Calving percentage is also based on the SPA adjusted females exposed. The formula is number of females that calved divided by the SPA adjusted females exposed. Calf crop or weaning percentage, or the percent of the females exposed to bulls that had a live calf at weaning. This turns out to be one of the most important economic variables measured in a beef cow herd. It is calculated by dividing the number of calves weaned by the SPA adjusted females exposed.
Top producers wean more live calves.
Calf death loss, or the percent of the calves born that died. Note that this percentage is not based on females exposed it is based on calves born. Calving distribution has a primary impact on pounds of calf produced. Recommendations are that producers design a breeding program that bunches calving dates into a calving interval of 63 days or less. The benchmark herds produced 58.5 percent of their calves in the first 21 days of the calving interval, and 85.9 percent in the first 42 days.