Degradabilidade in situ e observações microscópicas de volumosos em bovinos suplementados com enzimas fibrolíticas exógenas
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Data
2007-12-01
Autores
Martins, Adriana de Souza
Vieira, Paulo de Figueiredo
Berchielli, Telma Teresinha [UNESP]
Prado, Ivanor Nunes do
Lempp, Beatriz
Paula, Meiby Carneiro de
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Editor
Sociedade Brasileira de Zootecnia
Resumo
Avaliou-se o efeito de enzimas fibrolíticas (celulase e xilanase) sobre a degradabilidade in situ da MS, PB, FDN, FDA e hemicelulose do feno de Tifton-85 (Cynodon spp.) cortado aos 30 e 90 dias e do bagaço de cana, utilizando-se seis bovinos com cânula no rúmen. As enzimas foram extraídas dos fungos Aspergillus niger e Trichoderma longibrachiatum e fornecidas, na quantidade de 0,75 g/kgMS.dia, por meio da cânula ruminal. Os tempos de incubação ruminal foram de 0, 3, 6, 12, 24, 48, 72 e 96 horas. Os resíduos de incubação foram avaliados por meio de microscopia eletrônica de varredura (MEV). O efeito da adição de enzimas sobre a degradação da MS e PB variou em função do volumoso estudado. A degradabilidade efetiva da MS do feno Tifton cortado aos 30 e 90 dias e do bagaço de cana sem a adição de enzimas foi de 61,85; 42,35 e 28,22%, respectivamente, e de 63,51; 40,64 e 31,43%, respectivamente, com a adição das enzimas. Não houve efeito das enzimas sobre a degradação da fibra. As observações ao MEV indicaram aumento da colonização bacteriana sobre a parede celular com a suplementação enzimática. A adição de enzimas fibrolíticas na dieta de ruminantes apresentou efeito pouco expressivo sobre os parâmetros de degradação ruminal dos volumosos estudados.
The effect of fibrolytic enzymes addition (cellulase and xylanase) on the DM, CP, NDF, ADF, and hemicellulose in situ degradability of Tifton 85 hay (Cynodon spp.) cut at 30 and 90 days and sugarcane bagasse were evaluated with six bovines cannulated on the rumen. The enzymes were extracted from Aspergillus niger and Trichoderma longibrachiatum fungi and supplied 0.75 g/kg of DM/animal.day, through ruminal cannula. The incubation times were 0, 3, 6, 12, 24, 48, 72, and 96 hours. The incubation residues were compared by scanning electron micrographs (SEM). The effect of enzyme addition on the DM and CP degradation varied in function of roughage studied. The effective degradability of DM of Tifton 85 hay cut at 30 and 90 days and sugarcane bagasse, without enzymes addition, was 61.85, 42.35, and 28.22%, respectively, and 63.51, 40.64, and 31.43%, respectively, with enzymes addition. There was no effect of enzymes on the fiber degradation. The SEM observations showed that bacterial colonization increased on the cell wall of roughages with enzymatic supplementation. The fibrolytic enzyme addition to the ruminant diet presented little expressive effect on the degradation parameters of studied roughages.
The effect of fibrolytic enzymes addition (cellulase and xylanase) on the DM, CP, NDF, ADF, and hemicellulose in situ degradability of Tifton 85 hay (Cynodon spp.) cut at 30 and 90 days and sugarcane bagasse were evaluated with six bovines cannulated on the rumen. The enzymes were extracted from Aspergillus niger and Trichoderma longibrachiatum fungi and supplied 0.75 g/kg of DM/animal.day, through ruminal cannula. The incubation times were 0, 3, 6, 12, 24, 48, 72, and 96 hours. The incubation residues were compared by scanning electron micrographs (SEM). The effect of enzyme addition on the DM and CP degradation varied in function of roughage studied. The effective degradability of DM of Tifton 85 hay cut at 30 and 90 days and sugarcane bagasse, without enzymes addition, was 61.85, 42.35, and 28.22%, respectively, and 63.51, 40.64, and 31.43%, respectively, with enzymes addition. There was no effect of enzymes on the fiber degradation. The SEM observations showed that bacterial colonization increased on the cell wall of roughages with enzymatic supplementation. The fibrolytic enzyme addition to the ruminant diet presented little expressive effect on the degradation parameters of studied roughages.
Descrição
Palavras-chave
Cellulase, Fiber, Microrganisms, Celulase, Fibra, Microrganismos, ruminantes
Como citar
Revista Brasileira de Zootecnia. Sociedade Brasileira de Zootecnia, v. 36, n. 6, p. 1927-1936, 2007.