The ICBF has brought forward the publication of our quarterly evaluation for Dairy AI bulls which was not due to be published until May 2017. The decision was made at a Board meeting recently where the latest calving data coming through from Spring 2017 was reviewed.
What has happened?
ICBF have just released the new “Active Dairy Bull List” for the Spring 2017 breeding season.
The listing contains a number of notable improvements compared to previous years. These include; (i) the inclusion of 2-year old bulls on the listing for the first time, due to these bulls now having their first official evaluation for calving difficulty, based on calves born just this Spring, and (ii) more accurate genomic proofs for AI sires due to a number of improvements having being made by ICBF and Teagasc to the genomic evaluation system over the past 4 months. The improvements include; (i) a 15% increase in the size of the sire reference population against which the genomic prediction equations are generated, (ii) the inclusion of almost 1m more fertility records from the 2017 calving season to date and (iii) updates to the genomic evaluation systems and software from which the evaluations are generated.
Whilst the above changes were not anticipated until the next official evaluation (May 2017), the board of ICBF recently decided to implement these planned changes now, in advance of the forthcoming breeding season so as to ensure that Irish dairy farmers and the AI industry would have the most up to date information on which to base their breeding decisions this Spring.
What is the impact on the Active Bull List?
The average EBI of the ICBF Active Bull Listing continues to improve, with the latest listing being €7 ahead of last year’s listing, up from €222 in Spring 2016 (after accounting for the base correction in August 2016), to €229 for the current listing. Once again the listing is dominated with young Genomically Selected (GS) bulls, with a total of 68 of the total 75 bulls being these young GS bulls. In addition the listing is once again almost completely dominated by Irish bred bulls (74 out of the 75 bulls are Irish bred), reflecting the very significant investments that Irish owned AI companies have made in the national breeding program over the past 8 years, since the first introduction of genomics in 2009.
Will there be changes in the proofs for bulls as a result of the genomic and data updates?
Yes there will be changes, with on average these young GS bulls reducing by some €39 in EBI value (equivalent to about 2 days in calving interval CI and 1% for survival). This is based on the weighted average reduction in EBI value for the 285 GS sires that are currently available in Active AI. Some bulls will drop more and others less than this average figure, depending primarily on how the sires of these young GS bulls are performing on farms. The impact will be seen most in bulls that have a genomic “only” proof or a genomic component to their fertility proof (blended proof). These are generally the younger GS bulls, born in 2015 and 2016. Whilst the average drop is €39, the average ranking of bulls is staying very similar (with a correlation of 95% between the new evaluation and the last official evaluation), indicating that only a very small number of bulls are re-ranking significantly.
What will happen to reliability?
The reliability of bulls will increase as a result of the above improvements the genomic evaluation system, with latest analysis indicating an increase in average reliability from 60% for Spring 2016 listing, up to 63% for bulls on the Spring 2017 listing.
Should I continue to use genomic bulls, or should I now be considering using daughter proven bulls?
On average a group of genomic bulls will still be better than any daughter proven bull when it comes to delivering production and fertility. For example, the current average EBI for a team of the top 5 genomic bulls is still some €53 ahead of the best daughter proven bull available on the new ICBF Active Bull List. This is also apparent from the performance of the Teagasc Next Generation herd, at Teagasc Moorepark, which were all selected as calves based on their genomic EBI. Compared to animals of National average genetic merit animals, the elite animals have delivered more milk solids/lactation and with much better fertility (98% in calf at the end of a 12 week breeding season during 2016), under the same management conditions.
So the simple message to farmers is yes, they should still use the genomic bulls, but they should use them in teams, i.e., a minimum of 5 bulls used equally across the herd, so as to minimise the potential impact of any EBI changes to bulls (and their herd) in the future.
Are the ICBF Beef Euro-Star evaluations similarly affected?
No. The changes in proofs are just related to the genomic evaluations for the dairy milk and dairy fertility traits. The dairy and beef genetic evaluations systems are independent of each other.
Are we likely to see more changes to the proofs for GS sires in the future?
Improvements to genetic evaluations are an on-going process. Reasons for proof changes include; the addition of new data, the addition of new traits, changes to the economic values of traits over time, better prediction methods and increased computing power. The main aim of these changes is to improve the reliability of animals and ultimately help farmers breed the most profitable cows for the future. This is the ultimate goal of ICBF and therefore reflects completely the decision taken recently by the board of ICBF to bring forward the May evaluation run to March 2017, and in doing so, ensure farmers and industry have the best information on which to make their breeding decisions this Spring.
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