Genetic progress in dairy herds depends on more than production alone. Structural traits—often measured through linear type evaluations—play a key role in longevity, functionality, and overall herd performance.
To support producers in making more informed breeding decisions, Lactanet has released its updated Sire Proof Interpretation Tables for Linear Type Traits as of April 2026.
Why Type Traits Matter on Farm
Linear type traits describe physical characteristics such as udder structure, feet and legs, and body conformation. While these traits are often discussed in classification terms, they also have practical implications.
For producers, type traits can influence:
- milking efficiency
- durability and longevity
- risk of lameness or udder health issues
- overall herd management ease
That’s why sire proofs for these traits remain an important part of breeding decisions.
Turning Proof Numbers Into Practical Insight
One of the challenges with type traits is translating proof values into what they actually mean in the barn.
Genetic evaluations typically range from -15 to +15. While those numbers provide direction, they don’t always clearly show what to expect in terms of daughter performance.
The updated interpretation tables help bridge that gap by linking sire proofs to expected average daughter scores in first lactation.
👉 View the full interpretation table here:
Lactanet Sire Proof Interpretation Tables
What the Table Helps You Understand
The tables provide two key pieces of information:
1. Where “average” sits
The “Proof = 0” column shows the expected average score for daughters of an average bull within a breed.
2. What change looks like
The “Per 5-point proof increase” column shows how much improvement to expect when selecting a sire that is five points higher for a given trait.
This gives producers a more realistic expectation of genetic progress over time.
Not All Traits Should Be Maximized
One of the most important takeaways is that not every trait should be pushed higher.
Some traits have an intermediate optimum, meaning the goal is balance rather than extremes. In these cases, higher is not always better.
For example:
- overly deep udders may increase mastitis risk
- extremely straight or curved legs can affect mobility
Understanding where your herd currently sits—and where you want it to go—is key to making the right selection decisions.
Applying This on Farm
Using type trait information effectively comes down to combining data with herd goals.
Producers should consider:
- current herd strengths and weaknesses
- cow family trends within the herd
- management system and housing setup
- long-term breeding objectives
Working with a genetic advisor or veterinarian can also help align sire selection with overall herd strategy.
Keep Expectations Realistic
While the interpretation tables provide useful benchmarks, they reflect population averages. Individual results may vary based on both genetics and management.
Environmental factors, nutrition, and herd management all play a role in how traits express on farm.
The Bottom Line
Linear type trait proofs offer more than just classification insight—they are a practical tool for improving herd function and longevity.
With updated interpretation tables, producers now have clearer guidance on what those numbers mean in real terms. Used alongside production and health data, they can help support more balanced and effective breeding decisions.
