Test schemes for evaluation of the effect of a probiotic feed additive on the gut microflora of young calves and newly hatched turkeys

Probiotic feed additives have to undergo a strict assessment according to EU regula-tions, including the evaluation of the influence on the gut microflora of the host animal. A probiotic strain of the genus Enterococcus faecium and two different host animal species, young calves and newly hatched turkeys, were chosen as a test model for the establishment of schemes for feeding trials. Investigations included faeces samples and pooled swab samples of faeces as well as samples from gut sections derived from diagnostic slaughtering. The samples were tested for aerobic total count, for enterococci count and for Enterobacteriaceae and E. coli. The test schemes were appropriate for the evaluation of the influence of the probiotic feed additive on the physiological gut microflora of the host animals. Additional information could be gathered concerning safety aspects and effectiveness.