Addressing imported semen risk in NZ

Addressing the Risk of Historically Imported Semen in New Zealand’s Eradication Effort Against Mycoplasma bovis


In September 2022 a new strain of Mycoplasma bovis was detected on a farm in mid-Canterbury. Investigations concluded the use of imported semen was the most likely pathway onto this farm. The semen used was imported prior to the current Import Health Standard (IHS) being in place.

This situation highlighted the need to address the potential transmission of M. bovis through semen imported under the previous IHS, despite what is believed to be a very low risk. A new Import Health Standard (IHS) took effect from May 2022. This IHS provides two options for bovine semen before it can be imported; to undergo enhanced antibiotic treatment or have two straws per batch PCR tested for M. bovis. The new strain detected in September 2022 suggests that semen imported before the new IHS took effect may harbour M. bovis, and there are significant quantities of semen imported before May 2022 still in storage. To address this risk, the Mycoplasma bovis Eradication Programme is now conducting PCR testing on batches of semen imported before May 2022 that weren’t treated with the USA’s Certified Semen Services (CSS) enhanced antibiotic protocol at the time of collection. This testing aims to further reduce the risk associated with older batches that were potentially not treated effectively by testing them in accordance with the requirements of the current IHS.

The Ministry for Primary Industries (MPI) has issued a Notice of Direction under the Biosecurity Act 1993 to importers, mandating the provision of two semen straws from each eligible batch for PCR testing. This directive includes imported semen stored on behalf of farmers. The PCR testing process will destroy the semen in the straws taken for analysis.

Semen importers are now communicating with their clients and coordinating the testing process with the MPI-contracted laboratory. Farmers who possess eligible batches of imported semen or own those held in storage will be required to:

  1.  submit or approve the submission of eligible straws for PCR testing, or

  2.  opt to destroy unused straws

Batches that are eligible for testing are those imported before 1 May 2022 from all countries, except those treated with the CSS protocol since 1990 (this includes all straws from USA).

Affected owners can claim compensation for the value of straws required to be submitted for testing.

We acknowledge this testing process might be an inconvenience for those with batches of semen imported before the IHS change. However, it is a vital step to help minimise potential risks and safeguard the substantial personal and financial investments made to date by New Zealand cattle farmers in our collective efforts to eradicate M. bovis.

The ongoing commitment to eradicate M. bovis from New Zealand is critical due to the significant health and financial risks it poses to our cattle industry. M. bovis infection can lead to a range of serious health issues in cattle, including mastitis, pneumonia, arthritis, and reproductive losses.

MPI, in partnership with DairyNZ and Beef + Lamb New Zealand, launched the Mycoplasma bovis Eradication Programme in 2018 to prevent the impacts of the disease on New Zealand’s dairy and beef industries. After five years of hard work, sacrifice and collaboration, in August we reached the important milestone of having no known farm infections. The PCR testing requirement for historically imported batches of semen is another necessary step as efforts continue in the journey to reach our goal of eradicating M. bovis from New Zealand.

If you have any questions, please contact