As part of our ongoing improvements to the ICBF dairy genetic/genomic evaluations systems and processes, there will be a number of new developments for 2018. These include; (i) an update of the economic values based on latest data from Teagasc regarding the values and costs of milk production systems in Ireland, (ii) the implementation of a Test Day Model for routine genetic evaluations of milk production traits, as opposed to the current approach which is based on 305-day yields and (iii) an updating of the training population on which the genomic predictions for young sires (and females) are derived.
The collective impact of these changes are minimal, with the average EBI of bulls on the ICBF Active Bull List expected to increase by some €30 (this is due primarily to the increase in milk price and value of fat kg within the EBI, compared to previous estimates taken in 2014). The average correlation amongst all Active AI sires is 0.97, with relatively little re-ranking amongst the high EBI sires on the ICBF Active Bull List.
It has little impact on the top 100 bulls on the active bull list. 6 out of the top 10 are still in the top ten and 85 out of 100 are still in the top 100 bulls based on 886 active Ai sires. The variance has increased which indicates more accurate predictions which is a major positive. Overall younger bulls increased on average €30 and in the context of all bulls there was an average increase of €20.
A new and technically more accurate approach to calculating the reliability of EBI evaluations has also been applied, which has resulted in a slight reduction in the average reliability for some animals.
Improving genetic evaluation is an on-going process. The more accurate the data included in the genetic evaluations for bulls the more reliable it will be. It is therefore incumbent upon the ICBF to constantly take account of any new data, new traits, better processing software or changes to the economic values over time.
It is only by constantly updating the Active Bull List in an open and transparent manner that the ICBF can help farmers and breeders have the best information on which to make confident breeding decisions.
In the past, some farmers and breeders have been impacted by the movement in EBI values. For that reason we continue to emphasise the same fundamental advice. Farmers who want to improve their herd performance should use genomic bulls, but they should use them in teams. We advocate a minimum of 8 bulls for a typical 100 cow herd.
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 €40 ahead of the best daughter proven bull available in active AI.