Elephant grass (Pennisetum purpureum Schum.) is a tropical forage with high biomass yield, making it suitable for silage production. However, its low dry matter (DM) at the recommended harvest stage may lead to fermentation problems and increased gas and effluent losses. Therefore, this study aimed to evaluate the use of different additives on the fermentative profile and nutritional value of elephant grass silage. The experimental design was completely randomized, with eight replicates. The treatments were elephant grass without additives (control), elephant grass with cornmeal, and elephant grass with wheat bran. Elephant grass was harvested at 22.47% DM, and additives were included at 12% of fresh matter (FM). After 150 days of fermentation, DM recovery index (DMRI), gas and effluent losses, buffering capacity, ammonia nitrogen, and nutritional value were evaluated and lactic acid concentration was estimated. Including cornmeal or wheat bran in silage reduces the pH from 5.55 to 4.22. Wheat bran led to higher DMRI and lower gas losses. Both additives increased DM from 20.32% to 28.04% (cornmeal) and 27.94% (wheat bran). In addition, the use of additives reduced effluent losses (56.54 kg/t of FM) and ammonia nitrogen (mean 1.65% of total N) and increased lactic acid (mean 13.47 mg/g DM). Cornmeal produced the highest in vitro DM digestibility (ivDMd), followed by wheat bran and control. Including 12% of additives in elephant grass silage was effective in absorbing moisture, reducing fermentative losses, and improving the nutritional value. Despite the improved fermentative process with the addition of wheat bran and corn meal, future studies should evaluate these silages in animals to assess their effects on productive performance.
Massena et al. (Thu,) studied this question.