Nutritive value and fermentation characteristics of silages produced from different sweet sorghum plant components with or without microbial inoculation

Abstract

Objective: The objective of this study was to evaluate nutritive value and fermentation characteristics of silage made with different plant components of sweet sorghum [Sorghum bicolor (L.) Moench] with or without microbial inoculation. Materials and Methods: The experiments were conducted at Ona, Florida, in 2012 (Exp. 1) and 2013 (Exp. 2). In Exp. 1, treatments were the ensiling of different plant components, whole plant (leaves, stem, and inflorescence; WP), stem (stem only, ST), and bagasse (stem pressed to remove the juice, BAG). In Exp. 2, treatments were distributed in a factorial 3 × 2 arrangement with the same plant component treatments from Exp. 1 with or without microbial inoculant (B500). Results and Discussion: In Exp. 1, BAG had greater (P < 0.04) DM, NDF, and ADF and lesser nonfibrous carbohydrate and TDN concentrations than WP and ST. The WP had greater (P = 0.003) CP and lactic and acetic acids and lower (P = 0.04) pH than BAG. The BAG had greater (P = 0.04) yeast count than WP and ST. In Exp. 2, there were no differences in pH among treatments (P = 0.90); however, WP had greater (P < 0.001) TDN and lactic acid concentrations than BAG, and WP silage treated with inoculant had greater (P < 0.05) CP and nonfibrous carbohydrate concentrations. Implications and Applications: Sweet sorghum BAG had acceptable nutritive value and fermentation characteristics and can be used as forage for ruminants. Microbial inoculants may not improve the fermentation characteristics and nutritive value of sweet sorghum BAG silage.