With over five years of genomics under our belts, it now seems like “old news.” Our tendency to question the relevance and accuracy has now diminished.
Instead, we use genomic-proven bulls with great confidence as part of a balanced breeding program. However, if you’re still uncertain of the stability on specific traits or looking for comparisons on genomic-proven versus daughter-proven options, read more for the answers you’re looking for.
Past Selection Decisions
Tables 1 and 2 show the top ten daughter-proven and top ten genomic-proven bulls available in August 2010 based on TPI. They are listed here with today’s TPI values. Based on these tables, you can clearly see that the August 2010 genomic sires are a superior group.
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| Comparison between daughter-proven and genomic-proven bulls in August 2010 |
Those who chose to use sires from the genomic-proven list in 2010 now have numerous milking daughters of these exciting, high-profile sires that are finishing their first or starting their second lactations. These herds are genetically ahead of those who chose to use daughter-proven bulls back in 2010.
More data means more stable 1st crop proofs
The graphs below show the expected change for different traits from a genomic to first crop proof. In total, 3085 bulls were genomic-tested in August 2010 and now have official daughter evaluations. Looking at the TPI graph, we see that of those 3085 bulls, more than 75 had zero change in TPI, and the average change of all bulls was just 71 TPI point decrease.
Meanwhile, only fifteen bulls in the entire breed either gained or lost more than 400 TPI points. This means you can be confident that a genomic bull you use now has only a 0.04% chance (15/3085) of dropping or gaining more than 400 TPI points by the time he gets a daughter proof.
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| Change in TPI from August 2010 Genomic proofs to August 2014 daughter proofs |
Click any of the following graphs to see a larger version:
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Current versus Historic GTPI
The graph to the right shows the trend of current TPI versus GTPI values from August 2010. The change from a genomic to 1st crop proof is now more stable than what we saw in the first years of genomics. This proves that the extra 35 daughter equivalents from genomics add significant proof stability. It is still important to note that many of the bulls that dropped more than expected in TPI from their genomic to 1st crop proofs tended to be among the highest-ranked genomic bulls.
This change certainly proves that using a group of genomic sires with pedigree diversity to match a farm’s customized genetic criteria is the best way to limit risks. Rather than focus on the single highest sire, create a customized genetic plan and utilize a group of sires that meet an individual herd’s genetic goals. The reliability gained from using a package of bulls provides the confidence and reassurance that genetic progress is being made in the right direction.
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| Graph to show the current GTPI of sires as compared to their GTPI in August 2010 |
Today’s Selection Decisions
Just as in August 2010, selection options today are much the same. You could use the best daughter-proven sires or Alta’s best genomic bulls (Tables 3 and 4). While the bulls on the proven list (Table 3) get a lot of publicity and have made some great daughters, the genetic predictions of the genomic group (Table 4) certainly exceed those of the daughter-proven group.
Using genomic-proven sires as part of a customized genetic plan will certainly maximize genetic progress within a herd. Limit risk by increasing the number of different sires used and by ensuring there is pedigree diversity within the group.
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| Comparison between top daughter-proven and top genomic-proven sires in August 2014 |
Keep this in mind…
There are a couple things to consider when seeing that the average bull dropped about 70 TPI points from his genomic prediction in 2010 to his daughter proof in August 2014:
- The ranking stayed relatively consistent among sires, and the genomic sires still clearly outpaced daughter-proven sires.
- The highest ranking bulls tend to have the largest decrease in TPI. The top 100 GTPI sires from August 2010 dropped an average of 200 TPI points from their genomic proof to their daughter proof, compared to the average of all bulls dropping just 70 TPI points.
- There have been numerous improvements to the genomic model since 2010 that continue to adjust for any over-prediction in genomic proofs.The model changes along the way force us to use caution as we compare current genomic proofs to future daughter proofs.
- A large portion of the average TPI change is due to the previous overestimation for Productive Life. An adjustment for PL at the end of 2012 dropped the PL figure for all genomic-proven sires to account for the previous over inflation. The change shown in the PL histogram below is mostly accounted for within that model adjustment. While it’s not ideal to see bulls go down, the PL model change affected all bulls the same, and sire rankings stayed nearly constant.
- As the graphs below also show, the average combined fat and protein (CFP) only changed by about 5 pounds from genomic proofs in August 2010 to daughter proofs in August 2014! That means those who chose to use genomic proven sires originally, are certainly realizing the benefits of the components for which they selected.
Analysis for this information done by Gerbrand Van Burgsteden. Email Gerbrand by clicking HERE.
Source: Alta Genetics/Chrissy Meyer