Herd-level economic losses associated with Johne's disease on US dairy operations

Johne's disease ('paratuberculosis') is a chronic, infectious, wasting dise ase that affects dairy cattle. Estimation of its impact on herd productivit y and corresponding economic loss on US dairy operations was part of the US DA National Animal Health Monitoring System's (NAHMS) 1996 national dairy s tudy. Johne's-positive herds experience an economic loss of almost US$ 100 per cow when compared to Johne's-negative herds due to reduced milk product ion and increased cow-replacement costs. For johne's-positive herds that re ported at least 10% of their cull cows as having clinical signs consistent with Johne's disease, economic losses were over US$ 200 per cow. These high -prevalence herds experienced reduced milk production of over 700 kg per co w, culled more cows but had lower cull-cow revenues, and had greater cow mo rtality than Johne's-negative herds. Averaged across all herds, Johne's dis ease costs the US dairy industry, in reduced productivity, US$ 22 to US$ 27 per cow or US$ 200 to US$ 250 million annually. Published by Elsevier Scie nce B.V.