Efficacy of Monensin Fed to Cattle Inoculated with Coccidia Oocysts

Abstract

Monensin has been used to prevent coccidiosis in broilers since 1971. Coccidiosis is the third most prevalent health problem of cattle, and the clinical signs which include poor performance, bloody diarrhea, and mortality are readily identifiable.Therapeutic treatment of animals when signs are clinically visible does not always ensure survival. Coccidiosis infection can damage the absorptive surface of the intestine which leads to lower rates of gain and feed efficiency by the infected animal. Therefore, it is important that intestinal damage be prevented. The purpose of this investigation was to determine the prophylactic dose range of monensin which is effective against cattle coccidiosis as measured by coccidial oocyst shedding, weight gain, feed intake, clinical signs, and mortality of ruminating cattle challenged with Eimeria bovis and /or E. zuernii oocysts. One hundred thirty-nine ruminating Holstein-Friesian bull calves weighing initially an average of 150 to 188 lbs were used in four trials at three locations to determine the prophylactic effects of monensin fed at 0, 10, 20, or 30 g/ ton of air-dry feed on cattle coccidiosis. Monensin at a range of 10-30 g / ton effectively controls coccidiosis in cattle exposed to severe oocyst challenges.