Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of Lentilactobacillus buchneri DSM 32651 when used as a technological additive to improve ensiling of fresh plant material. The additive is intended for use in all fresh material for all animal species at a proposed minimum concentration of 1 × 108 colony forming units (CFU)/kg fresh plant material. The bacterial species L. buchneri is considered by EFSA to be suitable for the qualified presumption of safety approach to safety assessment. The identity of the strain was established and no acquired antimicrobial resistance genes of concern were detected. Therefore, the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) concluded that the use of the strain as a silage additive is considered safe for all the animal species, for consumers of products from animals fed the treated silage and for the environment. Regarding user safety, the additive should be considered as a potential skin and respiratory sensitiser, and any exposure through skin and respiratory tract is considered a risk. The additive is not an eye irritant. The FEEDAP Panel concluded that the additive consisting of L. buchneri DSM 32651 at a minimum concentration of 1 × 108 CFU/kg fresh material may extend the aerobic stability of silage prepared from fresh plant material with a DM range of 28%-45%.