Degradabilidade ruminal da cana-de-açúcar integral tratada com diferentes níveis de hidróxido de sódio / Degradability of integral sugar cane treated with different sodium hidroxide levels

RESUMO

O experimento foi realizado utilizando-se quatro bovinos fistulados no rúmen. Durante o experimento, osanimais receberam uma dieta à base de silagem de milho e cana-de-açúcar picada e tratada com 2% deNaOH. Foram avaliados quatro tratamentos à base de cana-de-açúcar com diferentes níveis de NaOH (0,2, 4 e 6%) incubados no rúmen usando-se sacos de náilon. Determinou-se o desaparecimento da matériaseca (MS), matéria orgânica (MO), fibra em detergente neutro (FDN), fibra em detergente ácido (FDA),celulose (CEL) e hemicelulose (HEM) em 0; 6; 12; 24; 48; 72; 96 e 144 horas de incubações no rúmen. Asdegradabilidades potencial (DP) e efetiva (DE) foram determinadas segundo o modelo proposto porOrskov & McDonald (1979) a uma taxa de passagem de 5%/h. Dentro dos tempos de incubação, houvemaior desaparecimento de MS, MO, FDN, FDA, CEL e HEM. para o tratamento com 6% de NaOH.Observou-se maior (P<0,05) DP e DE, respectivamente, para MS (62,01% e 49,39%), MO (62,98% e49,10%), FDN (57,61% e 34,75%), FDA (55,67% e 35,25%), CEL (64,89% e 36,73%) e HEM (61,44% e35,72%), da cana-de-açúcar tratada com 6% de NaOH. Pode-se concluir que o tratamento químico dacana-de-açúcar com 6% de NaOH promoveu maior degradabilidade potencial e efetiva da MS, MO e dafração fibrosa. Os valores de DP e DE da fração fibrosa da cana de açúcar tratada com 6% de NaOH,justificam a utilização deste tratamento nas condições em que estas foram utilizadas.

ABSTRACT

The experiment was carried out being used four bovine cannulated at rumen. Corn silage and chopped sugar cane, treated with 2% NaOH were furnished to the animals during the experiment. Four treatments consisting of sugar cane treated with 0, 2, 4 and 6% NaOH were evaluated by ruminal incubation usingnylon bags. Dry matter (DM), organic matter (OM), neutral detergent fiber (NDF), acid detergent fiber (ADF), cellulose (CELL) and hemicellulose (HEM) disappearance were evaluated in 0, 6, 12, 24, 48, 72, 96 and 144 hours of ruminal incubation. Potencial degradability (PD) and effective degradability (ED) were determinated using the model suggested by Orskov & Mc Donald (1979), accepting a passage rate of potassium permanganate; conditioned fruits, in groups of 5, in carton boxes with cover, covered internally or no with low density polyethylene film addictived with potassium permanganate. The fruits were stored under storage room at 24,4 ¨¬C, 70 % RH. The evaluated variables were loss of fresh mass, appearance, firmness of the pulp, soluble solids, titratable acidity and ascorbic acid. It were verified that the best treatments of modified atmosphere were individual packaging of the mango fruits in plastictrays, covered with plastic film of polivinila chloride (PVC) of 14 ¥ìm, without and with sachet of potassiumpermanganate. The potassium permanganate, in the form used in this study (sachet and impregnated inplastic film), did not interfere in the results obtained for the conservation of the fruits.