Today a rancher called with an excellent question about how our performance numbers on the bulls relate to each other. It merits some explanation. The three measurements of performance that we include in our catalog are 205 Day Adjusted Weight, Average Daily Gain, and Weight Per Day of Age.
- 205 Day Adjusted Weight is calculated by American Simmental Association, based on the weaning weight we submit for each animal. They adjust to exactly 205 days, and also make an adjustment based on the age of the dam.
- Average Daily Gain (ADG) is calculated by us, based only on the performance of the bulls while on feed test. They are weighed every 4 weeks for 16 weeks.
- Weight Per Day of Age (WDA) is calculated by us, based on the bulls’ weight at time of ultrasound, which is usually mid to late January. It reflects their average gain over their entire life up to that point, including the time on test.
These are basically three snapshots of a bull’s performance during different phases of his life. Some useful things can be determined by looking at the patterns: for example, if there is a significant difference between ADG and WDA, then the bull performed significantly better during one phase or the other. Or, if the 205 Adjusted Weaning weight is way above average but the bull’s weaning weight EPD is not, then we might assume his performance was environmentally rather than genetically driven.
Our goal is to collect and present enough data to help cattlemen make a well rounded evaluation of what kind of package each bull offers. Happy studying!