Comparative cost-effectiveness of ivermectin versus topical organophosphate in feedlot calves.

A study was conducted in a commercial feedlot in western Canada to evaluate the impact of treatment with ivermectin versus a topical organophosphate on growth rate and feed efficiency in calves entering a feedlot at an average 275 kg liveweight.A total of 9527 head of cattle was used. Variables measured included average daily gain, average days occupation, and feed conversion.Ivermectin treated animals gained an average 0.08 kg per day more than those treated with topical organophosphate. In addition, they required an average 0.23 kg less feed/kg gain. Based on an average 227 kg of gain, this would result in 11 fewer days occupation and 52.3 kg less feed for ivermectin treated animals. This equaled a net benefit of $7.04 per head over treatment costs for ivermectin treatment versus topical organophosphate.