Adjusted 365-day Yearling Weight Formula:

= (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

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