The Dairy Wellness Profit $ and Wellness Trait $ indexes may have you wondering whether you should adjust your genetic plan to include this new information. Here we have answers to 14 questions to help you decide what’s best for your dairy to make the maximum genetic progress in the direction of your goals!
What is Dairy Wellness Profit $ (DWP$) and Wellness Trait $ (WT$?)
These are genetic indexes calculated by Zoetis from producer-recorded data, in herds that are genomic testing or have genomic tested in the past.
How is the WT$ index compiled?
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.
How is DWP$ compiled?
DWP$ is a genetic selection index that 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 weight on WT$, leaving 26% for the CDCB evaluated health traits of PL, DPR, SCS, DSB, DCE, CCR, HCR.
Are the Wellness traits developed by Zoetis?
The WT$ calculation is not a new concept, as it was first published in 2004, however this is the first routine evaluation and first genomic prediction for those traits.
Did Alta test all bulls for DWP$ and WT$?
No, but we tested the sires that we predicted would do well on the respective indexes based on their health trait values and how they rank on a 34% Production-56% Health-10% Conformation index. We are listing the top ten DWP$ sires and top five WT$ bulls in each of three categories: G-Stars, FutureStars 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 34-56-10 index is very high, we can predict quite well which sires will rank well on the DWP$ index.
How do these 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. Of course many cows are affected, but do not leave the herd. Therefore the Wellness traits measure different things than Productive Life, however there is obviously a strong relationship between PL and WT$, with a stated correlation of 0.41. The relationship gets stronger if the combination of PL, DPR, and SCS is used, reinforcing that all the health traits are related to each other.
How should you use this information?
It’s still as important as ever to create your own, customized genetic plan based on your goals and the situation on your dairy.
Our stance at Alta has always been that the most important part of setting a genetic plan is getting the correct amount of weight in each of the three ‘buckets’ for production, health, and conformation – based on the current situation and future goals for your dairy. Once your genetic plan is decided, changing which individual traits are emphasized within each bucket will have far less impact.
If you select sires based on TPI (46% Production-28% Health-26% Conformation) or NM$ (43-41-16), the current DWP$ weighting of 34-56-10 puts significantly more weight on health than those two indexes, at the cost of production and conformation.
If your current genetic plan is set at 70-30-0, changing to DWP$ as a selection goal would be analogous to changing from 70-30-0 to 34-56-0. That doesn’t mean the change is wrong – it is just a VERY significant change, which should only be made because your goals or situation have changed, not just because there are new traits available.
However, if your genetic plan is set at 50-50-0, moving some of the 50% weight on health, and putting it towards the wellness traits, is a much less drastic adjustment.
Changing the bucket weights in a genetic plan is always a strategic decision. Therefore, plans should change only when economics or the situation on your farm changes, not just because new traits become available.
Is there anywhere else to get information on these traits?
In Canada, CDN 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 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. The correlation between NM and DWP$ is 0.92. The correlation between a 34-56-10 index calculated with Alta’s Bull Search or AltaGPS is 0.94.
Are the Wellness traits heritable, or driven more by management?
Many traits that are heavily influenced by environment still have a genetic component, and the Wellness traits are no different. While the heritability of these traits ranges from 6%-8%, they should not be eliminated from a selection plan simply because of low heritability. Daughter fertility, Productive Life, and other traits also have relatively low heritability, but many herds have made 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 that are routinely selected for. This means more re-ranking can occur between animals as more data is gathered.
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.
Source: Alta Genetics