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7 Reasons Why You Shouldn’t Use Sires with DGV’s lower than Their Parent Averages

In our recent article, Is the Genomic System Really Working? we pointed out that the early numbers indicate that the genomic system is a 27.1% improvement over the old system.  In taking a closer look, we also noticed an interesting trend that sires with LPI DGV’s (Direct Genomic Values) lower than their parent average actually did a nose dive, when they added daughter information.

In God we trust.  All others must bring data

Now some of you would say that the system is already putting too much weight on DGV’s and that it is too early.  I get that.  However, here are some actual facts from the most recent proof round (August 2012) for you to consider. (Again please note we use the CDN system as a result of being able to have access to the genomic information on it.):

  1. For the sires who dropped more than 200 GLPI points from their genomic parent average index to their official proof, 96% (25/26) of them had DGV LPI’s lower than their parent averages.  Note that 118 bulls received official proofs in the CDN system in August 2012.
  2. For sires with DGV’s higher than PA’s, 33% (11/33) actually increased their LPI ratings with the addition of daughter data.
  3. When we take a look at the 5 sires who took the biggest jump with the addition of daughter information when compared to their parent average (COMESTAR LAUTREC, L-RIDGEVIEW NOAK-ET, GEN-I-BEQ BRAWLER, OCONNORS JAY, FAVREAUTIERE GRIZZLY) we notice that they on average had DGV LPI’s that were on average 536 LPI points higher than their parent averages.
  4.  Conversely when we look at the 5 sires who dropped the most (BIG TIME WILTON, STANTONS BRAKE, EXPRESS DOLSUNN, STANTONS UNLIMITED, WEST PORT BRUTUS) we notice that on average they have DGV LPI values over 1000 points lower than that of their parent averages.
  5. When you take the top 5 sires with the highest DGV LPI values (GEN-I-BEQ BRAWLER, OCONNORS JAY, MORSAN BORIS, EXPRESS BOLLY, COMESTAR LAUTREC) they on average had an increase of 151 LPI points with the addition of daughter information.
  6. Of the 33 sires that increased with the addition of daughter information 30 of them had DGV’s higher than their parent averages.  That compares to only 3 of the 83 sires who dropped having DGV LPI’s higher that their parent averages.
  7. So then it comes to the question, “what if a sire has high genomic values but they are just below his parent averages?”  To answer that, we looked at the sires that had GPA LPI’s of over 2000 and DGV’s lower than their parent averages (ARDROSS STERLING, STANTONS UNLIMITED, and STANTONS BRAKE).They dropped by an average of 787 points with the addition of daughter information.  Conversely those sires that where over 2000 GPA LPI points and had DGV’s higher than their PA’s (GEN-I-BEQ BRAWLER and MORSAN BORIS) actually increased by an average of 134 over their GPA LPI values.

The Bullvine Bottom Line

While the numbers are still early, the facts clearly indicate the merits of only using sires who have DGV’s higher than their parent average.  No matter how high they are.  Breeders need to have access to the DGV LPI values for the young sires they help sample for breeding companies.


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Comments

  1. Does this indicate that there should be more weighting on the DGV’s (compared to 50-60% currently) and less on Parent Averages? The 3 bulls in point 7 (sterling, Unlimited and Brake) have official evaluations with daughters that are within 12, 28 and 30 points of their current DGV’s, which is very accurate. How much did the DGV’s of these bulls change from when they had no daughters compared to their current DGV’s?

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