CINÉTICA DE FERMENTAÇÃO RUMINAL DA MATÉRIA SECA E DOS CARBOIDRATOS DE SILAGENS DE CANA - DE - AÇÚCAR COM ADITIVOS

Abstract

The aim of this study was to evaluate the kinetics of ruminal fermentation dry matter and car-bohydrates of two varieties of sugar cane ensiled with different additives using a semiautomatic technique in vitro gas production. We used a completely randomized design with a factorial 2 x 5, two varieties of cane sug-ar (RB 86 7515 and IAC 86 2480) and five additives (urea, NaOH, CaO, corn and L. buchneri) and without additive treatments, with the opening of the silos being made at 60 days after ensiling. Pressure readings were performed on days 0; 2; 4; 6; 8; 10; 12; 15; 19; 24; 30; 36; 48; 72 and 96 h. The pressure caused by organic matter was recorded in a pressure transducer universal and for adjusting the parameters kinetic model was used bicompartmental. The technique of in vitro gas production satisfactorily estimated the volume of gases from silage and sugarcane raw. The higher gas volume fraction of fiber was not in IAC 86 2480, with the additive NaOH. In the fiber fraction only difference between varieties with the additive urea, and the IAC 86 2480 that had the highest volume. The cane silage IAC 86 2480, showed the best values for most of the evaluated kinetic parameters. The best results for the parameters of degradability were in silages with NaOH and CaO.