Genetics & Reproduction

How do I order semen?

If you are not currently working with a CentralStar representative on farm, call 800.631.3510 and the customer care team will help determine the best options for ordering. CentralStar is limited to selling semen in the states of Wisconsin, Michigan and Indiana (north of Hwy 50). If you live outside this area, contact your local Select Sires Cooperative.

How long does it take to get semen I want to order?

Delivery depends on availability of the semen and if there is adequate inventory. Most semen is delivered through the area CentralStar team and how long to deliver depends on availability and your location. For more immediate access, direct-ship or picking up semen at CentralStar’s Lansing, Michigan or Waupun, Wisconsin facilities may be an option. With direct shipment you are responsible for the cost of shipping.

Do you offer A.I. training?

Yes, we offer A.I. training several times throughout the year based on interest. Learn more about A.I. training, including any upcoming scheduled courses. To register for a future A.I. training course that has yet to be planned, email [email protected] and provide your name, address, email and phone. We will reach out when the next class is available in your state.


Can I submit samples between DHI test days?

Yes. Work with your CentralStar DHI technician who can arrange shipping with the lab.

Do you provide DHI testing for goats?

CentralStar offers training and certification for DHI testing goats. Access how to be trained and certified here.

How do I know the lab results are accurate?

The lab machines are audited every hour to assure accurate results.

Why don’t my DHI test results match my bulk tank?

DHI is a snapshot of one milking of a given day, while your bulk tank represents several milkings. While the results should be similar, they are never exact.

Does CentralStar calibrate milk meters or scales?

Yes, CentralStar calibrates removable meters and scales. Contact the CentralStar lab nearest you to schedule service.

Do your testing records work with other software, like DC-305 or BoviSync?

Yes you can use CentralStar’s DHI testing services and use dairy herd management software, other than DART (previously called PCDART). DHI testing data is sent to you as a DNL file, which is the industry standard for loading data into software after test day. We also use DART dairy management software to interface with these programs to get status updates of your herd.


Do you offer culture testing for mastitis?

No, we don’t currently offer culture testing for mastitis. Instead, we offer Mastitis PCR testing which will give you results in 2 days upon receiving samples at the laboratory.

When will I receive my test results?

How soon you receive test results depends on the type of test you have run. Consult the diagnostic test web page you are submitting samples for more details.

What type of sample is needed for each test?

See the Diagnostic Services to find the individual test requirements, or reference the submission form.

Where can I find the submission form?

Find the submission form here

Can I run multiple tests done on the same sample?

Yes, so long as those tests require the same sample type identified on the sample submission form. 

Do I need to set up an account before sending in samples?

No, but be sure to fill in all contact information on the submission form so we can reach you if there are questions. We will create an account when samples arrive with the information you provide.

How many days after calving should we wait to test a milk sample?
  • Component testing should be performed no earlier than 4 days post calving to avoid the thickness of colostrum interfering with the equipment. 
  • Disease testing should be performed no earlier than 7 days post calving to avoid the detection of colostrum antibodies. 
  • Pregnancy testing should be performed no earlier than 60 days post calving to avoid the detection of residual PAG levels. 
When should I ship my samples?

Shipping samples earlier in the week is better to avoid packages getting “stuck” in a shipping company warehouse over a weekend, thus delaying your results.

Do any of your tests tell me if my animal’s milk is safe to consume?


Is it safe to consume milk from a cow positive for any of the tests offered (Johne’s BLV, BVD, Staph aureus, etc.)?

CentralStar is not able to speak to the safety of consuming milk from animals positive for any disease or mastitis causing pathogen.

What should I test for?

That decision depends on your goals. See diagnostic services to view what tests are available and how you might use the information. If you need help deciding those goals, please call our Customer Support Team.

How do I collect milk or blood samples?

See instructions. There is a video available along with photos and listed steps.

How do I get sampling supplies?

You can order sampling supplies or complete sample and collection kits online here.

How do I receive results?

Results will be available within the guaranteed turnaround time via our WebReports portal. If an email is provided on the submission form, you will receive a link to set up a WebReports account, and later links to specific results will be sent upon completion. If an email is not provided, the standard reporting method is printed mail. Fax options are available upon request, and text results are available for certain tests (primarily pregnancy).

Should I choose ELISA or PCR?

Choosing which test type depends on what challenges your farm is facing and your goals. For most general screening purposes, ELISA is sufficient and ideal for BLV, BVD, and Johne’s. To learn more about the differences and advantages between test types, visit the individual test web page under Diagnostic Services.

Mastitis PCR

What is PCR?

PCR stands for Polymerase chain reaction is an advanced laboratory technique that amplifies DNA so it can be detected even when present in very, very small quantities. It is the same technique used to investigate crime scenes.

How does PCR determine how much DNA is detected?

PCR replicates DNA in similar ways to nature, but at a drastically increased rate with the help of specialized equipment and chemical reagents. When DNA is detected, the test returns a Ct (cycles to threshold) value that can be used to determine the relative abundance of particular pathogens.

What is a Ct value and what does it mean?

The specialized equipment determines how many cycles of a reaction are necessary to cross a certain threshold, yielding a Ct value. The lower the Ct value, the fewer the cycles, and the more DNA present in the sample. This is how the Ct values are inversely related to the quantity. Lower Ct values mean higher quantities of DNA, which indicates that pathogen is likely the cause of mastitis.

Why try to detect the DNA?

DNA provides a unique ‘signature’ for each mastitis pathogen. If a unique DNA signature is detected, we know that particular pathogen is in the milk sample. Unlike culture, which relies on pathogen growth, DNA can be detected whether the pathogen is alive or dead in the sample. The presence of the pathogen, along with evidence of a pre-existing udder infection (e.g. high SCC or clinical appearance) is strongly indicative that the pathogen is responsible for existing health conditions.

What if DNA from more than one species or pathogen is detected in a milk sample?

You should focus on the pathogen with the lowest value first because the lower value indicates stronger presence of that pathogen. This is especially true when one of the detected pathogens has a much lower value relative to the rest (e.g. 26 vs 35 or +++ vs +).

What should be done with positive results when PCR values for different organisms are similar?

There are many factors that should be considered when interpreting mastitis PCR results, including the interpretation of any other diagnostic test result, testing history, clinical observations, environmental conditions, and management factors.

When can pooling be considered for mastitis testing?

There are a wide range of pooling strategies available to help reduce cost while still providing valuable management decision guidance. String samples and group screenings are two strategies commonly used. With any strategy there is a maximum of five animals per single pool. These strategies should be discussed with one of the technical specialists listed below to determine the best option for your operation.

Why use PCR rather than culture?

PCR is faster and more sensitive than culture and can be used where culture cannot; specifically, on milk samples from treated cows and preserved samples from DHI test day. Without additional effort on the your part, the very same high SCC sample from a DHI test day can be used to determine causative pathogens, rather than waiting days to obtain a hand-stripped sample for testing.

Can PCR and culture be used together?

While PCR and culture both provide information on mastitis, they are two different tools detecting pathogens by very different methods. Culture is a simple tool to use on-farm to guide treatment decisions for clinical cows. PCR is a convenient way to screen multiple cows (including subclinical animals) for proactive detection of potential mastitis causing pathogens. PCR can also be used to more definitively identify cows infected with contagious pathogens such as Staph aureus, to ensure informed management and/or culling decisions are made. In the case of Mycoplasma bovis, standard culture cannot be performed without special media and incubation, and results can take up to two weeks. PCR can provide results in the same 48-hour time frame as all other listed pathogens.

If the test is so sensitive is contamination a concern for PCR on DHI samples?

It can be. CentralStar DHI Specialists are trained on the importance of controlling potential carryover to reduce the risk of contamination. This is also why it is important to take other factors, like those listed above, into consideration when evaluating results.

What if results return no pathogens detected?

There are a couple reasons this could happen with PCR testing. First, the immune system of the cow works to fight off mastitis infections. This process causes pathogens to be shed in “waves” sometimes at such low levels that they are not detectable, even by tests as sensitive as PCR. A resubmission of that same cow within a week or two may show a positive result. Second, there are a handful of known mastitis causing pathogens not included in the PCR Complete 16 Panel, such as Bacillus, Pseudomonas, or Lactococcus. These pathogens tend to be rarely identified as causing mastitis compared to those included in the panel.

What is the turnaround time for PCR?

Results are available within two business days from the time they arrive in the laboratory. Allow for additional time for shipping, whether on a DHI route truck or via a postal carrier such as FedEx or UPS.

Diagnostic Sample Collection and Shipping FAQs

How much milk, blood, feces or tissue is needed to run a test?
  • Johne’s Fecal Test: 3 grams
  • Johne’s Milk Pooled or Bulk Tank: 50 ML
  • BVD Tissue: Ear Notch
  • All other test types: 4 mL
How do samples have to be stored?
  • Milk: fresh, frozen, or preserved
  • Feces: fresh or frozen
  • Tissue: fresh or frozen
  • Blood: fresh, spun and separated; OR serum OR EDTA plasma
How should I package samples to ship?
  1. Place sample containers in Styrofoam cooler or any tightly sealable container.
  2. Pack absorbent material (such as paper towel) around milk, blood and fecal samples to soak up the contents in the event of leakage.
  3. Place frozen ice packs over samples for proper cooling during shipping.
  4. Include Sample Submission Form(s). Place inside container in a plastic bag to avoid damage from any leakage or condensation.
  5. Seal shipping container with packaging tape.
What are best practices for shipping samples?
  • Ship samples Monday – Wednesday to avoid weekend deliveries.
  • FedEx or UPS are acceptable carriers.
  • Second day delivery/expedited shipping is not necessary unless desired.
  • When using shipping arranged by CentralStar
    • United States Postal Service (USPS) – if size appropriate, the box can be put in your mailbox. If the box is too large, contact your postal carrier or take it to your local post office.
    • UPS – Contact UPS directly for a pickup or take it to your local UPS drop off location.
  • When shipping from Canada, please include the U.S. Department of Agriculture import permit with shipping documents.
Where do I ship samples?

Ship samples to the CentralStar lab nearest you.

  • CentralStar Michigan Lab, 1163 Comet Lane, Grand Ledge, MI 48837. Phone: 517.333.8381
  • CentralStar Wisconsin Lab, 200 East Kelso Road, Kaukauna, WI 54130. Phone: 920.733.6598
Can I deliver samples direct to the lab?

Yes, you can deliver samples direct to the lab. CentralStar laboratories are generally open Monday – Friday, with hours depending on sample volume. Call before driving to the lab to deliver samples. Be sure samples are properly identified and complete a sample submission form prior to arrival.