Effects of homofermentative lactic acid bacteria and powdered molasses on fermentative losses, chemical composition and aerobic stability in whole-plant soybean silage

Abstract

ABSTRACT This study evaluated the effects of homolactic bacteria and molasses (MOL) in whole-plant soybean silage on dry matter (DM) losses, content of organic acids, bromatological composition, in situ degradation of DM and aerobic stability. Mini-silos (n = 200) were blocked (n = 5) by phenological stage and assigned into a 2×2 factorial treatment arrangement with 2 levels of microbial inoculation (INO, 0 or 105 colony forming units of Lactobacillus plantarum and Pediococcus pentosaceus per kg of fresh forage) and 2 levels of powdered MOL (0 and 40 g/kg fresh forage). Mini-silos were opened after 90 days of fermentation. Total losses were lower in silos with MOL. Whole-plant soybean ensiled with the combination of INO and MOL had the highest DM recovery. Adding MOL increased lactic acid content and decreased ammonia nitrogen content (marker of proteolysis), pH and buffering capacity. MOL reduced the contents of NDF. Silage with both INO and MOL had the highest DM content. MOL increased DM degradation. No effects were detected on aerobic stability. INO does not show positive effects on soybean silage nutritive quality when not associated with MOL. Molasses has a positive impact on whole-plant soybean silage by decreasing fermentation losses and pH, while increasing silage nutritive value.