Effects of Bacterial Inoculants and Ground Corn Grain on Fermentation Profile and In Situ Rumen Degradability of Tropical Grass Silage

The aim of this study was to evaluate different doses of bacterial inoculants and the inclusion of 8% ground corn grain (GCG) on fermentative characteristics, chemical composition, and in situ ruminal degradability of low-DM elephant grass (cv. BRS Capiaçu) silage. The experiment followed a completely randomized design in a 6 × 3 factorial arrangement (six treatments × three fermentation periods). Treatments were a control without additive (CTR); 0.5 or 1 g/ton of Lentilactobacillus buchneri (LBU0.5 and LBU1); 1 or 2 g/ton of a Lactiplantibacillus plantarum + Pediococcus acidilactici inoculant (LPP1 and LPP2); and 8% GCG. After 60 d of fermentation, in situ ruminal degradability was evaluated using rumen-fistulated lactating cows with incubation times from 0 to 240 h. The GCG treatment increased DM, CP, and ether extract concentrations and reduced NDF, ADF, and lignin contents. Additionally, GCG silage exhibited lower pH, butyric acid, and ammonia nitrogen concentrations, along with higher lactic acid levels. No treatment effects were observed for water-soluble carbohydrates or total DM losses. The effective NDF degradability, degradation rate of the slowly degradable fraction, and undigested NDF after 240 h were not affected by treatments. In conclusion, the inclusion of GCG improved the fermentative profile of low-DM elephant grass silage, whereas bacterial inoculants did not significantly enhance the silage quality under the conditions evaluated.