This European Standard defines general rules for the enumeration of probiotic lactobacilli in feed samples (additives, premixtures and feeding stuffs) that contain lactobacilli as a single bacterial component or in a mixture with other microorganisms. This standard is not applicable to mineral feeds, which are defined as complementary feeding stuffs composed mainly of minerals and containing at least 40% crude ash (Council Directive 79/373/EEC [3]). There are different categories of feed samples: a) Additives containing about 1010 colony forming units (CFU)/g; b) Premixtures containing about 108 CFU/g; c) Feeds, meal or pellets, which contain about 106 CFU/g and include complete feeding stuffs and milk replacers.The detection limit is as defined in EN ISO 7218.