Step by Step on How to Tail Bleed Cattle

After a 60-120 day breeding season, cattle producers should plan to pregnancy check their cattle, so they know who is bred and who is open. Considering the annual feed/forage costs associated with maintaining a mature cow can become costly for any producer. One way to check for pregnancy rates in your herd is by sending a blood sample to a BIOPRYN or a DG29 Blood Pregnancy Test lab. Blood samples are a suitable way to determine pregnancy in your herd. Here are a few steps on how to tail bleed cattle.

Supplies: 1) Vacutainer needle, 2) needle holder, 3) Vacutainer tube, & 4) marker to label tube

Preparing the Bleeding Samples:

  1. Make sure the cow is secure in the chute.
  2. Screw the Vacutainer needle onto the needle holder.
  3. Insert the Vacutainer Tube into the other end of the needle holder until the stopper touches the back portion of the needle. DO NOT puncture the stopper until the needle is inserted into the cow’s tail.
  4. Lift the cow’s tail with the other hand or have someone else there to hold it up.
  5. Insert the needle about 1/2 inch deep and perpendicular to the tail at the underside, midline and at about 3 to 6 inches from the base of the tail.









Figure 1. Picture depicting location for collection of blood samples from the tail vein. Photo by Lizzie Whitehead

  1. Blood will appear at the junction of the stopper and the back portion of the needle once the vein is punctured. If blood does not appear, pull slightly and insert in a different direction until the view is punctured. The vein is relatively small.
  2. Once blood is seen, push the tube onto the needle. Make sure to keep the needle under the skin so the vacuum will not be lost. The vacuum will pull the blood into the tube.
    1. If the vacuum seal is lost, blood cannot be collected. 
    2. If you have a clean need and syringe, you can pull air out of the tube, and it should create the vacuum suction again.
  3. Collect 2 cc or more of blood.
  4. Remove the needle from the skin and remove the tube from the tube holder.
  5. Make sure your tube is labeled with the cows ID or sequence number.
  6.  Place the tube in a refrigerator until shipment
  7. Discard the needle into the “sharps” container and reuse the needle holder.
    1. Use a new needle for each cow

Video of the steps listed above: Tail Bleeding Video by UF/IFAS CFLAG Group


Interested in using a blood test can find additional information on the following websites:

DG29 Preg Test



Thank you,


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Posted: October 25, 2022

Category: Agriculture, EDUCATION, Farm Management, Livestock, UF/IFAS Extension, Work & Life
Tags: Bleed, Blood, Cattle, Pregnancy, Sample, Season, Tail

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