Evaluation of Sweet Sorghum Bagasse as an Alternative Livestock Feed

Abstract

ABSTRACTRecently, sweet sorghum [Sorghum bicolor (L) Moench] has garnered renewed attention as a promising feedstock for ethanol production. A byproduct of this is bagasse, which is sweet sorghum stalks remaining after juice extraction. It is possible that sweet sorghum bagasse could provide a source of livestock feed and that its nutritive value could be increased by ammoniation. Ammoniation refers to the treatment of low‐quality forages with NH3 to improve crude protein concentration, digestibility, and animal intake. The main objective of this study was to evaluate sweet sorghum bagasse as a livestock feed and determine the effect of ammoniation on in vitro true digestibility (IVTD) and crude protein (CP) of sweet sorghum bagasse. In vitro true digestibility and CP were determined on bagasse of 12 sweet sorghum cultivars grown in three environments and treated with and without anhydrous NH3 (39.0 g kg−1). Across environments, ammoniation increased bagasse IVTD from a mean of 731 g kg−1 dry matter (DM) to a mean of 750 g kg−1 DM, but IVTD of bagasse from only two of three environments was increased. Crude protein averaged 117 g kg−1 DM for ammoniated samples compared to 26 g kg−1 DM for nontreated samples. Ammoniation increased CP in every cultivar and in every environment. Sweet sorghum bagasse IVTD and CP characteristics combined with large yields indicate that this byproduct could serve as livestock feed and merits further investigation.