Sheep Genetics Percentile Band Tables - explained
The Sheep Genetics Percentile Band tables are a great tool, however there can be a lot of confusion around how to use them. One of the main reasons is that they are updated each run (every 14 days) and as more data comes in. The other confusion is associated with the drop that they are reporting. Below is an explanation of how to use them, where to find them and what questions you need to ask your ram source about the data they are presenting to you.
Explaining percentile band tables
1. The percentile band tables are a quick way to see the range within the industry and to get an idea of where individual animals sit. For example, an animal in the 20th percentile for clean fleece weight is in the top 20% of the industry for the clean fleece weight trait. An animal in the 80th percentile is in the bottom 20%.
2. It is important to note which drop the percentile band table relates to – for example the percentile band table associated with the run on the 21st June 2021 related to animals that were born in 2019, however on the 21st July 2021 it related to animals born in 2020. The change over to a new drop relates to having a sufficient number of animals and data submitted to Sheep Genetics for that drop to start generating the percentile band table.
3. An example between the 21st June (2019 drop) and 7th August (2020 drop) runs for YCFW (Yearling Clean Fleece Weight) 50th percentile was 16.6 and 18.5 respectively. This shows the progress that the industry has made (or not made) for the particular trait. In this example the average of the 2020 drop has improved by 1.9% for YCFW.
Where to find the percentile band tables
1. There are 2 places to find the percentile band tables
a. The current run percentile band table which gets updated each run is located on your dashboard once you have signed into the Sheep Genetics search site.
b. A PDF version is also available, however this only gets updated every couple of months. To find it go to the main Sheep Genetics website
Go to Resources;
MERINOSELECT or LAMBPLAN and on the right side you will find the link to download the PDF version.
What questions to ask your ram source
When ram breeders are putting their data together before their ram sale we have to pick a date to download the data from Sheep Genetics to generate the sale catalogue and pencards. It is important to know the Sheep Genetics run and percentile band table date that the hard copy data relates to. For example, was the data from the run on the 7th July or the 21st August. The date will have an impact on how breeders may report which animals fall into which percentile band.
At SheepMetriX we help clients present the data by colour coding the ASBVs and indexes with the following colour codes. The coding relates to the percentile band table for the run that the data has been exported from Sheep Genetics.
It could be argued that we have a set percentile band however in reality ASBVs are estimated breeding values they are not set in concrete and can change as more data is submitted on the animal, its sibling and progeny, however it is the best information that we have at the time when making the breeding or purchase decision.