Proceedings of the 10th International Colloquium on Paratuberculosis

#234 Johne’s disease vaccine: a cohort study measuring long-term effectiveness <strong>of</strong> <strong>the</strong> whole
cell killed bacterin
Barbara Knust, Darlene Konkle, Jeffery Bohn, Scott Wells, Elisabeth Patton, University <strong>of</strong> Minnesota, USA;
Wisconsin Department <strong>of</strong> Agriculture, Trade and Consumer Protection, USA
In this prospective cohort study, three commercial dairy herds vaccinated every o<strong>the</strong>r heifer calf using a whole
cell killed Johne’s vaccine until two cohorts were obtained. O<strong>the</strong>r Johne’s disease management efforts on <strong>the</strong>
farms were used, including annual risk assessments, but <strong>the</strong> management <strong>of</strong> vaccinates and controls was
<strong>the</strong> same in <strong>the</strong> herd. Fecal samples from heifers from <strong>the</strong> cohort groups were collected at first calving and at
90 days <strong>of</strong> pregnancy at each subsequent lactation and tested using bacterial culture with liquid media. Fecal
samples from <strong>the</strong> rest <strong>of</strong> <strong>the</strong> herd were also collected and cultured annually at 90 days <strong>of</strong> pregnancy. Herd
production data was collected on a semiannual basis, and data regarding culling and reasons for culling was
recorded. Baseline prevalence estimates indicated <strong>the</strong> herds were moderately to heavily infected with Johne’s
disease at <strong>the</strong> start <strong>of</strong> <strong>the</strong> study. Five years after <strong>the</strong> initial cohort animals were vaccinated, significantly fewer
vaccinates were culled due to clinical Johne’s disease, and vaccinates had a significantly lower level <strong>of</strong> fecal
shedding. Survival analysis found vaccinates survived a significantly longer time until being culled for clinical
disease, and had a longer time to first positive test result than controls. Vaccination however did not have an
effect on <strong>the</strong> overall survival in <strong>the</strong> herd if culling for any reason was measured. Whole herd fecal shedding
prevalence decreased on all three farms from <strong>the</strong> beginning <strong>of</strong> <strong>the</strong> study. The results <strong>of</strong> this study demonstrate
that use <strong>of</strong> <strong>the</strong> commercially available Johne’s disease vaccine serves as a valuable tool in reduction <strong>of</strong> clinical
signs and eventual disease eradication.
#236 Producer’s perception <strong>of</strong> a voluntary Johne’s disease control program in Ontario and
Western Canada
Ulrike Sorge, David Kelton, Kerry Lissemore, Ann Godkin, Steve Henrick, Scott Wells, University <strong>of</strong> Guelph,
Canada; Ontario Ministry <strong>of</strong> Agriculture, Food and Rural Affairs, Canada; University <strong>of</strong> Saskatchewan, Canada;
University <strong>of</strong> Minnesota, USA
Producer’s compliance with recommended management practices is crucial for <strong>the</strong> success <strong>of</strong> Risk Assessment
(RA) based Johne’s disease (JD) control programs. The objective <strong>of</strong> this study was to assess dairy producers’
perception <strong>of</strong> JD and a JD RA based control program.
A voluntary RA based control program for JD was initiated in Ontario and Western Canada in 2005-07. A
subset <strong>of</strong> 238 producers were contacted through a telephone survey in 2008 asking about <strong>the</strong>ir perception <strong>of</strong>
<strong>the</strong> importance <strong>of</strong> JD, <strong>the</strong> program and costs for implementation <strong>of</strong> farm-specific recommendations as well as
<strong>the</strong>ir reasons against implementing suggestions.
In 2005-07 most farms were test-negative and in 2008 most producers did not see JD as a problem for
<strong>the</strong>ir farm. Producers indicated that <strong>the</strong>y were participating in <strong>the</strong> program, because <strong>the</strong>y saw <strong>the</strong> economic
impact <strong>of</strong> <strong>the</strong> disease, wanted to be proactive or because <strong>the</strong>y were concerned that <strong>the</strong> consumer’s perception
<strong>of</strong> an association between MAP and Crohn’s disease could affect <strong>the</strong> dairy industry. The program and <strong>the</strong>
farm-specific recommendations were generally well received. The majority <strong>of</strong> producers had implemented at
least one recommendation. However, on average only 2 out <strong>of</strong> 6 suggestions were implemented. The recommendation
that had <strong>the</strong> highest compliance was culling <strong>of</strong> test-positive cows. This was also <strong>the</strong> main reason
why producers decided against fur<strong>the</strong>r changes. After <strong>the</strong>y culled <strong>the</strong> test-positive cow, <strong>the</strong>y did not see <strong>the</strong> necessity
for additional changes. Most producers were unable to quantify <strong>the</strong> costs associated with management
changes, but felt that some changes actually saved time and money. In addition, many producers reported better
herd health or less calf disease after implementation <strong>of</strong> at least one recommendation. In conclusion, <strong>the</strong>se
results indicate that <strong>the</strong>se recommendations can lead to improved herd health which may be used to convince
producers to implement recommended management changes.
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