The European Food Safety Authority (EFSA) was asked to deliver a scientific opinion on the safety for the target animals, consumer, user and environment, and on the efficacy of two specific bacterial strains of Lactobacillus salivarius and Lactobacillus casei, when used as technological additives to improve the ensiling process at a proposed dose of 1.3 x 107 and 1.3 x 106 CFU/kg fresh material, respectively. Both species are considered by EFSA to be suitable for the qualified presumption of safety approach. As the identity of the strains has been clearly established and as no antibiotic resistance of concern was detected, their use in the production of silage is considered safe for livestock species, consumers of products from animals fed the treated silage and for the environment. The indicative data on particle size distribution of the L. casei product and the proteinaceous nature and high dusting potential of both products indicate a toxic hazard by exposure via a respiratory route for those handling the additives, with a consequent risk of sensitisation. Studies with laboratory-scale silos were made using samples of forage of differing water-soluble carbohydrate content. In each case, replicate silos containing treated forage were compared to identical silos containing the same untreated forage. The additive containing L. casei has the potential to improve the production of silage from easy to ensile material by reducing the pH and increasing the preservation of dry matter. The additive containing the L. salivarius strain showed limited potential to reduce dry matter loss in moderately difficult and difficult to ensile forage species. However, given that the magnitude of the response to the additive in the studies provided was small and the effects inconsistent, the FEEDAP Panel is doubtful of the benefits that may be provided by the use of this additive in the ensiling process.
