Performance records
Adjusted 205-day weaning weight calculator
Put calves weaned at different ages, and out of young and mature cows, on the same footing before you rank them.
Adjusted 205-day weight = ((weaning weight − birth weight) ÷ age in days) × 205 + birth weight + age-of-dam adjustment. A bull calf that weighs 560 lb at 212 days, born at 78 lb to a 3-year-old cow, adjusts to about 584 lb.
Example numbers. Change them to your own.
How it is calculated
- Gain per day of age. Weaning weight minus birth weight, divided by age in days.
- Standardize to 205 days. Multiply by 205 and add the birth weight back.
- Adjust for age of dam. Bull and steer calves: +60 lb for a 2-year-old dam, +40 lb for 3, +20 lb for 4, 0 for 5 to 10, +20 lb for 11 and older. Heifer calves: +54, +36, +18, 0 and +18 lb.
- Compare inside a contemporary group. Rank calves only against others of the same sex raised together. Breed associations apply their own adjustments when they compute EPDs.
What is adjusted 205-day weight?
It is a calf’s weaning weight standardized to 205 days of age and corrected for the age of its dam, so calves weaned at different ages and out of cows of different ages can be compared fairly.
At what age should calves be weighed for a 205-day weight?
The Beef Improvement Federation recommends weighing calves between 160 and 250 days of age, with the whole group weighed on the same day.
Why add weight for calves from young cows?
First-calf heifers and young cows give less milk than mature cows, so their calves wean lighter for reasons that are not genetic. The age-of-dam adjustment credits those calves so they are not penalized.