Deciding if metaphylaxis is the right choice for a particular group of cattle can be difficult and is based on a number of considerations. Managers and veterinarians are essentially estimating two possible closeouts (one where metaphylaxis is used and one where only pull-and-treat management for bovine respiratory disease (BRD) cases is used). When using metaphylaxis, a greater initial BRD prevention and treatment cost is added to the expense side of the ledger, but if metaphylaxis is not used and the pen has a lot of BRD pulls, the increased treatment cost, decrease in gain (and increased cost of gain), increased number of realizers, and decreased weight/value of the cattle sold may more than offset that expense.
About 10 years ago, a spreadsheet tool was developed to answer whether metaphylaxis or pull-and-treat as a BRD management strategy would be more profitable; and which factors are most important when determining the economic value of metaphylaxis. At that time we determined that the most important variables in the decision whether or not to utilize metaphylaxis were: 1) the extent to which metaphylaxis reduced morbidity and mortality, 2) the price of cattle at sale, 3) the potential gain performance of the cattle, and the 4) cost of gain. Metaphylaxis is most economically advantageous when its use greatly reduces morbidity and mortality at a time when fed cattle prices are high, healthy cattle gain well, and cost-of-gain is low.
Using today’s numbers
Today’s feeding situation is quite different than a few years ago — with higher cattle prices and higher cost-of-gain. Based on our earlier work we expect the value of metaphylaxis to have received pressure to increase with the higher prices received for fed cattle, but at the same time to have received pressure to decrease due to higher cost-of-gain.
We went back to our spreadsheet to investigate whether or not the value of metaphylaxis has increased or decreased due to changing market and feed price conditions — assum-ing the same cattle performance and effectiveness of metaphylactic treatment. We found that in today’s feeding situation metaphylaxis has a higher value compared to situations with lower cattle prices and lower feed prices.
Using a scenario where 500-lb. calves are fed for 265 days and have a 30% morbidity if no metaphylaxis is used but 15% morbidity with metaphylaxis, and a 0.7% BRD mortality without metaphylaxis but 0.5% mortality with metaphylaxis, with metaphylaxis costing $24.65 per head — if fed cattle prices are $85 and feed cost is $125 per ton, the value of metaphylaxis is $47.61 per head. In contrast, using the same assumptions, except fed cattle prices being $92.04 and feed costs being $200 per ton, the value of metaphylaxis is $52.78 per head.
If lower assumptions are used about the morbidity and mortality with and without metaphylaxis (but still with an advantage for cattle receiving metaphylaxis), we continued to see a greater advantage for metaphylaxis under today’s feeding situation than in a situation with lower cattle and feed prices.