Two big changes happened in the US dairy genetics industry with April 2025 proofs: a base change and an update to the NM$ index formula. Here, we break down the details of the NM$ update, including the new calculation and what that means for your operation.
What does the new NM$ index look like?
Below you will see the category breakdowns and specific trait weights for NM$ 2025.
How does the new NM$ 2025 compare to the previous NM$?
The last update to the NM$ formula took place in 2021. The graphic below shows the comparison between NM$ 2025 on the left and NM$ 2021 on the right. You’ll notice that the category weights on Production, Health & Efficiency, and Conformation are not significantly different between the two versions of NM$. However, the individual trait weights within each category have shifted.
What are the most significant changes in the new NM$?
Within the NM$ formula, the following changes are most notable, and important to be aware of:
- Production Traits
- Emphasis on protein decreases by 6.6%.
- Emphasis on milk and fat increase by 3% for each of these two traits.
- Health & Efficiency
- Weight on Feed Saved, which is a combination of Residual Feed Intake & Body Weight Composite, increases by 3.6%.
- Emphasis on Productive Life (PL) decreases by 3%.
- Weight on Daughter Pregnancy Rate (DPR) goes down by 2.0%.
- Conformation
- Index weight on Udder Composite drops by 2.0%.
What does this mean for your farm?
If NM$ is the genetic index you use to choose your sires or rank your females, then this is a critical time for you to review your genetic plan.
For example, if you are paid primarily for pounds of protein, then the reduced emphasis on PTA Protein within NM$ does not align as well for your future profitability potential. And a shift in emphasis from Productive Life to Cow & Heifer Livability is another opportunity for discussion on whether the NM$ index is still aligned with your goals.
Not sure how to consider these changes as it relates to your own farm’s genetic plan and strategy? If so, we invite you to connect with your trusted Alta advisor for guidance on setting a genetic plan that’s tailored to fit your farm’s goals.
