Adjusted Birth Weight Calculator
Many different factors can change a calf’s weight — from age to environment. Calculating the adjusted birth weight for your cattle helps account for these factors, standardize weight metrics, and supports more accurate comparisons among calves.
What is adjusted birth weight in cattle?
Adjusted birth weight is the weight of a calf that accounts for the age of its dam, as well as its sex. In other words, certain environmental factors can impact a calf’s weight at various ages. Adjusted birth weight in cattle helps to standardize weights and take out the effect of those environmental factors.
Having an adjusted birth weight in cattle helps you compare various genetics — and select for the most successful traits. This standardized data is an important piece of information to have before making breeding decisions.
How to calculate adjusted birth weight?
To calculate the adjusted birth weight in cattle, you first need the raw birth weight. It’s important to calculate the initial birth weight using a precise digital scale (not just a mechanical scale or visual inspection). Then, add a certain number of pounds based on the dam’s age at the time of birth.
Adjusted Birth Weight = Birth Weight + Age of Dam (Adjusted)
The Beef Improvement Federation releases guidelines for how many pounds to add for each age of dam. For example:
2 years old: 8 lbs
4 years old: 2 lbs
5-10 years old: 0 lbs
Different breed associations will also sometimes have their own adjustments, since the impact of age can differ depending on breed.
Why adjusted birth weight calculations are important?
By accounting for various environmental factors that can make calf weights fluctuate, adjusted birth weight metrics help you better compare and evaluate your herd’s genetics.
Use the calculator above to figure out the adjusted birth weight for a specific calf.
