AHDC Update: Johne’s pooled PCR is replacing Johne's pooled culture for bovine fecal samples
For clients of the Animal Health Diagnostic Center
The Johne’s pooled culture test will be replaced by Johne’s pooled PCR beginning Sept. 15, 2025. This test is for domestic cattle fecal samples only and will shorten the turnaround time for pooled results from 35-42 days down to 7 to 10 business days. The test prices and client submission process have not changed.
Individual fecal samples should be collected in wide-mouth, screw-capped containers filled no more than half-full. Ensure that each container is tightly closed and the animal identification is clearly marked using waterproof marker or adequate alternative. Do not pool prior to submission; a special process will be used to pool samples in groups of 5 upon receipt at the AHDC.
All individual samples from any positive pool will automatically be tested by Johne’s Fecal PCR, and additional fees will accrue. PCR is a highly sensitive test, and some herds may notice a small increase in PCR positive pools compared to traditional pooled culture method.
There will be 3 testing options:
- Johne’s Pooled PCR NY non-NYSHCAP (test code: JPPI)
- Johne’s Pooled PCR NYSCHAP (test code: JPPN)
- Johne’s Pooled, non-NY (test code: JPPO)
All PCR results will be reported as Detected, Not Detected or Inconclusive with a Ct value which can be interpreted as follows:
Bovine
Ct Value | Interpretation |
---|---|
Less than 30.9 | Heavy shedder |
Greater than or equal to 30.9 and less than 34.4 | Moderate shedder |
Greater than or equal to 34.4 | Light shedder |
Note: Caprine Johne’s fecal PCR is currently not available for pooling. Starting Sept. 2, 2025, individual test results will be reported as Detected, Not Detected or Inconclusive with a Ct value which can be interpreted as follows:
Ct Value | Interpretation |
---|---|
Less than 25.2 | Heavy shedder |
Greater than or equal to 25.2 | Positive, Not Heavy shedder |