Silagem de cana-de-açúcar com uréia e farelo de mandioca

• Autor(a) principal: Oliveira, Hellenn Cardoso
• Data de Publicação: 2009
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/5622
• topic: Valor nutritivo; Aditivos; Perdas; Fracionamento; Nutritive value; Additives; Losses; Fractions; CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA::PASTAGEM E FORRAGICULTURA

Two experiments were conducted, in completely randomized design, to evaluate the nutritive value, the carbohydrates fractions, the fermentation characteristics and the losses of sugar cane silages produced without or with urea (0 and 5.4 % of dry matter) and added of cassava meal (0; 7; 14; 21; and 28 % of natural matter). PVC silos with 50 cm height and 10 cm diameter, provided with Bunsen valve for output of gases from the fermentation, and sand in the bottom to capture the possible effluent, were used. In experiment I, the evaluation of the nutritive value of silages was realized by means of the determination of the chemical composition, the in vitro dry matter digestibility (IVDMD), the total digestible nutrients (TDN) and the carbohydrates fractions. The urea and the cassava meal increased the dry matter values and reduced the contents of neutral detergent fiber, acid detergent fiber, hemicellulose, cellulose and lignin. The association of urea with cassava meal in the silages increased the contents of organic matter, crude protein and TDN and reduced the ether extract, neutral detergent fiber ash and protein free, neutral detergent insoluble nitrogen and acid detergent insoluble nitrogen contents. The cassava meal addition in sugar cane silage production increased the IVDMD and reduced the ash contents. The urea had effect on all the variables studied. In the regression analysis, it was found increasing linear increase of total carbohydrates content in function of cassava meal addition in the silage without urea and quadratic effect in the silage with urea. The association of urea with the different levels of cassava meal increased the A + B1 fraction and reduced the B2 and C fractions of the carbohydrates. In the experiment II, the losses of dry matter by gases, the effluent losses, dry matter recoveryand silage fermentation profile, through the determination of pH values, ammonia nitrogen and organic acids content were evaluated. The losses by gases and effluent were influenced, presenting decreasing lineareffect in function of the cassava meal levels for both silages. For the variable dry matter recovery, it was verified increasing linear effect for the silage without urea and quadratic effect for the silage added with urea. Regarding the variables inherent to the fermentation characteristics of the silages, the association urea and cassava meal resulted in silages with greater pH values, being within the range considered ideal for a good fermentation, and smaller lactic acid and ammonia nitrogen contents. For the butyric acid and ethanol contents, the regression analysis reveled that no model fitted the data. However, for propionic acid content, it was verified decreasing linear effect in function of cassava meal levels added and quadratic effect for acetic acid content in the silage with urea, with no effect observed in the silage without the additive.