NZAEL understates Genomics Problems Key Points

New Zealand Animal Evaluation Ltd (NZAEL) understates Genomics Problems Key Points:

On August 10th Interbull confirmed that NZ animal evaluation data has “passed the GBV test” for both Friesians and Jerseys. However this test was only conducted for one breeding value (the protein BV which is a key driver of BW$). The results and test description are available at: http://www.interbull.org/index.php?option=com_content&view=article&id=80:gebvtest& catid=5&Itemid=114

The files provided to Interbull included crossbred sires, see pg 5 of Aug 3rd 2010 Memorandum to Users of NZAEL. On page 7, Table 3 shows the results for the pure breeds when the crossbreds are excluded. Based on these “pure” breed results the Jerseys would clearly fail the Interbull test on the protein BV.

The tables in the Aug 3rd 2010 Memorandum to Users of NZAEL pages 6-13 show that 15 out of 28 breed and trait combinations would fail the Interbull test. These identified biases confirm that the high BW estimates including genomics are substantially overstated. In many cases the test identified that the reliability of the genomic information was also overestimated.

In the 2009-10 season, the top Jersey genomic selections dropped by $40 between August 2009 and May 2010 (From average BW $254 to $215, May PA_PT index =$200) and looks likely to drop further as the indexes converge towards true daughter production. In each of the three breeds, the genomic teams tracked back significantly towards their original ancestry averages.

NZBVs BW=PA_PT index

Chart 1: Convergence of BW with Ancestry and daughter proof for the top genomic selections during the daughter lactations in 2009-1010, Jersey

(NZBVs BW= PA_PT index, i.e. ancestry plus progeny performance, data from Animal Evaluation) The above convergence is only the change over the daughter lactation, and will have been preceeded by 2.5 -3years of reranking (downward drift) since the original team selection and when the semen was used

In the current genomic team selections the bulls are on average approx $70 BW above their parent averages, with a number more than $100 BW above ancestry. This is an indication of the potential downside risk for the current bull teams selected on genomics.

Young sire teams without genomics in their evaluation are also overestimated relative to their daughter production in the range $15-25 BW. This is similar to the effect for reproof of proven sires that get their first proof in sire proving schemes, as they move to a widespread proof. These effects are different from the overstatement of genomic influences, and are usually of a lesser magnitude. NZAEL is working to identify the factors involved in these situations.

NZAEL has downplayed the problem and has failed to implement best practice in governance and implementation relating to genomics, which may relate to significant conflicts of interest for the board, and contractors to NZAEL.

NZAEL needs to make corrections to the AE model so farmers can accurately reassess if they have the appropriate herd mating plans in place, or need to make changes to get better value.

For further information contact: David L

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