Safety and efficacy of Lactobacillus brevis NCIMB 42149 as a silage additive for all animal species

Abstract

Lactobacillus brevis is a technological additive intended to improve the ensiling process at a minimum proposed dose of 1 × 108 colony-forming units (CFU)/kg fresh material. The species L. brevis is considered by EFSA to be suitable for the qualified presumption of safety approach to safety assessment and not to require specific demonstration of safety other than the susceptibility to antibiotics of human and veterinary significance. Although identity was established, the strain was found resistant to ampicillin and clindamycin and may pose a risk for the spread of genes coding for resistance to these antibiotics. Therefore, the use of this strain as a silage additive is not considered safe for target animals, and consumers of products from animals fed the treated silage. In the absence of data, no conclusion can be drawn on the skin and eye irritancy or skin sensitisation of the additive. The additive should be considered as a potential respiratory sensitiser. Although L. brevis is ubiquitous in the environment, due to its antibiotic resistance, the FEEDAP Panel cannot conclude on the extent of the risk of horizontal gene transfer to other bacteria in the environment. Six studies with laboratory-scale silos were made using forage of differing water-soluble carbohydrate content. Replicate silos containing forages treated at the proposed application rate were compared to identical silos containing the same but untreated forage. After opening and exposure to air, an increase of 3°C over ambient was taken to indicate aerobic deterioration. The additive showed a potential to significantly improve the aerobic stability of silage produced from easy, moderately difficult and difficult to ensile forage at a minimum application rate of 1 × 108 CFU/kg plant material.