This invention relates to a composition comprising benzoic acid or a derivative of benzoic. It has been found surprisingly that benzoic acid and salts thereof have the advantage of being able to improve digestibility of proteins in animal feeds, i.e. to promote amino acid and nitrogen assimilation, and to increase total energy levels. Moreover, it has been found that benzoic acid improves the digestibility of animal feed containing maize-soybean meal as a major part of the feed diet. The benzoic acid or its derivative can be administered to the animal either in its feed composition or in its drinking water. It is particularly effective in pigs.
