Scientific Opinion on the safety and efficacy of Enterococcus faecium (NCIMB 10415, DSM 22502, ATCC 53519 and ATCC 55593) as silage additives for all animal species

Abstract

Four strains of Enterococcus faecium are each intended to improve the ensiling process at doses ranging from 5 × 106 to 1.0 × 108 colony-forming units (CFU)/kg forage. The strains do not contain marker genes typical of hospital-associated isolates responsible for clinical infections and are susceptible to clinically relevant antibiotics. Therefore, the use of these strains as silage additives is safe for consumers of animal products. It is not expected that the use of E. faecium at the doses proposed would substantially increase the exposure of animals given the silage. Therefore, the use of these strains in the preparation of silage is safe for the target animals. In the absence of evidence, these additives should be regarded as skin and eye irritants and potential skin sensitisers. Given the proteinaceous nature of the active agents, the Panel considers it prudent to treat these additives as respiratory sensitisers. Given the high dusting potential of most of the preparations tested, there is a need to take measures to minimise inhalation exposure of workers. The use of these strains as silage additives is considered safe for the environment. The results of efficacy studies showed that two of the E. faecium strains have the potential to improve the production of silage from easy, moderately difficult and difficult to ensile forage materials at a minimum dose of 1 × 108 CFU/kg fresh materials. Given the magnitude of the responses recorded and the absence of any substantive evidence of nutrient preservation, the data for the other two E. faecium strains, taken overall, provide little evidence of a benefit when used in the production of silage.