For genetic evaluation and contemporary group ratios, weaning weights are standardized to a calf age of 205 days and a mature dam equivalent. Breed-specific nonlinear equations are used to adjust calf weights to a common age.

This allows fair, age-equivalent comparisons among calves weaned between 120-280 days. The lower minimum acceptable weaning age of 120 days provides flexibility to breeders in weaning dates, along with allowing younger calves to remain in their respective contemporary groups for National Cattle Evaluation.

Weaning Age of Dam Adjustment Chart
If Age-of-dam (at 205) is Add Lbs. to Age Adjusted Weaning Weight
thru 2 yrs. 243 days 68 57
2 yrs. 244 days thru 3 yrs. 91 days 67 55
3 yrs. 92 days thru 3 yrs. 273 days 37 32
3 yrs. 274 days thru 4 yrs. 91 days 29 21
4 yrs. 92 days thru 5 yrs. 91 days 15 13
5 yrs. 92 days thru 10 yrs. 91 days 0 0
10 yrs. 92 days and older 22 19

= (actual yearling wt - actual weaning wt)      x 160      + 205-day adj. weaning wt
     No. of days between measure ages


Actual yearling weight 1085 lb       yearling measure age 363 days
Actual weaning weight 660 lb        weaning measure age 209 days

205-adjusted weaning weight 731 lb

Adjusted 365-d Yearling Weight = (1085 - 660) x 160 + 731
=1173 lb


Adjusted 365-day weights are computed to adjust an actual yearling weight taken by the breeder to a standard animal age (365-day, typically) and age of dam (this adjustment takes place through the use of the 205-d weaning weight). Acceptable calf ages for yearling measures are 320-440 days of age.

The suggested period between weaning and yearling weight is 160 days. A common mistake is that the two weights are taken too closely together. Although the window of acceptable weaning weight ages is 120 to 280, and yearling wt age 320 to 440 days of age, you need to try to allow for more postweaning gain growth time to better characterize the trait.

Weight per Day of Age (WDA)

Many times, weight per day of age (WDA) calculations provide a source of confusion. In contrast to the 365-day yearling weight, the WDA is calculated as follows:

WDA = Actual weight/days of age

In the above example using weaning weight as the actual weight taken, WDA= 660/209 = 3.16 lb per day of age

Docility Scores

The scores provided are designed to evaluate disposition differences when processing animals through the chute. Scores should be an observation of how animals enter, exit and react while being handled in the chute.

Docility may be reported on:

1. Cows when they wean their calves
2. Calves when yearling data is reported
1 Docile
Acceptable, mild disposition, most favorable temperament.
2 Restless
Restless during processing.
3 Nervous
Nervous and impatient.
4 Flighty (Wild)
Jumpy and out of control, quivers and struggles violently.
5 Aggressive
Added aggressive behavior, extreme agitation.
6 Very Aggressive
Extremely aggressive temperament.

Foot Scoring

Proper foot structure is essential to an animal’s longevity, and Angus is leading the U.S cattle industry in assessing an issue pertinent to all breeds – structural soundness. The American Angus Association accepts foot scores from its member through a simple recording system using two categories, foot scores and claw set on a 1 – 9 scale where a score of 5 would be ideal. Foot scores on bulls and females should be collected during yearling data collection. Older females can be scored using those same guidelines when collecting mature cow weights. Large group data on 18-month or 2-year-old bulls can also be submitted. For more information on the individual 1-9 scores click here.


These ultrasound images are collected by a UGC certified field technician between 320 and 440 days of age for bulls and 320 and 460 days for heifers. Weaning weights submitted prior to the scanning date are required to process ultrasound data. The ultrasound field technician sends the images to one of the American Angus Association's authorized ultrasound processing labs for interpretation by a UGC certified lab technician, along with the barnsheet generated when weaning weights are submitted. If you do not have a barnsheet, contact the Performance Programs department. The interpreted records from the scans are then sent to the Association for adjustments, EPD calculations and summaries that are provided to the breeders.

As a reminder for weaning time, cow weights with a body condition score need to be taken +/- 45 days of the calf's weaning measure date. Cow hip heights may be captured at this time, also. It is important to collect this information after the cow has weaned her first calf, and then again in subsequent years.

A body condition score must be included with the cow weight in order for data to be utilized to calculate mature size EPDs in the National Cattle Evaluation. Any cow weights submitted without a body condition score will not be used.

For more information on body condition score, click on the link below.

The American Angus Association generates mature size EPDs that utilize cow weights and heights on breeding females, as well as their yearling measures (submitted on the AHIR yearling report form). The Mature Weight EPDs and the Mature Height EPDs are also used in the $Value index calculations for Weaned Calf Value ($W) and Cow Energy Value ($EN).