No significant seasonal effects on S/P ratios or the proportion of dairy cows seropositive to MAP were observed. In addition, no evidence was found to support a hypothesis linking seasonality to an increased risk of MAP fecal culture positivity. At present, based on information derived from this study, the testing protocols currently being employed in JD control and management programs can be interpreted as being free of seasonal variability.
This study was funded by USDA-APHIS grant #02-9148-0717-GR. The efforts of the TVMDL laboratory scientists and staff and the cooperation and participation of the dairy producer and his staff are gratefully acknowledged.
* Supported in part by USDA-APHIS Grant No. 02-9148-0717-GR. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the authors and do not necessarily reflect the view of the U.S. Department of Agriculture.
Present affiliation: Department of Veterinary Pathobiology.
Received for publication October 9, 2004. Accepted for publication March 31, 2005.