Table 4.
Constrained optimization model results of farm costs by region. Tti is the testing interval, in months; NWHT is the number of whole-herd tests required for the herd to clear quarantine. The historical government test-and-removal plan is as described in (USDA:APHIS:VS, 2005). All costs are thousands of US dollars per herd detected. A depopulation preference is noted when the cost of depopulation is predicted to be smaller than the cost of test-and-removal for that iteration.
| Region | Farm Optimal Tti, Nwht | Optimal Farm Cost (range) | Historical Farm Cost (range) | Farm Depopulation Cost (range) | Herds with Depopulation Preference /herd detected (proportion) |
|---|---|---|---|---|---|
| National | 2,2 | 0.16 (0.04;0.71) | 0.16 (0.04;0.38) | 0.40 (0.40;24.25) | 4/642 (0.01) |
| Heartland | 2,3 | 0.11 (0.02;0.42) | 0.11 (0.02;0.31) | 0.40 (0.40;16.12) | 1/633 (0) |
| Northern Great Plains | 2,3 | 0.27 (0.10;0.86) | 0.28 (0.1;0.62) | 0.41 (0.40;54.53) | 32/626 (0.05) |
| Prairie Gateway | 2,2 | 0.17 (0.04;0.5) | 0.17 (0.04;0.44) | 0.41 (0.40;28.84) | 5/653 (0.01) |
| Eastern Uplands | 2,3 | 0.13 (0.01;0.67) | 0.13 (0.03;0.37) | 0.40 (0.40;17.4) | 4/649 (0.01) |
| Basin and Range | 2,3 | 0.37 (0.13;1.15) | 0.38 (0.11;0.89) | 0.41 (0.4;61.89) | 200/664 (0.3) |
| Mississippi Portal | 2,2 | 0.12 (0.02;0.45) | 0.12 (0.03;0.34) | 0.40 (0.40;14.95) | 1/610 (0) |
| Southern Seaboard | 2,3 | 0.11 (0.01;0.27) | 0.11 (0.02;0.32) | 0.40 (0.40;15.16) | 0/614 (0) |
| Fruitful Rim | 2,2 | 0.2 (0.05;0.67) | 0.21 (0.05;0.52) | 0.41 (0.4;33.57) | 5/619 (0.01) |