Pediococcus pentosaceus 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 P. pentosaceus strain was found to
be resistant to tetracycline by an unidentified mechanism and thus may pose a risk for the spread of genes coding for resistance to an antibiotic of human and veterinary importance. Thus, the additive containing this strain is not
considered safe for the target animals and consumers of products from animals fed the treated silage. The additive should be regarded as a skin and eye irritant and a potential skin and respiratory sensitiser, and treated
accordingly. Since the P. pentosaceus strain carries an uncharacterised resistance to tetracycline, the FEEDAP Panel cannot conclude on its safety for the environment. A total of four 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 with identical silos containing the same but untreated forage. Although the additive showed a tendency to increase lactic acid production and reduce pH in the ensiled material, overall there was insufficient evidence of a beneficial effect on the preservation of nutrients.
