Points added to January article “Calving Tips” by Heather Smith Thomas by Ronald Olsen, DVM.
As a veterinarian with 40 years' experience, plus an instructor of veterinary obstetrics at Washington State University, I would add the following points to the January article “Calving Tips” by Heather Smith Thomas:
If the calf is in anterior presentation, with the head into the birth canal, and two people pulling on one leg can't visualize the leg 4 in. past the carpus (knee), that calf isn't going to come without severe damage to the cow and calf. If it's a posterior presentation, then the same two people should be able to exteriorize the hock with both feet through the pelvis. If these criteria can't be met, it's time for either a cesarean if the calf is alive or a fetotomy if the calf is dead.
To prevent hiplock when delivering a calf, it's important to remember that the largest dimension of the cow's pelvis is top to bottom and the largest dimension of the calf is side to side. So if you're helping the cow calve, the first thing to do, once the calf's head is exteriorized, is to rotate the calf 180° (turn the front of the calf until its sternum is facing the cow's tail; this will rotate the hips of the calf 45° and likely prevent hiplock).
If there is a posterior presentation, rotate the calf 45° before you begin to put any tension on the calf. If you come upon a cow with a hiplock and anterior presentation, grasp the wing of her ilium (the broad, dorsal, upper and largest of the three principal bones that comprise either half of the pelvis) and push the calf back into the cow about 1 in., and rotate the calf 45° by twisting the calf's pelvis.
I always told students that the calf is like pulling on a rope, not pulling on a 2×4. Pulling at the cow's heels will just force the calf farther down into the small part of the pelvis, whereas pulling at a 5-10° angle past her spine will help lift the calf up to the larger part of the pelvis. The back of the calf won't rise up as the front is forced down. The calf can breathe once the head is outside so be careful to not exert continuous pressure on it.
The best lubricant for obstetric use in my experience is Crisco shortening, which is cheap and readily available. It sticks to the calf and to your arm and won't kill the cow if it makes its way into her abdomen.
One trick for a calf that's been stressed in delivery is to always pull the hind legs under the calf past its ears. Thus, the calf will be lying on its sternum and can breathe without having to lift its weight to expand its lungs.
Ronald Olsen, DVM
Moses Lake, WA