listeria spp. no capim-Tifton 85 (híbrido de Cynodon, PI 290884 originário da África do Sul com o Tifton 68 (Cynodon nlemfuensis) ensilado sem emurchecimento (umidade 60-70%), submetido a pré-secagem (umidade 40-50%) e com adição ou não de polpa cítrica (5% do peso verde). As amostras foram colhidas na abertura dos silos e aos 15 e 30 dias após a abertura, para avaliação da ocorrência de Listeria spp e de fungos, do padrão de fermentação (pH, N amoniacal, ácidos orgânicos), teores de matéria seca, de proteína bruta, de nitrogênio associado a parede celular, dos constituintes da parede celular e digestibilidade in vitro da matéria seca (DIVMS). Os dados foram analisados segundo o delineamento em blocos completos casualisados, em esquema de parcela subdividida, sendo que nas parcelas foram avaliadas as silagens submetidas ao emurchecimento e uso ou não de polpa cítrica e nas subparcelas os períodos de exposição ao ar, com quatro repetições. Constatou-se a presença de Listeria spp em 65,6% das silagens de alta matéria seca, sendo que destas 10% foram positivas para Listeria monocytogenes. As silagens de alta matéria seca apresentaram pouca estabilidade aeróbia, tendo sido registrado aumento na ocorrência dos fungos Penicillium, Fusarium e Pithomyces com o prolongamento do período de exposição ao ar. Esses resultados evidenciaram o risco potencial que silagens de gramíneas com alto conteúdo de matéria seca pode representar para a saúde dos animais e humanos. Em termos de padrão de fermentação observou-se baixos teores de ácidos orgânicos e de N amoniacal, altos valores de pH, provavelmente devido aos elevados conteúdos de matéria seca causados pelo emurchecimento e adição de polpa cítrica...
This research was conducted to evaluate the nutritive value and fungal and Listeria spp. occurrence of the no wilted (60 to 70% of moisture) and wilted (40 to 50% of moisture) Tifton 85 ensiled with or without citrus pulp (5.0% of the wet weight). The high dry matter silage were harvested, immediately after the silos opening, also 15 and 30 days after the air exposition. It was evaluated the Listeria and fungal occurrences, fermentation characteristics (pH, amoniacal nitrogen, organic acids), values of dry matter, crude protein (CP), neutral detergent insoluble nitrogen (NDIN), acid detergent insoluble nitrogen (ADIN), neutral detergent fiber (NDF), acid detergent fiber (ADF), and in vitro dry matter digestibility (IVDMD). The data were analyzed according to a randomized block design in split plot scheme, being the silages studied in plots and the periods of air exposure in the split plots, with four replications. It was observed Listeria spp in 65.6% of the high dry matter silage samples, and Listeria monocytogenes occurred in 10.0% of these samples. The high dry matter silage was air unstable and Penicillium, Fusarium e Pithomyces occurrence increased during the air exposition period. These data showed the potential risk that the high dry matter grass silage could represent to the animal and human health. In relation to the fermentation characteristics, it was observed lowest values of amoniacal nitrogen, organic acid, and highest pH values, probably due to the high dry matter content of the silage. The high dry matter silage showed lowest N-NH3/N total values, preserving the crude protein content, probably caused by the low Clostridium activity. The NDIN and ADIN contents increased during the air exposition periods, in function of the microorganism's activity, resulted in high temperature of the high dry matter silage... (Complete abstract, access undermentioned eletronic address)
This research was conducted to evaluate the nutritive value and fungal and Listeria spp. occurrence of the no wilted (60 to 70% of moisture) and wilted (40 to 50% of moisture) Tifton 85 ensiled with or without citrus pulp (5.0% of the wet weight). The high dry matter silage were harvested, immediately after the silos opening, also 15 and 30 days after the air exposition. It was evaluated the Listeria and fungal occurrences, fermentation characteristics (pH, amoniacal nitrogen, organic acids), values of dry matter, crude protein (CP), neutral detergent insoluble nitrogen (NDIN), acid detergent insoluble nitrogen (ADIN), neutral detergent fiber (NDF), acid detergent fiber (ADF), and in vitro dry matter digestibility (IVDMD). The data were analyzed according to a randomized block design in split plot scheme, being the silages studied in plots and the periods of air exposure in the split plots, with four replications. It was observed Listeria spp in 65.6% of the high dry matter silage samples, and Listeria monocytogenes occurred in 10.0% of these samples. The high dry matter silage was air unstable and Penicillium, Fusarium e Pithomyces occurrence increased during the air exposition period. These data showed the potential risk that the high dry matter grass silage could represent to the animal and human health. In relation to the fermentation characteristics, it was observed lowest values of amoniacal nitrogen, organic acid, and highest pH values, probably due to the high dry matter content of the silage. The high dry matter silage showed lowest N-NH3/N total values, preserving the crude protein content, probably caused by the low Clostridium activity. The NDIN and ADIN contents increased during the air exposition periods, in function of the microorganism's activity, resulted in high temperature of the high dry matter silage... (Complete abstract, access undermentioned eletronic address)
Descrição
Palavras-chave
grass silage, aerobic stability, Listeria, Silagem, Bactérias, Gramínea
Como citar
SILVA, Jussimara Manoela Nascimento. Desenvolvimento de microrganismos e valor nutritivo de silagens de capim-Tifton 85. 2002. viii, 80 f. Tese (doutorado) - Universidade Estadual Paulista, Faculdade de Ciências Agrárias e Veterinárias, 2002.