You’ll need a 10ml vacutainer, a needle holder and a 18g vacutainer needle.

Screw the needle onto the holder.

Push the vacutainer into the holder far enough for the needle to JUST pierce the rubber. NOTE the gap at the end of the holder in the image. This will ensure the vacutainer doesn’t fall out while you are trying to perform the task.

DON’T push it all the way in like this or you’ll loose the vacuum and won’t be able to get a sample.

Vacutainers work by “sucking” blood out of the vein using negative vacuum.

You should always wear gloves when sampling cows.

Always use a new needle.

Now lift the cows tail like this.

The tail vein runs down the middle of the underside of the tail where the black texter marks.

Ensure where you are going to sample is clean.

TIP. The closer to the base of the tail the bigger the vein is and the easier it is to hit. But the vein is much deeper.

Push your index finger into where the vein is to steady the needle. This helps a lot if the cow is moving.

Push the needle into the tail until you hit bone.

Now push the vacutainer fully onto the needle and blood will flow.

If it doesn’t I wriggle the needle and try slightly changing angle. Otherwise pull the vacutainer back off the needle and have another go. If you pull the needle out before you pull the vacutainer back off the needle you’ll loose the vaccuum and need a new vacutainer.

For the welfare of the cow only have 2 attempts.