Efficacy of tilmicosin for on-arrival treatment of bovine respiratory disease in backgrounded winter-placed feedlot calves

Abstract

A trial was conducted in a commercial feedlot in southern Alberta, Canada to evaluate the cost-effectiveness of metaphylactic treatment with tilmicosin for control of bovine respiratory disease. First-pull treatment rates for BRD (P=0.006) and arthritis (P=0.02) were significantly lower in calves administered tilmicosin on arrival compared to non-medicated controls. Calves treated with tilmicosin at arrival-processing had gained an additional 20 lb (9.1 kg) at terminal weight sort (P=0.0002), with higher average daily gain (P=0.0001) and lower dry matter conversion (P=0.008). The cost- benefit of tilmicosin metaphylaxis in these feedlot calves depended on the method of calculation. Based on reductions in BRD and arthritis treatment rates and reduced feed costs because of improved dry matter conversion, there was a net advantage of $3.41CAN/head for those calves given tilmicosin on arrival compared to non-medicated controls. Based on improved treatment rates and additional weight gain, the net advantage was $8.09CAN/head for those calves given tilmicosin compared to non-medicated controls. These economic calculations assumed performance benefits observed at terminal weight sort were retained until slaughter, approximately 30 to 40 days later.