How to Take Blood Samples from Cattle
Order your blood test kit and have it shipped to you., Confine and restrain the animal., Raise the tail and locate the coccygeal blood vessels underneath the tail., Clean the area to be sampled., Insert the needle directly into the vein., Draw...
Step-by-Step Guide
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Step 1: Order your blood test kit and have it shipped to you.
The number of samples that need to be taken should be one per bovine.
Thus, the number of tubes needed will depend on how many animals you need to draw blood from. , It makes taking blood much easier and safer for both you and the animal if the animal is confined to a head-gate or squeeze chute.
For this method, a head-gate with a neck extender isn't really necessary., The tail needs to be raised right up in the air so that its perpendicular to the ground.
The blood vessel of choice is located under the tail, which is where you will be taking blood from.
Note though that the vessels actually form an upside-down V from either side of the anus up a couple inches the tail.
Where the V ends and the vessels continue parallel to the length of the tail is where you should take your blood sample from. , Because the sample is being taken from under the tail, close vicinity to the anus, bacteria from feces could potentially contaminate the sample if the area is not swabbed with alcohol first.
A cotton ball dipped in 70% rubbing alcohol will work, just by holding the cotton ball to the opening of the bottle and tipping the bottle nearly upside down to wet the ball. (You can also use a 4x4 gauze.) Rub, in an upward motion only away from the anal region, the area you will be inserting the needle into., The needle needs to be carefully inserted perpendicular to the angle of the tail; but not all the way in.
It is easier to put the needle in perpendicular to the tail rather than try to put it in parallel because it may be more difficult to puncture the vein when the needle is at more of an angle to the vein than when it's 90-degrees to that vein.
Use a short needle: an 1-inch, 18-gauge needle is good enough for this job.
And as mentioned, only insert the needle slightly over half-way in, never all the way.
The syringe accompanying the needle should not be more than 5 cc; but, there's nothing wrong with having a 10 cc syringe, just note that you don't need to fill it up completely with blood. , Allow 3 to 5 mL (or 3 to 5 cc) of blood to enter the syringe.
Most labs only need a small amount of blood to do the test and to have some left over in case the lab technicians make a mistake., Apply pressure to the area to stem excess bleeding with a gauze or cotton swab.
Then lower the tail when bleeding appears to have stopped., The vacuum-sealed tube will vacate the contents of the syringe without you needing to apply pressure to the plunger.
Remove the needle when all contents have been vacated., The vacutainer tube must be labelled with the identifying number and/or name of the animal, sample number (Sample #1, 2, 3, etc., or Sample A, B, C, etc.), and name of your farm., Usually the box that contained the kit has a built-in tray to place the vacutainer tubes in.
Place the tubes in that box with the bubble wrap surrounding each tube to protect them. -
Step 2: Confine and restrain the animal.
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Step 3: Raise the tail and locate the coccygeal blood vessels underneath the tail.
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Step 4: Clean the area to be sampled.
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Step 5: Insert the needle directly into the vein.
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Step 6: Draw slowly back on the plunger of the syringe.
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Step 7: Remove the needle the same way you inserted it.
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Step 8: Take a rubber-capped test tube (called a "vacutainer tube") and insert the needle into the top of the cap.
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Step 9: Label the tube.
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Step 10: Put the tube back in its place.
Detailed Guide
The number of samples that need to be taken should be one per bovine.
Thus, the number of tubes needed will depend on how many animals you need to draw blood from. , It makes taking blood much easier and safer for both you and the animal if the animal is confined to a head-gate or squeeze chute.
For this method, a head-gate with a neck extender isn't really necessary., The tail needs to be raised right up in the air so that its perpendicular to the ground.
The blood vessel of choice is located under the tail, which is where you will be taking blood from.
Note though that the vessels actually form an upside-down V from either side of the anus up a couple inches the tail.
Where the V ends and the vessels continue parallel to the length of the tail is where you should take your blood sample from. , Because the sample is being taken from under the tail, close vicinity to the anus, bacteria from feces could potentially contaminate the sample if the area is not swabbed with alcohol first.
A cotton ball dipped in 70% rubbing alcohol will work, just by holding the cotton ball to the opening of the bottle and tipping the bottle nearly upside down to wet the ball. (You can also use a 4x4 gauze.) Rub, in an upward motion only away from the anal region, the area you will be inserting the needle into., The needle needs to be carefully inserted perpendicular to the angle of the tail; but not all the way in.
It is easier to put the needle in perpendicular to the tail rather than try to put it in parallel because it may be more difficult to puncture the vein when the needle is at more of an angle to the vein than when it's 90-degrees to that vein.
Use a short needle: an 1-inch, 18-gauge needle is good enough for this job.
And as mentioned, only insert the needle slightly over half-way in, never all the way.
The syringe accompanying the needle should not be more than 5 cc; but, there's nothing wrong with having a 10 cc syringe, just note that you don't need to fill it up completely with blood. , Allow 3 to 5 mL (or 3 to 5 cc) of blood to enter the syringe.
Most labs only need a small amount of blood to do the test and to have some left over in case the lab technicians make a mistake., Apply pressure to the area to stem excess bleeding with a gauze or cotton swab.
Then lower the tail when bleeding appears to have stopped., The vacuum-sealed tube will vacate the contents of the syringe without you needing to apply pressure to the plunger.
Remove the needle when all contents have been vacated., The vacutainer tube must be labelled with the identifying number and/or name of the animal, sample number (Sample #1, 2, 3, etc., or Sample A, B, C, etc.), and name of your farm., Usually the box that contained the kit has a built-in tray to place the vacutainer tubes in.
Place the tubes in that box with the bubble wrap surrounding each tube to protect them.
About the Author
Ashley Gordon
Experienced content creator specializing in lifestyle guides and tutorials.
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