Dairy Wellness Profit $ and Wellness Trait $ indexes
The Dairy Wellness Profit $ and Wellness Trait $ indexes may have you wondering whether you should adjust your genetic plan to include this information. We want to help you decide what’s best for your dairy. So we answer a few questions about DWP$ and WT$ to help you better understand these indexes.
What is Dairy Wellness Profit $ (DWP$)?
Dairy Wellness Profit $ (DWP$) is a genetic selection index. It equates to a genetic plan of 34% production–56% health–10% conformation. This differs from TPI (46-28-26) and the overall NM$ index (43-41-16).
The breakdown of the weight on health is different as well. DWP$ puts 30% of the health trait weight on WT$. This leaves 26% for the CDCB evaluated health traits of PL, DPR, SCS, DSB, DCE, CCR, HCR.
What is Wellness Trait $ (WT$?)
WT$ is a combination of the Wellness Traits (ketosis, displaced abomasum, retained placenta, metritis, mastitis and lameness). This means it is an index analogous to a 0-100-0 index, with 100% weight on health traits. However, those weights are divided between the various Wellness traits that Zoetis calculates.
Do each of the Wellness Traits get their own evaluation?
Yes. They are then combined into a Wellness Trait $ index to combine the expected impact.
Does Alta test all bulls for DWP$ and WT$?
No, but we test the sires that we predict will do well on the respective indexes. We test our bulls that have favorable health trait values and rank well on a 34% Production-56% Health-10% Conformation index. We list the top ten DWP$ sires and top five WT$ bulls in each of three categories: G-STARS, FUTURE STARS and daughter-proven sires.
What is Alta’s testing plan going forward?
This will be dependent on the feedback from the customers and the demand for this information. In the short-term we will continue to test those sires that rank well on a traditional 34-56-10 index.
How can we predict which sires will do well on these indexes?
Because the correlation between DWP$ and a traditional 34% production – 56% health – 10% conformation index is very high, we can predict quite well which sires will rank well on the DWP$ index.
How do the wellness traits compare to Productive life?
Productive life encompasses every reason an animal leaves the herd, and the length of time she is productive compared to herdmates.
The Wellness traits are some of the exact reasons cows may leave, but instead measure incidence of disease, not departure from the herd. Many affected cows do not leave the herd. Therefore the Wellness traits measure different things than Productive Life, however there is a strong relationship between PL and WT$, with a stated correlation of 0.41. The relationship gets stronger if the combination of PL, DPR, and SCS is used, reinforcing that all the health traits are related to each other.
How should you use this information?
It’s still as important as ever to create your own, customized genetic plan based on your goals and the situation on your dairy.
Our stance at Alta has always been that the most important part of setting your genetic plan is getting your correct amount of weight in each of the three ‘buckets’ for production, health, and conformation. You can set these weights based on the current situation and future goals for your dairy. Once you decide on your genetic plan bucket weights, changing which individual traits are emphasized within each bucket will have far less impact.
The current DWP$ index of 34-56-10 puts significantly more weight on health than TPI (46% Production-28% Health-26% Conformation) or NM$ (43% Production-41% Health-16% Conformation). But, what DWP$ adds to health, it sacrifices on production and conformation.
If your current genetic plan is set at 70-30-0, changing to DWP$ as a selection goal would be the same as changing from 70-30-0 to 34-56-0. That change isn’t necessarily wrong. It’s just a VERY drastic change. You only need to consider genetic plan adjustments like that if your farm’s goals or situation change, not just because new traits are available.
If your current genetic plan is 50-50-0, you’d see a more subtle difference by switching to selection for DWP$. Moving some of the 50% weight on health toward the wellness traits is a much less drastic adjustment.
Changing your bucket weights in your genetic plan is always a strategic decision. Therefore, keep with what you’ve set to maximize progress toward your goals. Only make adjustments when economics or your farm’s situation changes – not just because new traits become available.
Is there anywhere else to get information on these traits?
In Canada, CDN ( Canadian Dairy Network ) has been calculating an evaluation on clinical mastitis for some time now, and those evaluations are readily available. They are also collecting data on each of the other five traits, and expect to have evaluations available within the next year.
In the Netherlands, these traits are routinely collected and evaluated. In the US, the CDCB (Council on Dairy Cattle Breeding) is currently evaluating the possibilities to do genetic evaluations for these traits.
What is the correlation between DWP$ and other indexes?
The correlation between TPI and DWP$ is 0.89. NM and DWP$ have a 0.92 correlation. The correlation between a 34-56-10 index calculated with Alta’s Bull Search or Alta GPS is 0.94.
Are the wellness traits heritable, or driven by management?
Many traits heavily influenced by environment still have a genetic component. The Wellness traits are no different. While the heritability of these traits ranges from 6%-8%, you do not need to eliminate them from your selection plan simply because of that low heritability. Daughter fertility, Productive Life, and other traits also have relatively low heritability. But many herds make substantial genetic progress and see real results for these traits through genetic selection.
What is the reliability of the Wellness Traits?
The reliability of the Wellness Traits is ~0.50. This is relatively low compared to other traits. It means more animals may re-rank as more data is added.
Comparatively, the reliability of other CDCB health traits such as PL, DPR, and SCS is around .70 on young AI bulls because there is more historical data available for these traits.
Reliability is a measure of the precision of an estimate, and the likelihood that estimate changes over time. It is NOT how likely traits are to pass from one generation to the next.
If you have questions, or would like to include these traits as part of your genetic plan, please speak with your trusted Alta advisor.
To view a listing of Alta’s top 10 DWP$, top 5 WT$ sires and a ranking for all tested Alta bulls, follow this link.