Resumen
Sorghum grain structure, along with its accompanying proteins, hinders nutrient availability. The objective was to assess the impact of the addition of a protease on the fermentative and digestive characteristics of ensiled wet sorghum grains. A dual-purpose hybrid sorghum was planted in experimental plots, and panicles were manually harvested in the hard-grain stage. The grains were separated and ground mechanically before being mixed with a protease (PROT; 2 g kg-1 of fresh matter) or water (CONTROL), to be subsequently ensiled in PVC microsilos. Grain samples before and after ensiling were analyzed for dry matter (DM), ash, crude protein, alcohol soluble carbohydrates, starch, in vitro dry matter digestibility, and net cumulative gas production. At harvest, grains showed 566 g DM kg-1 of fresh matter. Ensiling reduced alcohol soluble carbohydrates (ca. 50%), and no differences were found between treatments in chemical composition, but the degradation rate increased (“c”; CONTROL= 0.04, PROT= 0.05). Principal component analysis revealed that ensiling was the primary driver of change, rather than protease application; however, 22% of the combined variation in chemical and nutritional variables was attributed to protease addition. Overall, although the digestion rate increased in PROT treatment, changes in nutritional profile were mainly associated with the ensiling process.