Johne’s Disease: Voluntary Herd Classification Program
IMPORTANT NOTE: As of August 1, 2012 the classification system in Wisconsin has changed to that noted below. Please contact us at DATCPJohnes@wi.gov or 608-224-4393 with any questions as to how a herd participating in the new classification system would compare to that participating in the old classification system.
Herd Classification System
Replacement Animal Selection Guidelines
Herd Testing Guidelines
Receiving and Using Classification
Dairy and beef producers wanting to help prevent and control Johne’s disease within their herds are encouraged to participate in the Voluntary Bovine Johne’s Disease Control Program. Herds that are not tested for the bacteria are automatically classified as maximum risk. A classification program is available only for cattle and goat producers.
The herd classification program seeks to identify herds that are less likely to be infected with Johne’s disease. Depending on test results, herds are assigned a classification level 1-6. The higher the level, the less likely a herd is infected. No classification guarantees a herd is free of Johne’s disease.
Herds participating at levels 1-3 could have a low percentage of positive test results. Herds participating at levels 4-6 have multiple years of negative test results. All herds at any given level are considered to have the same risk of being infected with Johne’s disease.
Although the program is voluntary, the advantages to testing are many, including having the opportunity to achieve a Classification Level that shows buyers your commitment to helping prevent and control the spread of Johne’s disease in their herds.
Getting StartedTalk to your veterinarian to determine which animals are eligible and decide what testing option is best. Tested animals should be officially identified. Eligible tests include the ELISA (milk or blood test), or MAP Detection Test (a fecal (manure) culture or direct PCR). If the fecal culture results indicate contamination, the animals must be retested. Contamination will be considered a "no test." If the animal has been vaccinated for Johne's disease, you will need to use either a fecal culture or PCR test. A licensed, accredited veterinarian must take blood or fecal samples, however a veterinarian or a certified veterinary technician or DHIA technician can draw milk samples. All testing must be conducted at an approved laboratory.
All cattle 36 months of age or older and male bovine animals 24 months of age or older must be tested in herds of 300 head or fewer. For herds with more than 300 head, a number of randomly selected cattle can be tested per the guidelines outlined in the Johne’s Disease Control Program booklet. For herds with fewer than 30 animals 36 months of age or older, animals 24 months of age or older must be included, until a total of 30 animals OR all animals 24 months of age and older have been tested.
Herds can also achieve classification level 1 (or maintain levels 4-6) by obtaining negative test results on a minimum number of cattle. The number to test based on test type is noted in the booklet. If there is fewer than the minimum number of cattle in the herd, the whole herd must be tested.
Official IdentificationAnimals must be officially identified when tested. The official identification can be a USDA uniform series metal ear tag, breed association tattoo (only if it uniquely identifies the animal), breed association registration number, USDA “840” button tag number, Bangs tag number, or USDA-approved RFID number.
See “Goat Herds” below for accepted official identification for these animals.
Herd Classification SystemAnyone interested in participating in the Voluntary Herd Classification Program, should familiarize themselves with the Johne’s Disease Control Program booklet. The booklet contains detailed information about classification levels, minimum testing requirements and other program details. Talk to your veterinarian for guidance on specific options for your herd. You can also contact us at DATCPJohnes@wi.gov or 608-224-4893.
Replacement Animal Selection Guidelines
Herds participating at levels 1-3:
Herds participating at levels 4-6:
- There are no purchasing restrictions.
- However, it is recommended:
- that replacement animals are purchased from a herd that meets or exceeds the level of the herd they will enter.
- that source herds have an active RAMP.
- that heifers are raised with at least minimum biosecurity and control measures if a heifer raiser is used (see booklet).
- If the purchase is from an unclassified herd or a level 1 to 3 herd, the herd will be demoted to level 3.
- If the purchase is from a herd at the same or higher level, the herd retains its classification with no additional testing requirements.
- If the purchased animals are from a lower classified herd (level 4 or 5), contact your veterinarian for testing requirements to avoid possible demotion of your herd classification.
- It is recommended that heifers are raised with at least minimum biosecurity and control measures if a heifer raiser is used (see booklet).
Goat HerdsGoat herds may participate in the same way as cattle herds except that all animals 18 months of age or older must be included in the whole herd test.
Accepted official identification for goats includes scrapie “flock” or “serial” ear tags, official USDA RFID tags, legible tattoos that consist of EITHER a flock identification and unique management number OR breed association/registration tattoo with management number (with registration papers in owner’s name), or USDA approved implanted microchip.
Herd Testing Guidelines
- Eligible cows should be randomly selected and sampled.
- Large herds should include representatives of high-producing group, low-producing group and dry cows, with the percentage of samples collected from each group equal to the percentage of each group of animals in the herd. For example, if 10 percent of the animals in the herd are low producers, then 10 percent of the samples collected should be from low producers.
- Unless a producer is suspicious of infection in the herd, high-risk animals should not be targeted.
- All testing for herd classification should be as close to random as possible.
Confirmation TestsIf your animals test positive with the ELISA blood or milk sample, you can request a fecal culture or PCR test to confirm the test results. The manure sample must be collected within 45 days of receiving the positive ELISA results.
The fecal test can take between 1 and 16 weeks to complete. Your herd will be classified based upon initial test results. However, if the confirmatory results are negative, the herd's classification will be adjusted. If the fecal culture is contaminated, the animal will need to be sampled again.
If an animal tests positive on a fecal culture or PCR test and you would like to appeal the positive result, please contact us at DATCPJohnes@wi.gov or 608-224-4893 for options.
Annual TestingHerds participating at levels 1-4 must test every year. Herds participating at levels 5 and 6 must test every two years. If not tested within that timeframe, the herd automatically reverts to a maximum risk category.
Receiving and Using ClassificationFor the herd to be officially classified, please provide a written request by e-mail or regular mail to the Department with supporting test documentation each year testing for classification is performed. We will accept requests from producers or their veterinarians. When the department receives the request and results, we will then notify you of your classification by mail within 30 days. If you do not receive your classification, please contact us at DATCPJohnes@wi.gov or 608-224-4893.
How you use the information is your choice. You do not have to make it public. But remember that if you sell replacement animals and want to avoid liability, you must provide in writing the herd's classification level. Animals sold for slaughter are exempt.
Buyer GuidelinesWhen purchasing additions and replacement animals, you can reduce your risk of bringing Johne’s into your herd by purchasing from classified herds. Herds are classified at levels ranging from 1 to 6. Johne’s disease risk decreases as the classification goes from 1 to 6. Although each higher level indicates a greater probability a herd does not have Johne’s disease, no herd is certified to be free of Johne’s disease.
Classifying herds are provided a certificate indicating the level at which they are classified. Buyers should request to see a copy of the certificate before making purchases. Check the certificate for:
Producers with a herd classification of level 4-6 may voluntarily list their herds for potential buyers to view. Click here for Wisconsin herds participating in the Voluntary Johne’s Disease Herd Classification Program.
- Classification level
- “Expires” date to make sure the classification is current
- How long the classification has been maintained (the longer a herd maintains a higher level classification, the less risk the herd is infected with Johne’s disease)