A LINEAR-PROGRAMMING ASSESSMENT OF THE PROFIT FROM STRATEGIES TO REDUCE THE PREVALENCE OF STAPHYLOCOCCUS-AUREUS MASTITIS

We used a linear programming model to estimate the financial returns t o a Staphylococcus aureus testing and control program over a 1-year pe riod for a 100-cow herd, with a 8636-kg rolling-herd average. Six test s, which vary in sensitivity from 0.80 to 0.98 and specificity of 0.99 , were examined in simulated herds with 10, 20 and 30% prevalence of S . aureus infection. Sensitivity of these results to a range of assumpt ions regarding rolling-herd average, milk price, somatic cell-count pr emium, and cost and cure rate of dry treatment were examined to determ ine the profits from the program. The profits of a control program are most dependent upon prevalence, cell-count premium, and cost of dry t reatment. In our simulation for a 100-cow herd, a testing and control program appears to cost less than US$10 per cow per year, and pays for itself within 1 yr, except under the lowest prevalence and most-adver se conditions (low yield, high cost of dry treatment, or low SCC premi um). (C) 1998 Elsevier Science B.V.