FAQ: How is a bull’s ‘Docility’ figure calculated?

There are 3 factors that will both contribute to what ‘Docility’ index figure your bull starts out with and also how it changes over time.1.Backpedigree, 2.Genotype, 3. Docility Data

1.Backpedigree

The first ‘Docility’ index that a bull will receive is called a ‘Parent Average’ index. As the name suggests it is an average figure that is calculated from the index figures that his sire & dam have at the time of his birth. If the index figure of a close relative of the bull moves up or down significantly then this will also affect the index figure of the bull himself.

  1. Genotype

When a sample of DNA (e.g. straw of semen) is sent off and the genotype comes back this will then alter the figure that the bull got in his first evaluation run which would have been through his ‘parent average’ as explained above. So there could be a difference in a bull’s ‘Docility’ from the calf’s very first evaluation compared to the one after the genotype has been included.

  1. Foreign Data

If a bull already has an index for docility in another country and this data is sent to ICBF then this will also have an impact on shaping his docility index in Ireland. ICBF routinely gets files of such index values from countries such as the UK and France. 

4.Docility Data

When the bull then starts to sire calves and their docility is recorded this will be the final piece of the jigsaw in terms of his docility evaluation. By this stage his reliability % figure is probably around the 50% mark. It will be his progeny’s docility that will increase this figure. The number of herds that his progeny have their docility recorded in together with the number of herdmates that their docility is recorded against will determine by how much this reliability figure increases.

Bull examples:

Bull 1: ‘Omorga Prince’ is a Simmental AI Sire. In terms of steps 1-3 above: His backpedigree is in the ICBF database, as is his genotype. ‘Docility’ is not evaluated in his country of origin, the UK, so there is no foreign data to include in his evaluation here.

In terms of step 4 above, the docility data of his progeny, this data can be seen in the ICBF ‘Animal Search’ facility:

  1. Go to icbf.com
  2. Go to the Animal Search facility down the right handside of the website and enter in ’Omorga Prince’ (or his AI Code ‘ORP’.
  3. Click on ‘Docility (1-5 scale) which is shaded in blue.
  4. Scroll down to the 2 tables that say ‘Animal Welfare farmer recorded scores’ and ‘Linear scorer recorded scores’.

Animal Welfare farmer recorded scores

This is docility data that farmers recorded on their own cattle. So, progeny of ‘Omorga Prince’ would have been evaluated by farmers for docility in their own herds. The scale here goes from 1-5 with a low score meaning better docility – quieter cattle. So, his progeny got an average score of ‘2.6’ versus the herdmates average of ‘2.2’ so they were not rated by Irish farmers as being as quiet as their herdmates.

 

Linear scorer recorded scores

This is docility data that an ICBF Linear scorer recorded on pedigree cattle in their owner’s herd. The scale here goes from 1-10 with a high score meaning better docility – quieter cattle. So, his progeny got an average score of ‘7.7’ versus the herdmates average of ‘8.0’ so they were not rated by ICBF Linear scorers as being as quiet as their herdmates either.

Putting these 4 pieces of information together results in ‘Omorga Prince’ being rated as a 1 star bull for docility with a 90% reliability rating.

Bull 2: ‘Milnafua Graduate’ is another UK Simmental AI Sire. In terms of steps 1-3 above: His backpedigree is in the ICBF database, as is his genotype. As explained above, ‘Docility’ is not evaluated in the UK, so there is no foreign data to include in his evaluation here.

By going through the ICBF ‘Animal Search’ as described earlier, a summary of the docility scores recorded on his progeny can also be found:

Animal Welfare farmer recorded scores

Again, the scale here goes from 1-5 with a low score meaning better docility – quieter cattle. So his progeny got an average score of ‘2.1’ versus the herdmates average of ‘2.3’ so they were rated by Irish farmers as being quieter than their herdmates.

Linear scorer recorded scores

The scale here goes from 1-10 with a high score meaning better docility – quieter cattle. So his progeny got an average score of ‘8.1’ versus the herdmates average of ‘7.6’ so they were also rated by ICBF Linear scorers as being quieter than their herdmates.

All of this data combined with his backpedigree and genomic data results in him being rated as a 5 star bull for docility.