By measuring the diameter of a newborn calf's hoof, you can get accurate birthweights without doing the heavy lifting required by spring scales, according to Farm Home Offices, Garrison, Iowa, about its Calf Scale measuring tape.
You can even use the tape to measure birthweights during labor to help predict difficult births.
The tape has weights printed on it. You place the tape around the coronary band of the front hoof, tighten it, and read the circumference in centimeters and the birthweight in pounds from the tape scale. One side measures bulls and the other side heifers. Weight at birth may vary by 7 lbs. for bulls and 6.4 lbs. for heifers due to hour of age and shrink or fill.
To predict calving difficulty, take the pelvic measurements (height and width to the nearest 1/10th centimeter) within 30 days before calving. Then use the Calf Scale to measure the calf's front hoof as it emerges during birth. Subtracting the average pelvic measurement from the hoof circumference gives the calving score expected (CSE). If the CSE is less than .4, little or no pull is required. A score of more than 3.0 means extremely hard pull or C-section will be required.