Disclosed is a composition comprising a gluconic acid and/or one or more gluconic acid derivatives and a controlled release agent, wherein the controlled release agent allows partial, substantial, or substantially complete ruminal bypass of the composition. The composition may be used as a ruminant feed or feed supplement, particularly for increasing milk fat production in a lactating ruminant, for improving the health status of the hindgut of a ruminant, for increasing the production of butyrate in the hindgut of a ruminant, and/or for increasing somatic growth of a ruminant.