Table 2.
Average and range of annual economic losses from MAP seropositivity for the entire Canadian dairy industry, per 100 cows
| 95% C.I.
|
|||||
|---|---|---|---|---|---|
| Variable # | Variable name (units) | Distribution or formula | Mean | Lower limit | Upper limit |
| 1 | Average cattle population in herd | Fixed | 100 | ||
| 2 | Prevalence of infection among cows in the Canadian dairy population | Normal | 0.031 | 0.023 | 0.038 |
| 3 | Milk yield (L per cow per y) | Fixed | 9519 | — | — |
| 4 | Milk price ($ per L) | Fixed | 0.59 | — | — |
| 5 | Reduced milk yield (%) | Normal | 0.023 | 0.0012 | 0.0472 |
| 6 | Losses associated with each low producing animal | (3)*(4)*(5) | 132 | 1.5 | 262 |
| 7 | Percentage of infected animals affected | Triangular | 0.25 | — | — |
| ML | Herd milk loss ($) | (1)*(2)*(6)*(7) | 102 | 1 | 216 |
| 8 | Replacement cost of cow ($ per head) | Triangular | 2000 | — | — |
| 9 | Percentage increased mortality risk in affected cattle (% per y) | Normal | 3.15 | 0.21 | 6.09 |
| MO | Herd mortality loss ($) | (1)*(2)*(8)*(9) | 195 | 12 | 404 |
| 10 | Slaughter value of healthy cattle ($ per head) | Triangular | 500 | — | — |
| 11 | Percent of affected cattle with reduced slaughter value (%) | Triangular | 25 | — | — |
| 12 | Losses associated with each culled animal | (8)-[10-{(11)*(10)}] | 1625 | 1215 | 2034 |
| 13 | Excess culling risk for infected cattle (%) | Normal | 10.9 | 3.1 | 18.7 |
| CL | Herd additional culling loss ($) | (1)*(2)*(12)*(13) | 549 | 143 | 1035 |
| 14 | Increased calving interval (d) | Normal | 28 | 6 | 50 |
| 15 | Cost of increased calving interval ($ per d) | Triangular | 4 | — | — |
| RL | Herd reproductive losses | {(1)*(2)*(14)*(15)}*0.923 | 350 | 64 | 718 |
| AL | Herd annual losses | ML + MO + CL + RL | 1196 | 610 | 1901 |
*
— multiplied by