This is a subscriber-only article
As has always been the case between evaluation runs, the €uro-Star percentiles have changed after the most recent evaluation run (Aug 2016). The new four-star “cut-off” is €73 while the five-star is €91. Table 1 compares the May 2016 and August 2016 percentiles.
How are the percentiles calculated?
The percentiles are calculated by ranking all of the animals born in the previous five years. You firstly evaluate these animals to create their index figures and you then divide them into five equal groupings (one to five stars). All other animals born outside of this five year period are assigned a star rating based on where their €uro-Star Index values sit on the star rating spectrum. The current population of animals used to calculate the €uro-Star percentiles (cut-offs) were born between January 2011 and August 2016.
Why do the percentiles change?
A large number of the animals used in the percentiles calculation are still alive and their performance data is constantly flowing into the database. Therefore, we are constantly finding out more about the genetic merit of these animals. For this reason, the percentiles will change slightly after each evaluation run.
Why not set the percentiles?
It is important to rank animals against a contemporary population. To say that an animal is a five star (top 20%) on a given index or trait, relative to a population of animals from 20 years ago, would be meaningless. The purpose of the star rating system is to tell you where an animal ranks in the current population. As the genetic merit of the national herd changes, the star rating percentiles move in line with it.
Look at the index figure as well
While the star rating system is a useful tool which tells you where an animal ranks, it is very important to look at the actual index figure as well. You could have two animals that are both five stars (top 20%) but their actual index figures could be very different.
Currently, there are 176 bulls on the ICBF Active Bull List that are five stars, across breed, on the Replacement Index. The highest-ranked bull has a Replacement Index of €202, whereas the bull in 176th place has an index of €91. Both rank in the top 20%, but there is in excess of €100 of a difference between their index figures. Table 2 gives a more detailed breakdown of the five-star, across breed, Replacement Index percentile.
When assessing an animal’s index (male or female), use the star rating to give you an initial idea as to where the animal ranks, but then look at the index or trait figure to get a better idea as to how high the index actually is. This is particularly important when comparing animals with the same star rating.
Carbon Navigator and tissue tags
All applicants are reminded to make arrangements with an approved agricultural advisor ASAP to complete the Carbon Navigator as per the programme terms and conditions. The new deadline for the Carbon Navigator is 30 November. Any applicants who have yet to return tissue samples are urged to do so ASAP.
Table 1: Comparison of May 2016 and Aug 2016 across breed €uro-Star percentiles.
★ | ★★ | ★★★ | ★★★★ | ★★★★★ | |
May 2016 | Up to €32 | €33-€54 | €55-€73 | €74-€97 | €98 and Over |
Aug 2016 | Up to €38 | €39-€56 | €57-€72 | €73-€90 | €91 and Over |
Table 2: Breakdown of the 5 star, across breed, Replacement Index percentiles.
5 Star (top 20%) | 5 Star (top 10%) | 5 Star (top 5%) | 5 Star (top 1%) | |
Index Value | €91 and over | €105 and over | €116 and over | €139 and over |
Q. Will the €uro-Star percentiles (cut-offs) increase or decrease in the future?
A. This all depends on whether the national herd is experiencing genetic gain or not. If there is genetic gain, then the percentile cut-offs will steadily increase over time in line with this. The €uro-Star index looks at many different traits. While gains can be experienced in some traits, there may be regress in others.
Q. If the percentiles increase and some of my animals star ratings drop, will they still be eligible for the BDGP.
A. If an animal was four or five stars on its first genomic proof on the relevant index, then it will remain eligible in your herd even if its star rating later drops. If you decide to sell on such animals then they will be not eligible in the next herd if they are not four or five stars at the time of sale.
Placing more emphasis on AI
Name: Maria & Michael Curtin, Listowel, Co Kerry
Farming system: Suckler to weanling.
Four- and five-star females: Cows: 15 Heifers: 16
Stock bull or AI: Stock Bull & AI
Replacement strategy: Breed my own.
Michael & Maria Curtin run a 25-cow suckler herd outside of Listowel, Co Kerry. They participated in the ICBF/Teagasc weighing project where all cows and calves were weighed. The data collected from this project in 2015 demonstrated the benefits of high Replacement index cows. The cows themselves had a lighter mature weight, but weaned heavier calves.
What is your farming system?
We operate a spring-calving herd, calving in February and March. All progeny are sold as weanlings apart from the heifers that are retained for breeding. We breed all of our own replacements.
What changes have you made to your replacement strategy?
We are now placing more emphasis on using AI to breed replacements. I had a five-star stock bull, but had to change him as his daughters were coming into the herd. Our plan is to use AI on the 10 best cows to breed replacements. We have a very high Terminal Index Charolais stock bull. He will be used to breed high-quality weanlings from the remainder of the cows.
Have you taken time to look through your latest BDGP report?
I did take a look at the new indexes. There are a few cows that have low indexes and I feel they are better cows on the ground. The fact that we are weighing stock now as part of the weighing project should hopefully increase the indexes of these cows and increase their reliability figures.
