Abstract:
BACKGROUND: Efforts to educate producers and veterinarians in the United States regarding the management,
prevention and control of Mycobacterium avium subspecies paratuberculosis (MAP) infection have increased over
recent years. While nationwide awareness about MAP infection is improving, current level of awareness among beef
producers and veterinarians is largely unknown. This study compares the perceptions of beef producers and
veterinarians on the burden of MAP infection in cow-calf herds and on measures to control new infections.
Questionnaires were mailed to 989 US beef producers through state Designated Johne’s Coordinators and to 1080
bovine veterinarians belonging to a US nationwide professional association.
RESULTS: Twenty-two percent (34/155) of producers reported having infected animals in their herds. The mean
(minimum, median, maximum) prevalence reported by producers was 0.8% (0, 0, 10). Twenty-seven percent (27/100) of
producers had at least one clinical animal during the previous year. Compared to the small herds (<50 head), the mean
test-positive percentages and estimated prevalences were higher in medium (50–149) and highest in large (≥150)
herds. Seedstock herds had a lower prevalence and these producers were more likely to enroll in Johne’s disease (JD)
control programs and test their herds. Veterinarians reported a mean overall animal level prevalence in their client
herds of 5% (0, 2, 60). Similarly, 26% (0, 10, 100) of client herds had at least one infected animal. Mean percentage of
infected cows within infected herds was 9% (0.01, 5, 80). Producers generally performed activities to control MAP
transmission more frequently than perceived by veterinarians. Compared to veterinarians’ opinions, producers were less
likely to cull cows with signs consistent with JD (P < 0.01), but more likely to test purchased additions (P < 0.01). Testing
recommendations by veterinarians (n = 277) for beef cow-calf herds were bacterial culture of feces (3%), PCR (14%),
ELISA (35%) and a combination of these tests (47%). Seventy-nine percent of veterinarians recommended a 12-month
interval between testing. CONCLUSIONS: Seedstock producers who had had JD risk assessments performed on their farms were more supportive
of JD control programs and had a correspondingly lower prevalence. It is important to increase educational activities to
provide relevant information to veterinarians and producers for better management and control of JD. Educational
programs should target larger herds to maximize the impact.
