A method for improving the performance of a subject or for improving digestibility of a raw material in a feed (e.g. nutrient digestibility, such as amino acid digestibility), or for improving nitrogen retention, or for improving dietary phosphorus absorption and retention, or for improving the efficacy of the phytase, or for improving the subject's resistance to necrotic enteritis or for improving feed conversion ratio (FCR) or for improving weight gain in a subject or for improving feed efficiency in a subject or for modulating (e.g. improving) the immune response of the subject or for reducing populations of pathogenic bacteria in the gastrointestinal tract of a subject, or for reducing nutrient excretion in manure, which method comprising administering to a subject at least one direct fed microbial in combination with a phytase, wherein the phytase is administered to the subject at a dosage of more than about 1500 FTU/kg feed.