Microbiological assay of low levels of monensin in animal feeds

Abstract

The method for the determination of monensin in animal feedingstuffs published previously was developed at a time when this material was being incorporated in feeds at the 100 mg kg^–1 level. As a need has arisen for a method that would determine monensin when present in amounts of 20–40 mg kg^–1, the original method has been re-examined and a concentration step introduced that enabled satisfactory results to be obtained on a sample of feed containing 18 mg kg^–1 of monensin.