Effectiveness of combining Lentilactobacillus buchneri, Lentilactobacillus hilgardii, and lemongrass essential oil in rehydrated corn silage preservation

Abstract

Heterofermentative lactic acid bacteria and essential oils have been investigated as strategies to control undesirable microorganisms in silages. This study evaluated the effects of Lentilactobacillus buchneri and Lentilactobacillus hilgardii inoculation (INO) and lemongrass essential oil (LEO) addition on fermentation profile and losses, chemical composition, in vitro degradation, and aerobic stability of rehydrated corn silage (RCS). Thirty-two experimental silos were arranged in a randomized block design to evaluate four treatments in a 2 × 2 arrangement, assessing the following factors: I. Microbial inoculation: -INO: without inoculation or +INO: containing 300,000 colony-forming units (CFU)/g of L. buchneri NCIMB 40788 and 300,000 CFU/g of L. hilgardii CNCM I-4785; and II. lemongrass essential oil: -EO: no essential oil or +EO: 2 mL/kg LEO on an as-fed basis. No interaction was observed between INO and EO. Inoculation increased silage pH and acetic acid, while reducing lactic acid from 79.5 to 24.8 g/kg. In contrast, EO had no effect on the fermentation profile. INO also increased fermentation losses and reduced DM recovery. Additionally, inoculation decreased dry matter and neutral detergent fiber content, whereas EO slightly increased organic matter. After aerobic exposure, +INO exhibited higher silage pH without affecting temperature. Thus, the combination of L. buchneri and L. hilgardii with lemongrass essential oil does not provide synergistic benefits for the preservation of rehydrated corn silage.