Sample types used for DNA testing

DNA can be extracted from a range of biological samples collected from cattle.

  • Ear notch, hair and semen samples are the most common sample types collected
  • Historically, blood samples were collected but this is less common now

Samples are typically collected by breeders. Most breed societies will have agreements in place with genotyping service providers and will be able to outline the processes of sample collection, submission and reporting of results.

For those outside of a breed society structure, please follow the recommendations of your chosen genotyping service provider for sample collection and storage.

Sample Type


Tissue Sampling Unit (TSU)

  • Ear plug samples are collected using specialised equipment (available for purchase)
  • TSUs can be collected from birth (often collected in conjunction with calf tagging)


  • Hair samples are collected by pulling approximately 40 hairs from the tail switch of an animal (these must be clean and dry)
  • Recommended that hair samples are only collected on calves aged 60 days or older; this ensures that the hair root bulb (where DNA is contained) has developed


  • Semen can only be collected from sexually mature bulls, and only unopened semen straws can be used for DNA testing purposes
  • One advantage of semen is that it can be used to extract DNA when the physical animal is not available (e.g. overseas and/or deceased)