Pulling on a calf should only be done when the presentation and posture of the calf are normal. This applies both to a normal anterior (forward) position and a posterior (backward) position. A large calf, with shoulders too wide for the pelvis, is sometimes held up at this stage. If so, pull one limb only so that the elbow and shoulder of one limb only enter the pelvis. Then, while the pull on the limb is continued, the other limb is treated in the same way until both feet project equally from the genital passage. Now apply traction on both limbs and on the head until the head protrudes from the vulva, and from this stage the principle traction is exerted on the limbs again. It can be seen that traction on both limbs at the same time will result in both shoulders entering the pelvis at once.
The pelvis has an oval shaped opening with the largest dimension being the vertical axis, and the smaller dimension is the horizontal width. If the shoulders of a large birth weight calf can be made to enter on a slant and can be pulled through in that position, delivery will be made easier. Apply traction that will allow the calf to be turned about 90 degrees so that the widest part of the shoulders will match the largest dimension of the pelvic opening.
After the shoulders have passed the pelvic opening, the calf can be returned to the normal upright position because the torso is larger in the vertical dimension.
Hiplock is the next likely obstruction that is met when pulling a calf. If the passage of the hind end of the calf presents any difficulty, the body of the calf should be grasped and twisted to an angle of about 45 degrees. Delivery is then made with the calf half-turned on its side. This allows for easier passage of a calf with well developed stifle joints.
To learn more about how to assist cows or heifers at calving check out two video tapes available from your local OSU Extension Office. These two videos are called "Calving Management-Parturition" (VT-323) and "Calving Management-Dystocia" (VT-324). In the second video (VT-324), Dr. Larry Rice, Professor-Emeritus, demonstrates how to check for cervical dilation. Also purchase a copy of "Calving Management" E-906, a 40-page OSU Extension Circular that thoroughly discusses working with cows and heifers at before and during calving season.