ABSTRACT
Oral administration of ionophores allows, initially, for regulation of body function at the site of digestion by positively affecting feed conversion efficiency and negatively affecting developmental stages of coccidia. As with any chemical introduced to food animals, it is important to understand the basis of veterinary use, the pharmacology, and single species and comparative toxicology. Resistance patterns, the residue profile and the depletion profile in edible tissues must also be understood. The neutral ionophores, such as monensin, lasalocid, salinomycin, and narasin as charged molecules are capable of grossly distorting biological membrane and action potentials. Liquid chromatographic techniques using fluorometric detection have been developed and validated for quantitation of beef liver tissue residues of monensin, salinomycin, lasalocid, and narasin. Residues of the ionophores themselves have also been separated using thin-layer chromatography and bioautography.
