Assessing the fermentation characteristics, nutritional value and in vitro ruminal digestibility of sweet sorghum silage mixed with peanut vine hay or distiller grains

Abstract

This study aimed to evaluate the fermentation characteristics, nutritive value and in vitro ruminal digestibility of a mixed silage of sweet sorghum (SS) with peanut vine hay (PVH) or distiller grains (DG). Silage was produced without any additives (CON) or with 10% (P1) or 20% (P2) PVH or 10% (D1) or 20% (D2) DG on fresh matter. All silage was ensiled in capped bottles and preserved for 60 days. The lowest pH value was found in D2 silage, followed by D1, CON, P1 and P2 silage (P < .05). The D2 silage exhibited the highest lactic acid content, which was significantly greater than that observed in P2 silage (P < .05). The ammonia-N content of the CON silage was higher than that of the P2- and DG-treated silage (P < .05). The inclusion of PVH or DG in SS ensilage resulted in a linear increase in dry matter, crude protein, total digestible nutrients, and relative feed value and a decrease in organic matter, neutral detergent fiber, acid detergent fiber and water-soluble carbohydrates. Most in vitro rumen fermentation parameters tended to increase in silage treated with PVH or DG compared with CON silage, although no significant effect (P > .05) was found for the treatments. Furthermore, PVH- or DG-treated silage had a lower ruminal fermentation pH (P < .05). Our study demonstrates that the addition of PVH or DG can improve the fermentation quality, nutritional value and in vitro ruminal digestibility of SS silage. Notably, the fermentation efficacy of DG was higher than that of PVH. Therefore, inclusion of 20% PVH or DG in the silage formulation is recommended.