Abnormal Calving - Pulling the Calf
Material edited from the Calving Management Manual by Robert Mortimer MS, DVM, Colorado State University, Dept of Clinical Sciences
Always determine if the calf is in a normal presentation, posture and position. If the calf is not in the correct position or posture at the examination, then these must be corrected before beginning to pull. For instructions on this topic see the next section.
After examination and a determination that the calf is in the correct position and posture, chains should be placed on both limbs. They may be placed either above the fetlock joint or below the fetlock above the hoof of the calf or a combination of the two. In most instances, it is recommended to place the chains above the fetlock and take a half-hitch below the fetlock joint as well. The chain above the fetlock should be placed where the bone is decreasing in size on the leg above the growth plate of the bone.
Have the cow on her right side. It is easier to pull the calf when the cow is on her right side and the calf is lined up with the birth canal. Also, when the cow is lying down, she can push with each contraction and help deliver the calf.
Be sure you are in an area large enough for the cow to safely and comfortably lie down.
An example of casting the cow:
To lay the cow down, take a long sturdy rope (about 10 feet long) and
place across the back of the cow's neck. Take the two ends of the rope
and place them under the front legs. Bring the ends of the rope up and
cross them over the middle of her back. Now take the two ends and place
between her hind legs and her udder. Pull the two ends of the rope from
behind the sow until she lies down. Usually the cow will remain lying
down.
Another way to cast the cow is:
Take a long rope that has a honda at one end and place the rope around the flank of the cow. Put the one end through the honda and pull tight. Be sure that the rope is in front of the udder. Pull the rope in the direction you want the cow to fall.
You are now at a point to determine if delivery by forced extraction is possible. This test for delivery is valid only if certain criteria are followed relative to position of cow, type and amount of traction, and direction of pull. Traction should only be applied when the cow is assisting with an abdominal press.
Whenever the birth canal is evaluated, and during the entire process of calving assistance, it is extremely important to maintain excellent hygiene. The operator's hands and arms and the cow's vulva and surrounding area must be cleaned and disinfected repeatedly. Clean/sterile lubricant should be used liberally and frequently. During attempts to pull the calf, the birth canal should be dilated using your hands and forearms.
To repeat - for any of the assistance procedures it is
extremely important to:
Clean
Lubricate
Dilate
Always manually dilate the vulva for at least 5 minutes.
Delivery of the Frontwards (Anterior) Calf by Forced Extraction
In the frontwards presentation with normal position and
posture of the fetus, the guideline is whether both shoulders of the calf
can pass through the pelvis of the cow using recommended traction techniques.
To actually determine this, the cow should be down, on her right side,
and traction should be applied to one leg at a time (unilateral traction)
to walk the shoulders through the pelvis of the cow. Positioning of the
cow on her right side allows the frontwards calf to enter the pelvis of
the cow relatively straight. In a difficult delivery this is important.
It is preferable to start with the down leg (left) of the calf. This usually
comes through easily -- so the actual test for delivery is if you can
get the second shoulder past the cow's pelvis. You should be able to feel
the shoulder move past the pelvis as you are applying traction. However,
a suggested rule to determine if the shoulder of the calf is past the
pelvis of the cow is if the calf's fetlock joint is one hand's breadth
or about 10 cm outside the vulva of the cow or when the knees (carpi)
of the calf are at the vulva.
Once the first shoulder is through the pelvis of the cow, it should be held in place and traction applied to the other leg. The amount of traction should be limited to the force of one strong person per leg. Two strong people can exert a force of from 400-600 pounds while erroneous use of a fetal extractor could exceed 2000 pounds of pressure.
Using the force of two people (one on each leg of the calf).
Pull one leg at a time
If both people pull at the same time the elbows of the calf will lock up against the pelvis of the cow making it difficult the deliver the calf.
The pressure exerted by two people pulling is about 400 psi
The pressure exerted by a calf jack can be as much as 2000 psi if used imporperly.
Good clinical judgment in the application of traction is important and necessary. Our goal is to deliver a live calf with the maximal opportunity for survival. Exceeding this rule may result in the delivery of the calf, but will markedly increase the chances for the loss of the calf during delivery or subsequently to disease, cold, or starvation. The direction of pull should be straight back from the cow, which is difficult unless the cow is down.
Once the shoulders of the calf are through the pelvis of the cow, delivery
by forced extraction is possible. If not, call for professional assistance,
as a C-section is recommended if you want a live calf. Bilateral traction
(pulling done by two people) can be exerted at this point to further pull
the calf before the pelvis of the calf enters the pelvis of the cow. As
in the normal delivery, this is when the umbilical cord is compressed
and the cow usually takes a break for a short period of time. This is
a point when the calf should be allowed to breathe on its own or oxygen
can be administered. It is also a point with the oversized fetus where
90 degree rotation of the calf should occur. This rotation is necessary
to bring the widest part of the calf pelvis through the widest diameter
of the cow's pelvis. This can usually be accomplished by crossing the
front legs (trade chains between people), but occasionally needs a little
more force. This can be done in a "half nelson" manner.
Rotating the calf will allow the hips to line up better with the pelvis of the cow making delivery of the hips easier.
Once breathing has been established, completion of delivery is possible in most instances. Occasionally, calves are lost because of failure to allow the calf to breathe. Constant pulling on the calf at this point will not allow the calf to expand its chest and take in any oxygen and it is possible to lose the calf if breathing is not allowed.
Delivery of the Backwards (Posterior) Calf By Forced Extraction
The test for delivery of a calf in the backwards presentation but normal position and posture differ because the fetus should be FIRST rotated 45-90 degrees by crossing the legs before attempting delivery to take advantage of the widest diameter of the cow's pelvis.
In addition, the direction of pull on the calf is in a
direction that is slightly up from a line straight out from the back of
the cow.
Traction can be applied in the amount of two strong people and should
be applied bilaterally (both legs at the same time). The test for delivery
is if both hips of the calf can pass through the pelvis of the cow. This
is determined in most instances by the extension of the hocks of the calf
beyond the vulva. If this is easily accomplished, possible delivery can
be made. However, now we have very little time left to accomplish rotation
of the fetus to a right-side up position for the chest of the calf to
come through the pelvis of the cow and deliver the calf. We have probably
no more than 2-3 minutes to complete the delivery. If the test fails in
either case, call for professional assistance as surgical delivery is
probably indicated if you want a live calf and maybe even a live cow.
