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Thursday, April 5, 2018 |
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Johne's disease more common in beef cattle than realized
 The attached report provides rates of MAP infection in beef cattle based on submissions to the Johne’s Testing Center in 2017. Clients submit samples for a variety of reasons: to test clinical suspects, perform pre-purchase testing, or in attempt to achieve herd classification in the voluntary USDA program based on certainty of MAP infection freedom. A list of samples tested at the JTC was generated from the lab’s accession program and sorted by state. Samples tested by direct real-time PCR for IS900 on fecal samples were used to determine infection rates as they indicate the animal is currently shedding the organism. Fecal samples were either tested individually or pooled by animal age into groups of up to five animals.
In 2017, 18.1% (105/578) beef cattle tested were PCR-positive, this includes all pools and individuals. Of the 941 fecal samples grouped into 195 pools, 49 (25.1%) were PCR-positive. Individuals comprising 27 pools were tested identifying 27 PCR-positive animals. The other pools were not tested individually, per client decision. Certain states accounted for a larger portion of samples received and positive results. For example, Missouri, Montana, Nebraska, and Texas accounted for 63% (63/100) of PCR-positive samples. |
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