Steam-exploded sugarcane bagasse as a potential beef cattle feedstock: effects of different pretreatment conditions1

Sugarcane bagasse, a lignocellulosic biomass produced by sugar production, is rarely utilized directly due to economic concerns. However, pretreatment of this biomass could make it suitable as a feedstock for the beef cattle industry. Accordingly, this study investigated the effects of different steam explosion conditions on bagasse digestibility using in vitro fermentation techniques, scanning electron microscopy, and detailed chemical analyses. In vitro incubation of an untreated sample and samples pretreated at 6 different pressures ranging from 0.6 to 1.6 MPa at intervals of 0.2 MPa for 5 min was conducted out for 96 h. Results showed that increasing the pressure in the steam explosion pretreatment induced degradation of the hemicellulose and increased soluble sugar content, especially for arabinose (L; P < 0.01) and xylose contents (Q; P < 0.01). In vitro incubation showed that compared with untreated bagasse, gas production and degradation rate of the bagasse improved linearly (L; P < 0.01) after all treatments. The lag time disappeared with steam pressure above 1.0 MPa and the maximum gas production was obtained under pretreatment at 1.4 MPa for 5 min. Furthermore, pretreatment of bagasse by steam explosion enhanced (Q: P < 0.01) quadratically estimated energy values and OM digestibility. Thus, the current results demonstrate that sugarcane bagasse may be effectively used as a potential beef cattle feedstock after steam explosion pretreatment.