Euro-Star Replacement Index Changes

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New Euro-Star indexes were published this week by ICBF. There have been some changes to the make-up of the Replacement Index.

Euro-Star Replacement Index Changes (August 2015)

Updated Euro-Star indexes were published this week for all beef animals by the ICBF, following the August genetic evaluation run.

There have been some significant changes to the new indexes, due principally to a number of improvements implemented by ICBF, following a comprehensive review of the indexes, undertaken by the ICBF board in conjunction with the beef breeding industry. The recommendations from that review process included:

  • Changing the definition of the index. The new replacement index is based on the performance of a cow per calving (which includes the performance of any progeny born from that calving). It is expressed on a per calving basis. Thus a cow with a replacement index of €100 is expected to leave €100 more profit/calving (including her progeny performance from that calving), compared to a cow with a value of zero. This is in contrast to the previous index, which was based on the performance of a breeding bull, including male calves (destined for slaughter), female calves (retained for breeding) and all of her subsequent progeny (both male and female). This index was also expressed over the lifetime of the breeding female. The net effect of these changes has been to increase the emphasis on key maternal traits, such as milk and fertility within the Replacement Index (see Table 1). It has also had the effect of substantially reducing the replacement index value of all animals (down dome €60) as the index is now expressed on a per calving basis as opposed to over the lifetime of the female replacement.

The Replacement Index is now expressed as profit per calf of each daughter of a bull retained for breeding. Therefore, there is now more emphasis on key maternal traits such as milk and fertility.

Table 1. Comparison of trait emphasis in old and new Replacement Index.
Table 1. Comparison of trait emphasis in old and new Replacement Index.
  • Removal of the terminal index from all females. The terminal index will now only be available on breeding males, as these are the animals destined to produce animals for slaughter.
  • Across breed stars for commercial animals. Whilst within and across breed stars will still be available for pure-bred animals, there will be only one set of stars for all commercial (cross-bred) animals. These will be based on an across breed comparison.
  • Removal of half stars. Half stars will be removed from all relevant indexes.

Whilst Replacement Index average values have dropped (due to the redefinition of the index), there has been little change in star rankings above and beyond what one would expect between routine runs even after accounting for the changes in index weightings detailed in Table 1. Indeed, of the top 100 active AI sires based on the Replacement index from the April 2015 genetic evaluation run, 80 of those sires remain in the top 100 based on the new August 2015 genetic evaluation run.

Euro-star reports which will include these new indexes will be posted to all herds participating in the Beef Data and Genomics Program (BDGP) from next week. They are also available to view online at www.icbf.com through the Euro-Star profile. Indexes for all pedigree stock and AI bulls can be viewed through the online bull search and the ICBF Active Bull List.