Prevalence of and risk factors for paratuberculosis in purebred beef cattle
To estimate the prevalence of paratuberculosis in purebred beef cattle in Texas and identify risk factors for seropositivity.
4,579 purebred cattle from 115 beef ranches in Texas.
Blood was collected, and serum was analyzed for antibodies with a commercial ELISA. Fecal samples were collected and frozen at -80 degrees C until results of the ELISA were obtained, and feces from seropositive cattle were submitted for mycobacterial culture. Herd owners completed a survey form on management factors.
Results of the ELISA were positive for 137 of the 4,579 (3.0%) cattle, and 50 of the 115 (43.8%) herds had at least 1 seropositive animal. Results of mycobacterial culture were positive for 10 of the 137 (7.3%) seropositive cattle, and 9 of the 50 (18%) seropositive herds had at least 1 animal for which results of mycobacterial culture were positive. Risk factors for seropositivity included water source, use of dairy-type nurse cows, previous clinical signs of paratuberculosis, species of cattle (Bos taurus vs Bos indicus), and location.
Results suggested that seroprevalence of paratuberculosis among purebred beef cattle in Texas may be greater than seroprevalence among beef cattle in the United States as a whole; however, this difference could be attributable to breed or regional differences in infection rates or interference by cross-reacting organisms. Veterinarians should be aware of risk factors for paratuberculosis as well as the possibility that unexpected serologic results may be found in some herds.
Available from: PubMed Central
- "Similarly, a nationwide study estimated that 0.4% of US beef cattle were seropositive [4,8]. Other studies have reported a seroprevalence of 3% , 5% , and 9%  and this suggests that the true prevalence might be 7% to 28% after adjustment for the sensitivity and specificity of available serum ELISA . Producers with infected herds (22%) and the mean percentage of infected herds estimated by veterinarians (26%) were lower than previous field studies. "
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ABSTRACT: 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.
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.
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.
Available from: James W O'Shaughnessy
- "There have been few international and no published Irish studies on herd health management practices and herd health status in suckler beef herds, with previous Irish studies conducted mainly on estimates of disease prevalence [4-6]. Studies performed internationally on suckler beef herds have tended to focus on particular areas of interest, namely, calf health [7-12] or on individual disease conditions [13,14]. Due to differences in production and rearing systems from those practiced in Ireland, predominantly grass-based, adoption of findings from international studies is not always possible or appropriate. "
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ABSTRACT: There have been few studies published internationally which document herd health management practices in suckler beef herds and no published Irish studies. The study objective was to document herd health status and management practices on sixteen Irish suckler beef herds over a two year period (2009--2010). The farms used in the study were part of the Teagasc BETTER farm beef programme. The mean (s.d.) herd size, stocking rate and farm size was 68 cows (27.6), 2.0 LU/ha (0.3) and 64.3 (21.6) adjusted hectares, respectively. Two questionnaires were designed; 1) a farmer questionnaire to collect information on farm background and current herd health control practices and 2) a veterinary questionnaire to collect information on the extent of animal health advice given by veterinarians to their clients and identification of any on-farm herd health issues.
Dystocia, calf pneumonia, and calf diarrhoea, in that order, were identified as the primary herd health issues in these Irish suckler beef herds. In addition, substantial deficiencies in biosecurity practices were also identified on these farms.
The findings of this study may serve as the focus for future research in animal health management practices in Irish suckler beef herds.
Available from: Corliss O’Bryan
- "Thorne and Hardin (1997) tested 1,954 cattle from 19 dairy and 68 beef herds by ELISA and determined animal and herd-level prevalence of 8% and 5% and 74% and 40% for dairy and beef herds, respectively. Roussel et al. (2005) "
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ABSTRACT: Mycobacterium avium subsp. paratuberculosis (MAP) causes the disease of cattle, Johne's. The economic impact of this disease includes early culling of infected cattle, reduced milk yield, and weight loss of cattle sold for slaughter. There is a possible link between MAP and Crohn's disease, a human inflammatory bowel disease. MAP is also a potential human food borne pathogen because it survives current pasteurization treatments. We review the current knowledge of MAP, Johne's disease and Crohn's disease and note directions for future work with this organism including rapid and economical detection, effective management plans and preventative measures.
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