Scientific Opinion on the safety and efficacy of Lactobacillus buchneri (NCIMB 30139) as a silage additive for all species

The European Food Safety Authority (EFSA) was asked to deliver a scientific opinion on the safety for the target animals, consumer, user and for the environment and on the efficacy of a product based on a specific strain of Lactobacillus buchneri, when used as a technological additive intended to improve the ensiling process at a dose of 1.0 x 108 CFU/kg fresh material. The bacterial species L. buchneri is considered by EFSA to be suitable for the Qualified Presumption of Safety approach. As the identity of the strain has been clearly established and as no antibiotic resistance was detected, the use of the strain in the production of silage is considered safe for livestock species, consumers of products from animals fed the treated silage and for the environment. Although users at the farm level are exposed to silage additives only for a short period of time when preparing the aqueous suspension, indicative data on particle size distribution and the proteinaceous nature of the active agent indicate a possible hazard for those handling the additive of exposure by a respiratory route with a consequent risk of sensitisation. Eight studies with laboratory-scale silos are described, each lasting at least 105 days, made using samples of cereals covering a range of dry matter content from 30 to 45 %. In each case, replicate silos containing treated forage were compared to identical silos containing the same untreated forage. Three inter-related parameters were measured to indicate the time to aerobic spoilage: increasing pH, increasing numbers of lactate-utilising yeasts and the consequent rise in temperature. All eight studies gave consistent and significant results showing that the additive containing the L. buchneri strain has the potential to improve the preservation of silage by increasing acetic acid production resulting in an extended aerobic stability of the treated silage.