Optimum Level of Monensin for Fattening Lambs

Abstract

One-hundred-twenty white-face wether lambs were allotted to one of five treatment groups with two replicate pens of 12 lambs each. Lambs were fed a standard fattening ration to which 0, 5.5, 11, 22, or 33 ppm monensin had been added. Over the 70-day feeding trial, lambs fed 5.5 and 11 ppm monensin had improved (P<.05) gains as compared to those fed 0, 22 and 33 ppm monensin. Overall feed efficiency for the monensin groups was 9% higher than in controls, although the difference was not significant. Carcass characterisitcs were not significantly altered (P>.05) by feeding monensin at any level.