Pasture grazing of beef feeder cattle destined for subsequent grain-fed feedlot production and slaughter can be a cost-effective production approach for regions with large areas of available pasture, as opposed to dry lot production programs. However, due to reproductive cycling, rates of gain (and presumably grass utilization) for heifers on pasture are lower than for steers. Spaying heifers has been identified as a potential way to improve rates of gain in grazing heifers. The purpose ofthis study was to describe the effects of spaying on rate of gain and health of heifers on pasture in western Canada.