Sugarcane silage (SS) is generally susceptible to yeast action, resulting in dry matter losses due to high soluble carbohydrate concentration. We evaluated the effects of adding corn grain and microbial inoculant at ensiling on fermentative profile, losses, chemical composition and degradation of silages. Forty experimental silos (PVC tubing) were assigned at random to a 5 × 2 factorial arrangement with: (1) 5 corn additions at ensiling: CONT - straight sugarcane silage; GC2 - sugarcane with ground corn (processed through a 2 mm sieve) added at ensiling; GC8 - sugarcane with ground corn (processed through an 8 mm sieve) added at ensiling; WC - sugarcane with whole corn grain added at ensiling; and RCS - rehydrated corn ensiled without sugarcane; and (2) 2 microbial inoculant additions at ensiling: 0 and 8 mg of commercial inoculant per kg of feed. Corn grain was added at the rate of 100 g per kg of fresh sugarcane. Adding corn grain to sugarcane at ensiling improved SS fermentation and silage chemical composition. There was no benefit from grinding the grain before adding it to sugarcane. Microbial inoculant had little effect on SS fermentation. Studies comparing corn grain with other energy sources, e.g. molasses or cassava, for addition at ensiling sugarcane seem warranted along with feeding studies with livestock to assess intake and subsequent performance. The overall benefits of adding the energy sources at ensiling versus feeding them directly to animals with untreated sugarcane silage should be determined.