Tobia et al., 2008. Livest. Res. Rur. Dev., 20 (7): 106

Protein is often limiting in ruminant diets in the tropics. Soybean (Glycine max L. Merr.) varieties developed for grain production in tropical environments could potentially be harvested as forage to supplement protein in diets of ruminant livestock. The nutritional value of ‘CIGRAS-06’ soybean forage fermented with molasses and inoculated with Lactobacillus brevis 3 (Lb3) was evaluated. The above ground part of the soybean plants was harvested at the R6 (full seed) stage of development and chopped in approximately 2-cm sections. Molasses was applied in concentrations of 0, 3, 6 or 9% of forage fresh weight and the herbage was sprayed with an equivalent of 6.5 x 107 Lb3 colony forming units per ml of air, before storing in plastic micro-silos (1 kg).    Molasses treatment resulted in a proportional increase in silage dry matter (DM), ash (As) and neutral detergent soluble carbohydrates (NDSC). Conversely, a dilution effect was observed in crude protein (CP), ether extract (EE) and neutral detergent fiber (NDF). Molasses improved silage sensorial indicators and reduced pH, NH3 as a percentage of total nitrogen (NH3/%TN), acetic (AA) and butyric (BA) acids concentration. Molasses increased lactic acid (LA) and energy concentration, with best results (72% of total digestible nutrients) obtained with the 3% treatment. Lb3 decreased silage NH3/%TN content and BA, but decreased EE concentration and DM. Although Lb3 effectiveness was not as obvious as that of molasses, a synergistic effect between both additives was observed for pH, AA, BA and NDF reduction.  Both additives improved the fermentation and production of high quality soybean silage that due to its high buffer capacity and relatively low soluble carbohydrate content, would otherwise be difficult to ensile.